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_HAS_PMD_SOFTLEAVES if TRANSPARENT_HUGEPAGE 26 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 27 select ARCH_HAS_BINFMT_FLAT 28 select ARCH_HAS_CC_CAN_LINK 29 select ARCH_HAS_CURRENT_STACK_POINTER 30 select ARCH_HAS_DEBUG_VIRTUAL if MMU 31 select ARCH_HAS_DEBUG_VM_PGTABLE 32 select ARCH_HAS_DEBUG_WX 33 select ARCH_HAS_DELAY_TIMER 34 select ARCH_HAS_ELF_CORE_EFLAGS if BINFMT_ELF && ELF_CORE 35 select ARCH_HAS_FAST_MULTIPLIER 36 select ARCH_HAS_FORTIFY_SOURCE 37 select ARCH_HAS_GCOV_PROFILE_ALL 38 select ARCH_HAS_GIGANTIC_PAGE 39 select ARCH_HAS_HW_PTE_YOUNG 40 select ARCH_HAS_KCOV 41 select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU 42 select ARCH_HAS_MEMBARRIER_CALLBACKS 43 select ARCH_HAS_MEMBARRIER_SYNC_CORE 44 select ARCH_HAS_MMIOWB 45 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 46 select ARCH_HAS_PMEM_API 47 select ARCH_HAS_PREEMPT_LAZY 48 select ARCH_HAS_PREPARE_SYNC_CORE_CMD 49 select ARCH_HAS_PTDUMP if MMU 50 select ARCH_HAS_PTE_SPECIAL 51 select ARCH_HAS_SET_DIRECT_MAP if MMU 52 select ARCH_HAS_SET_MEMORY if MMU 53 select ARCH_HAS_STRICT_KERNEL_RWX if MMU 54 select ARCH_HAS_STRICT_MODULE_RWX if MMU 55 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 56 select ARCH_HAS_SYSCALL_WRAPPER 57 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 58 select ARCH_HAS_UBSAN 59 select ARCH_HAS_VDSO_ARCH_DATA 60 select ARCH_HAVE_NMI_SAFE_CMPXCHG 61 select ARCH_KEEP_MEMBLOCK if ACPI || KEXEC 62 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU 63 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 64 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 65 select ARCH_STACKWALK 66 select ARCH_SUPPORTS_ATOMIC_RMW 67 select ARCH_SUPPORTS_CFI 68 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU 69 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 70 select ARCH_SUPPORTS_HUGETLBFS if MMU 71 select ARCH_SUPPORTS_LTO_CLANG if CMODEL_MEDANY 72 select ARCH_SUPPORTS_LTO_CLANG_THIN 73 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS if 64BIT && MMU 74 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 75 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 76 select ARCH_HAS_PTE_PROTNONE if MMU 77 select ARCH_SUPPORTS_RT 78 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK 79 select ARCH_SUPPORTS_SCHED_MC if SMP 80 select ARCH_USE_CMPXCHG_LOCKREF if 64BIT 81 select ARCH_USE_MEMTEST 82 select ARCH_USE_QUEUED_RWLOCKS 83 select ARCH_USE_SYM_ANNOTATIONS 84 select ARCH_USES_CFI_TRAPS if CFI 85 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU 86 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 87 select ARCH_WANT_FRAME_POINTERS 88 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 89 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 90 select ARCH_WANT_LD_ORPHAN_WARN 91 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP 92 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 93 select ARCH_WANTS_NO_INSTR 94 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 95 select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS 96 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 97 select BUILDTIME_TABLE_SORT if MMU 98 select CLINT_TIMER if RISCV_M_MODE 99 select CLONE_BACKWARDS 100 select COMMON_CLK 101 select CPU_NO_EFFICIENT_FFS if !RISCV_ISA_ZBB 102 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND 103 select DYNAMIC_FTRACE if FUNCTION_TRACER 104 select EDAC_SUPPORT 105 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) 106 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE 107 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 108 select GENERIC_ARCH_TOPOLOGY 109 select GENERIC_ATOMIC64 if !64BIT 110 select GENERIC_BITREVERSE if HAVE_ARCH_BITREVERSE 111 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 112 select GENERIC_CPU_DEVICES 113 select GENERIC_CPU_VULNERABILITIES 114 select GENERIC_EARLY_IOREMAP 115 select GENERIC_ENTRY 116 select GENERIC_GETTIMEOFDAY if MMU && 64BIT 117 select GENERIC_IDLE_POLL_SETUP 118 select GENERIC_IOREMAP if MMU 119 select HAVE_IOREMAP_PROT if MMU 120 select GENERIC_IRQ_IPI if SMP 121 select GENERIC_IRQ_IPI_MUX if SMP 122 select GENERIC_IRQ_MULTI_HANDLER 123 select GENERIC_IRQ_SHOW 124 select GENERIC_IRQ_SHOW_LEVEL 125 select GENERIC_LIB_DEVMEM_IS_ALLOWED 126 select GENERIC_PENDING_IRQ if SMP 127 select GENERIC_PCI_IOMAP 128 select GENERIC_SCHED_CLOCK 129 select GENERIC_SMP_IDLE_THREAD 130 select HARDIRQS_SW_RESEND 131 select HAS_IOPORT if MMU 132 select HAVE_ALIGNED_STRUCT_PAGE 133 select HAVE_ARCH_AUDITSYSCALL 134 select HAVE_ARCH_BITREVERSE if RISCV_ISA_ZBKB && BITREVERSE 135 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 136 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT 137 select HAVE_ARCH_JUMP_LABEL 138 select HAVE_ARCH_JUMP_LABEL_RELATIVE 139 select HAVE_ARCH_KASAN if MMU && 64BIT 140 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 141 select HAVE_ARCH_KFENCE if MMU && 64BIT 142 select HAVE_ARCH_KSTACK_ERASE 143 select HAVE_ARCH_KGDB 144 select HAVE_ARCH_KGDB_QXFER_PKT 145 select HAVE_ARCH_MMAP_RND_BITS if MMU 146 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 147 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 148 select HAVE_ARCH_SECCOMP_FILTER 149 select HAVE_ARCH_SOFT_DIRTY if 64BIT && MMU && RISCV_ISA_SVRSW60T59B 150 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 151 select HAVE_ARCH_TRACEHOOK 152 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU 153 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if 64BIT && MMU 154 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD 155 select HAVE_ARCH_USERFAULTFD_WP if 64BIT && MMU && USERFAULTFD && RISCV_ISA_SVRSW60T59B 156 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 157 select HAVE_ASM_MODVERSIONS 158 select HAVE_BUILDTIME_MCOUNT_SORT 159 select HAVE_CONTEXT_TRACKING_USER 160 select HAVE_DEBUG_KMEMLEAK 161 select HAVE_DMA_CONTIGUOUS if MMU 162 select HAVE_DYNAMIC_FTRACE if MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 163 select FUNCTION_ALIGNMENT_4B if DYNAMIC_FTRACE && RISCV_ISA_C 164 