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_REDUCED_HARDWARE_ONLY if ACPI 17 select ARCH_DMA_DEFAULT_COHERENT 18 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 19 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 20 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 21 select ARCH_HAS_BINFMT_FLAT 22 select ARCH_HAS_CURRENT_STACK_POINTER 23 select ARCH_HAS_DEBUG_VIRTUAL if MMU 24 select ARCH_HAS_DEBUG_VM_PGTABLE 25 select ARCH_HAS_DEBUG_WX 26 select ARCH_HAS_FORTIFY_SOURCE 27 select ARCH_HAS_GCOV_PROFILE_ALL 28 select ARCH_HAS_GIGANTIC_PAGE 29 select ARCH_HAS_KCOV 30 select ARCH_HAS_MEMBARRIER_CALLBACKS 31 select ARCH_HAS_MEMBARRIER_SYNC_CORE 32 select ARCH_HAS_MMIOWB 33 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 34 select ARCH_HAS_PMEM_API 35 select ARCH_HAS_PREPARE_SYNC_CORE_CMD 36 select ARCH_HAS_PTE_SPECIAL 37 select ARCH_HAS_SET_DIRECT_MAP if MMU 38 select ARCH_HAS_SET_MEMORY if MMU 39 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL 40 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL 41 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 42 select ARCH_HAS_SYSCALL_WRAPPER 43 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 44 select ARCH_HAS_UBSAN 45 select ARCH_HAS_VDSO_DATA 46 select ARCH_KEEP_MEMBLOCK if ACPI 47 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 48 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 49 select ARCH_STACKWALK 50 select ARCH_SUPPORTS_ATOMIC_RMW 51 select ARCH_SUPPORTS_CFI_CLANG 52 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU 53 select ARCH_SUPPORTS_HUGETLBFS if MMU 54 # LLD >= 14: https://github.com/llvm/llvm-project/issues/50505 55 select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000 56 select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000 57 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 58 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 59 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK 60 select ARCH_USE_MEMTEST 61 select ARCH_USE_QUEUED_RWLOCKS 62 select ARCH_USES_CFI_TRAPS if CFI_CLANG 63 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP && MMU 64 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 65 select ARCH_WANT_FRAME_POINTERS 66 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 67 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 68 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL 69 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 70 select ARCH_WANTS_NO_INSTR 71 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 72 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 73 select BUILDTIME_TABLE_SORT if MMU 74 select CLINT_TIMER if !MMU 75 select CLONE_BACKWARDS 76 select COMMON_CLK 77 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND 78 select EDAC_SUPPORT 79 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) 80 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE 81 select GENERIC_ARCH_TOPOLOGY 82 select GENERIC_ATOMIC64 if !64BIT 83 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 84 select GENERIC_CPU_DEVICES 85 select GENERIC_EARLY_IOREMAP 86 select GENERIC_ENTRY 87 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 88 select GENERIC_IDLE_POLL_SETUP 89 select GENERIC_IOREMAP if MMU 90 select GENERIC_IRQ_IPI if SMP 91 select GENERIC_IRQ_IPI_MUX if SMP 92 select GENERIC_IRQ_MULTI_HANDLER 93 select GENERIC_IRQ_SHOW 94 select GENERIC_IRQ_SHOW_LEVEL 95 select GENERIC_LIB_DEVMEM_IS_ALLOWED 96 select GENERIC_PCI_IOMAP 97 select GENERIC_PTDUMP if MMU 98 select GENERIC_SCHED_CLOCK 99 select GENERIC_SMP_IDLE_THREAD 100 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 101 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO 102 select HARDIRQS_SW_RESEND 103 select HAS_IOPORT if MMU 104 select HAVE_ARCH_AUDITSYSCALL 105 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 106 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL 107 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL 108 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL 109 select HAVE_ARCH_KASAN if MMU && 64BIT 110 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 111 select HAVE_ARCH_KFENCE if MMU && 64BIT 112 select HAVE_ARCH_KGDB if !XIP_KERNEL 113 select HAVE_ARCH_KGDB_QXFER_PKT 114 select HAVE_ARCH_MMAP_RND_BITS if MMU 115 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 116 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 117 select HAVE_ARCH_SECCOMP_FILTER 118 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 119 select HAVE_ARCH_TRACEHOOK 120 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU 121 