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_PPTT if ACPI 17 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 18 select ACPI_SPCR_TABLE if ACPI 19 select ARCH_DMA_DEFAULT_COHERENT 20 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 21 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM_VMEMMAP 22 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 23 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 24 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 25 select ARCH_HAS_BINFMT_FLAT 26 select ARCH_HAS_CURRENT_STACK_POINTER 27 select ARCH_HAS_DEBUG_VIRTUAL if MMU 28 select ARCH_HAS_DEBUG_VM_PGTABLE 29 select ARCH_HAS_DEBUG_WX 30 select ARCH_HAS_FAST_MULTIPLIER 31 select ARCH_HAS_FORTIFY_SOURCE 32 select ARCH_HAS_GCOV_PROFILE_ALL 33 select ARCH_HAS_GIGANTIC_PAGE 34 select ARCH_HAS_KCOV 35 select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU 36 select ARCH_HAS_MEMBARRIER_CALLBACKS 37 select ARCH_HAS_MEMBARRIER_SYNC_CORE 38 select ARCH_HAS_MMIOWB 39 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 40 select ARCH_HAS_PMEM_API 41 select ARCH_HAS_PREPARE_SYNC_CORE_CMD 42 select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU 43 select ARCH_HAS_PTE_SPECIAL 44 select ARCH_HAS_SET_DIRECT_MAP if MMU 45 select ARCH_HAS_SET_MEMORY if MMU 46 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL 47 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL 48 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 49 select ARCH_HAS_SYSCALL_WRAPPER 50 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 51 select ARCH_HAS_UBSAN 52 select ARCH_HAS_VDSO_DATA 53 select ARCH_KEEP_MEMBLOCK if ACPI 54 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU 55 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 56 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 57 select ARCH_STACKWALK 58 select ARCH_SUPPORTS_ATOMIC_RMW 59 select ARCH_SUPPORTS_CFI_CLANG 60 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU 61 select ARCH_SUPPORTS_HUGETLBFS if MMU 62 # LLD >= 14: https://github.com/llvm/llvm-project/issues/50505 63 select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000 64 select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000 65 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 66 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 67 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK 68 select ARCH_USE_CMPXCHG_LOCKREF if 64BIT 69 select ARCH_USE_MEMTEST 70 select ARCH_USE_QUEUED_RWLOCKS 71 select ARCH_USES_CFI_TRAPS if CFI_CLANG 72 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU 73 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 74 select ARCH_WANT_FRAME_POINTERS 75 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 76 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 77 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL 78 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP 79 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 80 select ARCH_WANTS_NO_INSTR 81 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 82 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 83 select BUILDTIME_TABLE_SORT if MMU 84 select CLINT_TIMER if RISCV_M_MODE 85 select CLONE_BACKWARDS 86 select COMMON_CLK 87 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND 88 select EDAC_SUPPORT 89 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) 90 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE 91 select GENERIC_ARCH_TOPOLOGY 92 select GENERIC_ATOMIC64 if !64BIT 93 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 94 select GENERIC_CPU_DEVICES 95 select GENERIC_EARLY_IOREMAP 96 select GENERIC_ENTRY 97 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 98 select GENERIC_IDLE_POLL_SETUP 99 select GENERIC_IOREMAP if MMU 100 select GENERIC_IRQ_IPI if SMP 101 select GENERIC_IRQ_IPI_MUX if SMP 102 select GENERIC_IRQ_MULTI_HANDLER 103 select GENERIC_IRQ_SHOW 104 select GENERIC_IRQ_SHOW_LEVEL 105 select GENERIC_LIB_DEVMEM_IS_ALLOWED 106 select GENERIC_PCI_IOMAP 107 select GENERIC_PTDUMP if MMU 108 select GENERIC_SCHED_CLOCK 109 select GENERIC_SMP_IDLE_THREAD 110 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 111 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO 112 select HARDIRQS_SW_RESEND 113 select HAS_IOPORT if MMU 114 select HAVE_ARCH_AUDITSYSCALL 115 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 116 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT 117 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL 118 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL 119 select HAVE_ARCH_KASAN if MMU && 64BIT 120 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 121 select HAVE_ARCH_KFENCE if MMU && 64BIT 122 select HAVE_ARCH_KGDB if !XIP_KERNEL 123 select HAVE_ARCH_KGDB_QXFER_PKT 124 select HAVE_ARCH_MMAP_RND_BITS if MMU 125 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 126 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 127 select HAVE_ARCH_SECCOMP_FILTER 128 select HAVE_ARCH_STACKLEAK 