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_RIMT if ACPI 20 select ACPI_SPCR_TABLE if ACPI 21 select ARCH_DMA_DEFAULT_COHERENT 22 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 23 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM_VMEMMAP 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_CC_CAN_LINK 28 select ARCH_HAS_CURRENT_STACK_POINTER 29 select ARCH_HAS_DEBUG_VIRTUAL if MMU 30 select ARCH_HAS_DEBUG_VM_PGTABLE 31 select ARCH_HAS_DEBUG_WX 32 select ARCH_HAS_ELF_CORE_EFLAGS if BINFMT_ELF && ELF_CORE 33 select ARCH_HAS_FAST_MULTIPLIER 34 select ARCH_HAS_FORTIFY_SOURCE 35 select ARCH_HAS_GCOV_PROFILE_ALL 36 select ARCH_HAS_GIGANTIC_PAGE 37 select ARCH_HAS_HW_PTE_YOUNG 38 select ARCH_HAS_KCOV 39 select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU 40 select ARCH_HAS_MEMBARRIER_CALLBACKS 41 select ARCH_HAS_MEMBARRIER_SYNC_CORE 42 select ARCH_HAS_MMIOWB 43 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 44 select ARCH_HAS_PMEM_API 45 select ARCH_HAS_PREEMPT_LAZY 46 select ARCH_HAS_PREPARE_SYNC_CORE_CMD 47 select ARCH_HAS_PTDUMP if MMU 48 select ARCH_HAS_PTE_SPECIAL 49 select ARCH_HAS_SET_DIRECT_MAP if MMU 50 select ARCH_HAS_SET_MEMORY if MMU 51 select ARCH_HAS_STRICT_KERNEL_RWX if MMU 52 select ARCH_HAS_STRICT_MODULE_RWX if MMU 53 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 54 select ARCH_HAS_SYSCALL_WRAPPER 55 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 56 select ARCH_HAS_UBSAN 57 select ARCH_HAS_VDSO_ARCH_DATA if HAVE_GENERIC_VDSO 58 select ARCH_HAVE_NMI_SAFE_CMPXCHG 59 select ARCH_KEEP_MEMBLOCK if ACPI || KEXEC 60 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU 61 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 62 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 63 select ARCH_STACKWALK 64 select ARCH_SUPPORTS_ATOMIC_RMW 65 select ARCH_SUPPORTS_CFI 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 select ARCH_SUPPORTS_LTO_CLANG if CMODEL_MEDANY 70 select ARCH_SUPPORTS_LTO_CLANG_THIN 71 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS if 64BIT && MMU 72 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 73 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 74 select ARCH_SUPPORTS_RT 75 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK 76 select ARCH_SUPPORTS_SCHED_MC if SMP 77 select ARCH_USE_CMPXCHG_LOCKREF if 64BIT 78 select ARCH_USE_MEMTEST 79 select ARCH_USE_QUEUED_RWLOCKS 80 select ARCH_USE_SYM_ANNOTATIONS 81 select ARCH_USES_CFI_TRAPS if CFI 82 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU 83 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 84 select ARCH_WANT_FRAME_POINTERS 85 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 86 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 87 select ARCH_WANT_LD_ORPHAN_WARN 88 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP 89 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 90 select ARCH_WANTS_NO_INSTR 91 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 92 select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS 93 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 94 select BUILDTIME_TABLE_SORT if MMU 95 select CLINT_TIMER if RISCV_M_MODE 96 select CLONE_BACKWARDS 97 select COMMON_CLK 98 select CPU_NO_EFFICIENT_FFS if !RISCV_ISA_ZBB 99 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND 100 select DYNAMIC_FTRACE if FUNCTION_TRACER 101 select EDAC_SUPPORT 102 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) 103 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE 104 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 105 select GENERIC_ARCH_TOPOLOGY 106 select GENERIC_ATOMIC64 if !64BIT 107 select GENERIC_BITREVERSE if HAVE_ARCH_BITREVERSE 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 && 64BIT 114 select GENERIC_IDLE_POLL_SETUP 115 select GENERIC_IOREMAP if MMU 116 select HAVE_IOREMAP_PROT if MMU 117 select GENERIC_IRQ_IPI if SMP 118 select GENERIC_IRQ_IPI_MUX if SMP 119 select GENERIC_IRQ_MULTI_HANDLER 120 select GENERIC_IRQ_SHOW 121 select GENERIC_IRQ_SHOW_LEVEL 122 select GENERIC_LIB_DEVMEM_IS_ALLOWED 123 select GENERIC_PENDING_IRQ if SMP 124 select GENERIC_PCI_IOMAP 125 select GENERIC_SCHED_CLOCK 126 select GENERIC_SMP_IDLE_THREAD 127 select HARDIRQS_SW_RESEND 128 select HAS_IOPORT if MMU 129 select HAVE_ALIGNED_STRUCT_PAGE 130 select HAVE_ARCH_AUDITSYSCALL 131 select HAVE_ARCH_BITREVERSE if RISCV_ISA_ZBKB && BITREVERSE 132 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 133 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT 134 select HAVE_ARCH_JUMP_LABEL 135 select HAVE_ARCH_JUMP_LABEL_RELATIVE 136 select HAVE_ARCH_KASAN if MMU && 64BIT 137 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 138 select HAVE_ARCH_KFENCE if MMU && 64BIT 139 select HAVE_ARCH_KSTACK_ERASE 140 select HAVE_ARCH_KGDB 141 select HAVE_ARCH_KGDB_QXFER_PKT 142 select HAVE_ARCH_MMAP_RND_BITS if MMU 143 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 144 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 145 select HAVE_ARCH_SECCOMP_FILTER 146 select HAVE_ARCH_SOFT_DIRTY if 64BIT && MMU && RISCV_ISA_SVRSW60T59B 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_USERFAULTFD_WP if 64BIT && MMU && USERFAULTFD && RISCV_ISA_SVRSW60T59B 153 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 154 select HAVE_ASM_MODVERSIONS 155 select HAVE_BUILDTIME_MCOUNT_SORT 156 select HAVE_CONTEXT_TRACKING_USER 157 select HAVE_DEBUG_KMEMLEAK 158 select HAVE_DMA_CONTIGUOUS if MMU 159 select HAVE_DYNAMIC_FTRACE if MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 160 select FUNCTION_ALIGNMENT_4B if DYNAMIC_FTRACE && RISCV_ISA_C 161 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS if HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS 162 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS