1# SPDX-License-Identifier: GPL-2.0-only 2# 3# For a description of the syntax of this configuration file, 4# see Documentation/kbuild/kconfig-language.rst. 5# 6 7config 64BIT 8 bool 9 10config 32BIT 11 bool 12 13config RISCV 14 def_bool y 15 select ACPI_GENERIC_GSI if ACPI 16 select ACPI_MCFG if (ACPI && PCI) 17 select ACPI_PPTT if ACPI 18 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 19 select ACPI_SPCR_TABLE if ACPI 20 select ARCH_DMA_DEFAULT_COHERENT 21 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 22 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM_VMEMMAP 23 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 24 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 25 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 26 select ARCH_HAS_BINFMT_FLAT 27 select ARCH_HAS_CURRENT_STACK_POINTER 28 select ARCH_HAS_DEBUG_VIRTUAL if MMU 29 select ARCH_HAS_DEBUG_VM_PGTABLE 30 select ARCH_HAS_DEBUG_WX 31 select ARCH_HAS_FAST_MULTIPLIER 32 select ARCH_HAS_FORTIFY_SOURCE 33 select ARCH_HAS_GCOV_PROFILE_ALL 34 select ARCH_HAS_GIGANTIC_PAGE 35 select ARCH_HAS_KCOV 36 select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU 37 select ARCH_HAS_MEMBARRIER_CALLBACKS 38 select ARCH_HAS_MEMBARRIER_SYNC_CORE 39 select ARCH_HAS_MMIOWB 40 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 41 select ARCH_HAS_PMEM_API 42 select ARCH_HAS_PREPARE_SYNC_CORE_CMD 43 select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU 44 select ARCH_HAS_PTE_SPECIAL 45 select ARCH_HAS_SET_DIRECT_MAP if MMU 46 select ARCH_HAS_SET_MEMORY if MMU 47 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL 48 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL 49 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 50 select ARCH_HAS_SYSCALL_WRAPPER 51 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 52 select ARCH_HAS_UBSAN 53 select ARCH_HAS_VDSO_DATA 54 select ARCH_KEEP_MEMBLOCK if ACPI 55 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU 56 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 57 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 58 select ARCH_STACKWALK 59 select ARCH_SUPPORTS_ATOMIC_RMW 60 select ARCH_SUPPORTS_CFI_CLANG 61 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU 62 select ARCH_SUPPORTS_HUGETLBFS if MMU 63 # LLD >= 14: https://github.com/llvm/llvm-project/issues/50505 64 select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000 65 select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000 66 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 67 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 68 select ARCH_SUPPORTS_RT 69 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK 70 select ARCH_USE_CMPXCHG_LOCKREF if 64BIT 71 select ARCH_USE_MEMTEST 72 select ARCH_USE_QUEUED_RWLOCKS 73 select ARCH_USE_SYM_ANNOTATIONS 74 select ARCH_USES_CFI_TRAPS if CFI_CLANG 75 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU 76 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 77 select ARCH_WANT_FRAME_POINTERS 78 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 79 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 80 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL 81 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP 82 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 83 select ARCH_WANTS_NO_INSTR 84 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 85 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 86 select BUILDTIME_TABLE_SORT if MMU 87 select CLINT_TIMER if RISCV_M_MODE 88 select CLONE_BACKWARDS 89 select COMMON_CLK 90 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND 91 select EDAC_SUPPORT 92 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) 93 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE 94 select GENERIC_ARCH_TOPOLOGY 95 select GENERIC_ATOMIC64 if !64BIT 96 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 97 select GENERIC_CPU_DEVICES 98 select GENERIC_CPU_VULNERABILITIES 99 select GENERIC_EARLY_IOREMAP 100 select GENERIC_ENTRY 101 