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD 122 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 123 select HAVE_ASM_MODVERSIONS 124 select HAVE_CONTEXT_TRACKING_USER 125 select HAVE_DEBUG_KMEMLEAK 126 select HAVE_DMA_CONTIGUOUS if MMU 127 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 128 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 129 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE 130 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL 131 select HAVE_FUNCTION_GRAPH_TRACER 132 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 133 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION 134 select HAVE_EBPF_JIT if MMU 135 select HAVE_GUP_FAST if MMU 136 select HAVE_FUNCTION_ARG_ACCESS_API 137 select HAVE_FUNCTION_ERROR_INJECTION 138 select HAVE_GCC_PLUGINS 139 select HAVE_GENERIC_VDSO if MMU && 64BIT 140 select HAVE_IRQ_TIME_ACCOUNTING 141 select HAVE_KPROBES if !XIP_KERNEL 142 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL 143 select HAVE_KRETPROBES if !XIP_KERNEL 144 # https://github.com/ClangBuiltLinux/linux/issues/1881 145 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD 146 select HAVE_MOVE_PMD 147 select HAVE_MOVE_PUD 148 select HAVE_PAGE_SIZE_4KB 149 select HAVE_PCI 150 select HAVE_PERF_EVENTS 151 select HAVE_PERF_REGS 152 select HAVE_PERF_USER_STACK_DUMP 153 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 154 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL 155 select HAVE_REGS_AND_STACK_ACCESS_API 156 select HAVE_RETHOOK if !XIP_KERNEL 157 select HAVE_RSEQ 158 select HAVE_SAMPLE_FTRACE_DIRECT 159 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 160 select HAVE_STACKPROTECTOR 161 select HAVE_SYSCALL_TRACEPOINTS 162 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 163 select IRQ_DOMAIN 164 select IRQ_FORCED_THREADING 165 select KASAN_VMALLOC if KASAN 166 select LOCK_MM_AND_FIND_VMA 167 select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU 168 select MODULES_USE_ELF_RELA if MODULES 169 select MODULE_SECTIONS if MODULES 170 select OF 171 select OF_EARLY_FLATTREE 172 select OF_IRQ 173 select PCI_DOMAINS_GENERIC if PCI 174 select PCI_MSI if PCI 175 select RISCV_ALTERNATIVE if !XIP_KERNEL 176 select RISCV_APLIC 177 select RISCV_IMSIC 178 select RISCV_INTC 179 select RISCV_TIMER if RISCV_SBI 180 select SIFIVE_PLIC 181 select SPARSE_IRQ 182 select SYSCTL_EXCEPTION_TRACE 183 select THREAD_INFO_IN_TASK 184 select TRACE_IRQFLAGS_SUPPORT 185 select UACCESS_MEMCPY if !MMU 186 select ZONE_DMA32 if 64BIT 187 188config CLANG_SUPPORTS_DYNAMIC_FTRACE 189 def_bool CC_IS_CLANG 190 # https://github.com/ClangBuiltLinux/linux/issues/1817 191 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 192 193config GCC_SUPPORTS_DYNAMIC_FTRACE 194 def_bool CC_IS_GCC 195 depends on $(cc-option,-fpatchable-function-entry=8) 196 197config HAVE_SHADOW_CALL_STACK 198 def_bool $(cc-option,-fsanitize=shadow-call-stack) 199 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 200 depends on $(ld-option,--no-relax-gp) 201 202config RISCV_USE_LINKER_RELAXATION 203 def_bool y 204 # https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985 205 depends on !LD_IS_LLD || LLD_VERSION >= 150000 206 207# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 208config ARCH_HAS_BROKEN_DWARF5 209 def_bool y 210 depends on RISCV_USE_LINKER_RELAXATION 211 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a 212 depends on AS_IS_LLVM && AS_VERSION < 180000 213 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77 214 depends on LD_IS_LLD && LLD_VERSION < 180000 215 216config ARCH_MMAP_RND_BITS_MIN 217 default 18 if 64BIT 218 default 8 219 220config ARCH_MMAP_RND_COMPAT_BITS_MIN 221 default 8 222 223# max bits determined by the following formula: 224# VA_BITS - PAGE_SHIFT - 3 225config ARCH_MMAP_RND_BITS_MAX 226 default 24 if 64BIT # SV39 based 227 default 17 228 229config ARCH_MMAP_RND_COMPAT_BITS_MAX 230 default 17 231 232# set if we run in machine mode, cleared if we run in supervisor mode 233config RISCV_M_MODE 234 bool 235 default !MMU 236 237# set if we are running in S-mode and can use SBI calls 238config RISCV_SBI 239 bool 240 depends on !RISCV_M_MODE 241 default y 242 243config MMU 244 bool "MMU-based Paged Memory Management Support" 245 default y 246 help 247 Select if you want MMU-based virtualised addressing space 248 support by paged memory management. If unsure, say 'Y'. 