if (DYNAMIC_FTRACE_WITH_ARGS && !CFI) 163 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE 164 select HAVE_FTRACE_GRAPH_FUNC 165 select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS 166 select HAVE_FUNCTION_GRAPH_FREGS 167 select HAVE_FUNCTION_TRACER if HAVE_DYNAMIC_FTRACE 168 select HAVE_EBPF_JIT if MMU 169 select HAVE_GENERIC_TIF_BITS 170 select HAVE_GUP_FAST if MMU 171 select HAVE_FUNCTION_ARG_ACCESS_API 172 select HAVE_FUNCTION_ERROR_INJECTION 173 select HAVE_GCC_PLUGINS 174 select HAVE_GENERIC_VDSO if MMU 175 select HAVE_IRQ_TIME_ACCOUNTING 176 select HAVE_KERNEL_BZIP2 if !EFI_ZBOOT 177 select HAVE_KERNEL_GZIP if !EFI_ZBOOT 178 select HAVE_KERNEL_LZ4 if !EFI_ZBOOT 179 select HAVE_KERNEL_LZMA if !EFI_ZBOOT 180 select HAVE_KERNEL_LZO if !EFI_ZBOOT 181 select HAVE_KERNEL_UNCOMPRESSED if !EFI_ZBOOT 182 select HAVE_KERNEL_ZSTD if !EFI_ZBOOT 183 select HAVE_KERNEL_XZ if !EFI_ZBOOT 184 select HAVE_KPROBES 185 select HAVE_KRETPROBES 186 # https://github.com/ClangBuiltLinux/linux/issues/1881 187 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD 188 select HAVE_MOVE_PMD 189 select HAVE_MOVE_PUD 190 select HAVE_PAGE_SIZE_4KB 191 select HAVE_PCI 192 select HAVE_PERF_EVENTS 193 select HAVE_PERF_REGS 194 select HAVE_PERF_USER_STACK_DUMP 195 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 196 select HAVE_PREEMPT_DYNAMIC_KEY 197 select HAVE_REGS_AND_STACK_ACCESS_API 198 select HAVE_RETHOOK 199 select HAVE_RSEQ 200 select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG 201 select HAVE_SAMPLE_FTRACE_DIRECT 202 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 203 select HAVE_STACKPROTECTOR 204 select HAVE_SYSCALL_TRACEPOINTS 205 select HOTPLUG_PARALLEL if HOTPLUG_CPU 206 select IRQ_DOMAIN 207 select IRQ_FORCED_THREADING 208 select KASAN_VMALLOC if KASAN 209 select LOCK_MM_AND_FIND_VMA 210 select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU 211 select MODULES_USE_ELF_RELA if MODULES 212 select OF 213 select OF_EARLY_FLATTREE 214 select OF_IRQ 215 select PCI_DOMAINS_GENERIC if PCI 216 select PCI_ECAM if (ACPI && PCI) 217 select PCI_MSI if PCI 218 select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED 219 select RISCV_ALTERNATIVE 220 select RISCV_APLIC 221 select RISCV_IMSIC 222 select RISCV_INTC 223 select RISCV_TIMER if RISCV_SBI 224 select SIFIVE_PLIC 225 select SPARSE_IRQ 226 select SYSCTL_EXCEPTION_TRACE 227 select THREAD_INFO_IN_TASK 228 select TRACE_IRQFLAGS_SUPPORT 229 select UACCESS_MEMCPY if !MMU 230 select VDSO_GETRANDOM if HAVE_GENERIC_VDSO && 64BIT 231 select USER_STACKTRACE_SUPPORT 232 select ZONE_DMA32 if 64BIT 233 234config RUSTC_SUPPORTS_RISCV 235 def_bool y 236 depends on 64BIT 237 238config CLANG_SUPPORTS_DYNAMIC_FTRACE 239 def_bool CC_IS_CLANG 240 # https://github.com/ClangBuiltLinux/linux/issues/1817 241 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 242 243config GCC_SUPPORTS_DYNAMIC_FTRACE 244 def_bool CC_IS_GCC 245 depends on $(cc-option,-fpatchable-function-entry=8) 246 depends on CC_HAS_MIN_FUNCTION_ALIGNMENT || !RISCV_ISA_C 247 248config HAVE_SHADOW_CALL_STACK 249 def_bool $(cc-option,-fsanitize=shadow-call-stack) 250 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 251 depends on $(ld-option,--no-relax-gp) 252 253# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 254config ARCH_HAS_BROKEN_DWARF5 255 def_bool y 256 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a 257 depends on AS_IS_LLVM && AS_VERSION < 180000 258 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77 259 depends on LD_IS_LLD && LLD_VERSION < 180000 260 261config ARCH_MMAP_RND_BITS_MIN 262 default 18 if 64BIT 263 default 8 264 265config ARCH_MMAP_RND_COMPAT_BITS_MIN 266 default 8 267 268# max bits determined by the following formula: 269# VA_BITS - PAGE_SHIFT - 3 270config ARCH_MMAP_RND_BITS_MAX 271 default 24 if 64BIT # SV39 based 272 default 17 273 274config ARCH_MMAP_RND_COMPAT_BITS_MAX 275 default 17 276 277# set if we run in machine mode, cleared if we run in supervisor mode 278config RISCV_M_MODE 279 bool "Build a kernel that runs in machine mode" 280 depends on !MMU 281 default y 282 help 283 Select this option if you want to run the kernel in M-mode, 284 without the assistance of any other firmware. 285 286# set if we are running in S-mode and can use SBI calls 287config RISCV_SBI 288 bool 289 depends on !RISCV_M_MODE 290 default y 291 292config MMU 293 bool "MMU-based Paged Memory Management Support" 294 default y 295 help 296 Select if you want MMU-based virtualised addressing space 297 support by paged memory management. If unsure, say 'Y'. 298 299config KASAN_SHADOW_OFFSET 300 hex 301 depends on KASAN_GENERIC 302 default 0xdfffffff00000000 if 64BIT 303 default 0xffffffff if 32BIT 304 305config ARCH_FLATMEM_ENABLE 306 def_bool !NUMA 307 308config ARCH_SPARSEMEM_ENABLE 309 def_bool y 310 depends on MMU 311 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 312 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 313 314config ARCH_SELECT_MEMORY_MODEL 315 def_bool ARCH_SPARSEMEM_ENABLE 316 317config ARCH_SUPPORTS_UPROBES 318 def_bool y 319 320config STACKTRACE_SUPPORT 321 def_bool y 322 323config GENERIC_BUG 324 def_bool y 325 depends on BUG 326 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 327 328config GENERIC_BUG_RELATIVE_POINTERS 329 bool 330 331config GENERIC_CALIBRATE_DELAY 332 def_bool y 333 334config GENERIC_CSUM 335 def_bool y 336 337config GENERIC_HWEIGHT 338 def_bool y 339 340config FIX_EARLYCON_MEM 341 def_bool MMU 342 343config ILLEGAL_POINTER_VALUE 344 hex 345 default 0 if 32BIT 346 default 0xdead000000000000 if 64BIT 347 348config PGTABLE_LEVELS 349 int 350 default 5 if 64BIT 351 default 2 352 353config LOCKDEP_SUPPORT 354 def_bool y 355 356config RISCV_DMA_NONCOHERENT 357 bool 358 select ARCH_HAS_DMA_PREP_COHERENT 359 select ARCH_HAS_SETUP_DMA_OPS 360 select ARCH_HAS_SYNC_DMA_FOR_CPU 361 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 362 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 363 364config RISCV_NONSTANDARD_CACHE_OPS 365 bool 366 help 367 This enables function pointer support for non-standard noncoherent 368 systems to handle cache management. 