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS if HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS 165 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS if (DYNAMIC_FTRACE_WITH_ARGS && !CFI) 166 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE 167 select HAVE_FTRACE_GRAPH_FUNC 168 select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS 169 select HAVE_FUNCTION_GRAPH_FREGS 170 select HAVE_FUNCTION_TRACER if HAVE_DYNAMIC_FTRACE 171 select HAVE_EBPF_JIT if MMU 172 select HAVE_GENERIC_TIF_BITS 173 select HAVE_GUP_FAST if MMU 174 select HAVE_FUNCTION_ARG_ACCESS_API 175 select HAVE_FUNCTION_ERROR_INJECTION 176 select HAVE_GCC_PLUGINS 177 select HAVE_IRQ_TIME_ACCOUNTING 178 select HAVE_KERNEL_BZIP2 if !EFI_ZBOOT 179 select HAVE_KERNEL_GZIP if !EFI_ZBOOT 180 select HAVE_KERNEL_LZ4 if !EFI_ZBOOT 181 select HAVE_KERNEL_LZMA if !EFI_ZBOOT 182 select HAVE_KERNEL_LZO if !EFI_ZBOOT 183 select HAVE_KERNEL_UNCOMPRESSED if !EFI_ZBOOT 184 select HAVE_KERNEL_ZSTD if !EFI_ZBOOT 185 select HAVE_KERNEL_XZ if !EFI_ZBOOT 186 select HAVE_KPROBES 187 select HAVE_KRETPROBES 188 # https://github.com/ClangBuiltLinux/linux/issues/1881 189 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD 190 select HAVE_MOVE_PMD 191 select HAVE_MOVE_PUD 192 select HAVE_PAGE_SIZE_4KB 193 select HAVE_PCI 194 select HAVE_PERF_EVENTS 195 select HAVE_PERF_REGS 196 select HAVE_PERF_USER_STACK_DUMP 197 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 198 select HAVE_PREEMPT_DYNAMIC_KEY 199 select HAVE_REGS_AND_STACK_ACCESS_API 200 select HAVE_RETHOOK 201 select HAVE_RSEQ 202 select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG 203 select HAVE_SAMPLE_FTRACE_DIRECT 204 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 205 select HAVE_STACKPROTECTOR 206 select HAVE_SYSCALL_TRACEPOINTS 207 select HOTPLUG_PARALLEL if HOTPLUG_CPU 208 select IRQ_DOMAIN 209 select IRQ_FORCED_THREADING 210 select KASAN_VMALLOC if KASAN 211 select LOCK_MM_AND_FIND_VMA 212 select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU 213 select MODULES_USE_ELF_RELA if MODULES 214 select OF 215 select OF_EARLY_FLATTREE 216 select OF_IRQ 217 select PCI_DOMAINS_GENERIC if PCI 218 select PCI_ECAM if (ACPI && PCI) 219 select PCI_MSI if PCI 220 select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED 221 select RISCV_ALTERNATIVE 222 select RISCV_APLIC 223 select RISCV_IMSIC 224 select RISCV_INTC 225 select RISCV_TIMER if RISCV_SBI 226 select SIFIVE_PLIC 227 select SPARSE_IRQ 228 select SYSCTL_EXCEPTION_TRACE 229 select THREAD_INFO_IN_TASK 230 select TRACE_IRQFLAGS_SUPPORT 231 select UACCESS_MEMCPY if !MMU 232 select VDSO_DATASTORE if MMU 233 select VDSO_GETRANDOM if MMU && 64BIT 234 select USER_STACKTRACE_SUPPORT 235 select ZONE_DMA32 if 64BIT 236 237config RUSTC_SUPPORTS_RISCV 238 def_bool y 239 depends on 64BIT 240 241config CLANG_SUPPORTS_DYNAMIC_FTRACE 242 def_bool CC_IS_CLANG 243 # https://github.com/ClangBuiltLinux/linux/issues/1817 244 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 245 246config GCC_SUPPORTS_DYNAMIC_FTRACE 247 def_bool CC_IS_GCC 248 depends on $(cc-option,-fpatchable-function-entry=8) 249 depends on CC_HAS_MIN_FUNCTION_ALIGNMENT || !RISCV_ISA_C 250 251config HAVE_SHADOW_CALL_STACK 252 def_bool $(cc-option,-fsanitize=shadow-call-stack) 253 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 254 depends on $(ld-option,--no-relax-gp) 255 256# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 257config ARCH_HAS_BROKEN_DWARF5 258 def_bool y 259 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a 260 depends on AS_IS_LLVM && AS_VERSION < 180000 261 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77 262 depends on LD_IS_LLD && LLD_VERSION < 180000 263 264config ARCH_MMAP_RND_BITS_MIN 265 default 18 if 64BIT 266 default 8 267 268config ARCH_MMAP_RND_COMPAT_BITS_MIN 269 default 8 270 271# max bits determined by the following formula: 272# VA_BITS - PAGE_SHIFT - 3 273config ARCH_MMAP_RND_BITS_MAX 274 default 24 if 64BIT # SV39 based 275 default 17 276 277config ARCH_MMAP_RND_COMPAT_BITS_MAX 278 default 17 279 280# set if we run in machine mode, cleared if we run in supervisor mode 281config RISCV_M_MODE 282 bool "Build a kernel that runs in machine mode" 283 depends on !MMU 284 default y 285 help 286 Select this option if you want to run the kernel in M-mode, 287 without the assistance of any other firmware. 288 289# set if we are running in S-mode and can use SBI calls 290config RISCV_SBI 291 bool 292 depends on !RISCV_M_MODE 293 default y 294 295config MMU 296 bool "MMU-based Paged Memory Management Support" 297 default y 298 help 299 Select if you want MMU-based virtualised addressing space 300 support by paged memory management. If unsure, say 'Y'. 301 302config KASAN_SHADOW_OFFSET 303 hex 304 depends on KASAN_GENERIC 305 default 0xdfffffff00000000 if 64BIT 306 default 0xffffffff if 32BIT 307 308config ARCH_FLATMEM_ENABLE 309 def_bool !NUMA 310 311config ARCH_SPARSEMEM_ENABLE 312 def_bool y 313 depends on MMU 314 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 315 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 316 317config ARCH_SELECT_MEMORY_MODEL 318 def_bool ARCH_SPARSEMEM_ENABLE 319 320config ARCH_SUPPORTS_UPROBES 321 def_bool y 322 323config STACKTRACE_SUPPORT 324 def_bool y 325 326config GENERIC_BUG 327 def_bool y 328 depends on BUG 329 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 330 331config GENERIC_BUG_RELATIVE_POINTERS 332 bool 333 334config GENERIC_CALIBRATE_DELAY 335 def_bool y 336 337config GENERIC_CSUM 338 def_bool y 339 340config GENERIC_HWEIGHT 341 def_bool y 342 343config FIX_EARLYCON_MEM 344 def_bool MMU 345 346config ILLEGAL_POINTER_VALUE 347 hex 348 default 0 if 32BIT 349 default 0xdead000000000000 if 64BIT 350 351config PGTABLE_LEVELS 352 int 353 default 5 if 64BIT 354 default 2 355 356config LOCKDEP_SUPPORT 357 def_bool y 358 359config RISCV_DMA_NONCOHERENT 360 bool 361 select ARCH_HAS_DMA_PREP_COHERENT 362 select ARCH_HAS_SETUP_DMA_OPS 363 select ARCH_HAS_SYNC_DMA_FOR_CPU 364 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 365 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 366 367config RISCV_NONSTANDARD_CACHE_OPS 368 bool 369 help 370 This enables function pointer support for non-standard noncoherent 371 systems to handle cache management. 