129 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 130 select HAVE_ARCH_TRACEHOOK 131 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU 132 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD 133 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 134 select HAVE_ASM_MODVERSIONS 135 select HAVE_CONTEXT_TRACKING_USER 136 select HAVE_DEBUG_KMEMLEAK 137 select HAVE_DMA_CONTIGUOUS if MMU 138 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 139 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 140 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE 141 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL 142 select HAVE_FUNCTION_GRAPH_TRACER 143 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 144 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION 145 select HAVE_EBPF_JIT if MMU 146 select HAVE_GUP_FAST if MMU 147 select HAVE_FUNCTION_ARG_ACCESS_API 148 select HAVE_FUNCTION_ERROR_INJECTION 149 select HAVE_GCC_PLUGINS 150 select HAVE_GENERIC_VDSO if MMU && 64BIT 151 select HAVE_IRQ_TIME_ACCOUNTING 152 select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT 153 select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT 154 select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT 155 select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT 156 select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT 157 select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT 158 select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT 159 select HAVE_KPROBES if !XIP_KERNEL 160 select HAVE_KRETPROBES if !XIP_KERNEL 161 # https://github.com/ClangBuiltLinux/linux/issues/1881 162 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD 163 select HAVE_MOVE_PMD 164 select HAVE_MOVE_PUD 165 select HAVE_PAGE_SIZE_4KB 166 select HAVE_PCI 167 select HAVE_PERF_EVENTS 168 select HAVE_PERF_REGS 169 select HAVE_PERF_USER_STACK_DUMP 170 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 171 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL 172 select HAVE_REGS_AND_STACK_ACCESS_API 173 select HAVE_RETHOOK if !XIP_KERNEL 174 select HAVE_RSEQ 175 select HAVE_RUST if 64BIT 176 select HAVE_SAMPLE_FTRACE_DIRECT 177 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 178 select HAVE_STACKPROTECTOR 179 select HAVE_SYSCALL_TRACEPOINTS 180 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 181 select IRQ_DOMAIN 182 select IRQ_FORCED_THREADING 183 select KASAN_VMALLOC if KASAN 184 select LOCK_MM_AND_FIND_VMA 185 select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU 186 select MODULES_USE_ELF_RELA if MODULES 187 select OF 188 select OF_EARLY_FLATTREE 189 select OF_IRQ 190 select PCI_DOMAINS_GENERIC if PCI 191 select PCI_MSI if PCI 192 select RISCV_ALTERNATIVE if !XIP_KERNEL 193 select RISCV_APLIC 194 select RISCV_IMSIC 195 select RISCV_INTC 196 select RISCV_TIMER if RISCV_SBI 197 select SIFIVE_PLIC 198 select SPARSE_IRQ 199 select SYSCTL_EXCEPTION_TRACE 200 select THREAD_INFO_IN_TASK 201 select TRACE_IRQFLAGS_SUPPORT 202 select UACCESS_MEMCPY if !MMU 203 select ZONE_DMA32 if 64BIT 204 205config CLANG_SUPPORTS_DYNAMIC_FTRACE 206 def_bool CC_IS_CLANG 207 # https://github.com/ClangBuiltLinux/linux/issues/1817 208 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 209 210config GCC_SUPPORTS_DYNAMIC_FTRACE 211 def_bool CC_IS_GCC 212 depends on $(cc-option,-fpatchable-function-entry=8) 213 214config HAVE_SHADOW_CALL_STACK 215 def_bool $(cc-option,-fsanitize=shadow-call-stack) 216 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 217 depends on $(ld-option,--no-relax-gp) 218 219config RISCV_USE_LINKER_RELAXATION 220 def_bool y 221 # https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985 222 depends on !LD_IS_LLD || LLD_VERSION >= 150000 223 224# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 225config ARCH_HAS_BROKEN_DWARF5 226 def_bool y 227 depends on RISCV_USE_LINKER_RELAXATION 228 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a 229 depends on AS_IS_LLVM && AS_VERSION < 180000 230 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77 231 depends on LD_IS_LLD && LLD_VERSION < 180000 232 233config ARCH_MMAP_RND_BITS_MIN 234 default 18 if 64BIT 235 default 8 236 237config ARCH_MMAP_RND_COMPAT_BITS_MIN 238 default 8 239 240# max bits determined by the following formula: 241# VA_BITS - PAGE_SHIFT - 3 242config ARCH_MMAP_RND_BITS_MAX 243 default 24 if 64BIT # SV39 based 244 default 17 245 246config ARCH_MMAP_RND_COMPAT_BITS_MAX 247 default 17 248 249# set if we run in machine mode, cleared if we run in supervisor mode 250config RISCV_M_MODE 251 bool "Build a kernel that runs in machine mode" 252 depends on !MMU 253 default y 254 help 255 Select this option if you want to run the kernel in M-mode, 256 without the assistance of any other firmware. 257 258# set if we are running in S-mode and can use SBI calls 259config RISCV_SBI 260 bool 261 depends on !RISCV_M_MODE 262 default y 263 264config MMU 265 bool "MMU-based Paged Memory Management Support" 266 default y 267 help 268 Select if you want MMU-based virtualised addressing space 269 support by paged memory management. If unsure, say 'Y'. 