369 370config AS_HAS_INSN 371 def_bool $(as-instr,.insn 0x100000f) 372 373config AS_HAS_OPTION_ARCH 374 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4 375 def_bool y 376 depends on $(as-instr, .option arch$(comma) +m) 377 378source "arch/riscv/Kconfig.socs" 379source "arch/riscv/Kconfig.errata" 380 381menu "Platform type" 382 383config NONPORTABLE 384 bool "Allow configurations that result in non-portable kernels" 385 help 386 RISC-V kernel binaries are compatible between all known systems 387 whenever possible, but there are some use cases that can only be 388 satisfied by configurations that result in kernel binaries that are 389 not portable between systems. 390 391 Selecting N does not guarantee kernels will be portable to all known 392 systems. Selecting any of the options guarded by NONPORTABLE will 393 result in kernel binaries that are unlikely to be portable between 394 systems. 395 396 If unsure, say N. 397 398choice 399 prompt "Base ISA" 400 default ARCH_RV64I 401 help 402 This selects the base ISA that this kernel will target and must match 403 the target platform. 404 405config ARCH_RV32I 406 bool "RV32I" 407 depends on NONPORTABLE 408 select 32BIT 409 select GENERIC_LIB_UCMPDI2 410 411config ARCH_RV64I 412 bool "RV64I" 413 select 64BIT 414 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 415 select SWIOTLB if MMU 416 417endchoice 418 419# We must be able to map all physical memory into the kernel, but the compiler 420# is still a bit more efficient when generating code if it's setup in a manner 421# such that it can only map 2GiB of memory. 422choice 423 prompt "Kernel Code Model" 424 default CMODEL_MEDLOW if 32BIT 425 default CMODEL_MEDANY if 64BIT 426 427 config CMODEL_MEDLOW 428 bool "medium low code model" 429 config CMODEL_MEDANY 430 bool "medium any code model" 431endchoice 432 433config MODULE_SECTIONS 434 bool 435 select HAVE_MOD_ARCH_SPECIFIC 436 437config SMP 438 bool "Symmetric Multi-Processing" 439 help 440 This enables support for systems with more than one CPU. If 441 you say N here, the kernel will run on single and 442 multiprocessor machines, but will use only one CPU of a 443 multiprocessor machine. If you say Y here, the kernel will run 444 on many, but not all, single processor machines. On a single 445 processor machine, the kernel will run faster if you say N 446 here. 447 448 If you don't know what to do here, say N. 449 450config NR_CPUS 451 int "Maximum number of CPUs (2-512)" 452 depends on SMP 453 range 2 512 if !RISCV_SBI_V01 454 range 2 32 if RISCV_SBI_V01 && 32BIT 455 range 2 64 if RISCV_SBI_V01 && 64BIT 456 default "32" if 32BIT 457 default "64" if RISCV_SBI_V01 && 64BIT 458 default "256" if !RISCV_SBI_V01 && 64BIT 459 460config HOTPLUG_CPU 461 bool "Support for hot-pluggable CPUs" 462 depends on SMP 463 select GENERIC_IRQ_MIGRATION 464 help 465 466 Say Y here to experiment with turning CPUs off and on. CPUs 467 can be controlled through /sys/devices/system/cpu. 468 469 Say N if you want to disable CPU hotplug. 470 471choice 472 prompt "CPU Tuning" 473 default TUNE_GENERIC 474 475config TUNE_GENERIC 476 bool "generic" 477 478endchoice 479 480# Common NUMA Features 481config NUMA 482 bool "NUMA Memory Allocation and Scheduler Support" 483 depends on SMP && MMU 484 select ARCH_SUPPORTS_NUMA_BALANCING 485 select GENERIC_ARCH_NUMA 486 select HAVE_SETUP_PER_CPU_AREA 487 select NEED_PER_CPU_EMBED_FIRST_CHUNK 488 select NEED_PER_CPU_PAGE_FIRST_CHUNK 489 select OF_NUMA 490 select USE_PERCPU_NUMA_NODE_ID 491 help 492 Enable NUMA (Non-Uniform Memory Access) support. 493 494 The kernel will try to allocate memory used by a CPU on the 495 local memory of the CPU and add some more NUMA awareness to the kernel. 496 497config NODES_SHIFT 498 int "Maximum NUMA Nodes (as a power of 2)" 499 range 1 10 500 default "2" 501 depends on NUMA 502 help 503 Specify the maximum number of NUMA Nodes available on the target 504 system. Increases memory reserved to accommodate various tables. 505 506choice 507 prompt "RISC-V spinlock type" 508 default RISCV_COMBO_SPINLOCKS 509 510config RISCV_TICKET_SPINLOCKS 511 bool "Using ticket spinlock" 512 513config RISCV_QUEUED_SPINLOCKS 514 bool "Using queued spinlock" 515 depends on SMP && MMU && NONPORTABLE 516 select ARCH_USE_QUEUED_SPINLOCKS 517 help 518 The queued spinlock implementation requires the forward progress 519 guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or 520 LR/SC with Ziccrse provide such guarantee. 521 522 Select this if and only if Zabha or Ziccrse is available on your 523 platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms 524 without one of those extensions. 525 526 If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks 527 when supported and otherwise ticket spinlocks. 528 529config RISCV_COMBO_SPINLOCKS 530 bool "Using combo spinlock" 531 depends on SMP && MMU 532 select ARCH_USE_QUEUED_SPINLOCKS 533 help 534 Embed both queued spinlock and ticket lock so that the spinlock 535 implementation can be chosen at runtime. 