372 373config AS_HAS_INSN 374 def_bool $(as-instr,.insn 0x100000f) 375 376config AS_HAS_OPTION_ARCH 377 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4 378 def_bool y 379 depends on $(as-instr, .option arch$(comma) +m) 380 381source "arch/riscv/Kconfig.socs" 382source "arch/riscv/Kconfig.errata" 383 384menu "Platform type" 385 386config NONPORTABLE 387 bool "Allow configurations that result in non-portable kernels" 388 help 389 RISC-V kernel binaries are compatible between all known systems 390 whenever possible, but there are some use cases that can only be 391 satisfied by configurations that result in kernel binaries that are 392 not portable between systems. 393 394 Selecting N does not guarantee kernels will be portable to all known 395 systems. Selecting any of the options guarded by NONPORTABLE will 396 result in kernel binaries that are unlikely to be portable between 397 systems. 398 399 If unsure, say N. 400 401choice 402 prompt "Base ISA" 403 default ARCH_RV64I 404 help 405 This selects the base ISA that this kernel will target and must match 406 the target platform. 407 408config ARCH_RV32I 409 bool "RV32I" 410 depends on NONPORTABLE 411 select 32BIT 412 select GENERIC_LIB_UCMPDI2 413 414config ARCH_RV64I 415 bool "RV64I" 416 select 64BIT 417 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 418 select SWIOTLB if MMU 419 420endchoice 421 422# We must be able to map all physical memory into the kernel, but the compiler 423# is still a bit more efficient when generating code if it's setup in a manner 424# such that it can only map 2GiB of memory. 425choice 426 prompt "Kernel Code Model" 427 default CMODEL_MEDLOW if 32BIT 428 default CMODEL_MEDANY if 64BIT 429 430 config CMODEL_MEDLOW 431 bool "medium low code model" 432 config CMODEL_MEDANY 433 bool "medium any code model" 434endchoice 435 436config MODULE_SECTIONS 437 bool 438 select HAVE_MOD_ARCH_SPECIFIC 439 440config SMP 441 bool "Symmetric Multi-Processing" 442 help 443 This enables support for systems with more than one CPU. If 444 you say N here, the kernel will run on single and 445 multiprocessor machines, but will use only one CPU of a 446 multiprocessor machine. If you say Y here, the kernel will run 447 on many, but not all, single processor machines. On a single 448 processor machine, the kernel will run faster if you say N 449 here. 450 451 If you don't know what to do here, say N. 452 453config NR_CPUS 454 int "Maximum number of CPUs (2-512)" 455 depends on SMP 456 range 2 512 if !RISCV_SBI_V01 457 range 2 32 if RISCV_SBI_V01 && 32BIT 458 range 2 64 if RISCV_SBI_V01 && 64BIT 459 default "32" if 32BIT 460 default "64" if RISCV_SBI_V01 && 64BIT 461 default "256" if !RISCV_SBI_V01 && 64BIT 462 463config HOTPLUG_CPU 464 bool "Support for hot-pluggable CPUs" 465 depends on SMP 466 select GENERIC_IRQ_MIGRATION 467 help 468 469 Say Y here to experiment with turning CPUs off and on. CPUs 470 can be controlled through /sys/devices/system/cpu. 471 472 Say N if you want to disable CPU hotplug. 473 474choice 475 prompt "CPU Tuning" 476 default TUNE_GENERIC 477 478config TUNE_GENERIC 479 bool "generic" 480 481endchoice 482 483# Common NUMA Features 484config NUMA 485 bool "NUMA Memory Allocation and Scheduler Support" 486 depends on SMP && MMU 487 select ARCH_SUPPORTS_NUMA_BALANCING 488 select GENERIC_ARCH_NUMA 489 select HAVE_SETUP_PER_CPU_AREA 490 select NEED_PER_CPU_EMBED_FIRST_CHUNK 491 select NEED_PER_CPU_PAGE_FIRST_CHUNK 492 select OF_NUMA 493 select USE_PERCPU_NUMA_NODE_ID 494 help 495 Enable NUMA (Non-Uniform Memory Access) support. 496 497 The kernel will try to allocate memory used by a CPU on the 498 local memory of the CPU and add some more NUMA awareness to the kernel. 499 500config NODES_SHIFT 501 int "Maximum NUMA Nodes (as a power of 2)" 502 range 1 10 503 default "2" 504 depends on NUMA 505 help 506 Specify the maximum number of NUMA Nodes available on the target 507 system. Increases memory reserved to accommodate various tables. 508 509choice 510 prompt "RISC-V spinlock type" 511 default RISCV_COMBO_SPINLOCKS 512 513config RISCV_TICKET_SPINLOCKS 514 bool "Using ticket spinlock" 515 516config RISCV_QUEUED_SPINLOCKS 517 bool "Using queued spinlock" 518 depends on SMP && MMU && NONPORTABLE 519 select ARCH_USE_QUEUED_SPINLOCKS 520 help 521 The queued spinlock implementation requires the forward progress 522 guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or 523 LR/SC with Ziccrse provide such guarantee. 524 525 Select this if and only if Zabha or Ziccrse is available on your 526 platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms 527 without one of those extensions. 528 529 If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks 530 when supported and otherwise ticket spinlocks. 531 532config RISCV_COMBO_SPINLOCKS 533 bool "Using combo spinlock" 534 depends on SMP && MMU 535 select ARCH_USE_QUEUED_SPINLOCKS 536 help 537 Embed both queued spinlock and ticket lock so that the spinlock 538 implementation can be chosen at runtime. 539 540endchoice 541 542config RISCV_ALTERNATIVE 543 bool 544 help 545 This Kconfig allows the kernel to automatically patch the 546 erratum or cpufeature required by the execution platform at run 547 time. The code patching overhead is minimal, as it's only done 548 once at boot and once on each module load. 549 550config RISCV_ALTERNATIVE_EARLY 551 bool 552 depends on RISCV_ALTERNATIVE 553 help 554 Allows early patching of the kernel for special errata 555 556config RISCV_ISA_C 557 bool "Emit compressed instructions when building Linux" 558 default y 559 help 560 Adds "C" to the ISA subsets that the toolchain is allowed to emit 561 when building Linux, which results in compressed instructions in the 562 Linux binary. This option produces a kernel that will not run on 563 systems that do not support compressed instructions. 