270 271config PAGE_OFFSET 272 hex 273 default 0x80000000 if !MMU && RISCV_M_MODE 274 default 0x80200000 if !MMU 275 default 0xc0000000 if 32BIT 276 default 0xff60000000000000 if 64BIT 277 278config KASAN_SHADOW_OFFSET 279 hex 280 depends on KASAN_GENERIC 281 default 0xdfffffff00000000 if 64BIT 282 default 0xffffffff if 32BIT 283 284config ARCH_FLATMEM_ENABLE 285 def_bool !NUMA 286 287config ARCH_SPARSEMEM_ENABLE 288 def_bool y 289 depends on MMU 290 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 291 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 292 293config ARCH_SELECT_MEMORY_MODEL 294 def_bool ARCH_SPARSEMEM_ENABLE 295 296config ARCH_SUPPORTS_UPROBES 297 def_bool y 298 299config STACKTRACE_SUPPORT 300 def_bool y 301 302config GENERIC_BUG 303 def_bool y 304 depends on BUG 305 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 306 307config GENERIC_BUG_RELATIVE_POINTERS 308 bool 309 310config GENERIC_CALIBRATE_DELAY 311 def_bool y 312 313config GENERIC_CSUM 314 def_bool y 315 316config GENERIC_HWEIGHT 317 def_bool y 318 319config FIX_EARLYCON_MEM 320 def_bool MMU 321 322config PGTABLE_LEVELS 323 int 324 default 5 if 64BIT 325 default 2 326 327config LOCKDEP_SUPPORT 328 def_bool y 329 330config RISCV_DMA_NONCOHERENT 331 bool 332 select ARCH_HAS_DMA_PREP_COHERENT 333 select ARCH_HAS_SETUP_DMA_OPS 334 select ARCH_HAS_SYNC_DMA_FOR_CPU 335 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 336 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 337 338config RISCV_NONSTANDARD_CACHE_OPS 339 bool 340 help 341 This enables function pointer support for non-standard noncoherent 342 systems to handle cache management. 343 344config AS_HAS_INSN 345 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) 346 347config AS_HAS_OPTION_ARCH 348 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4 349 def_bool y 350 depends on $(as-instr, .option arch$(comma) +m) 351 352source "arch/riscv/Kconfig.socs" 353source "arch/riscv/Kconfig.errata" 354 355menu "Platform type" 356 357config NONPORTABLE 358 bool "Allow configurations that result in non-portable kernels" 359 help 360 RISC-V kernel binaries are compatible between all known systems 361 whenever possible, but there are some use cases that can only be 362 satisfied by configurations that result in kernel binaries that are 363 not portable between systems. 364 365 Selecting N does not guarantee kernels will be portable to all known 366 systems. Selecting any of the options guarded by NONPORTABLE will 367 result in kernel binaries that are unlikely to be portable between 368 systems. 369 370 If unsure, say N. 371 372choice 373 prompt "Base ISA" 374 default ARCH_RV64I 375 help 376 This selects the base ISA that this kernel will target and must match 377 the target platform. 378 379config ARCH_RV32I 380 bool "RV32I" 381 depends on NONPORTABLE 382 select 32BIT 383 select GENERIC_LIB_ASHLDI3 384 select GENERIC_LIB_ASHRDI3 385 select GENERIC_LIB_LSHRDI3 386 select GENERIC_LIB_UCMPDI2 387 388config ARCH_RV64I 389 bool "RV64I" 390 select 64BIT 391 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 392 select SWIOTLB if MMU 393 394endchoice 395 396# We must be able to map all physical memory into the kernel, but the compiler 397# is still a bit more efficient when generating code if it's setup in a manner 398# such that it can only map 2GiB of memory. 399choice 400 prompt "Kernel Code Model" 401 default CMODEL_MEDLOW if 32BIT 402 default CMODEL_MEDANY if 64BIT 403 404 config CMODEL_MEDLOW 405 bool "medium low code model" 406 config CMODEL_MEDANY 407 bool "medium any code model" 408endchoice 409 410config MODULE_SECTIONS 411 bool 412 select HAVE_MOD_ARCH_SPECIFIC 413 414config SMP 415 bool "Symmetric Multi-Processing" 416 help 417 This enables support for systems with more than one CPU. If 418 you say N here, the kernel will run on single and 419 multiprocessor machines, but will use only one CPU of a 420 multiprocessor machine. If you say Y here, the kernel will run 421 on many, but not all, single processor machines. On a single 422 processor machine, the kernel will run faster if you say N 423 here. 424 425 If you don't know what to do here, say N. 426 427config SCHED_MC 428 bool "Multi-core scheduler support" 429 depends on SMP 430 help 431 Multi-core scheduler support improves the CPU scheduler's decision 432 making when dealing with multi-core CPU chips at a cost of slightly 433 increased overhead in some places. If unsure say N here. 434 435config NR_CPUS 436 int "Maximum number of CPUs (2-512)" 437 depends on SMP 438 range 2 512 if !RISCV_SBI_V01 439 range 2 32 if RISCV_SBI_V01 && 32BIT 440 range 2 64 if RISCV_SBI_V01 && 64BIT 441 default "32" if 32BIT 442 default "64" if 64BIT 443 444config HOTPLUG_CPU 445 bool "Support for hot-pluggable CPUs" 446 depends on SMP 447 select GENERIC_IRQ_MIGRATION 448 help 449 450 Say Y here to experiment with turning CPUs off and on. CPUs 451 can be controlled through /sys/devices/system/cpu. 452 453 Say N if you want to disable CPU hotplug. 