536 537endchoice 538 539config RISCV_ALTERNATIVE 540 bool 541 help 542 This Kconfig allows the kernel to automatically patch the 543 erratum or cpufeature required by the execution platform at run 544 time. The code patching overhead is minimal, as it's only done 545 once at boot and once on each module load. 546 547config RISCV_ALTERNATIVE_EARLY 548 bool 549 depends on RISCV_ALTERNATIVE 550 help 551 Allows early patching of the kernel for special errata 552 553config RISCV_ISA_C 554 bool "Emit compressed instructions when building Linux" 555 default y 556 help 557 Adds "C" to the ISA subsets that the toolchain is allowed to emit 558 when building Linux, which results in compressed instructions in the 559 Linux binary. This option produces a kernel that will not run on 560 systems that do not support compressed instructions. 561 562 If you don't know what to do here, say Y. 563 564config RISCV_ISA_SUPM 565 bool "Supm extension for userspace pointer masking" 566 depends on 64BIT 567 default y 568 help 569 Add support for pointer masking in userspace (Supm) when the 570 underlying hardware extension (Smnpm or Ssnpm) is detected at boot. 571 572 If this option is disabled, userspace will be unable to use 573 the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API. 574 575config RISCV_ISA_SVNAPOT 576 bool "Svnapot extension support for supervisor mode NAPOT pages" 577 depends on 64BIT && MMU 578 depends on RISCV_ALTERNATIVE 579 default y 580 help 581 Enable support for the Svnapot ISA-extension when it is detected 582 at boot. 583 584 The Svnapot extension is used to mark contiguous PTEs as a range 585 of contiguous virtual-to-physical translations for a naturally 586 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 587 size. When HUGETLBFS is also selected this option unconditionally 588 allocates some memory for each NAPOT page size supported by the kernel. 589 When optimizing for low memory consumption and for platforms without 590 the Svnapot extension, it may be better to say N here. 591 592 If you don't know what to do here, say Y. 593 594config RISCV_ISA_SVPBMT 595 bool "Svpbmt extension support for supervisor mode page-based memory types" 596 depends on 64BIT && MMU 597 depends on RISCV_ALTERNATIVE 598 default y 599 help 600 Add support for the Svpbmt ISA-extension (Supervisor-mode: 601 page-based memory types) in the kernel when it is detected at boot. 602 603 The memory type for a page contains a combination of attributes 604 that indicate the cacheability, idempotency, and ordering 605 properties for access to that page. 606 607 The Svpbmt extension is only available on 64-bit cpus. 608 609 If you don't know what to do here, say Y. 610 611config TOOLCHAIN_HAS_V 612 bool 613 default y 614 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv) 615 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv) 616 depends on LD_IS_LLD || LD_VERSION >= 23800 617 depends on AS_HAS_OPTION_ARCH 618 619config RISCV_ISA_V 620 bool "Vector extension support" 621 depends on TOOLCHAIN_HAS_V 622 depends on FPU 623 select DYNAMIC_SIGFRAME 624 default y 625 help 626 Add support for the Vector extension when it is detected at boot. 627 When this option is disabled, neither the kernel nor userspace may 628 use vector procedures. 629 630 If you don't know what to do here, say Y. 631 632config RISCV_ISA_V_DEFAULT_ENABLE 633 bool "Enable userspace Vector by default" 634 depends on RISCV_ISA_V 635 default y 636 help 637 Say Y here if you want to enable Vector in userspace by default. 638 Otherwise, userspace has to make explicit prctl() call to enable 639 Vector, or enable it via the sysctl interface. 640 641 If you don't know what to do here, say Y. 642 643config RISCV_ISA_V_UCOPY_THRESHOLD 644 int "Threshold size for vectorized user copies" 645 depends on RISCV_ISA_V 646 default 768 647 help 648 Prefer using vectorized copy_to_user()/copy_from_user() when the 649 workload size exceeds this value. 650 651config RISCV_ISA_V_PREEMPTIVE 652 bool "Run kernel-mode Vector with kernel preemption" 653 depends on PREEMPTION 654 depends on RISCV_ISA_V 655 default y 656 help 657 Usually, in-kernel SIMD routines are run with preemption disabled. 658 Functions which invoke long running SIMD thus must yield the core's 659 vector unit to prevent blocking other tasks for too long. 660 661 This config allows the kernel to run SIMD without explicitly disabling 662 preemption. Enabling this config will result in higher memory consumption 663 due to the allocation of per-task's kernel Vector context. 664 665config RISCV_ISA_ZAWRS 666 bool "Zawrs extension support for more efficient busy waiting" 667 depends on RISCV_ALTERNATIVE 668 default y 669 help 670 The Zawrs extension defines instructions to be used in polling loops 671 which allow a hart to enter a low-power state or to trap to the 672 hypervisor while waiting on a store to a memory location. Enable the 673 use of these instructions in the kernel when the Zawrs extension is 674 detected at boot. 675 676config TOOLCHAIN_HAS_ZABHA 677 bool 678 default y 679 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha) 680 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha) 681 depends on AS_HAS_OPTION_ARCH 682 683config RISCV_ISA_ZABHA 684 bool "Zabha extension support for atomic byte/halfword operations" 685 depends on TOOLCHAIN_HAS_ZABHA 686 depends on RISCV_ALTERNATIVE 687 default y 688 help 689 Enable the use of the Zabha ISA-extension to implement kernel 690 byte/halfword atomic memory operations when it is detected at boot. 691 692 If you don't know what to do here, say Y. 693 694config TOOLCHAIN_HAS_ZACAS 695 bool 696 default y 697 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas) 698 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas) 699 depends on AS_HAS_OPTION_ARCH 700 701config RISCV_ISA_ZACAS 702 bool "Zacas extension support for atomic CAS" 703 depends on RISCV_ALTERNATIVE 704 default y 705 help 706 Enable the use of the Zacas ISA-extension to implement kernel atomic 707 cmpxchg operations when it is detected at boot. 708 709 If you don't know what to do