564 565 If you don't know what to do here, say Y. 566 567config RISCV_ISA_SUPM 568 bool "Supm extension for userspace pointer masking" 569 depends on 64BIT 570 default y 571 help 572 Add support for pointer masking in userspace (Supm) when the 573 underlying hardware extension (Smnpm or Ssnpm) is detected at boot. 574 575 If this option is disabled, userspace will be unable to use 576 the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API. 577 578config RISCV_ISA_SVNAPOT 579 bool "Svnapot extension support for supervisor mode NAPOT pages" 580 depends on 64BIT && MMU 581 depends on RISCV_ALTERNATIVE 582 default y 583 help 584 Enable support for the Svnapot ISA-extension when it is detected 585 at boot. 586 587 The Svnapot extension is used to mark contiguous PTEs as a range 588 of contiguous virtual-to-physical translations for a naturally 589 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 590 size. When HUGETLBFS is also selected this option unconditionally 591 allocates some memory for each NAPOT page size supported by the kernel. 592 When optimizing for low memory consumption and for platforms without 593 the Svnapot extension, it may be better to say N here. 594 595 If you don't know what to do here, say Y. 596 597config RISCV_ISA_SSQOSID 598 bool "Ssqosid extension support for supervisor mode Quality of Service ID" 599 depends on 64BIT 600 default n 601 help 602 Adds support for the Ssqosid ISA extension (Supervisor-mode 603 Quality of Service ID). 604 605 Ssqosid defines the srmcfg CSR which allows the system to tag the 606 running process with an RCID (Resource Control ID) and MCID 607 (Monitoring Counter ID). The RCID is used to determine resource 608 allocation. The MCID is used to track resource usage in event 609 counters. 610 611 For example, a cache controller may use the RCID to apply a 612 cache partitioning scheme and use the MCID to track how much 613 cache a process, or a group of processes, is using. 614 615config RISCV_ISA_SVPBMT 616 bool "Svpbmt extension support for supervisor mode page-based memory types" 617 depends on 64BIT && MMU 618 depends on RISCV_ALTERNATIVE 619 default y 620 help 621 Add support for the Svpbmt ISA-extension (Supervisor-mode: 622 page-based memory types) in the kernel when it is detected at boot. 623 624 The memory type for a page contains a combination of attributes 625 that indicate the cacheability, idempotency, and ordering 626 properties for access to that page. 627 628 The Svpbmt extension is only available on 64-bit cpus. 629 630 If you don't know what to do here, say Y. 631 632config TOOLCHAIN_HAS_V 633 bool 634 default y 635 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv) 636 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv) 637 depends on LD_IS_LLD || LD_VERSION >= 23800 638 depends on AS_HAS_OPTION_ARCH 639 640config RISCV_ISA_V 641 bool "Vector extension support" 642 depends on TOOLCHAIN_HAS_V 643 depends on FPU 644 select DYNAMIC_SIGFRAME 645 default y 646 help 647 Add support for the Vector extension when it is detected at boot. 648 When this option is disabled, neither the kernel nor userspace may 649 use vector procedures. 650 651 If you don't know what to do here, say Y. 652 653config RISCV_ISA_V_DEFAULT_ENABLE 654 bool "Enable userspace Vector by default" 655 depends on RISCV_ISA_V 656 default y 657 help 658 Say Y here if you want to enable Vector in userspace by default. 659 Otherwise, userspace has to make explicit prctl() call to enable 660 Vector, or enable it via the sysctl interface. 661 662 If you don't know what to do here, say Y. 663 664config RISCV_ISA_V_UCOPY_THRESHOLD 665 int "Threshold size for vectorized user copies" 666 depends on RISCV_ISA_V 667 default 768 668 help 669 Prefer using vectorized copy_to_user()/copy_from_user() when the 670 workload size exceeds this value. 671 672config RISCV_ISA_V_PREEMPTIVE 673 bool "Run kernel-mode Vector with kernel preemption" 674 depends on PREEMPTION 675 depends on RISCV_ISA_V 676 default y 677 help 678 Usually, in-kernel SIMD routines are run with preemption disabled. 679 Functions which invoke long running SIMD thus must yield the core's 680 vector unit to prevent blocking other tasks for too long. 681 682 This config allows the kernel to run SIMD without explicitly disabling 683 preemption. Enabling this config will result in higher memory consumption 684 due to the allocation of per-task's kernel Vector context. 685 686config RISCV_ISA_ZAWRS 687 bool "Zawrs extension support for more efficient busy waiting" 688 depends on RISCV_ALTERNATIVE 689 default y 690 help 691 The Zawrs extension defines instructions to be used in polling loops 692 which allow a hart to enter a low-power state or to trap to the 693 hypervisor while waiting on a store to a memory location. Enable the 694 use of these instructions in the kernel when the Zawrs extension is 695 detected at boot. 696 697config TOOLCHAIN_HAS_ZABHA 698 bool 699 default y 700 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha) 701 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha) 702 depends on AS_HAS_OPTION_ARCH 703 704config RISCV_ISA_ZABHA 705 bool "Zabha extension support for atomic byte/halfword operations" 706 depends on TOOLCHAIN_HAS_ZABHA 707 depends on RISCV_ALTERNATIVE 708 default y 709 help 710 Enable the use of the Zabha ISA-extension to implement kernel 711 byte/halfword atomic memory operations when it is detected at boot. 712 713 If you don't know what to do here, say Y. 714 715config TOOLCHAIN_HAS_ZACAS 716 bool 717 default y 718 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas) 719 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas) 720 depends on AS_HAS_OPTION_ARCH 721 722config RISCV_ISA_ZACAS 723 bool "Zacas extension support for atomic CAS" 724 depends on RISCV_ALTERNATIVE 725 default y 726 help 727 Enable the use of the Zacas ISA-extension to implement kernel atomic 728 cmpxchg operations when it is detected at boot. 729 730 If you don't know what to do here, say Y. 731 732config TOOLCHAIN_HAS_ZBB 733 bool 734 default y 735 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 736 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 