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_MMIOWB 31 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 32 select ARCH_HAS_PMEM_API 33 select ARCH_HAS_PTE_SPECIAL 34 select ARCH_HAS_SET_DIRECT_MAP if MMU 35 select ARCH_HAS_SET_MEMORY if MMU 36 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL 37 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL 38 select ARCH_HAS_SYSCALL_WRAPPER 39 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 40 select ARCH_HAS_UBSAN_SANITIZE_ALL 41 select ARCH_HAS_VDSO_DATA 42 select ARCH_KEEP_MEMBLOCK if ACPI 43 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 44 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 45 select ARCH_STACKWALK 46 select ARCH_SUPPORTS_ATOMIC_RMW 47 select ARCH_SUPPORTS_CFI_CLANG 48 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU 49 select ARCH_SUPPORTS_HUGETLBFS if MMU 50 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 51 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 52 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK 53 select ARCH_USE_MEMTEST 54 select ARCH_USE_QUEUED_RWLOCKS 55 select ARCH_USES_CFI_TRAPS if CFI_CLANG 56 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 57 select ARCH_WANT_FRAME_POINTERS 58 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 59 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 60 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL 61 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 62 select ARCH_WANTS_NO_INSTR 63 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 64 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 65 select BUILDTIME_TABLE_SORT if MMU 66 select CLINT_TIMER if !MMU 67 select CLONE_BACKWARDS 68 select COMMON_CLK 69 select CPU_PM if CPU_IDLE || HIBERNATION 70 select EDAC_SUPPORT 71 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) 72 select GENERIC_ARCH_TOPOLOGY 73 select GENERIC_ATOMIC64 if !64BIT 74 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 75 select GENERIC_EARLY_IOREMAP 76 select GENERIC_ENTRY 77 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 78 select GENERIC_IDLE_POLL_SETUP 79 select GENERIC_IOREMAP if MMU 80 select GENERIC_IRQ_IPI if SMP 81 select GENERIC_IRQ_IPI_MUX if SMP 82 select GENERIC_IRQ_MULTI_HANDLER 83 select GENERIC_IRQ_SHOW 84 select GENERIC_IRQ_SHOW_LEVEL 85 select GENERIC_LIB_DEVMEM_IS_ALLOWED 86 select GENERIC_PCI_IOMAP 87 select GENERIC_PTDUMP if MMU 88 select GENERIC_SCHED_CLOCK 89 select GENERIC_SMP_IDLE_THREAD 90 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 91 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO 92 select HARDIRQS_SW_RESEND 93 select HAS_IOPORT if MMU 94 select HAVE_ARCH_AUDITSYSCALL 95 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 96 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL 97 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL 98 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL 99 select HAVE_ARCH_KASAN if MMU && 64BIT 100 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 101 select HAVE_ARCH_KFENCE if MMU && 64BIT 102 select HAVE_ARCH_KGDB if !XIP_KERNEL 103 select HAVE_ARCH_KGDB_QXFER_PKT 104 select HAVE_ARCH_MMAP_RND_BITS if MMU 105 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 106 select HAVE_ARCH_SECCOMP_FILTER 107 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 108 select HAVE_ARCH_TRACEHOOK 109 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU 110 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD 111 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 112 select HAVE_ASM_MODVERSIONS 113 select HAVE_CONTEXT_TRACKING_USER 114 select HAVE_DEBUG_KMEMLEAK 115 select HAVE_DMA_CONTIGUOUS if MMU 116 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 117 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE 118 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL 119 select HAVE_FUNCTION_GRAPH_TRACER 120 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 