249 250config PAGE_OFFSET 251 hex 252 default 0xC0000000 if 32BIT && MMU 253 default 0x80000000 if !MMU 254 default 0xff60000000000000 if 64BIT 255 256config KASAN_SHADOW_OFFSET 257 hex 258 depends on KASAN_GENERIC 259 default 0xdfffffff00000000 if 64BIT 260 default 0xffffffff if 32BIT 261 262config ARCH_FLATMEM_ENABLE 263 def_bool !NUMA 264 265config ARCH_SPARSEMEM_ENABLE 266 def_bool y 267 depends on MMU 268 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 269 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 270 271config ARCH_SELECT_MEMORY_MODEL 272 def_bool ARCH_SPARSEMEM_ENABLE 273 274config ARCH_SUPPORTS_UPROBES 275 def_bool y 276 277config STACKTRACE_SUPPORT 278 def_bool y 279 280config GENERIC_BUG 281 def_bool y 282 depends on BUG 283 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 284 285config GENERIC_BUG_RELATIVE_POINTERS 286 bool 287 288config GENERIC_CALIBRATE_DELAY 289 def_bool y 290 291config GENERIC_CSUM 292 def_bool y 293 294config GENERIC_HWEIGHT 295 def_bool y 296 297config FIX_EARLYCON_MEM 298 def_bool MMU 299 300config PGTABLE_LEVELS 301 int 302 default 5 if 64BIT 303 default 2 304 305config LOCKDEP_SUPPORT 306 def_bool y 307 308config RISCV_DMA_NONCOHERENT 309 bool 310 select ARCH_HAS_DMA_PREP_COHERENT 311 select ARCH_HAS_SETUP_DMA_OPS 312 select ARCH_HAS_SYNC_DMA_FOR_CPU 313 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 314 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 315 316config RISCV_NONSTANDARD_CACHE_OPS 317 bool 318 help 319 This enables function pointer support for non-standard noncoherent 320 systems to handle cache management. 321 322config AS_HAS_INSN 323 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) 324 325config AS_HAS_OPTION_ARCH 326 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4 327 def_bool y 328 depends on $(as-instr, .option arch$(comma) +m) 329 330source "arch/riscv/Kconfig.socs" 331source "arch/riscv/Kconfig.errata" 332 333menu "Platform type" 334 335config NONPORTABLE 336 bool "Allow configurations that result in non-portable kernels" 337 help 338 RISC-V kernel binaries are compatible between all known systems 339 whenever possible, but there are some use cases that can only be 340 satisfied by configurations that result in kernel binaries that are 341 not portable between systems. 342 343 Selecting N does not guarantee kernels will be portable to all known 344 systems. Selecting any of the options guarded by NONPORTABLE will 345 result in kernel binaries that are unlikely to be portable between 346 systems. 347 348 If unsure, say N. 349 350choice 351 prompt "Base ISA" 352 default ARCH_RV64I 353 help 354 This selects the base ISA that this kernel will target and must match 355 the target platform. 356 357config ARCH_RV32I 358 bool "RV32I" 359 depends on NONPORTABLE 360 select 32BIT 361 select GENERIC_LIB_ASHLDI3 362 select GENERIC_LIB_ASHRDI3 363 select GENERIC_LIB_LSHRDI3 364 select GENERIC_LIB_UCMPDI2 365 366config ARCH_RV64I 367 bool "RV64I" 368 select 64BIT 369 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 370 select SWIOTLB if MMU 371 372endchoice 373 374# We must be able to map all physical memory into the kernel, but the compiler 375# is still a bit more efficient when generating code if it's setup in a manner 376# such that it can only map 2GiB of memory. 377choice 378 prompt "Kernel Code Model" 379 default CMODEL_MEDLOW if 32BIT 380 default CMODEL_MEDANY if 64BIT 381 382 config CMODEL_MEDLOW 383 bool "medium low code model" 384 config CMODEL_MEDANY 385 bool "medium any code model" 386endchoice 387 388config MODULE_SECTIONS 389 bool 390 select HAVE_MOD_ARCH_SPECIFIC 391 392config SMP 393 bool "Symmetric Multi-Processing" 394 help 395 This enables support for systems with more than one CPU. If 396 you say N here, the kernel will run on single and 397 multiprocessor machines, but will use only one CPU of a 398 multiprocessor machine. If you say Y here, the kernel will run 399 on many, but not all, single processor machines. On a single 400 processor machine, the kernel will run faster if you say N 401 here. 402 403 If you don't know what to do here, say N. 404 405config SCHED_MC 406 bool "Multi-core scheduler support" 407 depends on SMP 408 help 409 Multi-core scheduler support improves the CPU scheduler's decision 410 making when dealing with multi-core CPU chips at a cost of slightly 411 increased overhead in some places. If unsure say N here. 412 413config NR_CPUS 414 int "Maximum number of CPUs (2-512)" 415 depends on SMP 416 range 2 512 if !RISCV_SBI_V01 417 range 2 32 if RISCV_SBI_V01 && 32BIT 418 range 2 64 if RISCV_SBI_V01 && 64BIT 419 default "32" if 32BIT 420 default "64" if 64BIT 421 422config HOTPLUG_CPU 423 bool "Support for hot-pluggable CPUs" 424 depends on SMP 425 select GENERIC_IRQ_MIGRATION 426 help 427 428 Say Y here to experiment with turning CPUs off and on. CPUs 429 can be controlled through /sys/devices/system/cpu. 430 431 Say N if you want to disable CPU hotplug. 