here, say Y. 710 711config TOOLCHAIN_HAS_ZBB 712 bool 713 default y 714 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 715 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 716 depends on LD_IS_LLD || LD_VERSION >= 23900 717 depends on AS_HAS_OPTION_ARCH 718 719# This symbol indicates that the toolchain supports all v1.0 vector crypto 720# extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once. 721# binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb. 722config TOOLCHAIN_HAS_VECTOR_CRYPTO 723 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb) 724 depends on AS_HAS_OPTION_ARCH 725 726config TOOLCHAIN_HAS_ZBA 727 bool 728 default y 729 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba) 730 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba) 731 depends on LD_IS_LLD || LD_VERSION >= 23900 732 depends on AS_HAS_OPTION_ARCH 733 734config RISCV_ISA_ZBA 735 bool "Zba extension support for bit manipulation instructions" 736 default y 737 help 738 Add support for enabling optimisations in the kernel when the Zba 739 extension is detected at boot. 740 741 The Zba extension provides instructions to accelerate the generation 742 of addresses that index into arrays of basic data types. 743 744 If you don't know what to do here, say Y. 745 746config RISCV_ISA_ZBB 747 bool "Zbb extension support for bit manipulation instructions" 748 depends on RISCV_ALTERNATIVE 749 default y 750 help 751 Add support for enabling optimisations in the kernel when the 752 Zbb extension is detected at boot. Some optimisations may 753 additionally depend on toolchain support for Zbb. 754 755 The Zbb extension provides instructions to accelerate a number 756 of bit-specific operations (count bit population, sign extending, 757 bitrotation, etc). 758 759 If you don't know what to do here, say Y. 760 761config TOOLCHAIN_HAS_ZBC 762 bool 763 default y 764 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc) 765 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc) 766 depends on LD_IS_LLD || LD_VERSION >= 23900 767 depends on AS_HAS_OPTION_ARCH 768 769config RISCV_ISA_ZBC 770 bool "Zbc extension support for carry-less multiplication instructions" 771 depends on TOOLCHAIN_HAS_ZBC 772 depends on MMU 773 depends on RISCV_ALTERNATIVE 774 default y 775 help 776 Adds support to dynamically detect the presence of the Zbc 777 extension (carry-less multiplication) and enable its usage. 778 779 The Zbc extension could accelerate CRC (cyclic redundancy check) 780 calculations. 781 782 If you don't know what to do here, say Y. 783 784config TOOLCHAIN_HAS_ZBKB 785 bool 786 default y 787 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb) 788 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb) 789 depends on LD_IS_LLD || LD_VERSION >= 23900 790 depends on AS_HAS_OPTION_ARCH 791 792config RISCV_ISA_ZBKB 793 bool "Zbkb extension support for bit manipulation instructions" 794 depends on TOOLCHAIN_HAS_ZBKB 795 depends on RISCV_ALTERNATIVE 796 default y 797 help 798 Adds support to dynamically detect the presence of the ZBKB 799 extension (bit manipulation for cryptography) and enable its usage. 800 801 The Zbkb extension provides instructions to accelerate a number 802 of common cryptography operations (pack, zip, etc). 803 804 If you don't know what to do here, say Y. 805 806config RISCV_ISA_ZICBOM 807 bool "Zicbom extension support for non-coherent DMA operation" 808 depends on MMU 809 depends on RISCV_ALTERNATIVE 810 default y 811 select RISCV_DMA_NONCOHERENT 812 select DMA_DIRECT_REMAP 813 help 814 Add support for the Zicbom extension (Cache Block Management 815 Operations) and enable its use in the kernel when it is detected 816 at boot. 817 818 The Zicbom extension can be used to handle for example 819 non-coherent DMA support on devices that need it. 820 821 If you don't know what to do here, say Y. 822 823config RISCV_ISA_ZICBOZ 824 bool "Zicboz extension support for faster zeroing of memory" 825 depends on RISCV_ALTERNATIVE 826 default y 827 help 828 Enable the use of the Zicboz extension (cbo.zero instruction) 829 in the kernel when it is detected at boot. 830 831 The Zicboz extension is used for faster zeroing of memory. 832 833 If you don't know what to do here, say Y. 834 835config RISCV_ISA_ZICBOP 836 bool "Zicbop extension support for cache block prefetch" 837 depends on MMU 838 depends on RISCV_ALTERNATIVE 839 default y 840 help 841 Adds support to dynamically detect the presence of the ZICBOP 842 extension (Cache Block Prefetch Operations) and enable its 843 usage. 844 845 The Zicbop extension can be used to prefetch cache blocks for 846 read/write fetch. 847 848 If you don't know what to do here, say Y. 849 850config RISCV_ISA_SVRSW60T59B 851 bool "Svrsw60t59b extension support for using PTE bits 60 and 59" 852 depends on MMU && 64BIT 853 depends on RISCV_ALTERNATIVE 854 default y 855 help 856 Adds support to dynamically detect the presence of the Svrsw60t59b 857 extension and enable its usage. 858 859 The Svrsw60t59b extension allows to free the PTE reserved bits 60 860 and 59 for software to use. 861 862 If you don't know what to do here, say Y. 863 864config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 865 def_bool y 866 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 867 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 868 depends on AS_IS_GNU && AS_VERSION >= 23600 869 help 870 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 871 20191213 version, which moves some instructions from the I extension to 872 the Zicsr and Zifencei extensions. This requires explicitly specifying 873 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 874 and Zifencei are supported in binutils from version 2.36 onwards. 