454 455choice 456 prompt "CPU Tuning" 457 default TUNE_GENERIC 458 459config TUNE_GENERIC 460 bool "generic" 461 462endchoice 463 464# Common NUMA Features 465config NUMA 466 bool "NUMA Memory Allocation and Scheduler Support" 467 depends on SMP && MMU 468 select ARCH_SUPPORTS_NUMA_BALANCING 469 select GENERIC_ARCH_NUMA 470 select HAVE_SETUP_PER_CPU_AREA 471 select NEED_PER_CPU_EMBED_FIRST_CHUNK 472 select NEED_PER_CPU_PAGE_FIRST_CHUNK 473 select OF_NUMA 474 select USE_PERCPU_NUMA_NODE_ID 475 help 476 Enable NUMA (Non-Uniform Memory Access) support. 477 478 The kernel will try to allocate memory used by a CPU on the 479 local memory of the CPU and add some more NUMA awareness to the kernel. 480 481config NODES_SHIFT 482 int "Maximum NUMA Nodes (as a power of 2)" 483 range 1 10 484 default "2" 485 depends on NUMA 486 help 487 Specify the maximum number of NUMA Nodes available on the target 488 system. Increases memory reserved to accommodate various tables. 489 490config RISCV_ALTERNATIVE 491 bool 492 depends on !XIP_KERNEL 493 help 494 This Kconfig allows the kernel to automatically patch the 495 erratum or cpufeature required by the execution platform at run 496 time. The code patching overhead is minimal, as it's only done 497 once at boot and once on each module load. 498 499config RISCV_ALTERNATIVE_EARLY 500 bool 501 depends on RISCV_ALTERNATIVE 502 help 503 Allows early patching of the kernel for special errata 504 505config RISCV_ISA_C 506 bool "Emit compressed instructions when building Linux" 507 default y 508 help 509 Adds "C" to the ISA subsets that the toolchain is allowed to emit 510 when building Linux, which results in compressed instructions in the 511 Linux binary. 512 513 If you don't know what to do here, say Y. 514 515config RISCV_ISA_SVNAPOT 516 bool "Svnapot extension support for supervisor mode NAPOT pages" 517 depends on 64BIT && MMU 518 depends on RISCV_ALTERNATIVE 519 default y 520 help 521 Allow kernel to detect the Svnapot ISA-extension dynamically at boot 522 time and enable its usage. 523 524 The Svnapot extension is used to mark contiguous PTEs as a range 525 of contiguous virtual-to-physical translations for a naturally 526 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 527 size. When HUGETLBFS is also selected this option unconditionally 528 allocates some memory for each NAPOT page size supported by the kernel. 529 When optimizing for low memory consumption and for platforms without 530 the Svnapot extension, it may be better to say N here. 531 532 If you don't know what to do here, say Y. 533 534config RISCV_ISA_SVPBMT 535 bool "Svpbmt extension support for supervisor mode page-based memory types" 536 depends on 64BIT && MMU 537 depends on RISCV_ALTERNATIVE 538 default y 539 help 540 Adds support to dynamically detect the presence of the Svpbmt 541 ISA-extension (Supervisor-mode: page-based memory types) and 542 enable its usage. 543 544 The memory type for a page contains a combination of attributes 545 that indicate the cacheability, idempotency, and ordering 546 properties for access to that page. 547 548 The Svpbmt extension is only available on 64-bit cpus. 549 550 If you don't know what to do here, say Y. 551 552config TOOLCHAIN_HAS_V 553 bool 554 default y 555 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv) 556 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv) 557 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800 558 depends on AS_HAS_OPTION_ARCH 559 560config RISCV_ISA_V 561 bool "VECTOR extension support" 562 depends on TOOLCHAIN_HAS_V 563 depends on FPU 564 select DYNAMIC_SIGFRAME 565 default y 566 help 567 Say N here if you want to disable all vector related procedure 568 in the kernel. 569 570 If you don't know what to do here, say Y. 571 572config RISCV_ISA_V_DEFAULT_ENABLE 573 bool "Enable userspace Vector by default" 574 depends on RISCV_ISA_V 575 default y 576 help 577 Say Y here if you want to enable Vector in userspace by default. 578 Otherwise, userspace has to make explicit prctl() call to enable 579 Vector, or enable it via the sysctl interface. 580 581 If you don't know what to do here, say Y. 582 583config RISCV_ISA_V_UCOPY_THRESHOLD 584 int "Threshold size for vectorized user copies" 585 depends on RISCV_ISA_V 586 default 768 587 help 588 Prefer using vectorized copy_to_user()/copy_from_user() when the 589 workload size exceeds this value. 590 591config RISCV_ISA_V_PREEMPTIVE 592 bool "Run kernel-mode Vector with kernel preemption" 593 depends on PREEMPTION 594 depends on RISCV_ISA_V 595 default y 596 help 597 Usually, in-kernel SIMD routines are run with preemption disabled. 598 Functions which envoke long running SIMD thus must yield core's 599 vector unit to prevent blocking other tasks for too long. 600 601 This config allows kernel to run SIMD without explicitly disable 602 preemption. Enabling this config will result in higher memory 603 consumption due to the allocation of per-task's kernel Vector context. 