121 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION 122 select HAVE_EBPF_JIT if MMU 123 select HAVE_FUNCTION_ARG_ACCESS_API 124 select HAVE_FUNCTION_ERROR_INJECTION 125 select HAVE_GCC_PLUGINS 126 select HAVE_GENERIC_VDSO if MMU && 64BIT 127 select HAVE_IRQ_TIME_ACCOUNTING 128 select HAVE_KPROBES if !XIP_KERNEL 129 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL 130 select HAVE_KRETPROBES if !XIP_KERNEL 131 # https://github.com/ClangBuiltLinux/linux/issues/1881 132 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD 133 select HAVE_MOVE_PMD 134 select HAVE_MOVE_PUD 135 select HAVE_PCI 136 select HAVE_PERF_EVENTS 137 select HAVE_PERF_REGS 138 select HAVE_PERF_USER_STACK_DUMP 139 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 140 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL 141 select HAVE_REGS_AND_STACK_ACCESS_API 142 select HAVE_RETHOOK if !XIP_KERNEL 143 select HAVE_RSEQ 144 select HAVE_STACKPROTECTOR 145 select HAVE_SYSCALL_TRACEPOINTS 146 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 147 select IRQ_DOMAIN 148 select IRQ_FORCED_THREADING 149 select KASAN_VMALLOC if KASAN 150 select LOCK_MM_AND_FIND_VMA 151 select MODULES_USE_ELF_RELA if MODULES 152 select MODULE_SECTIONS if MODULES 153 select OF 154 select OF_EARLY_FLATTREE 155 select OF_IRQ 156 select PCI_DOMAINS_GENERIC if PCI 157 select PCI_MSI if PCI 158 select RISCV_ALTERNATIVE if !XIP_KERNEL 159 select RISCV_INTC 160 select RISCV_TIMER if RISCV_SBI 161 select SIFIVE_PLIC 162 select SPARSE_IRQ 163 select SYSCTL_EXCEPTION_TRACE 164 select THREAD_INFO_IN_TASK 165 select TRACE_IRQFLAGS_SUPPORT 166 select UACCESS_MEMCPY if !MMU 167 select ZONE_DMA32 if 64BIT 168 169config CLANG_SUPPORTS_DYNAMIC_FTRACE 170 def_bool CC_IS_CLANG 171 # https://github.com/llvm/llvm-project/commit/6ab8927931851bb42b2c93a00801dc499d7d9b1e 172 depends on CLANG_VERSION >= 130000 173 # https://github.com/ClangBuiltLinux/linux/issues/1817 174 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 175 176config GCC_SUPPORTS_DYNAMIC_FTRACE 177 def_bool CC_IS_GCC 178 depends on $(cc-option,-fpatchable-function-entry=8) 179 180config HAVE_SHADOW_CALL_STACK 181 def_bool $(cc-option,-fsanitize=shadow-call-stack) 182 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 183 depends on $(ld-option,--no-relax-gp) 184 185config ARCH_MMAP_RND_BITS_MIN 186 default 18 if 64BIT 187 default 8 188 189config ARCH_MMAP_RND_COMPAT_BITS_MIN 190 default 8 191 192# max bits determined by the following formula: 193# VA_BITS - PAGE_SHIFT - 3 194config ARCH_MMAP_RND_BITS_MAX 195 default 24 if 64BIT # SV39 based 196 default 17 197 198config ARCH_MMAP_RND_COMPAT_BITS_MAX 199 default 17 200 201# set if we run in machine mode, cleared if we run in supervisor mode 202config RISCV_M_MODE 203 bool 204 default !MMU 205 206# set if we are running in S-mode and can use SBI calls 207config RISCV_SBI 208 bool 209 depends on !RISCV_M_MODE 210 default y 211 212config MMU 213 bool "MMU-based Paged Memory Management Support" 214 default y 215 help 216 Select if you want MMU-based virtualised addressing space 217 support by paged memory management. If unsure, say 'Y'. 218 219config PAGE_OFFSET 220 hex 221 default 0xC0000000 if 32BIT && MMU 222 default 0x80000000 if !MMU 223 default 0xff60000000000000 if 64BIT 224 225config KASAN_SHADOW_OFFSET 226 hex 227 depends on KASAN_GENERIC 228 default 0xdfffffff00000000 if 64BIT 229 default 0xffffffff if 32BIT 230 231config ARCH_FLATMEM_ENABLE 232 def_bool !NUMA 233 234config ARCH_SPARSEMEM_ENABLE 235 def_bool y 236 depends on MMU 237 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 238 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 239 240config ARCH_SELECT_MEMORY_MODEL 241 def_bool ARCH_SPARSEMEM_ENABLE 242 243config ARCH_SUPPORTS_UPROBES 244 def_bool y 245 246config STACKTRACE_SUPPORT 247 def_bool y 248 249config GENERIC_BUG 250 def_bool y 251 depends on BUG 252 