737 depends on LD_IS_LLD || LD_VERSION >= 23900 738 depends on AS_HAS_OPTION_ARCH 739 740# This symbol indicates that the toolchain supports all v1.0 vector crypto 741# extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once. 742# binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb. 743config TOOLCHAIN_HAS_VECTOR_CRYPTO 744 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb) 745 depends on AS_HAS_OPTION_ARCH 746 747config TOOLCHAIN_HAS_ZBA 748 bool 749 default y 750 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba) 751 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba) 752 depends on LD_IS_LLD || LD_VERSION >= 23900 753 depends on AS_HAS_OPTION_ARCH 754 755config RISCV_ISA_ZBA 756 bool "Zba extension support for bit manipulation instructions" 757 default y 758 help 759 Add support for enabling optimisations in the kernel when the Zba 760 extension is detected at boot. 761 762 The Zba extension provides instructions to accelerate the generation 763 of addresses that index into arrays of basic data types. 764 765 If you don't know what to do here, say Y. 766 767config RISCV_ISA_ZBB 768 bool "Zbb extension support for bit manipulation instructions" 769 depends on RISCV_ALTERNATIVE 770 default y 771 help 772 Add support for enabling optimisations in the kernel when the 773 Zbb extension is detected at boot. Some optimisations may 774 additionally depend on toolchain support for Zbb. 775 776 The Zbb extension provides instructions to accelerate a number 777 of bit-specific operations (count bit population, sign extending, 778 bitrotation, etc). 779 780 If you don't know what to do here, say Y. 781 782config TOOLCHAIN_HAS_ZBC 783 bool 784 default y 785 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc) 786 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc) 787 depends on LD_IS_LLD || LD_VERSION >= 23900 788 depends on AS_HAS_OPTION_ARCH 789 790config RISCV_ISA_ZBC 791 bool "Zbc extension support for carry-less multiplication instructions" 792 depends on TOOLCHAIN_HAS_ZBC 793 depends on MMU 794 depends on RISCV_ALTERNATIVE 795 default y 796 help 797 Adds support to dynamically detect the presence of the Zbc 798 extension (carry-less multiplication) and enable its usage. 799 800 The Zbc extension could accelerate CRC (cyclic redundancy check) 801 calculations. 802 803 If you don't know what to do here, say Y. 804 805config TOOLCHAIN_HAS_ZBKB 806 bool 807 default y 808 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb) 809 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb) 810 depends on LD_IS_LLD || LD_VERSION >= 23900 811 depends on AS_HAS_OPTION_ARCH 812 813config RISCV_ISA_ZBKB 814 bool "Zbkb extension support for bit manipulation instructions" 815 depends on TOOLCHAIN_HAS_ZBKB 816 depends on RISCV_ALTERNATIVE 817 default y 818 help 819 Adds support to dynamically detect the presence of the ZBKB 820 extension (bit manipulation for cryptography) and enable its usage. 821 822 The Zbkb extension provides instructions to accelerate a number 823 of common cryptography operations (pack, zip, etc). 824 825 If you don't know what to do here, say Y. 826 827config RISCV_ISA_ZICBOM 828 bool "Zicbom extension support for non-coherent DMA operation" 829 depends on MMU 830 depends on RISCV_ALTERNATIVE 831 default y 832 select RISCV_DMA_NONCOHERENT 833 select DMA_DIRECT_REMAP 834 help 835 Add support for the Zicbom extension (Cache Block Management 836 Operations) and enable its use in the kernel when it is detected 837 at boot. 838 839 The Zicbom extension can be used to handle for example 840 non-coherent DMA support on devices that need it. 841 842 If you don't know what to do here, say Y. 843 844config RISCV_ISA_ZICBOZ 845 bool "Zicboz extension support for faster zeroing of memory" 846 depends on RISCV_ALTERNATIVE 847 default y 848 help 849 Enable the use of the Zicboz extension (cbo.zero instruction) 850 in the kernel when it is detected at boot. 851 852 The Zicboz extension is used for faster zeroing of memory. 853 854 If you don't know what to do here, say Y. 855 856config RISCV_ISA_ZICBOP 857 bool "Zicbop extension support for cache block prefetch" 858 depends on MMU 859 depends on RISCV_ALTERNATIVE 860 default y 861 help 862 Adds support to dynamically detect the presence of the ZICBOP 863 extension (Cache Block Prefetch Operations) and enable its 864 usage. 865 866 The Zicbop extension can be used to prefetch cache blocks for 867 read/write fetch. 868 869 If you don't know what to do here, say Y. 870 871config RISCV_ISA_SVRSW60T59B 872 bool "Svrsw60t59b extension support for using PTE bits 60 and 59" 873 depends on MMU && 64BIT 874 depends on RISCV_ALTERNATIVE 875 default y 876 help 877 Adds support to dynamically detect the presence of the Svrsw60t59b 878 extension and enable its usage. 879 880 The Svrsw60t59b extension allows to free the PTE reserved bits 60 881 and 59 for software to use. 882 883 If you don't know what to do here, say Y. 884 885config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 886 def_bool y 887 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 888 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 889 depends on AS_IS_GNU && AS_VERSION >= 23600 890 help 891 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 892 20191213 version, which moves some instructions from the I extension to 893 the Zicsr and Zifencei extensions. This requires explicitly specifying 894 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 895 and Zifencei are supported in binutils from version 2.36 onwards. 896 To make life easier, and avoid forcing toolchains that default to a 897 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 898 For GCC < 11.3.0, for which this is not possible or need special 899 treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 900 901config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 902 def_bool y 903 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 904 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 905 depends on CC_IS_GCC && GCC_VERSION < 110300 906 help 907 Certain versions of GCC do not support zicsr and zifencei via -march. 