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 102 select GENERIC_IDLE_POLL_SETUP 103 select GENERIC_IOREMAP if MMU 104 select GENERIC_IRQ_IPI if SMP 105 select GENERIC_IRQ_IPI_MUX if SMP 106 select GENERIC_IRQ_MULTI_HANDLER 107 select GENERIC_IRQ_SHOW 108 select GENERIC_IRQ_SHOW_LEVEL 109 select GENERIC_LIB_DEVMEM_IS_ALLOWED 110 select GENERIC_PCI_IOMAP 111 select GENERIC_PTDUMP if MMU 112 select GENERIC_SCHED_CLOCK 113 select GENERIC_SMP_IDLE_THREAD 114 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 115 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO 116 select HARDIRQS_SW_RESEND 117 select HAS_IOPORT if MMU 118 select HAVE_ARCH_AUDITSYSCALL 119 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 120 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT 121 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL 122 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL 123 select HAVE_ARCH_KASAN if MMU && 64BIT 124 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 125 select HAVE_ARCH_KFENCE if MMU && 64BIT 126 select HAVE_ARCH_KGDB if !XIP_KERNEL 127 select HAVE_ARCH_KGDB_QXFER_PKT 128 select HAVE_ARCH_MMAP_RND_BITS if MMU 129 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 130 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 131 select HAVE_ARCH_SECCOMP_FILTER 132 select HAVE_ARCH_STACKLEAK 133 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 134 select HAVE_ARCH_TRACEHOOK 135 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU 136 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD 137 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 138 select HAVE_ASM_MODVERSIONS 139 select HAVE_CONTEXT_TRACKING_USER 140 select HAVE_DEBUG_KMEMLEAK 141 select HAVE_DMA_CONTIGUOUS if MMU 142 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 143 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 144 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE 145 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL 146 select HAVE_FUNCTION_GRAPH_TRACER 147 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 148 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION 149 select HAVE_EBPF_JIT if MMU 150 select HAVE_GUP_FAST if MMU 151 select HAVE_FUNCTION_ARG_ACCESS_API 152 select HAVE_FUNCTION_ERROR_INJECTION 153 select HAVE_GCC_PLUGINS 154 select HAVE_GENERIC_VDSO if MMU && 64BIT 155 select HAVE_IRQ_TIME_ACCOUNTING 156 select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT 157 select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT 158 select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT 159 select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT 160 select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT 161 select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT 162 select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT 163 select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT 164 select HAVE_KPROBES if !XIP_KERNEL 165 select HAVE_KRETPROBES if !XIP_KERNEL 166 # https://github.com/ClangBuiltLinux/linux/issues/1881 167 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD 168 select HAVE_MOVE_PMD 169 select HAVE_MOVE_PUD 170 select HAVE_PAGE_SIZE_4KB 171 select HAVE_PCI 172 select HAVE_PERF_EVENTS 173 select HAVE_PERF_REGS 174 select HAVE_PERF_USER_STACK_DUMP 175 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 176 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL 177 select HAVE_REGS_AND_STACK_ACCESS_API 178 select HAVE_RETHOOK if !XIP_KERNEL 179 select HAVE_RSEQ 180 select HAVE_RUST if 64BIT 181 select HAVE_SAMPLE_FTRACE_DIRECT 182 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 183 select HAVE_STACKPROTECTOR 184 select HAVE_SYSCALL_TRACEPOINTS 185 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 186 select IRQ_DOMAIN 187 select IRQ_FORCED_THREADING 188 select KASAN_VMALLOC if KASAN 189 select LOCK_MM_AND_FIND_VMA 190 select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU 191 select MODULES_USE_ELF_RELA if MODULES 192 select OF 