432 433choice 434 prompt "CPU Tuning" 435 default TUNE_GENERIC 436 437config TUNE_GENERIC 438 bool "generic" 439 440endchoice 441 442# Common NUMA Features 443config NUMA 444 bool "NUMA Memory Allocation and Scheduler Support" 445 depends on SMP && MMU 446 select ARCH_SUPPORTS_NUMA_BALANCING 447 select GENERIC_ARCH_NUMA 448 select HAVE_SETUP_PER_CPU_AREA 449 select NEED_PER_CPU_EMBED_FIRST_CHUNK 450 select NEED_PER_CPU_PAGE_FIRST_CHUNK 451 select OF_NUMA 452 select USE_PERCPU_NUMA_NODE_ID 453 help 454 Enable NUMA (Non-Uniform Memory Access) support. 455 456 The kernel will try to allocate memory used by a CPU on the 457 local memory of the CPU and add some more NUMA awareness to the kernel. 458 459config NODES_SHIFT 460 int "Maximum NUMA Nodes (as a power of 2)" 461 range 1 10 462 default "2" 463 depends on NUMA 464 help 465 Specify the maximum number of NUMA Nodes available on the target 466 system. Increases memory reserved to accommodate various tables. 467 468config RISCV_ALTERNATIVE 469 bool 470 depends on !XIP_KERNEL 471 help 472 This Kconfig allows the kernel to automatically patch the 473 erratum or cpufeature required by the execution platform at run 474 time. The code patching overhead is minimal, as it's only done 475 once at boot and once on each module load. 476 477config RISCV_ALTERNATIVE_EARLY 478 bool 479 depends on RISCV_ALTERNATIVE 480 help 481 Allows early patching of the kernel for special errata 482 483config RISCV_ISA_C 484 bool "Emit compressed instructions when building Linux" 485 default y 486 help 487 Adds "C" to the ISA subsets that the toolchain is allowed to emit 488 when building Linux, which results in compressed instructions in the 489 Linux binary. 490 491 If you don't know what to do here, say Y. 492 493config RISCV_ISA_SVNAPOT 494 bool "Svnapot extension support for supervisor mode NAPOT pages" 495 depends on 64BIT && MMU 496 depends on RISCV_ALTERNATIVE 497 default y 498 help 499 Allow kernel to detect the Svnapot ISA-extension dynamically at boot 500 time and enable its usage. 501 502 The Svnapot extension is used to mark contiguous PTEs as a range 503 of contiguous virtual-to-physical translations for a naturally 504 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 505 size. When HUGETLBFS is also selected this option unconditionally 506 allocates some memory for each NAPOT page size supported by the kernel. 507 When optimizing for low memory consumption and for platforms without 508 the Svnapot extension, it may be better to say N here. 509 510 If you don't know what to do here, say Y. 511 512config RISCV_ISA_SVPBMT 513 bool "Svpbmt extension support for supervisor mode page-based memory types" 514 depends on 64BIT && MMU 515 depends on RISCV_ALTERNATIVE 516 default y 517 help 518 Adds support to dynamically detect the presence of the Svpbmt 519 ISA-extension (Supervisor-mode: page-based memory types) and 520 enable its usage. 521 522 The memory type for a page contains a combination of attributes 523 that indicate the cacheability, idempotency, and ordering 524 properties for access to that page. 525 526 The Svpbmt extension is only available on 64-bit cpus. 527 528 If you don't know what to do here, say Y. 529 530config TOOLCHAIN_HAS_V 531 bool 532 default y 533 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv) 534 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv) 535 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800 536 depends on AS_HAS_OPTION_ARCH 537 538config RISCV_ISA_V 539 bool "VECTOR extension support" 540 depends on TOOLCHAIN_HAS_V 541 depends on FPU 542 select DYNAMIC_SIGFRAME 543 default y 544 help 545 Say N here if you want to disable all vector related procedure 546 in the kernel. 547 548 If you don't know what to do here, say Y. 549 550config RISCV_ISA_V_DEFAULT_ENABLE 551 bool "Enable userspace Vector by default" 552 depends on RISCV_ISA_V 553 default y 554 help 555 Say Y here if you want to enable Vector in userspace by default. 556 Otherwise, userspace has to make explicit prctl() call to enable 557 Vector, or enable it via the sysctl interface. 558 559 If you don't know what to do here, say Y. 560 561config RISCV_ISA_V_UCOPY_THRESHOLD 562 int "Threshold size for vectorized user copies" 563 depends on RISCV_ISA_V 564 default 768 565 help 566 Prefer using vectorized copy_to_user()/copy_from_user() when the 567 workload size exceeds this value. 