875 To make life easier, and avoid forcing toolchains that default to a 876 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 877 For GCC < 11.3.0, for which this is not possible or need special 878 treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 879 880config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 881 def_bool y 882 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 883 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 884 depends on CC_IS_GCC && GCC_VERSION < 110300 885 help 886 Certain versions of GCC do not support zicsr and zifencei via -march. 887 This option causes an older ISA spec compatible with these older 888 versions of 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 939config RISCV_SBI_FWFT_DELEGATE_MISALIGNED 940 bool "Request firmware delegation of unaligned access exceptions" 941 depends on RISCV_SBI 942 depends on NONPORTABLE 943 help 944 Use SBI FWFT to request delegation of load address misaligned and 945 store address misaligned exceptions, if possible, and prefer Linux 946 kernel emulation of these accesses to firmware emulation. 947 948 Unfortunately, Linux's emulation is still incomplete. Namely, it 949 currently does not handle vector instructions and KVM guest accesses. 950 On platforms where these accesses would have been handled by firmware, 951 enabling this causes unexpected kernel oopses, userspaces crashes and 952 KVM guest crashes. If you are sure that these are not a problem for 953 your platform, you can say Y here, which may improve performance. 954 955 Saying N here will not worsen emulation support for unaligned accesses 956 even in the case where the firmware also has incomplete support. It 957 simply keeps the firmware's emulation enabled. 958 959 If you don't know what to do here, say N. 960 961choice 962 prompt "Unaligned Accesses Support" 963 default RISCV_PROBE_UNALIGNED_ACCESS 964 help 965 This determines the level of support for unaligned accesses. This 966 information is used by the kernel to perform optimizations. It is also 967 exposed to user space via the hwprobe syscall. The hardware will be 968 probed at boot by default. 969 970config RISCV_PROBE_UNALIGNED_ACCESS 971 bool "Probe for hardware unaligned access support" 972 select RISCV_SCALAR_MISALIGNED 973 help 974 During boot, the kernel will run a series of tests to determine the 975 speed of unaligned accesses. This probing will dynamically determine 976 the speed of unaligned accesses on the underlying system. If unaligned 977 memory accesses trap into the kernel as they are not supported by the 978 system, the kernel will emulate the unaligned accesses to preserve the 979 UABI. 980 981config RISCV_EMULATED_UNALIGNED_ACCESS 982 bool "Emulate unaligned access where system support is missing" 983 select RISCV_SCALAR_MISALIGNED 984 help 985 If unaligned memory accesses trap into the kernel as they are not 986 supported by the system, the kernel will emulate the unaligned 987 accesses to preserve the UABI. When the underlying system does support 988 unaligned accesses, the unaligned accesses are assumed to be slow. 989 990config RISCV_SLOW_UNALIGNED_ACCESS 991 bool "Assume the system supports slow unaligned memory accesses" 992 depends on NONPORTABLE 993 help 994 Assume that the system supports slow unaligned memory accesses. The 995 kernel and userspace programs may not be able to run at all on systems 996 that do not support unaligned memory accesses. 997 998config RISCV_EFFICIENT_UNALIGNED_ACCESS 999 bool "Assume the system supports fast unaligned memory accesses" 1000 depends on NONPORTABLE 1001 select DCACHE_WORD_ACCESS if MMU 1002 select HAVE_EFFICIENT_UNALIGNED_ACCESS 1003 help 1004 Assume that the system supports fast unaligned memory accesses. When 1005 enabled, this option improves the performance of the kernel on such 1006 systems. However, the kernel and userspace programs will run much more 1007 slowly, or will not be able to run at all, on systems that do not 1008 support efficient unaligned memory accesses. 1009 1010endchoice 1011 1012choice 1013 prompt "Vector unaligned Accesses Support" 1014 depends on RISCV_ISA_V 1015 default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 1016 help 1017 This determines the level of support for vector unaligned accesses. This 1018 information is used by the kernel to perform optimizations. It is also 1019 exposed to user space via the hwprobe syscall. The hardware will be 1020 probed at boot by default. 1021 1022config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 1023 bool "Probe speed of vector unaligned accesses" 1024 select RISCV_VECTOR_MISALIGNED 1025 help 1026 During boot, the kernel will run a series of tests to determine the 1027 speed of vector unaligned accesses if they are supported. This probing 1028 will dynamically determine the speed of vector unaligned accesses on 1029 the underlying system if they are supported. 1030 1031config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS 1032 bool "Assume the system supports slow vector unaligned memory accesses" 1033 depends on NONPORTABLE 1034 help 1035 Assume that the system supports slow vector unaligned memory accesses. The 1036 kernel and userspace programs may not be able to run at all on systems 1037 that do not support unaligned memory accesses. 1038 1039config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS 1040 bool "Assume the system supports fast vector unaligned memory accesses" 1041 depends on NONPORTABLE 1042 help 1043 Assume that the system supports fast vector unaligned memory accesses. When 1044 enabled, this option improves the performance of the kernel on such 1045 systems. However, the kernel and userspace programs will run much more 1046 slowly, or will not be able to run at all, on systems that do not 1047 support efficient unaligned memory accesses. 