193 select OF_EARLY_FLATTREE 194 select OF_IRQ 195 select PCI_DOMAINS_GENERIC if PCI 196 select PCI_ECAM if (ACPI && PCI) 197 select PCI_MSI if PCI 198 select RISCV_ALTERNATIVE if !XIP_KERNEL 199 select RISCV_APLIC 200 select RISCV_IMSIC 201 select RISCV_INTC 202 select RISCV_TIMER if RISCV_SBI 203 select SIFIVE_PLIC 204 select SPARSE_IRQ 205 select SYSCTL_EXCEPTION_TRACE 206 select THREAD_INFO_IN_TASK 207 select TRACE_IRQFLAGS_SUPPORT 208 select UACCESS_MEMCPY if !MMU 209 select USER_STACKTRACE_SUPPORT 210 select ZONE_DMA32 if 64BIT 211 212config CLANG_SUPPORTS_DYNAMIC_FTRACE 213 def_bool CC_IS_CLANG 214 # https://github.com/ClangBuiltLinux/linux/issues/1817 215 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 216 217config GCC_SUPPORTS_DYNAMIC_FTRACE 218 def_bool CC_IS_GCC 219 depends on $(cc-option,-fpatchable-function-entry=8) 220 221config HAVE_SHADOW_CALL_STACK 222 def_bool $(cc-option,-fsanitize=shadow-call-stack) 223 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 224 depends on $(ld-option,--no-relax-gp) 225 226config RISCV_USE_LINKER_RELAXATION 227 def_bool y 228 # https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985 229 depends on !LD_IS_LLD || LLD_VERSION >= 150000 230 231# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 232config ARCH_HAS_BROKEN_DWARF5 233 def_bool y 234 depends on RISCV_USE_LINKER_RELAXATION 235 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a 236 depends on AS_IS_LLVM && AS_VERSION < 180000 237 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77 238 depends on LD_IS_LLD && LLD_VERSION < 180000 239 240config ARCH_MMAP_RND_BITS_MIN 241 default 18 if 64BIT 242 default 8 243 244config ARCH_MMAP_RND_COMPAT_BITS_MIN 245 default 8 246 247# max bits determined by the following formula: 248# VA_BITS - PAGE_SHIFT - 3 249config ARCH_MMAP_RND_BITS_MAX 250 default 24 if 64BIT # SV39 based 251 default 17 252 253config ARCH_MMAP_RND_COMPAT_BITS_MAX 254 default 17 255 256# set if we run in machine mode, cleared if we run in supervisor mode 257config RISCV_M_MODE 258 bool "Build a kernel that runs in machine mode" 259 depends on !MMU 260 default y 261 help 262 Select this option if you want to run the kernel in M-mode, 263 without the assistance of any other firmware. 264 265# set if we are running in S-mode and can use SBI calls 266config RISCV_SBI 267 bool 268 depends on !RISCV_M_MODE 269 default y 270 271config MMU 272 bool "MMU-based Paged Memory Management Support" 273 default y 274 help 275 Select if you want MMU-based virtualised addressing space 276 support by paged memory management. If unsure, say 'Y'. 277 278config PAGE_OFFSET 279 hex 280 default 0x80000000 if !MMU && RISCV_M_MODE 281 default 0x80200000 if !MMU 282 default 0xc0000000 if 32BIT 283 default 0xff60000000000000 if 64BIT 284 285config KASAN_SHADOW_OFFSET 286 hex 287 depends on KASAN_GENERIC 288 default 0xdfffffff00000000 if 64BIT 289 default 0xffffffff if 32BIT 290 291config ARCH_FLATMEM_ENABLE 292 def_bool !NUMA 293 294config ARCH_SPARSEMEM_ENABLE 295 def_bool y 296 depends on MMU 297 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 298 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 299 300config ARCH_SELECT_MEMORY_MODEL 301 def_bool ARCH_SPARSEMEM_ENABLE 302 303config ARCH_SUPPORTS_UPROBES 304 def_bool y 305 306config STACKTRACE_SUPPORT 307 def_bool y 308 309config GENERIC_BUG 310 def_bool y 311 depends on BUG 312 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 313 314config GENERIC_BUG_RELATIVE_POINTERS 315 bool 316 317config GENERIC_CALIBRATE_DELAY 318 def_bool y 319 320config GENERIC_CSUM 321 def_bool y 322 323config GENERIC_HWEIGHT 324 def_bool y 325 326config FIX_EARLYCON_MEM 327 def_bool MMU 328 329config ILLEGAL_POINTER_VALUE 330 hex 331 default 0 if 32BIT 332 default 0xdead000000000000 if 64BIT 333 334config PGTABLE_LEVELS 335 int 336 default 5 if 64BIT 337 default 2 338 339config LOCKDEP_SUPPORT 340 def_bool y 341 342config RISCV_DMA_NONCOHERENT 343 bool 344 select ARCH_HAS_DMA_PREP_COHERENT 345 select ARCH_HAS_SETUP_DMA_OPS 346 select ARCH_HAS_SYNC_DMA_FOR_CPU 347 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 348 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 349 350config RISCV_NONSTANDARD_CACHE_OPS 351 bool 352 help 353 This enables function pointer support for non-standard noncoherent 354 systems to handle cache management. 