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 253 254config GENERIC_BUG_RELATIVE_POINTERS 255 bool 256 257config GENERIC_CALIBRATE_DELAY 258 def_bool y 259 260config GENERIC_CSUM 261 def_bool y 262 263config GENERIC_HWEIGHT 264 def_bool y 265 266config FIX_EARLYCON_MEM 267 def_bool MMU 268 269config PGTABLE_LEVELS 270 int 271 default 5 if 64BIT 272 default 2 273 274config LOCKDEP_SUPPORT 275 def_bool y 276 277config RISCV_DMA_NONCOHERENT 278 bool 279 select ARCH_HAS_DMA_PREP_COHERENT 280 select ARCH_HAS_SETUP_DMA_OPS 281 select ARCH_HAS_SYNC_DMA_FOR_CPU 282 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 283 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 284 285config RISCV_NONSTANDARD_CACHE_OPS 286 bool 287 help 288 This enables function pointer support for non-standard noncoherent 289 systems to handle cache management. 290 291config AS_HAS_INSN 292 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) 293 294config AS_HAS_OPTION_ARCH 295 # https://reviews.llvm.org/D123515 296 def_bool y 297 depends on $(as-instr, .option arch$(comma) +m) 298 depends on !$(as-instr, .option arch$(comma) -i) 299 300source "arch/riscv/Kconfig.socs" 301source "arch/riscv/Kconfig.errata" 302 303menu "Platform type" 304 305config NONPORTABLE 306 bool "Allow configurations that result in non-portable kernels" 307 help 308 RISC-V kernel binaries are compatible between all known systems 309 whenever possible, but there are some use cases that can only be 310 satisfied by configurations that result in kernel binaries that are 311 not portable between systems. 312 313 Selecting N does not guarantee kernels will be portable to all known 314 systems. Selecting any of the options guarded by NONPORTABLE will 315 result in kernel binaries that are unlikely to be portable between 316 systems. 317 318 If unsure, say N. 319 320choice 321 prompt "Base ISA" 322 default ARCH_RV64I 323 help 324 This selects the base ISA that this kernel will target and must match 325 the target platform. 326 327config ARCH_RV32I 328 bool "RV32I" 329 depends on NONPORTABLE 330 select 32BIT 331 select GENERIC_LIB_ASHLDI3 332 select GENERIC_LIB_ASHRDI3 333 select GENERIC_LIB_LSHRDI3 334 select GENERIC_LIB_UCMPDI2 335 336config ARCH_RV64I 337 bool "RV64I" 338 select 64BIT 339 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 340 select SWIOTLB if MMU 341 342endchoice 343 344# We must be able to map all physical memory into the kernel, but the compiler 345# is still a bit more efficient when generating code if it's setup in a manner 346# such that it can only map 2GiB of memory. 347choice 348 prompt "Kernel Code Model" 349 default CMODEL_MEDLOW if 32BIT 350 default CMODEL_MEDANY if 64BIT 351 352 config CMODEL_MEDLOW 353 bool "medium low code model" 354 config CMODEL_MEDANY 355 bool "medium any code model" 356endchoice 357 358config MODULE_SECTIONS 359 bool 360 select HAVE_MOD_ARCH_SPECIFIC 361 362config SMP 363 bool "Symmetric Multi-Processing" 364 help 365 This enables support for systems with more than one CPU. If 366 you say N here, the kernel will run on single and 367 multiprocessor machines, but will use only one CPU of a 368 multiprocessor machine. If you say Y here, the kernel will run 369 on many, but not all, single processor machines. On a single 370 processor machine, the kernel will run faster if you say N 371 here. 372 373 If you don't know what to do here, say N. 374 375config SCHED_MC 376 bool "Multi-core scheduler support" 377 depends on SMP 378 help 379 Multi-core scheduler support improves the CPU scheduler's decision 380 making when dealing with multi-core CPU chips at a cost of slightly 381 increased overhead in some places. If unsure say N here. 382 383config NR_CPUS 384 int "Maximum number of CPUs (2-512)" 385 depends on SMP 386 range 2 512 if !RISCV_SBI_V01 387 range 2 32 if RISCV_SBI_V01 && 32BIT 388 range 2 64 if RISCV_SBI_V01 && 64BIT 389 default "32" if 32BIT 390 default "64" if 64BIT 391 392config HOTPLUG_CPU 393 bool "Support for hot-pluggable CPUs" 394 depends on SMP 395 select GENERIC_IRQ_MIGRATION 396 help 397 398 Say Y here to experiment with turning CPUs off and on. CPUs 399 can be controlled through /sys/devices/system/cpu. 400 401 Say N if you want to disable CPU hotplug. 