568 569config RISCV_ISA_V_PREEMPTIVE 570 bool "Run kernel-mode Vector with kernel preemption" 571 depends on PREEMPTION 572 depends on RISCV_ISA_V 573 default y 574 help 575 Usually, in-kernel SIMD routines are run with preemption disabled. 576 Functions which envoke long running SIMD thus must yield core's 577 vector unit to prevent blocking other tasks for too long. 578 579 This config allows kernel to run SIMD without explicitly disable 580 preemption. Enabling this config will result in higher memory 581 consumption due to the allocation of per-task's kernel Vector context. 582 583config TOOLCHAIN_HAS_ZBB 584 bool 585 default y 586 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 587 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 588 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 589 depends on AS_HAS_OPTION_ARCH 590 591# This symbol indicates that the toolchain supports all v1.0 vector crypto 592# extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once. 593# binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb. 594config TOOLCHAIN_HAS_VECTOR_CRYPTO 595 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb) 596 depends on AS_HAS_OPTION_ARCH 597 598config RISCV_ISA_ZBB 599 bool "Zbb extension support for bit manipulation instructions" 600 depends on TOOLCHAIN_HAS_ZBB 601 depends on MMU 602 depends on RISCV_ALTERNATIVE 603 default y 604 help 605 Adds support to dynamically detect the presence of the ZBB 606 extension (basic bit manipulation) and enable its usage. 607 608 The Zbb extension provides instructions to accelerate a number 609 of bit-specific operations (count bit population, sign extending, 610 bitrotation, etc). 611 612 If you don't know what to do here, say Y. 613 614config RISCV_ISA_ZICBOM 615 bool "Zicbom extension support for non-coherent DMA operation" 616 depends on MMU 617 depends on RISCV_ALTERNATIVE 618 default y 619 select RISCV_DMA_NONCOHERENT 620 select DMA_DIRECT_REMAP 621 help 622 Adds support to dynamically detect the presence of the ZICBOM 623 extension (Cache Block Management Operations) and enable its 624 usage. 625 626 The Zicbom extension can be used to handle for example 627 non-coherent DMA support on devices that need it. 628 629 If you don't know what to do here, say Y. 630 631config RISCV_ISA_ZICBOZ 632 bool "Zicboz extension support for faster zeroing of memory" 633 depends on MMU 634 depends on RISCV_ALTERNATIVE 635 default y 636 help 637 Enable the use of the Zicboz extension (cbo.zero instruction) 638 when available. 639 640 The Zicboz extension is used for faster zeroing of memory. 641 642 If you don't know what to do here, say Y. 643 644config TOOLCHAIN_HAS_ZIHINTPAUSE 645 bool 646 default y 647 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause) 648 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause) 649 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600 650 651config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 652 def_bool y 653 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 654 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 655 depends on AS_IS_GNU && AS_VERSION >= 23600 656 help 657 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 658 20191213 version, which moves some instructions from the I extension to 659 the Zicsr and Zifencei extensions. This requires explicitly specifying 660 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 661 and Zifencei are supported in binutils from version 2.36 onwards. 662 To make life easier, and avoid forcing toolchains that default to a 663 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 664 For clang < 17 or GCC < 11.3.0, for which this is not possible or need 665 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 666 667config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 668 def_bool y 669 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 670 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 671 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 672 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300) 673 help 674 Certain versions of clang and GCC do not support zicsr and zifencei via 675 -march. This option causes an older ISA spec compatible with these older 676 versions of clang and GCC to be passed to GAS, which has the same result 677 as passing zicsr and zifencei to -march. 678 679config FPU 680 bool "FPU support" 681 default y 682 help 683 Say N here if you want to disable all floating-point related procedure 684 in the kernel. 