355 356config AS_HAS_INSN 357 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) 358 359config AS_HAS_OPTION_ARCH 360 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4 361 def_bool y 362 depends on $(as-instr, .option arch$(comma) +m) 363 364source "arch/riscv/Kconfig.socs" 365source "arch/riscv/Kconfig.errata" 366 367menu "Platform type" 368 369config NONPORTABLE 370 bool "Allow configurations that result in non-portable kernels" 371 help 372 RISC-V kernel binaries are compatible between all known systems 373 whenever possible, but there are some use cases that can only be 374 satisfied by configurations that result in kernel binaries that are 375 not portable between systems. 376 377 Selecting N does not guarantee kernels will be portable to all known 378 systems. Selecting any of the options guarded by NONPORTABLE will 379 result in kernel binaries that are unlikely to be portable between 380 systems. 381 382 If unsure, say N. 383 384choice 385 prompt "Base ISA" 386 default ARCH_RV64I 387 help 388 This selects the base ISA that this kernel will target and must match 389 the target platform. 390 391config ARCH_RV32I 392 bool "RV32I" 393 depends on NONPORTABLE 394 select 32BIT 395 select GENERIC_LIB_ASHLDI3 396 select GENERIC_LIB_ASHRDI3 397 select GENERIC_LIB_LSHRDI3 398 select GENERIC_LIB_UCMPDI2 399 400config ARCH_RV64I 401 bool "RV64I" 402 select 64BIT 403 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 404 select SWIOTLB if MMU 405 406endchoice 407 408# We must be able to map all physical memory into the kernel, but the compiler 409# is still a bit more efficient when generating code if it's setup in a manner 410# such that it can only map 2GiB of memory. 411choice 412 prompt "Kernel Code Model" 413 default CMODEL_MEDLOW if 32BIT 414 default CMODEL_MEDANY if 64BIT 415 416 config CMODEL_MEDLOW 417 bool "medium low code model" 418 config CMODEL_MEDANY 419 bool "medium any code model" 420endchoice 421 422config MODULE_SECTIONS 423 bool 424 select HAVE_MOD_ARCH_SPECIFIC 425 426config SMP 427 bool "Symmetric Multi-Processing" 428 help 429 This enables support for systems with more than one CPU. If 430 you say N here, the kernel will run on single and 431 multiprocessor machines, but will use only one CPU of a 432 multiprocessor machine. If you say Y here, the kernel will run 433 on many, but not all, single processor machines. On a single 434 processor machine, the kernel will run faster if you say N 435 here. 436 437 If you don't know what to do here, say N. 438 439config SCHED_MC 440 bool "Multi-core scheduler support" 441 depends on SMP 442 help 443 Multi-core scheduler support improves the CPU scheduler's decision 444 making when dealing with multi-core CPU chips at a cost of slightly 445 increased overhead in some places. If unsure say N here. 446 447config NR_CPUS 448 int "Maximum number of CPUs (2-512)" 449 depends on SMP 450 range 2 512 if !RISCV_SBI_V01 451 range 2 32 if RISCV_SBI_V01 && 32BIT 452 range 2 64 if RISCV_SBI_V01 && 64BIT 453 default "32" if 32BIT 454 default "64" if 64BIT 455 456config HOTPLUG_CPU 457 bool "Support for hot-pluggable CPUs" 458 depends on SMP 459 select GENERIC_IRQ_MIGRATION 460 help 461 462 Say Y here to experiment with turning CPUs off and on. CPUs 463 can be controlled through /sys/devices/system/cpu. 464 465 Say N if you want to disable CPU hotplug. 466 467choice 468 prompt "CPU Tuning" 469 default TUNE_GENERIC 470 471config TUNE_GENERIC 472 bool "generic" 473 474endchoice 475 476# Common NUMA Features 477config NUMA 478 bool "NUMA Memory Allocation and Scheduler Support" 479 depends on SMP && MMU 480 select ARCH_SUPPORTS_NUMA_BALANCING 481 select GENERIC_ARCH_NUMA 482 select HAVE_SETUP_PER_CPU_AREA 483 select NEED_PER_CPU_EMBED_FIRST_CHUNK 484 select NEED_PER_CPU_PAGE_FIRST_CHUNK 485 select OF_NUMA 486 select USE_PERCPU_NUMA_NODE_ID 487 help 488 Enable NUMA (Non-Uniform Memory Access) support. 