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