604 605config RISCV_ISA_ZAWRS 606 bool "Zawrs extension support for more efficient busy waiting" 607 depends on RISCV_ALTERNATIVE 608 default y 609 help 610 The Zawrs extension defines instructions to be used in polling loops 611 which allow a hart to enter a low-power state or to trap to the 612 hypervisor while waiting on a store to a memory location. Enable the 613 use of these instructions in the kernel when the Zawrs extension is 614 detected at boot. 615 616 If you don't know what to do here, say Y. 617 618config TOOLCHAIN_HAS_ZBB 619 bool 620 default y 621 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 622 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 623 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 624 depends on AS_HAS_OPTION_ARCH 625 626# This symbol indicates that the toolchain supports all v1.0 vector crypto 627# extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once. 628# binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb. 629config TOOLCHAIN_HAS_VECTOR_CRYPTO 630 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb) 631 depends on AS_HAS_OPTION_ARCH 632 633config RISCV_ISA_ZBA 634 bool "Zba extension support for bit manipulation instructions" 635 default y 636 help 637 Add support for enabling optimisations in the kernel when the Zba 638 extension is detected at boot. 639 640 The Zba extension provides instructions to accelerate the generation 641 of addresses that index into arrays of basic data types. 642 643 If you don't know what to do here, say Y. 644 645config RISCV_ISA_ZBB 646 bool "Zbb extension support for bit manipulation instructions" 647 depends on TOOLCHAIN_HAS_ZBB 648 depends on RISCV_ALTERNATIVE 649 default y 650 help 651 Adds support to dynamically detect the presence of the ZBB 652 extension (basic bit manipulation) and enable its usage. 653 654 The Zbb extension provides instructions to accelerate a number 655 of bit-specific operations (count bit population, sign extending, 656 bitrotation, etc). 657 658 If you don't know what to do here, say Y. 659 660config TOOLCHAIN_HAS_ZBC 661 bool 662 default y 663 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc) 664 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc) 665 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 666 depends on AS_HAS_OPTION_ARCH 667 668config RISCV_ISA_ZBC 669 bool "Zbc extension support for carry-less multiplication instructions" 670 depends on TOOLCHAIN_HAS_ZBC 671 depends on MMU 672 depends on RISCV_ALTERNATIVE 673 default y 674 help 675 Adds support to dynamically detect the presence of the Zbc 676 extension (carry-less multiplication) and enable its usage. 677 678 The Zbc extension could accelerate CRC (cyclic redundancy check) 679 calculations. 680 681 If you don't know what to do here, say Y. 682 683config RISCV_ISA_ZICBOM 684 bool "Zicbom extension support for non-coherent DMA operation" 685 depends on MMU 686 depends on RISCV_ALTERNATIVE 687 default y 688 select RISCV_DMA_NONCOHERENT 689 select DMA_DIRECT_REMAP 690 help 691 Adds support to dynamically detect the presence of the ZICBOM 692 extension (Cache Block Management Operations) and enable its 693 usage. 694 695 The Zicbom extension can be used to handle for example 696 non-coherent DMA support on devices that need it. 697 698 If you don't know what to do here, say Y. 699 700config RISCV_ISA_ZICBOZ 701 bool "Zicboz extension support for faster zeroing of memory" 702 depends on RISCV_ALTERNATIVE 703 default y 704 help 705 Enable the use of the Zicboz extension (cbo.zero instruction) 706 when available. 707 708 The Zicboz extension is used for faster zeroing of memory. 709 710 If you don't know what to do here, say Y. 711 712config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 713 def_bool y 714 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 715 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 716 depends on AS_IS_GNU && AS_VERSION >= 23600 717 help 718 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 719 20191213 version, which moves some instructions from the I extension to 720 the Zicsr and Zifencei extensions. This requires explicitly specifying 721 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 722 and Zifencei are supported in binutils from version 2.36 onwards. 723 To make life easier, and avoid forcing toolchains that default to a 724 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 725 For clang < 17 or GCC < 11.3.0, for which this is not possible or need 726 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 727 728config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 729 def_bool y 730 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 731 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 732 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 733 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300) 734 help 735 Certain versions of clang and GCC do not support zicsr and zifencei via 736 -march. This option causes an older ISA spec compatible with these older 737 versions of clang and GCC to be passed to GAS, which has the same result 738 as passing zicsr and zifencei to -march. 