489 490 The kernel will try to allocate memory used by a CPU on the 491 local memory of the CPU and add some more NUMA awareness to the kernel. 492 493config NODES_SHIFT 494 int "Maximum NUMA Nodes (as a power of 2)" 495 range 1 10 496 default "2" 497 depends on NUMA 498 help 499 Specify the maximum number of NUMA Nodes available on the target 500 system. Increases memory reserved to accommodate various tables. 501 502config RISCV_ALTERNATIVE 503 bool 504 depends on !XIP_KERNEL 505 help 506 This Kconfig allows the kernel to automatically patch the 507 erratum or cpufeature required by the execution platform at run 508 time. The code patching overhead is minimal, as it's only done 509 once at boot and once on each module load. 510 511config RISCV_ALTERNATIVE_EARLY 512 bool 513 depends on RISCV_ALTERNATIVE 514 help 515 Allows early patching of the kernel for special errata 516 517config RISCV_ISA_C 518 bool "Emit compressed instructions when building Linux" 519 default y 520 help 521 Adds "C" to the ISA subsets that the toolchain is allowed to emit 522 when building Linux, which results in compressed instructions in the 523 Linux binary. 524 525 If you don't know what to do here, say Y. 526 527config RISCV_ISA_SVNAPOT 528 bool "Svnapot extension support for supervisor mode NAPOT pages" 529 depends on 64BIT && MMU 530 depends on RISCV_ALTERNATIVE 531 default y 532 help 533 Allow kernel to detect the Svnapot ISA-extension dynamically at boot 534 time and enable its usage. 535 536 The Svnapot extension is used to mark contiguous PTEs as a range 537 of contiguous virtual-to-physical translations for a naturally 538 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 539 size. When HUGETLBFS is also selected this option unconditionally 540 allocates some memory for each NAPOT page size supported by the kernel. 541 When optimizing for low memory consumption and for platforms without 542 the Svnapot extension, it may be better to say N here. 543 544 If you don't know what to do here, say Y. 545 546config RISCV_ISA_SVPBMT 547 bool "Svpbmt extension support for supervisor mode page-based memory types" 548 depends on 64BIT && MMU 549 depends on RISCV_ALTERNATIVE 550 default y 551 help 552 Adds support to dynamically detect the presence of the Svpbmt 553 ISA-extension (Supervisor-mode: page-based memory types) and 554 enable its usage. 555 556 The memory type for a page contains a combination of attributes 557 that indicate the cacheability, idempotency, and ordering 558 properties for access to that page. 559 560 The Svpbmt extension is only available on 64-bit cpus. 561 562 If you don't know what to do here, say Y. 563 564config TOOLCHAIN_HAS_V 565 bool 566 default y 567 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv) 568 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv) 569 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800 570 depends on AS_HAS_OPTION_ARCH 571 572config RISCV_ISA_V 573 bool "VECTOR extension support" 574 depends on TOOLCHAIN_HAS_V 575 depends on FPU 576 select DYNAMIC_SIGFRAME 577 default y 578 help 579 Say N here if you want to disable all vector related procedure 580 in the kernel. 581 582 If you don't know what to do here, say Y. 583 584config RISCV_ISA_V_DEFAULT_ENABLE 585 bool "Enable userspace Vector by default" 586 depends on RISCV_ISA_V 587 default y 588 help 589 Say Y here if you want to enable Vector in userspace by default. 590 Otherwise, userspace has to make explicit prctl() call to enable 591 Vector, or enable it via the sysctl interface. 592 593 If you don't know what to do here, say Y. 594 595config RISCV_ISA_V_UCOPY_THRESHOLD 596 int "Threshold size for vectorized user copies" 597 depends on RISCV_ISA_V 598 default 768 599 help 600 Prefer using vectorized copy_to_user()/copy_from_user() when the 601 workload size exceeds this value. 