685 686 If you don't know what to do here, say Y. 687 688config IRQ_STACKS 689 bool "Independent irq & softirq stacks" if EXPERT 690 default y 691 select HAVE_IRQ_EXIT_ON_IRQ_STACK 692 select HAVE_SOFTIRQ_ON_OWN_STACK 693 help 694 Add independent irq & softirq stacks for percpu to prevent kernel stack 695 overflows. We may save some memory footprint by disabling IRQ_STACKS. 696 697config THREAD_SIZE_ORDER 698 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT 699 range 0 4 700 default 1 if 32BIT && !KASAN 701 default 3 if 64BIT && KASAN 702 default 2 703 help 704 Specify the Pages of thread stack size (from 4KB to 64KB), which also 705 affects irq stack size, which is equal to thread stack size. 706 707config RISCV_MISALIGNED 708 bool 709 select SYSCTL_ARCH_UNALIGN_ALLOW 710 help 711 Embed support for emulating misaligned loads and stores. 712 713choice 714 prompt "Unaligned Accesses Support" 715 default RISCV_PROBE_UNALIGNED_ACCESS 716 help 717 This determines the level of support for unaligned accesses. This 718 information is used by the kernel to perform optimizations. It is also 719 exposed to user space via the hwprobe syscall. The hardware will be 720 probed at boot by default. 721 722config RISCV_PROBE_UNALIGNED_ACCESS 723 bool "Probe for hardware unaligned access support" 724 select RISCV_MISALIGNED 725 help 726 During boot, the kernel will run a series of tests to determine the 727 speed of unaligned accesses. This probing will dynamically determine 728 the speed of unaligned accesses on the underlying system. If unaligned 729 memory accesses trap into the kernel as they are not supported by the 730 system, the kernel will emulate the unaligned accesses to preserve the 731 UABI. 732 733config RISCV_EMULATED_UNALIGNED_ACCESS 734 bool "Emulate unaligned access where system support is missing" 735 select RISCV_MISALIGNED 736 help 737 If unaligned memory accesses trap into the kernel as they are not 738 supported by the system, the kernel will emulate the unaligned 739 accesses to preserve the UABI. When the underlying system does support 740 unaligned accesses, the unaligned accesses are assumed to be slow. 741 742config RISCV_SLOW_UNALIGNED_ACCESS 743 bool "Assume the system supports slow unaligned memory accesses" 744 depends on NONPORTABLE 745 help 746 Assume that the system supports slow unaligned memory accesses. The 747 kernel and userspace programs may not be able to run at all on systems 748 that do not support unaligned memory accesses. 749 750config RISCV_EFFICIENT_UNALIGNED_ACCESS 751 bool "Assume the system supports fast unaligned memory accesses" 752 depends on NONPORTABLE 753 select DCACHE_WORD_ACCESS if MMU 754 select HAVE_EFFICIENT_UNALIGNED_ACCESS 755 help 756 Assume that the system supports fast unaligned memory accesses. When 757 enabled, this option improves the performance of the kernel on such 758 systems. However, the kernel and userspace programs will run much more 759 slowly, or will not be able to run at all, on systems that do not 760 support efficient unaligned memory accesses. 761 762endchoice 763 764endmenu # "Platform type" 765 766menu "Kernel features" 767 768source "kernel/Kconfig.hz" 769 770config RISCV_SBI_V01 771 bool "SBI v0.1 support" 772 depends on RISCV_SBI 773 help 774 This config allows kernel to use SBI v0.1 APIs. This will be 775 deprecated in future once legacy M-mode software are no longer in use. 776 777config RISCV_BOOT_SPINWAIT 778 bool "Spinwait booting method" 779 depends on SMP 780 default y if RISCV_SBI_V01 || RISCV_M_MODE 781 help 782 This enables support for booting Linux via spinwait method. In the 783 spinwait method, all cores randomly jump to Linux. One of the cores 784 gets chosen via lottery and all other keep spinning on a percpu 785 variable. This method cannot support CPU hotplug and sparse hartid 786 scheme. It should be only enabled for M-mode Linux or platforms relying 787 on older firmware without SBI HSM extension. All other platforms should 788 rely on ordered booting via SBI HSM extension which gets chosen 789 dynamically at runtime if the firmware supports it. 790 791 Since spinwait is incompatible with sparse hart IDs, it requires 792 NR_CPUS be large enough to contain the physical hart ID of the first 793 hart to enter Linux. 