402 403choice 404 prompt "CPU Tuning" 405 default TUNE_GENERIC 406 407config TUNE_GENERIC 408 bool "generic" 409 410endchoice 411 412# Common NUMA Features 413config NUMA 414 bool "NUMA Memory Allocation and Scheduler Support" 415 depends on SMP && MMU 416 select ARCH_SUPPORTS_NUMA_BALANCING 417 select GENERIC_ARCH_NUMA 418 select NEED_PER_CPU_EMBED_FIRST_CHUNK 419 select OF_NUMA 420 select USE_PERCPU_NUMA_NODE_ID 421 help 422 Enable NUMA (Non-Uniform Memory Access) support. 423 424 The kernel will try to allocate memory used by a CPU on the 425 local memory of the CPU and add some more NUMA awareness to the kernel. 426 427config NODES_SHIFT 428 int "Maximum NUMA Nodes (as a power of 2)" 429 range 1 10 430 default "2" 431 depends on NUMA 432 help 433 Specify the maximum number of NUMA Nodes available on the target 434 system. Increases memory reserved to accommodate various tables. 435 436config RISCV_ALTERNATIVE 437 bool 438 depends on !XIP_KERNEL 439 help 440 This Kconfig allows the kernel to automatically patch the 441 erratum or cpufeature required by the execution platform at run 442 time. The code patching overhead is minimal, as it's only done 443 once at boot and once on each module load. 444 445config RISCV_ALTERNATIVE_EARLY 446 bool 447 depends on RISCV_ALTERNATIVE 448 help 449 Allows early patching of the kernel for special errata 450 451config RISCV_ISA_C 452 bool "Emit compressed instructions when building Linux" 453 default y 454 help 455 Adds "C" to the ISA subsets that the toolchain is allowed to emit 456 when building Linux, which results in compressed instructions in the 457 Linux binary. 458 459 If you don't know what to do here, say Y. 460 461config RISCV_ISA_SVNAPOT 462 bool "Svnapot extension support for supervisor mode NAPOT pages" 463 depends on 64BIT && MMU 464 depends on RISCV_ALTERNATIVE 465 default y 466 help 467 Allow kernel to detect the Svnapot ISA-extension dynamically at boot 468 time and enable its usage. 469 470 The Svnapot extension is used to mark contiguous PTEs as a range 471 of contiguous virtual-to-physical translations for a naturally 472 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 473 size. When HUGETLBFS is also selected this option unconditionally 474 allocates some memory for each NAPOT page size supported by the kernel. 475 When optimizing for low memory consumption and for platforms without 476 the Svnapot extension, it may be better to say N here. 477 478 If you don't know what to do here, say Y. 479 480config RISCV_ISA_SVPBMT 481 bool "Svpbmt extension support for supervisor mode page-based memory types" 482 depends on 64BIT && MMU 483 depends on RISCV_ALTERNATIVE 484 default y 485 help 486 Adds support to dynamically detect the presence of the Svpbmt 487 ISA-extension (Supervisor-mode: page-based memory types) and 488 enable its usage. 489 490 The memory type for a page contains a combination of attributes 491 that indicate the cacheability, idempotency, and ordering 492 properties for access to that page. 493 494 The Svpbmt extension is only available on 64-bit cpus. 495 496 If you don't know what to do here, say Y. 497 498config TOOLCHAIN_HAS_V 499 bool 500 default y 501 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv) 502 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv) 503 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800 504 depends on AS_HAS_OPTION_ARCH 505 506config RISCV_ISA_V 507 bool "VECTOR extension support" 508 depends on TOOLCHAIN_HAS_V 509 depends on FPU 510 select DYNAMIC_SIGFRAME 511 default y 512 help 513 Say N here if you want to disable all vector related procedure 514 in the kernel. 