602 603config RISCV_ISA_V_PREEMPTIVE 604 bool "Run kernel-mode Vector with kernel preemption" 605 depends on PREEMPTION 606 depends on RISCV_ISA_V 607 default y 608 help 609 Usually, in-kernel SIMD routines are run with preemption disabled. 610 Functions which envoke long running SIMD thus must yield core's 611 vector unit to prevent blocking other tasks for too long. 612 613 This config allows kernel to run SIMD without explicitly disable 614 preemption. Enabling this config will result in higher memory 615 consumption due to the allocation of per-task's kernel Vector context. 616 617config RISCV_ISA_ZAWRS 618 bool "Zawrs extension support for more efficient busy waiting" 619 depends on RISCV_ALTERNATIVE 620 default y 621 help 622 The Zawrs extension defines instructions to be used in polling loops 623 which allow a hart to enter a low-power state or to trap to the 624 hypervisor while waiting on a store to a memory location. Enable the 625 use of these instructions in the kernel when the Zawrs extension is 626 detected at boot. 627 628 If you don't know what to do here, say Y. 629 630config TOOLCHAIN_HAS_ZBB 631 bool 632 default y 633 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 634 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 635 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 636 depends on AS_HAS_OPTION_ARCH 637 638# This symbol indicates that the toolchain supports all v1.0 vector crypto 639# extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once. 640# binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb. 641config TOOLCHAIN_HAS_VECTOR_CRYPTO 642 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb) 643 depends on AS_HAS_OPTION_ARCH 644 645config RISCV_ISA_ZBA 646 bool "Zba extension support for bit manipulation instructions" 647 default y 648 help 649 Add support for enabling optimisations in the kernel when the Zba 650 extension is detected at boot. 651 652 The Zba extension provides instructions to accelerate the generation 653 of addresses that index into arrays of basic data types. 654 655 If you don't know what to do here, say Y. 656 657config RISCV_ISA_ZBB 658 bool "Zbb extension support for bit manipulation instructions" 659 depends on TOOLCHAIN_HAS_ZBB 660 depends on RISCV_ALTERNATIVE 661 default y 662 help 663 Adds support to dynamically detect the presence of the ZBB 664 extension (basic bit manipulation) and enable its usage. 665 666 The Zbb extension provides instructions to accelerate a number 667 of bit-specific operations (count bit population, sign extending, 668 bitrotation, etc). 669 670 If you don't know what to do here, say Y. 671 672config TOOLCHAIN_HAS_ZBC 673 bool 674 default y 675 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc) 676 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc) 677 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 678 depends on AS_HAS_OPTION_ARCH 679 680config RISCV_ISA_ZBC 681 bool "Zbc extension support for carry-less multiplication instructions" 682 depends on TOOLCHAIN_HAS_ZBC 683 depends on MMU 684 depends on RISCV_ALTERNATIVE 685 default y 686 help 687 Adds support to dynamically detect the presence of the Zbc 688 extension (carry-less multiplication) and enable its usage. 689 690 The Zbc extension could accelerate CRC (cyclic redundancy check) 691 calculations. 692 693 If you don't know what to do here, say Y. 694 695config RISCV_ISA_ZICBOM 696 bool "Zicbom extension support for non-coherent DMA operation" 697 depends on MMU 698 depends on RISCV_ALTERNATIVE 699 default y 700 select RISCV_DMA_NONCOHERENT 701 select DMA_DIRECT_REMAP 702 help 703 Adds support to dynamically detect the presence of the ZICBOM 704 extension (Cache Block Management Operations) and enable its 705 usage. 