794 795 If unsure what to do here, say N. 796 797config ARCH_SUPPORTS_KEXEC 798 def_bool y 799 800config ARCH_SELECTS_KEXEC 801 def_bool y 802 depends on KEXEC 803 select HOTPLUG_CPU if SMP 804 805config ARCH_SUPPORTS_KEXEC_FILE 806 def_bool 64BIT 807 808config ARCH_SELECTS_KEXEC_FILE 809 def_bool y 810 depends on KEXEC_FILE 811 select HAVE_IMA_KEXEC if IMA 812 select KEXEC_ELF 813 814config ARCH_SUPPORTS_KEXEC_PURGATORY 815 def_bool ARCH_SUPPORTS_KEXEC_FILE 816 817config ARCH_SUPPORTS_CRASH_DUMP 818 def_bool y 819 820config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 821 def_bool CRASH_RESERVE 822 823config COMPAT 824 bool "Kernel support for 32-bit U-mode" 825 default 64BIT 826 depends on 64BIT && MMU 827 help 828 This option enables support for a 32-bit U-mode running under a 64-bit 829 kernel at S-mode. riscv32-specific components such as system calls, 830 the user helper functions (vdso), signal rt_frame functions and the 831 ptrace interface are handled appropriately by the kernel. 832 833 If you want to execute 32-bit userspace applications, say Y. 834 835config PARAVIRT 836 bool "Enable paravirtualization code" 837 depends on RISCV_SBI 838 help 839 This changes the kernel so it can modify itself when it is run 840 under a hypervisor, potentially improving performance significantly 841 over full virtualization. 842 843config PARAVIRT_TIME_ACCOUNTING 844 bool "Paravirtual steal time accounting" 845 depends on PARAVIRT 846 help 847 Select this option to enable fine granularity task steal time 848 accounting. Time spent executing other tasks in parallel with 849 the current vCPU is discounted from the vCPU power. To account for 850 that, there can be a small performance impact. 851 852 If in doubt, say N here. 853 854config RELOCATABLE 855 bool "Build a relocatable kernel" 856 depends on MMU && 64BIT && !XIP_KERNEL 857 help 858 This builds a kernel as a Position Independent Executable (PIE), 859 which retains all relocation metadata required to relocate the 860 kernel binary at runtime to a different virtual address than the 861 address it was linked at. 862 Since RISCV uses the RELA relocation format, this requires a 863 relocation pass at runtime even if the kernel is loaded at the 864 same address it was linked at. 865 866 If unsure, say N. 867 868config RANDOMIZE_BASE 869 bool "Randomize the address of the kernel image" 870 select RELOCATABLE 871 depends on MMU && 64BIT && !XIP_KERNEL 872 help 873 Randomizes the virtual address at which the kernel image is 874 loaded, as a security feature that deters exploit attempts 875 relying on knowledge of the location of kernel internals. 876 877 It is the bootloader's job to provide entropy, by passing a 878 random u64 value in /chosen/kaslr-seed at kernel entry. 879 880 When booting via the UEFI stub, it will invoke the firmware's 881 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 882 to the kernel proper. In addition, it will randomise the physical 883 location of the kernel Image as well. 884 885 If unsure, say N. 886 887endmenu # "Kernel features" 888 889menu "Boot options" 890 891config CMDLINE 892 string "Built-in kernel command line" 893 help 894 For most platforms, the arguments for the kernel's command line 895 are provided at run-time, during boot. However, there are cases 896 where either no arguments are being provided or the provided 897 arguments are insufficient or even invalid. 898 899 When that occurs, it is possible to define a built-in command 900 line here and choose how the kernel should use it later on. 901 902choice 903 prompt "Built-in command line usage" if CMDLINE != "" 904 default CMDLINE_FALLBACK 905 help 906 Choose how the kernel will handle the provided built-in command 907 line. 908 909config CMDLINE_FALLBACK 910 bool "Use bootloader kernel arguments if available" 911 help 912 Use the built-in command line as fallback in case we get nothing 913 during boot. This is the default behaviour. 914 915config CMDLINE_EXTEND 916 bool "Extend bootloader kernel arguments" 917 help 918 The command-line arguments provided during boot will be 919 appended to the built-in command line. This is useful in 920 cases where the provided arguments are insufficient and 921 you don't want to or cannot modify them. 922 923config CMDLINE_FORCE 924 bool "Always use the default kernel command string" 925 help 926 Always use the built-in command line, even if we get one during 927 boot. This is useful in case you need to override the provided 928 command line on systems where you don't have or want control 929 over it. 930 931endchoice 932 933config EFI_STUB 934 bool 935 936config EFI 937 bool "UEFI runtime support" 938 depends on OF && !XIP_KERNEL 939 depends on MMU 940 default y 941 select ARCH_SUPPORTS_ACPI if 64BIT 942 select EFI_GENERIC_STUB 943 select EFI_PARAMS_FROM_FDT 944 select EFI_RUNTIME_WRAPPERS 945 select EFI_STUB 946 select LIBFDT 947 select RISCV_ISA_C 948 select UCS2_STRING 949 help 950 This option provides support for runtime services provided 951 by UEFI firmware (such as non-volatile variables, realtime 952 clock, and platform reset). A UEFI stub is also provided to 953 allow the kernel to be booted as an EFI application. This 954 is only useful on systems that have UEFI firmware. 