515 516 If you don't know what to do here, say Y. 517 518config RISCV_ISA_V_DEFAULT_ENABLE 519 bool "Enable userspace Vector by default" 520 depends on RISCV_ISA_V 521 default y 522 help 523 Say Y here if you want to enable Vector in userspace by default. 524 Otherwise, userspace has to make explicit prctl() call to enable 525 Vector, or enable it via the sysctl interface. 526 527 If you don't know what to do here, say Y. 528 529config TOOLCHAIN_HAS_ZBB 530 bool 531 default y 532 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 533 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 534 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 535 depends on AS_HAS_OPTION_ARCH 536 537config RISCV_ISA_ZBB 538 bool "Zbb extension support for bit manipulation instructions" 539 depends on TOOLCHAIN_HAS_ZBB 540 depends on MMU 541 depends on RISCV_ALTERNATIVE 542 default y 543 help 544 Adds support to dynamically detect the presence of the ZBB 545 extension (basic bit manipulation) and enable its usage. 546 547 The Zbb extension provides instructions to accelerate a number 548 of bit-specific operations (count bit population, sign extending, 549 bitrotation, etc). 550 551 If you don't know what to do here, say Y. 552 553config RISCV_ISA_ZICBOM 554 bool "Zicbom extension support for non-coherent DMA operation" 555 depends on MMU 556 depends on RISCV_ALTERNATIVE 557 default y 558 select RISCV_DMA_NONCOHERENT 559 select DMA_DIRECT_REMAP 560 help 561 Adds support to dynamically detect the presence of the ZICBOM 562 extension (Cache Block Management Operations) and enable its 563 usage. 564 565 The Zicbom extension can be used to handle for example 566 non-coherent DMA support on devices that need it. 567 568 If you don't know what to do here, say Y. 569 570config RISCV_ISA_ZICBOZ 571 bool "Zicboz extension support for faster zeroing of memory" 572 depends on MMU 573 depends on RISCV_ALTERNATIVE 574 default y 575 help 576 Enable the use of the Zicboz extension (cbo.zero instruction) 577 when available. 578 579 The Zicboz extension is used for faster zeroing of memory. 580 581 If you don't know what to do here, say Y. 582 583config TOOLCHAIN_HAS_ZIHINTPAUSE 584 bool 585 default y 586 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause) 587 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause) 588 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600 589 590config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 591 def_bool y 592 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 593 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 594 depends on AS_IS_GNU && AS_VERSION >= 23600 595 help 596 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 597 20191213 version, which moves some instructions from the I extension to 598 the Zicsr and Zifencei extensions. This requires explicitly specifying 599 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 600 and Zifencei are supported in binutils from version 2.36 onwards. 601 To make life easier, and avoid forcing toolchains that default to a 602 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 603 For clang < 17 or GCC < 11.3.0, for which this is not possible or need 604 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 605 606config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 607 def_bool y 608 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 609 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 610 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 611 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300) 612 help 613 Certain versions of clang and GCC do not support zicsr and zifencei via 614 -march. This option causes an older ISA spec compatible with these older 615 versions of clang and GCC to be passed to GAS, which has the same result 616 as passing zicsr and zifencei to -march. 