706 707 The Zicbom extension can be used to handle for example 708 non-coherent DMA support on devices that need it. 709 710 If you don't know what to do here, say Y. 711 712config RISCV_ISA_ZICBOZ 713 bool "Zicboz extension support for faster zeroing of memory" 714 depends on RISCV_ALTERNATIVE 715 default y 716 help 717 Enable the use of the Zicboz extension (cbo.zero instruction) 718 when available. 719 720 The Zicboz extension is used for faster zeroing of memory. 721 722 If you don't know what to do here, say Y. 723 724config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 725 def_bool y 726 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 727 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 728 depends on AS_IS_GNU && AS_VERSION >= 23600 729 help 730 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 731 20191213 version, which moves some instructions from the I extension to 732 the Zicsr and Zifencei extensions. This requires explicitly specifying 733 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 734 and Zifencei are supported in binutils from version 2.36 onwards. 735 To make life easier, and avoid forcing toolchains that default to a 736 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 737 For clang < 17 or GCC < 11.3.0, for which this is not possible or need 738 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 739 740config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 741 def_bool y 742 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 743 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 744 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 745 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300) 746 help 747 Certain versions of clang and GCC do not support zicsr and zifencei via 748 -march. This option causes an older ISA spec compatible with these older 749 versions of clang and GCC to be passed to GAS, which has the same result 750 as passing zicsr and zifencei to -march. 751 752config FPU 753 bool "FPU support" 754 default y 755 help 756 Say N here if you want to disable all floating-point related procedure 757 in the kernel. 758 759 If you don't know what to do here, say Y. 760 761config IRQ_STACKS 762 bool "Independent irq & softirq stacks" if EXPERT 763 default y 764 select HAVE_IRQ_EXIT_ON_IRQ_STACK 765 select HAVE_SOFTIRQ_ON_OWN_STACK 766 help 767 Add independent irq & softirq stacks for percpu to prevent kernel stack 768 overflows. We may save some memory footprint by disabling IRQ_STACKS. 769 770config THREAD_SIZE_ORDER 771 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT 772 range 0 4 773 default 1 if 32BIT && !KASAN 774 default 3 if 64BIT && KASAN 775 default 2 776 help 777 Specify the Pages of thread stack size (from 4KB to 64KB), which also 778 affects irq stack size, which is equal to thread stack size. 779 780config RISCV_MISALIGNED 781 bool 782 select SYSCTL_ARCH_UNALIGN_ALLOW 783 help 784 Embed support for emulating misaligned loads and stores. 785 786choice 787 prompt "Unaligned Accesses Support" 788 default RISCV_PROBE_UNALIGNED_ACCESS 789 help 790 This determines the level of support for unaligned accesses. This 791 information is used by the kernel to perform optimizations. It is also 792 exposed to user space via the hwprobe syscall. The hardware will be 793 probed at boot by default. 794 795config RISCV_PROBE_UNALIGNED_ACCESS 796 bool "Probe for hardware unaligned access support" 797 select RISCV_MISALIGNED 798 help 799 During boot, the kernel will run a series of tests to determine the 800 speed of unaligned accesses. This probing will dynamically determine 801 the speed of unaligned accesses on the underlying system. If unaligned 802 memory accesses trap into the kernel as they are not supported by the 803 system, the kernel will emulate the unaligned accesses to preserve the 804 UABI. 805 806config RISCV_EMULATED_UNALIGNED_ACCESS 807 bool "Emulate unaligned access where system support is missing" 808 select RISCV_MISALIGNED 809 help 810 If unaligned memory accesses trap into the kernel as they are not 811 supported by the system, the kernel will emulate the unaligned 812 accesses to preserve the UABI. When the underlying system does support 813 unaligned accesses, the unaligned accesses are assumed to be slow. 814 815config RISCV_SLOW_UNALIGNED_ACCESS 816 bool "Assume the system supports slow unaligned memory accesses" 817 depends on NONPORTABLE 818 help 819 Assume that the system supports slow unaligned memory accesses. The 820 kernel and userspace programs may not be able to run at all on systems 821 that do not support unaligned memory accesses. 