1048 1049endchoice 1050 1051source "arch/riscv/Kconfig.vendor" 1052 1053endmenu # "Platform type" 1054 1055menu "Kernel features" 1056 1057source "kernel/Kconfig.hz" 1058 1059config RISCV_SBI_V01 1060 bool "SBI v0.1 support" 1061 depends on RISCV_SBI 1062 help 1063 This config allows kernel to use SBI v0.1 APIs. This will be 1064 deprecated in future once legacy M-mode software are no longer in use. 1065 1066config RISCV_BOOT_SPINWAIT 1067 bool "Spinwait booting method" 1068 depends on SMP 1069 default y if RISCV_SBI_V01 || RISCV_M_MODE 1070 help 1071 This enables support for booting Linux via spinwait method. In the 1072 spinwait method, all cores randomly jump to Linux. One of the cores 1073 gets chosen via lottery and all other keep spinning on a percpu 1074 variable. This method cannot support CPU hotplug and sparse hartid 1075 scheme. It should be only enabled for M-mode Linux or platforms relying 1076 on older firmware without SBI HSM extension. All other platforms should 1077 rely on ordered booting via SBI HSM extension which gets chosen 1078 dynamically at runtime if the firmware supports it. 1079 1080 Since spinwait is incompatible with sparse hart IDs, it requires 1081 NR_CPUS be large enough to contain the physical hart ID of the first 1082 hart to enter Linux. 1083 1084 If unsure what to do here, say N. 1085 1086config ARCH_SUPPORTS_KEXEC 1087 def_bool y 1088 1089config ARCH_SELECTS_KEXEC 1090 def_bool y 1091 depends on KEXEC 1092 select HOTPLUG_CPU if SMP 1093 1094config ARCH_SUPPORTS_KEXEC_FILE 1095 def_bool 64BIT 1096 1097config ARCH_SELECTS_KEXEC_FILE 1098 def_bool y 1099 depends on KEXEC_FILE 1100 select HAVE_IMA_KEXEC if IMA 1101 select KEXEC_ELF 1102 1103config ARCH_SUPPORTS_KEXEC_PURGATORY 1104 def_bool ARCH_SUPPORTS_KEXEC_FILE 1105 1106config ARCH_SUPPORTS_CRASH_DUMP 1107 def_bool y 1108 1109config ARCH_DEFAULT_CRASH_DUMP 1110 def_bool y 1111 1112config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1113 def_bool CRASH_RESERVE 1114 1115config COMPAT 1116 bool "Kernel support for 32-bit U-mode" 1117 default 64BIT 1118 depends on 64BIT && MMU 1119 help 1120 This option enables support for a 32-bit U-mode running under a 64-bit 1121 kernel at S-mode. riscv32-specific components such as system calls, 1122 the user helper functions (vdso), signal rt_frame functions and the 1123 ptrace interface are handled appropriately by the kernel. 1124 1125 If you want to execute 32-bit userspace applications, say Y. 1126 1127config PARAVIRT 1128 bool "Enable paravirtualization code" 1129 depends on RISCV_SBI 1130 select HAVE_PV_STEAL_CLOCK_GEN 1131 help 1132 This changes the kernel so it can modify itself when it is run 1133 under a hypervisor, potentially improving performance significantly 1134 over full virtualization. 1135 1136config PARAVIRT_TIME_ACCOUNTING 1137 bool "Paravirtual steal time accounting" 1138 depends on PARAVIRT 1139 help 1140 Select this option to enable fine granularity task steal time 1141 accounting. Time spent executing other tasks in parallel with 1142 the current vCPU is discounted from the vCPU power. To account for 1143 that, there can be a small performance impact. 1144 1145 If in doubt, say N here. 1146 1147config RELOCATABLE 1148 bool "Build a relocatable kernel" 1149 select MODULE_SECTIONS if MODULES 1150 select ARCH_VMLINUX_NEEDS_RELOCS 1151 help 1152 This builds a kernel as a Position Independent Executable (PIE), 1153 which retains all relocation metadata required to relocate the 1154 kernel binary at runtime to a different virtual address than the 1155 address it was linked at. 1156 Since RISCV uses the RELA relocation format, this requires a 1157 relocation pass at runtime even if the kernel is loaded at the 1158 same address it was linked at. 1159 1160 If unsure, say N. 1161 1162config RANDOMIZE_BASE 1163 bool "Randomize the address of the kernel image" 1164 depends on RELOCATABLE 1165 depends on MMU && 64BIT 1166 help 1167 Randomizes the virtual address at which the kernel image is 1168 loaded, as a security feature that deters exploit attempts 1169 relying on knowledge of the location of kernel internals. 1170 1171 It is the bootloader's job to provide entropy, by passing a 1172 random u64 value in /chosen/kaslr-seed at kernel entry. 1173 1174 When booting via the UEFI stub, it will invoke the firmware's 1175 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1176 to the kernel proper. In addition, it will randomise the physical 1177 location of the kernel Image as well. 1178 1179 If unsure, say N. 1180 1181config RISCV_USER_CFI 1182 def_bool y 1183 bool "riscv userspace control flow integrity" 1184 depends on 64BIT && MMU && \ 1185 $(cc-option,-mabi=lp64 -march=rv64ima_zicfiss_zicfilp -fcf-protection=full) 1186 depends on RISCV_ALTERNATIVE 1187 select RISCV_SBI 1188 select ARCH_HAS_USER_SHADOW_STACK 1189 select ARCH_USES_HIGH_VMA_FLAGS 1190 select DYNAMIC_SIGFRAME 1191 help 1192 Provides CPU-assisted control flow integrity to userspace tasks. 1193 Control flow integrity is provided by implementing shadow stack for 1194 backward edge and indirect branch tracking for forward edge. 1195 Shadow stack protection is a hardware feature that detects function 1196 return address corruption. This helps mitigate ROP attacks. 1197 Indirect branch tracking enforces that all indirect branches must land 1198 on a landing pad instruction else CPU will fault. This mitigates against 1199 JOP / COP attacks. Applications must be enabled to use it, and old userspace 1200 does not get protection "for free". 