908 This option causes an older ISA spec compatible with these older 909 versions of GCC to be passed to GAS, which has the same result 910 as passing zicsr and zifencei to -march. 911 912config FPU 913 bool "FPU support" 914 default y 915 help 916 Add support for floating point operations when an FPU is detected at 917 boot. When this option is disabled, neither the kernel nor userspace 918 may use the floating point unit. 919 920 If you don't know what to do here, say Y. 921 922config IRQ_STACKS 923 bool "Independent irq & softirq stacks" if EXPERT 924 default y 925 select HAVE_IRQ_EXIT_ON_IRQ_STACK 926 select HAVE_SOFTIRQ_ON_OWN_STACK 927 help 928 Add independent irq & softirq stacks for percpu to prevent kernel stack 929 overflows. We may save some memory footprint by disabling IRQ_STACKS. 930 931config THREAD_SIZE_ORDER 932 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT 933 range 0 4 934 default 1 if 32BIT 935 default 2 936 help 937 Specify the Pages of thread stack size (from 4KB to 64KB), which also 938 affects irq stack size, which is equal to thread stack size. 939 940config RISCV_MISALIGNED 941 bool 942 help 943 Embed support for detecting and emulating misaligned 944 scalar or vector loads and stores. 945 946config RISCV_SCALAR_MISALIGNED 947 bool 948 select RISCV_MISALIGNED 949 select SYSCTL_ARCH_UNALIGN_ALLOW 950 help 951 Embed support for emulating misaligned loads and stores. 952 953config RISCV_VECTOR_MISALIGNED 954 bool 955 select RISCV_MISALIGNED 956 depends on RISCV_ISA_V 957 help 958 Enable detecting support for vector misaligned loads and stores. 959 960config RISCV_SBI_FWFT_DELEGATE_MISALIGNED 961 bool "Request firmware delegation of unaligned access exceptions" 962 depends on RISCV_SBI 963 depends on NONPORTABLE 964 help 965 Use SBI FWFT to request delegation of load address misaligned and 966 store address misaligned exceptions, if possible, and prefer Linux 967 kernel emulation of these accesses to firmware emulation. 968 969 Unfortunately, Linux's emulation is still incomplete. Namely, it 970 currently does not handle vector instructions and KVM guest accesses. 971 On platforms where these accesses would have been handled by firmware, 972 enabling this causes unexpected kernel oopses, userspaces crashes and 973 KVM guest crashes. If you are sure that these are not a problem for 974 your platform, you can say Y here, which may improve performance. 975 976 Saying N here will not worsen emulation support for unaligned accesses 977 even in the case where the firmware also has incomplete support. It 978 simply keeps the firmware's emulation enabled. 979 980 If you don't know what to do here, say N. 981 982choice 983 prompt "Unaligned Accesses Support" 984 default RISCV_PROBE_UNALIGNED_ACCESS 985 help 986 This determines the level of support for unaligned accesses. This 987 information is used by the kernel to perform optimizations. It is also 988 exposed to user space via the hwprobe syscall. The hardware will be 989 probed at boot by default. 990 991config RISCV_PROBE_UNALIGNED_ACCESS 992 bool "Probe for hardware unaligned access support" 993 select RISCV_SCALAR_MISALIGNED 994 help 995 During boot, the kernel will run a series of tests to determine the 996 speed of unaligned accesses. This probing will dynamically determine 997 the speed of unaligned accesses on the underlying system. If unaligned 998 memory accesses trap into the kernel as they are not supported by the 999 system, the kernel will emulate the unaligned accesses to preserve the 1000 UABI. 1001 1002config RISCV_EMULATED_UNALIGNED_ACCESS 1003 bool "Emulate unaligned access where system support is missing" 1004 select RISCV_SCALAR_MISALIGNED 1005 help 1006 If unaligned memory accesses trap into the kernel as they are not 1007 supported by the system, the kernel will emulate the unaligned 1008 accesses to preserve the UABI. When the underlying system does support 1009 unaligned accesses, the unaligned accesses are assumed to be slow. 1010 1011config RISCV_SLOW_UNALIGNED_ACCESS 1012 bool "Assume the system supports slow unaligned memory accesses" 1013 depends on NONPORTABLE 1014 help 1015 Assume that the system supports slow unaligned memory accesses. The 1016 kernel and userspace programs may not be able to run at all on systems 1017 that do not support unaligned memory accesses. 1018 1019config RISCV_EFFICIENT_UNALIGNED_ACCESS 1020 bool "Assume the system supports fast unaligned memory accesses" 1021 depends on NONPORTABLE 1022 select DCACHE_WORD_ACCESS if MMU 1023 select HAVE_EFFICIENT_UNALIGNED_ACCESS 1024 help 1025 Assume that the system supports fast unaligned memory accesses. When 1026 enabled, this option improves the performance of the kernel on such 1027 systems. However, the kernel and userspace programs will run much more 1028 slowly, or will not be able to run at all, on systems that do not 1029 support efficient unaligned memory accesses. 1030 1031endchoice 1032 1033choice 1034 prompt "Vector unaligned Accesses Support" 1035 depends on RISCV_ISA_V 1036 default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 1037 help 1038 This determines the level of support for vector unaligned accesses. This 1039 information is used by the kernel to perform optimizations. It is also 1040 exposed to user space via the hwprobe syscall. The hardware will be 1041 probed at boot by default. 1042 1043config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 1044 bool "Probe speed of vector unaligned accesses" 1045 select RISCV_VECTOR_MISALIGNED 1046 help 1047 During boot, the kernel will run a series of tests to determine the 1048 speed of vector unaligned accesses if they are supported. This probing 1049 will dynamically determine the speed of vector unaligned accesses on 1050 the underlying system if they are supported. 1051 1052config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS 1053 bool "Assume the system supports slow vector unaligned memory accesses" 1054 depends on NONPORTABLE 1055 help 1056 Assume that the system supports slow vector unaligned memory accesses. The 1057 kernel and userspace programs may not be able to run at all on systems 1058 that do not support unaligned memory accesses. 