955 956config CC_HAVE_STACKPROTECTOR_TLS 957 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 958 959config STACKPROTECTOR_PER_TASK 960 def_bool y 961 depends on !RANDSTRUCT 962 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 963 964config PHYS_RAM_BASE_FIXED 965 bool "Explicitly specified physical RAM address" 966 depends on NONPORTABLE 967 default n 968 969config PHYS_RAM_BASE 970 hex "Platform Physical RAM address" 971 depends on PHYS_RAM_BASE_FIXED 972 default "0x80000000" 973 help 974 This is the physical address of RAM in the system. It has to be 975 explicitly specified to run early relocations of read-write data 976 from flash to RAM. 977 978config XIP_KERNEL 979 bool "Kernel Execute-In-Place from ROM" 980 depends on MMU && SPARSEMEM && NONPORTABLE 981 # This prevents XIP from being enabled by all{yes,mod}config, which 982 # fail to build since XIP doesn't support large kernels. 983 depends on !COMPILE_TEST 984 select PHYS_RAM_BASE_FIXED 985 help 986 Execute-In-Place allows the kernel to run from non-volatile storage 987 directly addressable by the CPU, such as NOR flash. This saves RAM 988 space since the text section of the kernel is not loaded from flash 989 to RAM. Read-write sections, such as the data section and stack, 990 are still copied to RAM. The XIP kernel is not compressed since 991 it has to run directly from flash, so it will take more space to 992 store it. The flash address used to link the kernel object files, 993 and for storing it, is configuration dependent. Therefore, if you 994 say Y here, you must know the proper physical address where to 995 store the kernel image depending on your own flash memory usage. 996 997 Also note that the make target becomes "make xipImage" rather than 998 "make zImage" or "make Image". The final kernel binary to put in 999 ROM memory will be arch/riscv/boot/xipImage. 1000 1001 SPARSEMEM is required because the kernel text and rodata that are 1002 flash resident are not backed by memmap, then any attempt to get 1003 a struct page on those regions will trigger a fault. 1004 1005 If unsure, say N. 1006 1007config XIP_PHYS_ADDR 1008 hex "XIP Kernel Physical Location" 1009 depends on XIP_KERNEL 1010 default "0x21000000" 1011 help 1012 This is the physical address in your flash memory the kernel will 1013 be linked for and stored to. This address is dependent on your 1014 own flash usage. 1015 1016config RISCV_ISA_FALLBACK 1017 bool "Permit falling back to parsing riscv,isa for extension support by default" 1018 default y 1019 help 1020 Parsing the "riscv,isa" devicetree property has been deprecated and 1021 replaced by a list of explicitly defined strings. For compatibility 1022 with existing platforms, the kernel will fall back to parsing the 1023 "riscv,isa" property if the replacements are not found. 1024 1025 Selecting N here will result in a kernel that does not use the 1026 fallback, unless the commandline "riscv_isa_fallback" parameter is 1027 present. 1028 1029 Please see the dt-binding, located at 1030 Documentation/devicetree/bindings/riscv/extensions.yaml for details 1031 on the replacement properties, "riscv,isa-base" and 1032 "riscv,isa-extensions". 1033 1034config BUILTIN_DTB 1035 bool "Built-in device tree" 1036 depends on OF && NONPORTABLE 1037 help 1038 Build a device tree into the Linux image. 1039 This option should be selected if no bootloader is being used. 1040 If unsure, say N. 1041 1042 1043config BUILTIN_DTB_SOURCE 1044 string "Built-in device tree source" 1045 depends on BUILTIN_DTB 1046 help 1047 DTS file path (without suffix, relative to arch/riscv/boot/dts) 1048 for the DTS file that will be used to produce the DTB linked into the 1049 kernel. 1050 1051endmenu # "Boot options" 1052 1053config PORTABLE 1054 bool 1055 default !NONPORTABLE 1056 select EFI 1057 select MMU 1058 select OF 1059 1060config ARCH_PROC_KCORE_TEXT 1061 def_bool y 1062 1063menu "Power management options" 1064 1065source "kernel/power/Kconfig" 1066 1067config ARCH_HIBERNATION_POSSIBLE 1068 def_bool y 1069 1070config ARCH_HIBERNATION_HEADER 1071 def_bool HIBERNATION 1072 1073config ARCH_SUSPEND_POSSIBLE 1074 def_bool y 1075 1076endmenu # "Power management options" 1077 1078menu "CPU Power Management" 1079 1080source "drivers/cpuidle/Kconfig" 1081 1082source "drivers/cpufreq/Kconfig" 1083 1084endmenu # "CPU Power Management" 1085 1086source "arch/riscv/kvm/Kconfig" 1087 1088source "drivers/acpi/Kconfig" 1089