617 618config FPU 619 bool "FPU support" 620 default y 621 help 622 Say N here if you want to disable all floating-point related procedure 623 in the kernel. 624 625 If you don't know what to do here, say Y. 626 627config IRQ_STACKS 628 bool "Independent irq & softirq stacks" if EXPERT 629 default y 630 select HAVE_IRQ_EXIT_ON_IRQ_STACK 631 select HAVE_SOFTIRQ_ON_OWN_STACK 632 help 633 Add independent irq & softirq stacks for percpu to prevent kernel stack 634 overflows. We may save some memory footprint by disabling IRQ_STACKS. 635 636config THREAD_SIZE_ORDER 637 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT 638 range 0 4 639 default 1 if 32BIT && !KASAN 640 default 3 if 64BIT && KASAN 641 default 2 642 help 643 Specify the Pages of thread stack size (from 4KB to 64KB), which also 644 affects irq stack size, which is equal to thread stack size. 645 646config RISCV_MISALIGNED 647 bool "Support misaligned load/store traps for kernel and userspace" 648 select SYSCTL_ARCH_UNALIGN_ALLOW 649 default y 650 help 651 Say Y here if you want the kernel to embed support for misaligned 652 load/store for both kernel and userspace. When disable, misaligned 653 accesses will generate SIGBUS in userspace and panic in kernel. 654 655endmenu # "Platform type" 656 657menu "Kernel features" 658 659source "kernel/Kconfig.hz" 660 661config RISCV_SBI_V01 662 bool "SBI v0.1 support" 663 depends on RISCV_SBI 664 help 665 This config allows kernel to use SBI v0.1 APIs. This will be 666 deprecated in future once legacy M-mode software are no longer in use. 667 668config RISCV_BOOT_SPINWAIT 669 bool "Spinwait booting method" 670 depends on SMP 671 default y if RISCV_SBI_V01 || RISCV_M_MODE 672 help 673 This enables support for booting Linux via spinwait method. In the 674 spinwait method, all cores randomly jump to Linux. One of the cores 675 gets chosen via lottery and all other keep spinning on a percpu 676 variable. This method cannot support CPU hotplug and sparse hartid 677 scheme. It should be only enabled for M-mode Linux or platforms relying 678 on older firmware without SBI HSM extension. All other platforms should 679 rely on ordered booting via SBI HSM extension which gets chosen 680 dynamically at runtime if the firmware supports it. 681 682 Since spinwait is incompatible with sparse hart IDs, it requires 683 NR_CPUS be large enough to contain the physical hart ID of the first 684 hart to enter Linux. 685 686 If unsure what to do here, say N. 687 688config ARCH_SUPPORTS_KEXEC 689 def_bool y 690 691config ARCH_SELECTS_KEXEC 692 def_bool y 693 depends on KEXEC 694 select HOTPLUG_CPU if SMP 695 696config ARCH_SUPPORTS_KEXEC_FILE 697 def_bool 64BIT 698 699config ARCH_SELECTS_KEXEC_FILE 700 def_bool y 701 depends on KEXEC_FILE 702 select HAVE_IMA_KEXEC if IMA 703 select KEXEC_ELF 704 705config ARCH_SUPPORTS_KEXEC_PURGATORY 706 def_bool ARCH_SUPPORTS_KEXEC_FILE 707 708config ARCH_SUPPORTS_CRASH_DUMP 709 def_bool y 710 711config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 712 def_bool CRASH_CORE 713 714config COMPAT 715 bool "Kernel support for 32-bit U-mode" 716 default 64BIT 717 depends on 64BIT && MMU 718 help 719 This option enables support for a 32-bit U-mode running under a 64-bit 720 kernel at S-mode. riscv32-specific components such as system calls, 721 the user helper functions (vdso), signal rt_frame functions and the 722 ptrace interface are handled appropriately by the kernel. 723 724 If you want to execute 32-bit userspace applications, say Y. 725 726config PARAVIRT 727 bool "Enable paravirtualization code" 728 depends on RISCV_SBI 729 help 730 This changes the kernel so it can modify itself when it is run 731 under a hypervisor, potentially improving performance significantly 732 over full virtualization. 733 734config PARAVIRT_TIME_ACCOUNTING 735 bool "Paravirtual steal time accounting" 736 depends on PARAVIRT 737 help 738 Select this option to enable fine granularity task steal time 739 accounting. Time spent executing other tasks in parallel with 740 the current vCPU is discounted from the vCPU power. To account for 741 that, there can be a small performance impact. 