1059 1060config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS 1061 bool "Assume the system supports fast vector unaligned memory accesses" 1062 depends on NONPORTABLE 1063 help 1064 Assume that the system supports fast vector unaligned memory accesses. When 1065 enabled, this option improves the performance of the kernel on such 1066 systems. However, the kernel and userspace programs will run much more 1067 slowly, or will not be able to run at all, on systems that do not 1068 support efficient unaligned memory accesses. 1069 1070endchoice 1071 1072source "arch/riscv/Kconfig.vendor" 1073 1074endmenu # "Platform type" 1075 1076menu "Kernel features" 1077 1078source "kernel/Kconfig.hz" 1079 1080config RISCV_SBI_V01 1081 bool "SBI v0.1 support" 1082 depends on RISCV_SBI 1083 help 1084 This config allows kernel to use SBI v0.1 APIs. This will be 1085 deprecated in future once legacy M-mode software are no longer in use. 1086 1087config RISCV_BOOT_SPINWAIT 1088 bool "Spinwait booting method" 1089 depends on SMP 1090 default y if RISCV_SBI_V01 || RISCV_M_MODE 1091 help 1092 This enables support for booting Linux via spinwait method. In the 1093 spinwait method, all cores randomly jump to Linux. One of the cores 1094 gets chosen via lottery and all other keep spinning on a percpu 1095 variable. This method cannot support CPU hotplug and sparse hartid 1096 scheme. It should be only enabled for M-mode Linux or platforms relying 1097 on older firmware without SBI HSM extension. All other platforms should 1098 rely on ordered booting via SBI HSM extension which gets chosen 1099 dynamically at runtime if the firmware supports it. 1100 1101 Since spinwait is incompatible with sparse hart IDs, it requires 1102 NR_CPUS be large enough to contain the physical hart ID of the first 1103 hart to enter Linux. 1104 1105 If unsure what to do here, say N. 1106 1107config ARCH_SUPPORTS_KEXEC 1108 def_bool y 1109 1110config ARCH_SELECTS_KEXEC 1111 def_bool y 1112 depends on KEXEC 1113 select HOTPLUG_CPU if SMP 1114 1115config ARCH_SUPPORTS_KEXEC_FILE 1116 def_bool 64BIT 1117 1118config ARCH_SELECTS_KEXEC_FILE 1119 def_bool y 1120 depends on KEXEC_FILE 1121 select HAVE_IMA_KEXEC if IMA 1122 select KEXEC_ELF 1123 1124config ARCH_SUPPORTS_KEXEC_PURGATORY 1125 def_bool ARCH_SUPPORTS_KEXEC_FILE 1126 1127config ARCH_SUPPORTS_CRASH_DUMP 1128 def_bool y 1129 1130config ARCH_DEFAULT_CRASH_DUMP 1131 def_bool y 1132 1133config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1134 def_bool CRASH_RESERVE 1135 1136config COMPAT 1137 bool "Kernel support for 32-bit U-mode" 1138 default 64BIT 1139 depends on 64BIT && MMU 1140 help 1141 This option enables support for a 32-bit U-mode running under a 64-bit 1142 kernel at S-mode. riscv32-specific components such as system calls, 1143 the user helper functions (vdso), signal rt_frame functions and the 1144 ptrace interface are handled appropriately by the kernel. 1145 1146 If you want to execute 32-bit userspace applications, say Y. 1147 1148config PARAVIRT 1149 bool "Enable paravirtualization code" 1150 depends on RISCV_SBI 1151 select HAVE_PV_STEAL_CLOCK_GEN 1152 help 1153 This changes the kernel so it can modify itself when it is run 1154 under a hypervisor, potentially improving performance significantly 1155 over full virtualization. 1156 1157config PARAVIRT_TIME_ACCOUNTING 1158 bool "Paravirtual steal time accounting" 1159 depends on PARAVIRT 1160 help 1161 Select this option to enable fine granularity task steal time 1162 accounting. Time spent executing other tasks in parallel with 1163 the current vCPU is discounted from the vCPU power. To account for 1164 that, there can be a small performance impact. 1165 1166 If in doubt, say N here. 1167 1168config RELOCATABLE 1169 bool "Build a relocatable kernel" 1170 select MODULE_SECTIONS if MODULES 1171 select ARCH_VMLINUX_NEEDS_RELOCS 1172 help 1173 This builds a kernel as a Position Independent Executable (PIE), 1174 which retains all relocation metadata required to relocate the 1175 kernel binary at runtime to a different virtual address than the 1176 address it was linked at. 1177 Since RISCV uses the RELA relocation format, this requires a 1178 relocation pass at runtime even if the kernel is loaded at the 1179 same address it was linked at. 1180 1181 If unsure, say N. 1182 1183config RANDOMIZE_BASE 1184 bool "Randomize the address of the kernel image" 1185 depends on RELOCATABLE 1186 depends on MMU && 64BIT 1187 help 1188 Randomizes the virtual address at which the kernel image is 1189 loaded, as a security feature that deters exploit attempts 1190 relying on knowledge of the location of kernel internals. 1191 1192 It is the bootloader's job to provide entropy, by passing a 1193 random u64 value in /chosen/kaslr-seed at kernel entry. 1194 1195 When booting via the UEFI stub, it will invoke the firmware's 1196 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1197 to the kernel proper. In addition, it will randomise the physical 1198 location of the kernel Image as well. 1199 1200 If unsure, say N. 1201 1202config RISCV_USER_CFI 1203 def_bool y 1204 bool "riscv userspace control flow integrity" 1205 depends on 64BIT && MMU && \ 1206 $(cc-option,-mabi=lp64 -march=rv64ima_zicfiss_zicfilp -fcf-protection=full) 1207 depends on RISCV_ALTERNATIVE 1208 select RISCV_SBI 1209 select ARCH_HAS_USER_SHADOW_STACK 1210 select ARCH_USES_HIGH_VMA_FLAGS 1211 select DYNAMIC_SIGFRAME 1212 help 1213 Provides CPU-assisted control flow integrity to userspace tasks. 1214 Control flow integrity is provided by implementing shadow stack for 1215 backward edge and indirect branch tracking for forward edge. 1216 Shadow stack protection is a hardware feature that detects function 1217 return address corruption. This helps mitigate ROP attacks. 1218 Indirect branch tracking enforces that all indirect branches must land 1219 on a landing pad instruction else CPU will fault. This mitigates against 1220 JOP / COP attacks. Applications must be enabled to use it, and old userspace 1221 does not get protection "for free". 