739 740config FPU 741 bool "FPU support" 742 default y 743 help 744 Say N here if you want to disable all floating-point related procedure 745 in the kernel. 746 747 If you don't know what to do here, say Y. 748 749config IRQ_STACKS 750 bool "Independent irq & softirq stacks" if EXPERT 751 default y 752 select HAVE_IRQ_EXIT_ON_IRQ_STACK 753 select HAVE_SOFTIRQ_ON_OWN_STACK 754 help 755 Add independent irq & softirq stacks for percpu to prevent kernel stack 756 overflows. We may save some memory footprint by disabling IRQ_STACKS. 757 758config THREAD_SIZE_ORDER 759 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT 760 range 0 4 761 default 1 if 32BIT && !KASAN 762 default 3 if 64BIT && KASAN 763 default 2 764 help 765 Specify the Pages of thread stack size (from 4KB to 64KB), which also 766 affects irq stack size, which is equal to thread stack size. 767 768config RISCV_MISALIGNED 769 bool 770 select SYSCTL_ARCH_UNALIGN_ALLOW 771 help 772 Embed support for emulating misaligned loads and stores. 773 774choice 775 prompt "Unaligned Accesses Support" 776 default RISCV_PROBE_UNALIGNED_ACCESS 777 help 778 This determines the level of support for unaligned accesses. This 779 information is used by the kernel to perform optimizations. It is also 780 exposed to user space via the hwprobe syscall. The hardware will be 781 probed at boot by default. 782 783config RISCV_PROBE_UNALIGNED_ACCESS 784 bool "Probe for hardware unaligned access support" 785 select RISCV_MISALIGNED 786 help 787 During boot, the kernel will run a series of tests to determine the 788 speed of unaligned accesses. This probing will dynamically determine 789 the speed of unaligned accesses on the underlying system. If unaligned 790 memory accesses trap into the kernel as they are not supported by the 791 system, the kernel will emulate the unaligned accesses to preserve the 792 UABI. 793 794config RISCV_EMULATED_UNALIGNED_ACCESS 795 bool "Emulate unaligned access where system support is missing" 796 select RISCV_MISALIGNED 797 help 798 If unaligned memory accesses trap into the kernel as they are not 799 supported by the system, the kernel will emulate the unaligned 800 accesses to preserve the UABI. When the underlying system does support 801 unaligned accesses, the unaligned accesses are assumed to be slow. 802 803config RISCV_SLOW_UNALIGNED_ACCESS 804 bool "Assume the system supports slow unaligned memory accesses" 805 depends on NONPORTABLE 806 help 807 Assume that the system supports slow unaligned memory accesses. The 808 kernel and userspace programs may not be able to run at all on systems 809 that do not support unaligned memory accesses. 810 811config RISCV_EFFICIENT_UNALIGNED_ACCESS 812 bool "Assume the system supports fast unaligned memory accesses" 813 depends on NONPORTABLE 814 select DCACHE_WORD_ACCESS if MMU 815 select HAVE_EFFICIENT_UNALIGNED_ACCESS 816 help 817 Assume that the system supports fast unaligned memory accesses. When 818 enabled, this option improves the performance of the kernel on such 819 systems. However, the kernel and userspace programs will run much more 820 slowly, or will not be able to run at all, on systems that do not 821 support efficient unaligned memory accesses. 822 823endchoice 824 825source "arch/riscv/Kconfig.vendor" 826 827endmenu # "Platform type" 828 829menu "Kernel features" 830 831source "kernel/Kconfig.hz" 832 833config RISCV_SBI_V01 834 bool "SBI v0.1 support" 835 depends on RISCV_SBI 836 help 837 This config allows kernel to use SBI v0.1 APIs. This will be 838 deprecated in future once legacy M-mode software are no longer in use. 839 840config RISCV_BOOT_SPINWAIT 841 bool "Spinwait booting method" 842 depends on SMP 843 default y if RISCV_SBI_V01 || RISCV_M_MODE 844 help 845 This enables support for booting Linux via spinwait method. In the 846 spinwait method, all cores randomly jump to Linux. One of the cores 847 gets chosen via lottery and all other keep spinning on a percpu 848 variable. This method cannot support CPU hotplug and sparse hartid 849 scheme. It should be only enabled for M-mode Linux or platforms relying 850 on older firmware without SBI HSM extension. All other platforms should 851 rely on ordered booting via SBI HSM extension which gets chosen 852 dynamically at runtime if the firmware supports it. 853 854 Since spinwait is incompatible with sparse hart IDs, it requires 855 NR_CPUS be large enough to contain the physical hart ID of the first 856 hart to enter Linux. 