742 743 If in doubt, say N here. 744 745config RELOCATABLE 746 bool "Build a relocatable kernel" 747 depends on MMU && 64BIT && !XIP_KERNEL 748 help 749 This builds a kernel as a Position Independent Executable (PIE), 750 which retains all relocation metadata required to relocate the 751 kernel binary at runtime to a different virtual address than the 752 address it was linked at. 753 Since RISCV uses the RELA relocation format, this requires a 754 relocation pass at runtime even if the kernel is loaded at the 755 same address it was linked at. 756 757 If unsure, say N. 758 759config RANDOMIZE_BASE 760 bool "Randomize the address of the kernel image" 761 select RELOCATABLE 762 depends on MMU && 64BIT && !XIP_KERNEL 763 help 764 Randomizes the virtual address at which the kernel image is 765 loaded, as a security feature that deters exploit attempts 766 relying on knowledge of the location of kernel internals. 767 768 It is the bootloader's job to provide entropy, by passing a 769 random u64 value in /chosen/kaslr-seed at kernel entry. 770 771 When booting via the UEFI stub, it will invoke the firmware's 772 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 773 to the kernel proper. In addition, it will randomise the physical 774 location of the kernel Image as well. 775 776 If unsure, say N. 777 778endmenu # "Kernel features" 779 780menu "Boot options" 781 782config CMDLINE 783 string "Built-in kernel command line" 784 help 785 For most platforms, the arguments for the kernel's command line 786 are provided at run-time, during boot. However, there are cases 787 where either no arguments are being provided or the provided 788 arguments are insufficient or even invalid. 789 790 When that occurs, it is possible to define a built-in command 791 line here and choose how the kernel should use it later on. 792 793choice 794 prompt "Built-in command line usage" if CMDLINE != "" 795 default CMDLINE_FALLBACK 796 help 797 Choose how the kernel will handle the provided built-in command 798 line. 799 800config CMDLINE_FALLBACK 801 bool "Use bootloader kernel arguments if available" 802 help 803 Use the built-in command line as fallback in case we get nothing 804 during boot. This is the default behaviour. 805 806config CMDLINE_EXTEND 807 bool "Extend bootloader kernel arguments" 808 help 809 The command-line arguments provided during boot will be 810 appended to the built-in command line. This is useful in 811 cases where the provided arguments are insufficient and 812 you don't want to or cannot modify them. 813 814config CMDLINE_FORCE 815 bool "Always use the default kernel command string" 816 help 817 Always use the built-in command line, even if we get one during 818 boot. This is useful in case you need to override the provided 819 command line on systems where you don't have or want control 820 over it. 821 822endchoice 823 824config EFI_STUB 825 bool 826 827config EFI 828 bool "UEFI runtime support" 829 depends on OF && !XIP_KERNEL 830 depends on MMU 831 default y 832 select ARCH_SUPPORTS_ACPI if 64BIT 833 select EFI_GENERIC_STUB 834 select EFI_PARAMS_FROM_FDT 835 select EFI_RUNTIME_WRAPPERS 836 select EFI_STUB 837 select LIBFDT 838 select RISCV_ISA_C 839 select UCS2_STRING 840 help 841 This option provides support for runtime services provided 842 by UEFI firmware (such as non-volatile variables, realtime 843 clock, and platform reset). A UEFI stub is also provided to 844 allow the kernel to be booted as an EFI application. This 845 is only useful on systems that have UEFI firmware. 