1222 default y. 1223 1224endmenu # "Kernel features" 1225 1226menu "Boot options" 1227 1228config CMDLINE 1229 string "Built-in kernel command line" 1230 help 1231 For most platforms, the arguments for the kernel's command line 1232 are provided at run-time, during boot. However, there are cases 1233 where either no arguments are being provided or the provided 1234 arguments are insufficient or even invalid. 1235 1236 When that occurs, it is possible to define a built-in command 1237 line here and choose how the kernel should use it later on. 1238 1239choice 1240 prompt "Built-in command line usage" 1241 depends on CMDLINE != "" 1242 default CMDLINE_FALLBACK 1243 help 1244 Choose how the kernel will handle the provided built-in command 1245 line. 1246 1247config CMDLINE_FALLBACK 1248 bool "Use bootloader kernel arguments if available" 1249 help 1250 Use the built-in command line as fallback in case we get nothing 1251 during boot. This is the default behaviour. 1252 1253config CMDLINE_EXTEND 1254 bool "Extend bootloader kernel arguments" 1255 help 1256 The built-in command line will be appended to the command- 1257 line arguments provided during boot. This is useful in 1258 cases where the provided arguments are insufficient and 1259 you don't want to or cannot modify them. 1260 1261config CMDLINE_FORCE 1262 bool "Always use the default kernel command string" 1263 help 1264 Always use the built-in command line, even if we get one during 1265 boot. This is useful in case you need to override the provided 1266 command line on systems where you don't have or want control 1267 over it. 1268 1269endchoice 1270 1271config EFI_STUB 1272 bool 1273 1274config EFI 1275 bool "UEFI runtime support" 1276 depends on OF 1277 depends on MMU 1278 default y 1279 select ARCH_SUPPORTS_ACPI if 64BIT 1280 select EFI_GENERIC_STUB 1281 select EFI_PARAMS_FROM_FDT 1282 select EFI_RUNTIME_WRAPPERS 1283 select EFI_STUB 1284 select LIBFDT 1285 select RISCV_ISA_C 1286 select UCS2_STRING 1287 help 1288 This option provides support for runtime services provided 1289 by UEFI firmware (such as non-volatile variables, realtime 1290 clock, and platform reset). A UEFI stub is also provided to 1291 allow the kernel to be booted as an EFI application. This 1292 is only useful on systems that have UEFI firmware. 1293 1294config DMI 1295 bool "Enable support for SMBIOS (DMI) tables" 1296 depends on EFI 1297 default y 1298 help 1299 This enables SMBIOS/DMI feature for systems. 1300 1301 This option is only useful on systems that have UEFI firmware. 1302 However, even with this option, the resultant kernel should 1303 continue to boot on existing non-UEFI platforms. 1304 1305config CC_HAVE_STACKPROTECTOR_TLS 1306 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 1307 1308config STACKPROTECTOR_PER_TASK 1309 def_bool y 1310 depends on !RANDSTRUCT 1311 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 1312 1313config PHYS_RAM_BASE_FIXED 1314 bool "Explicitly specified physical RAM address" 1315 depends on NONPORTABLE 1316 default n 1317 1318config PHYS_RAM_BASE 1319 hex "Platform Physical RAM address" 1320 depends on PHYS_RAM_BASE_FIXED 1321 default "0x80000000" 1322 help 1323 This is the physical address of RAM in the system. It has to be 1324 explicitly specified to run early relocations of read-write data 1325 from flash to RAM. 1326 1327config RISCV_ISA_FALLBACK 1328 bool "Permit falling back to parsing riscv,isa for extension support by default" 1329 default y 1330 help 1331 Parsing the "riscv,isa" devicetree property has been deprecated and 1332 replaced by a list of explicitly defined strings. For compatibility 1333 with existing platforms, the kernel will fall back to parsing the 1334 "riscv,isa" property if the replacements are not found. 1335 1336 Selecting N here will result in a kernel that does not use the 1337 fallback, unless the commandline "riscv_isa_fallback" parameter is 1338 present. 1339 1340 Please see the dt-binding, located at 1341 Documentation/devicetree/bindings/riscv/extensions.yaml for details 1342 on the replacement properties, "riscv,isa-base" and 1343 "riscv,isa-extensions". 1344 1345config BUILTIN_DTB 1346 bool "Built-in device tree" 1347 depends on OF && NONPORTABLE 1348 select GENERIC_BUILTIN_DTB 1349 help 1350 Build a device tree into the Linux image. 1351 This option should be selected if no bootloader is being used. 1352 If unsure, say N. 1353 1354 1355config BUILTIN_DTB_NAME 1356 string "Built-in device tree source" 1357 depends on BUILTIN_DTB 1358 help 1359 DTS file path (without suffix, relative to arch/riscv/boot/dts) 1360 for the DTS file that will be used to produce the DTB linked into the 1361 kernel. 1362 1363endmenu # "Boot options" 1364 1365config PORTABLE 1366 bool 1367 default !NONPORTABLE 1368 select EFI 1369 select MMU 1370 select OF 1371 1372config ARCH_PROC_KCORE_TEXT 1373 def_bool y 1374 1375config ARCH_CC_CAN_LINK 1376 bool 1377 default $(cc_can_link_user,-march=rv64g -mabi=lp64d) if 64BIT && FPU 1378 default $(cc_can_link_user,-march=rv64g -mabi=lp64) if 64BIT 1379 default $(cc_can_link_user,-march=rv32g -mabi=ilp32d) if FPU 1380 default $(cc_can_link_user,-march=rv32g -mabi=ilp32) 1381 1382config ARCH_USERFLAGS 1383 string 1384 default "-march=rv64g -mabi=lp64d" if 64BIT && FPU 1385 default "-march=rv64g -mabi=lp64" if 64BIT 1386 default "-march=rv32g -mabi=ilp32d" if FPU 1387 default "-march=rv32g -mabi=ilp32" 1388 1389menu "Power management options" 1390 1391source "kernel/power/Kconfig" 1392 1393config ARCH_HIBERNATION_POSSIBLE 1394 def_bool y 1395 1396config ARCH_HIBERNATION_HEADER 1397 def_bool HIBERNATION 1398 1399config ARCH_SUSPEND_POSSIBLE 1400 def_bool y 1401 1402endmenu # "Power management options" 1403 1404menu "CPU Power Management" 1405 1406source "drivers/cpuidle/Kconfig" 1407 1408source "drivers/cpufreq/Kconfig" 1409 1410endmenu # "CPU Power Management" 1411 1412source "arch/riscv/kvm/Kconfig" 1413 1414source "drivers/acpi/Kconfig" 1415