857 858 If unsure what to do here, say N. 859 860config ARCH_SUPPORTS_KEXEC 861 def_bool y 862 863config ARCH_SELECTS_KEXEC 864 def_bool y 865 depends on KEXEC 866 select HOTPLUG_CPU if SMP 867 868config ARCH_SUPPORTS_KEXEC_FILE 869 def_bool 64BIT 870 871config ARCH_SELECTS_KEXEC_FILE 872 def_bool y 873 depends on KEXEC_FILE 874 select HAVE_IMA_KEXEC if IMA 875 select KEXEC_ELF 876 877config ARCH_SUPPORTS_KEXEC_PURGATORY 878 def_bool ARCH_SUPPORTS_KEXEC_FILE 879 880config ARCH_SUPPORTS_CRASH_DUMP 881 def_bool y 882 883config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 884 def_bool CRASH_RESERVE 885 886config COMPAT 887 bool "Kernel support for 32-bit U-mode" 888 default 64BIT 889 depends on 64BIT && MMU 890 help 891 This option enables support for a 32-bit U-mode running under a 64-bit 892 kernel at S-mode. riscv32-specific components such as system calls, 893 the user helper functions (vdso), signal rt_frame functions and the 894 ptrace interface are handled appropriately by the kernel. 895 896 If you want to execute 32-bit userspace applications, say Y. 897 898config PARAVIRT 899 bool "Enable paravirtualization code" 900 depends on RISCV_SBI 901 help 902 This changes the kernel so it can modify itself when it is run 903 under a hypervisor, potentially improving performance significantly 904 over full virtualization. 905 906config PARAVIRT_TIME_ACCOUNTING 907 bool "Paravirtual steal time accounting" 908 depends on PARAVIRT 909 help 910 Select this option to enable fine granularity task steal time 911 accounting. Time spent executing other tasks in parallel with 912 the current vCPU is discounted from the vCPU power. To account for 913 that, there can be a small performance impact. 914 915 If in doubt, say N here. 916 917config RELOCATABLE 918 bool "Build a relocatable kernel" 919 depends on MMU && 64BIT && !XIP_KERNEL 920 select MODULE_SECTIONS if MODULES 921 help 922 This builds a kernel as a Position Independent Executable (PIE), 923 which retains all relocation metadata required to relocate the 924 kernel binary at runtime to a different virtual address than the 925 address it was linked at. 926 Since RISCV uses the RELA relocation format, this requires a 927 relocation pass at runtime even if the kernel is loaded at the 928 same address it was linked at. 929 930 If unsure, say N. 931 932config RANDOMIZE_BASE 933 bool "Randomize the address of the kernel image" 934 select RELOCATABLE 935 depends on MMU && 64BIT && !XIP_KERNEL 936 help 937 Randomizes the virtual address at which the kernel image is 938 loaded, as a security feature that deters exploit attempts 939 relying on knowledge of the location of kernel internals. 940 941 It is the bootloader's job to provide entropy, by passing a 942 random u64 value in /chosen/kaslr-seed at kernel entry. 943 944 When booting via the UEFI stub, it will invoke the firmware's 945 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 946 to the kernel proper. In addition, it will randomise the physical 947 location of the kernel Image as well. 948 949 If unsure, say N. 950 951endmenu # "Kernel features" 952 953menu "Boot options" 954 955config CMDLINE 956 string "Built-in kernel command line" 957 help 958 For most platforms, the arguments for the kernel's command line 959 are provided at run-time, during boot. However, there are cases 960 where either no arguments are being provided or the provided 961 arguments are insufficient or even invalid. 962 963 When that occurs, it is possible to define a built-in command 964 line here and choose how the kernel should use it later on. 965 966choice 967 prompt "Built-in command line usage" 968 depends on CMDLINE != "" 969 default CMDLINE_FALLBACK 970 help 971 Choose how the kernel will handle the provided built-in command 972 line. 973 974config CMDLINE_FALLBACK 975 bool "Use bootloader kernel arguments if available" 976 help 977 Use the built-in command line as fallback in case we get nothing 978 during boot. This is the default behaviour. 979 980config CMDLINE_EXTEND 981 bool "Extend bootloader kernel arguments" 982 help 983 The command-line arguments provided during boot will be 984 appended to the built-in command line. This is useful in 985 cases where the provided arguments are insufficient and 986 you don't want to or cannot modify them. 987 988config CMDLINE_FORCE 989 bool "Always use the default kernel command string" 990 help 991 Always use the built-in command line, even if we get one during 992 boot. This is useful in case you need to override the provided 993 command line on systems where you don't have or want control 994 over it. 995 996endchoice 997 998config EFI_STUB 999 bool 1000 1001config EFI 1002 bool "UEFI runtime support" 1003 depends on OF && !XIP_KERNEL 1004 depends on MMU 1005 default y 1006 select ARCH_SUPPORTS_ACPI if 64BIT 1007 select EFI_GENERIC_STUB 1008 select EFI_PARAMS_FROM_FDT 1009 select EFI_RUNTIME_WRAPPERS 1010 select EFI_STUB 1011 select LIBFDT 1012 select RISCV_ISA_C 1013 select UCS2_STRING 1014 help 1015 This option provides support for runtime services provided 1016 by UEFI firmware (such as non-volatile variables, realtime 1017 clock, and platform reset). A UEFI stub is also provided to 1018 allow the kernel to be booted as an EFI application. This 1019 is only useful on systems that have UEFI firmware. 