846 847config CC_HAVE_STACKPROTECTOR_TLS 848 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 849 850config STACKPROTECTOR_PER_TASK 851 def_bool y 852 depends on !RANDSTRUCT 853 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 854 855config PHYS_RAM_BASE_FIXED 856 bool "Explicitly specified physical RAM address" 857 depends on NONPORTABLE 858 default n 859 860config PHYS_RAM_BASE 861 hex "Platform Physical RAM address" 862 depends on PHYS_RAM_BASE_FIXED 863 default "0x80000000" 864 help 865 This is the physical address of RAM in the system. It has to be 866 explicitly specified to run early relocations of read-write data 867 from flash to RAM. 868 869config XIP_KERNEL 870 bool "Kernel Execute-In-Place from ROM" 871 depends on MMU && SPARSEMEM && NONPORTABLE 872 # This prevents XIP from being enabled by all{yes,mod}config, which 873 # fail to build since XIP doesn't support large kernels. 874 depends on !COMPILE_TEST 875 select PHYS_RAM_BASE_FIXED 876 help 877 Execute-In-Place allows the kernel to run from non-volatile storage 878 directly addressable by the CPU, such as NOR flash. This saves RAM 879 space since the text section of the kernel is not loaded from flash 880 to RAM. Read-write sections, such as the data section and stack, 881 are still copied to RAM. The XIP kernel is not compressed since 882 it has to run directly from flash, so it will take more space to 883 store it. The flash address used to link the kernel object files, 884 and for storing it, is configuration dependent. Therefore, if you 885 say Y here, you must know the proper physical address where to 886 store the kernel image depending on your own flash memory usage. 887 888 Also note that the make target becomes "make xipImage" rather than 889 "make zImage" or "make Image". The final kernel binary to put in 890 ROM memory will be arch/riscv/boot/xipImage. 891 892 SPARSEMEM is required because the kernel text and rodata that are 893 flash resident are not backed by memmap, then any attempt to get 894 a struct page on those regions will trigger a fault. 895 896 If unsure, say N. 897 898config XIP_PHYS_ADDR 899 hex "XIP Kernel Physical Location" 900 depends on XIP_KERNEL 901 default "0x21000000" 902 help 903 This is the physical address in your flash memory the kernel will 904 be linked for and stored to. This address is dependent on your 905 own flash usage. 906 907config RISCV_ISA_FALLBACK 908 bool "Permit falling back to parsing riscv,isa for extension support by default" 909 default y 910 help 911 Parsing the "riscv,isa" devicetree property has been deprecated and 912 replaced by a list of explicitly defined strings. For compatibility 913 with existing platforms, the kernel will fall back to parsing the 914 "riscv,isa" property if the replacements are not found. 915 916 Selecting N here will result in a kernel that does not use the 917 fallback, unless the commandline "riscv_isa_fallback" parameter is 918 present. 919 920 Please see the dt-binding, located at 921 Documentation/devicetree/bindings/riscv/extensions.yaml for details 922 on the replacement properties, "riscv,isa-base" and 923 "riscv,isa-extensions". 924 925config BUILTIN_DTB 926 bool "Built-in device tree" 927 depends on OF && NONPORTABLE 928 default y if XIP_KERNEL 929 930endmenu # "Boot options" 931 932config PORTABLE 933 bool 934 default !NONPORTABLE 935 select EFI 936 select MMU 937 select OF 938 939config ARCH_PROC_KCORE_TEXT 940 def_bool y 941 942menu "Power management options" 943 944source "kernel/power/Kconfig" 945 946# Hibernation is only possible on systems where the SBI implementation has 947# marked its reserved memory as not accessible from, or does not run 948# from the same memory as, Linux 949config ARCH_HIBERNATION_POSSIBLE 950 def_bool NONPORTABLE 951 952config ARCH_HIBERNATION_HEADER 953 def_bool HIBERNATION 954 955config ARCH_SUSPEND_POSSIBLE 956 def_bool y 957 958endmenu # "Power management options" 959 960menu "CPU Power Management" 961 962source "drivers/cpuidle/Kconfig" 963 964source "drivers/cpufreq/Kconfig" 965 966endmenu # "CPU Power Management" 967 968source "arch/riscv/kvm/Kconfig" 969 970source "drivers/acpi/Kconfig" 971