1201 default y. 1202 1203endmenu # "Kernel features" 1204 1205menu "Boot options" 1206 1207config CMDLINE 1208 string "Built-in kernel command line" 1209 help 1210 For most platforms, the arguments for the kernel's command line 1211 are provided at run-time, during boot. However, there are cases 1212 where either no arguments are being provided or the provided 1213 arguments are insufficient or even invalid. 1214 1215 When that occurs, it is possible to define a built-in command 1216 line here and choose how the kernel should use it later on. 1217 1218choice 1219 prompt "Built-in command line usage" 1220 depends on CMDLINE != "" 1221 default CMDLINE_FALLBACK 1222 help 1223 Choose how the kernel will handle the provided built-in command 1224 line. 1225 1226config CMDLINE_FALLBACK 1227 bool "Use bootloader kernel arguments if available" 1228 help 1229 Use the built-in command line as fallback in case we get nothing 1230 during boot. This is the default behaviour. 1231 1232config CMDLINE_EXTEND 1233 bool "Extend bootloader kernel arguments" 1234 help 1235 The built-in command line will be appended to the command- 1236 line arguments provided during boot. This is useful in 1237 cases where the provided arguments are insufficient and 1238 you don't want to or cannot modify them. 1239 1240config CMDLINE_FORCE 1241 bool "Always use the default kernel command string" 1242 help 1243 Always use the built-in command line, even if we get one during 1244 boot. This is useful in case you need to override the provided 1245 command line on systems where you don't have or want control 1246 over it. 1247 1248endchoice 1249 1250config EFI_STUB 1251 bool 1252 1253config EFI 1254 bool "UEFI runtime support" 1255 depends on OF 1256 depends on MMU 1257 default y 1258 select ARCH_SUPPORTS_ACPI if 64BIT 1259 select EFI_GENERIC_STUB 1260 select EFI_PARAMS_FROM_FDT 1261 select EFI_RUNTIME_WRAPPERS 1262 select EFI_STUB 1263 select LIBFDT 1264 select RISCV_ISA_C 1265 select UCS2_STRING 1266 help 1267 This option provides support for runtime services provided 1268 by UEFI firmware (such as non-volatile variables, realtime 1269 clock, and platform reset). A UEFI stub is also provided to 1270 allow the kernel to be booted as an EFI application. This 1271 is only useful on systems that have UEFI firmware. 1272 1273config DMI 1274 bool "Enable support for SMBIOS (DMI) tables" 1275 depends on EFI 1276 default y 1277 help 1278 This enables SMBIOS/DMI feature for systems. 1279 1280 This option is only useful on systems that have UEFI firmware. 1281 However, even with this option, the resultant kernel should 1282 continue to boot on existing non-UEFI platforms. 1283 1284config CC_HAVE_STACKPROTECTOR_TLS 1285 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 1286 1287config STACKPROTECTOR_PER_TASK 1288 def_bool y 1289 depends on !RANDSTRUCT 1290 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 1291 1292config PHYS_RAM_BASE_FIXED 1293 bool "Explicitly specified physical RAM address" 1294 depends on NONPORTABLE 1295 default n 1296 1297config PHYS_RAM_BASE 1298 hex "Platform Physical RAM address" 1299 depends on PHYS_RAM_BASE_FIXED 1300 default "0x80000000" 1301 help 1302 This is the physical address of RAM in the system. It has to be 1303 explicitly specified to run early relocations of read-write data 1304 from flash to RAM. 1305 1306config RISCV_ISA_FALLBACK 1307 bool "Permit falling back to parsing riscv,isa for extension support by default" 1308 default y 1309 help 1310 Parsing the "riscv,isa" devicetree property has been deprecated and 1311 replaced by a list of explicitly defined strings. For compatibility 1312 with existing platforms, the kernel will fall back to parsing the 1313 "riscv,isa" property if the replacements are not found. 1314 1315 Selecting N here will result in a kernel that does not use the 1316 fallback, unless the commandline "riscv_isa_fallback" parameter is 1317 present. 1318 1319 Please see the dt-binding, located at 1320 Documentation/devicetree/bindings/riscv/extensions.yaml for details 1321 on the replacement properties, "riscv,isa-base" and 1322 "riscv,isa-extensions". 1323 1324config BUILTIN_DTB 1325 bool "Built-in device tree" 1326 depends on OF && NONPORTABLE 1327 select GENERIC_BUILTIN_DTB 1328 help 1329 Build a device tree into the Linux image. 1330 This option should be selected if no bootloader is being used. 1331 If unsure, say N. 1332 1333 1334config BUILTIN_DTB_NAME 1335 string "Built-in device tree source" 1336 depends on BUILTIN_DTB 1337 help 1338 DTS file path (without suffix, relative to arch/riscv/boot/dts) 1339 for the DTS file that will be used to produce the DTB linked into the 1340 kernel. 1341 1342endmenu # "Boot options" 1343 1344config PORTABLE 1345 bool 1346 default !NONPORTABLE 1347 select EFI 1348 select MMU 1349 select OF 1350 1351config ARCH_PROC_KCORE_TEXT 1352 def_bool y 1353 1354config ARCH_CC_CAN_LINK 1355 bool 1356 default $(cc_can_link_user,-march=rv64g -mabi=lp64d) if 64BIT && FPU 1357 default $(cc_can_link_user,-march=rv64g -mabi=lp64) if 64BIT 1358 default $(cc_can_link_user,-march=rv32g -mabi=ilp32d) if FPU 1359 default $(cc_can_link_user,-march=rv32g -mabi=ilp32) 1360 1361config ARCH_USERFLAGS 1362 string 1363 default "-march=rv64g -mabi=lp64d" if 64BIT && FPU 1364 default "-march=rv64g -mabi=lp64" if 64BIT 1365 default "-march=rv32g -mabi=ilp32d" if FPU 1366 default "-march=rv32g -mabi=ilp32" 1367 1368menu "Power management options" 1369 1370source "kernel/power/Kconfig" 1371 1372config ARCH_HIBERNATION_POSSIBLE 1373 def_bool y 1374 1375config ARCH_HIBERNATION_HEADER 1376 def_bool HIBERNATION 1377 1378config ARCH_SUSPEND_POSSIBLE 1379 def_bool y 1380 1381endmenu # "Power management options" 1382 1383menu "CPU Power Management" 1384 1385source "drivers/cpuidle/Kconfig" 1386 1387source "drivers/cpufreq/Kconfig" 1388 1389endmenu # "CPU Power Management" 1390 1391source "arch/riscv/kvm/Kconfig" 1392 1393source "drivers/acpi/Kconfig" 1394