1020 1021config DMI 1022 bool "Enable support for SMBIOS (DMI) tables" 1023 depends on EFI 1024 default y 1025 help 1026 This enables SMBIOS/DMI feature for systems. 1027 1028 This option is only useful on systems that have UEFI firmware. 1029 However, even with this option, the resultant kernel should 1030 continue to boot on existing non-UEFI platforms. 1031 1032config CC_HAVE_STACKPROTECTOR_TLS 1033 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 1034 1035config STACKPROTECTOR_PER_TASK 1036 def_bool y 1037 depends on !RANDSTRUCT 1038 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 1039 1040config PHYS_RAM_BASE_FIXED 1041 bool "Explicitly specified physical RAM address" 1042 depends on NONPORTABLE 1043 default n 1044 1045config PHYS_RAM_BASE 1046 hex "Platform Physical RAM address" 1047 depends on PHYS_RAM_BASE_FIXED 1048 default "0x80000000" 1049 help 1050 This is the physical address of RAM in the system. It has to be 1051 explicitly specified to run early relocations of read-write data 1052 from flash to RAM. 1053 1054config XIP_KERNEL 1055 bool "Kernel Execute-In-Place from ROM" 1056 depends on MMU && SPARSEMEM && NONPORTABLE 1057 # This prevents XIP from being enabled by all{yes,mod}config, which 1058 # fail to build since XIP doesn't support large kernels. 1059 depends on !COMPILE_TEST 1060 select PHYS_RAM_BASE_FIXED 1061 help 1062 Execute-In-Place allows the kernel to run from non-volatile storage 1063 directly addressable by the CPU, such as NOR flash. This saves RAM 1064 space since the text section of the kernel is not loaded from flash 1065 to RAM. Read-write sections, such as the data section and stack, 1066 are still copied to RAM. The XIP kernel is not compressed since 1067 it has to run directly from flash, so it will take more space to 1068 store it. The flash address used to link the kernel object files, 1069 and for storing it, is configuration dependent. Therefore, if you 1070 say Y here, you must know the proper physical address where to 1071 store the kernel image depending on your own flash memory usage. 1072 1073 Also note that the make target becomes "make xipImage" rather than 1074 "make zImage" or "make Image". The final kernel binary to put in 1075 ROM memory will be arch/riscv/boot/xipImage. 1076 1077 SPARSEMEM is required because the kernel text and rodata that are 1078 flash resident are not backed by memmap, then any attempt to get 1079 a struct page on those regions will trigger a fault. 1080 1081 If unsure, say N. 1082 1083config XIP_PHYS_ADDR 1084 hex "XIP Kernel Physical Location" 1085 depends on XIP_KERNEL 1086 default "0x21000000" 1087 help 1088 This is the physical address in your flash memory the kernel will 1089 be linked for and stored to. This address is dependent on your 1090 own flash usage. 1091 1092config RISCV_ISA_FALLBACK 1093 bool "Permit falling back to parsing riscv,isa for extension support by default" 1094 default y 1095 help 1096 Parsing the "riscv,isa" devicetree property has been deprecated and 1097 replaced by a list of explicitly defined strings. For compatibility 1098 with existing platforms, the kernel will fall back to parsing the 1099 "riscv,isa" property if the replacements are not found. 1100 1101 Selecting N here will result in a kernel that does not use the 1102 fallback, unless the commandline "riscv_isa_fallback" parameter is 1103 present. 1104 1105 Please see the dt-binding, located at 1106 Documentation/devicetree/bindings/riscv/extensions.yaml for details 1107 on the replacement properties, "riscv,isa-base" and 1108 "riscv,isa-extensions". 1109 1110config BUILTIN_DTB 1111 bool "Built-in device tree" 1112 depends on OF && NONPORTABLE 1113 help 1114 Build a device tree into the Linux image. 1115 This option should be selected if no bootloader is being used. 1116 If unsure, say N. 1117 1118 1119config BUILTIN_DTB_SOURCE 1120 string "Built-in device tree source" 1121 depends on BUILTIN_DTB 1122 help 1123 DTS file path (without suffix, relative to arch/riscv/boot/dts) 1124 for the DTS file that will be used to produce the DTB linked into the 1125 kernel. 1126 1127endmenu # "Boot options" 1128 1129config PORTABLE 1130 bool 1131 default !NONPORTABLE 1132 select EFI 1133 select MMU 1134 select OF 1135 1136config ARCH_PROC_KCORE_TEXT 1137 def_bool y 1138 1139menu "Power management options" 1140 1141source "kernel/power/Kconfig" 1142 1143config ARCH_HIBERNATION_POSSIBLE 1144 def_bool y 1145 1146config ARCH_HIBERNATION_HEADER 1147 def_bool HIBERNATION 1148 1149config ARCH_SUSPEND_POSSIBLE 1150 def_bool y 1151 1152endmenu # "Power management options" 1153 1154menu "CPU Power Management" 1155 1156source "drivers/cpuidle/Kconfig" 1157 1158source "drivers/cpufreq/Kconfig" 1159 1160endmenu # "CPU Power Management" 1161 1162source "arch/riscv/kvm/Kconfig" 1163 1164source "drivers/acpi/Kconfig" 1165