822 823config RISCV_EFFICIENT_UNALIGNED_ACCESS 824 bool "Assume the system supports fast unaligned memory accesses" 825 depends on NONPORTABLE 826 select DCACHE_WORD_ACCESS if MMU 827 select HAVE_EFFICIENT_UNALIGNED_ACCESS 828 help 829 Assume that the system supports fast unaligned memory accesses. When 830 enabled, this option improves the performance of the kernel on such 831 systems. However, the kernel and userspace programs will run much more 832 slowly, or will not be able to run at all, on systems that do not 833 support efficient unaligned memory accesses. 834 835endchoice 836 837source "arch/riscv/Kconfig.vendor" 838 839endmenu # "Platform type" 840 841menu "Kernel features" 842 843source "kernel/Kconfig.hz" 844 845config RISCV_SBI_V01 846 bool "SBI v0.1 support" 847 depends on RISCV_SBI 848 help 849 This config allows kernel to use SBI v0.1 APIs. This will be 850 deprecated in future once legacy M-mode software are no longer in use. 851 852config RISCV_BOOT_SPINWAIT 853 bool "Spinwait booting method" 854 depends on SMP 855 default y if RISCV_SBI_V01 || RISCV_M_MODE 856 help 857 This enables support for booting Linux via spinwait method. In the 858 spinwait method, all cores randomly jump to Linux. One of the cores 859 gets chosen via lottery and all other keep spinning on a percpu 860 variable. This method cannot support CPU hotplug and sparse hartid 861 scheme. It should be only enabled for M-mode Linux or platforms relying 862 on older firmware without SBI HSM extension. All other platforms should 863 rely on ordered booting via SBI HSM extension which gets chosen 864 dynamically at runtime if the firmware supports it. 865 866 Since spinwait is incompatible with sparse hart IDs, it requires 867 NR_CPUS be large enough to contain the physical hart ID of the first 868 hart to enter Linux. 869 870 If unsure what to do here, say N. 871 872config ARCH_SUPPORTS_KEXEC 873 def_bool y 874 875config ARCH_SELECTS_KEXEC 876 def_bool y 877 depends on KEXEC 878 select HOTPLUG_CPU if SMP 879 880config ARCH_SUPPORTS_KEXEC_FILE 881 def_bool 64BIT 882 883config ARCH_SELECTS_KEXEC_FILE 884 def_bool y 885 depends on KEXEC_FILE 886 select HAVE_IMA_KEXEC if IMA 887 select KEXEC_ELF 888 889config ARCH_SUPPORTS_KEXEC_PURGATORY 890 def_bool ARCH_SUPPORTS_KEXEC_FILE 891 892config ARCH_SUPPORTS_CRASH_DUMP 893 def_bool y 894 895config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 896 def_bool CRASH_RESERVE 897 898config COMPAT 899 bool "Kernel support for 32-bit U-mode" 900 default 64BIT 901 depends on 64BIT && MMU 902 help 903 This option enables support for a 32-bit U-mode running under a 64-bit 904 kernel at S-mode. riscv32-specific components such as system calls, 905 the user helper functions (vdso), signal rt_frame functions and the 906 ptrace interface are handled appropriately by the kernel. 907 908 If you want to execute 32-bit userspace applications, say Y. 909 910config PARAVIRT 911 bool "Enable paravirtualization code" 912 depends on RISCV_SBI 913 help 914 This changes the kernel so it can modify itself when it is run 915 under a hypervisor, potentially improving performance significantly 916 over full virtualization. 917 918config PARAVIRT_TIME_ACCOUNTING 919 bool "Paravirtual steal time accounting" 920 depends on PARAVIRT 921 help 922 Select this option to enable fine granularity task steal time 923 accounting. Time spent executing other tasks in parallel with 924 the current vCPU is discounted from the vCPU power. To account for 925 that, there can be a small performance impact. 926 927 If in doubt, say N here. 928 929config RELOCATABLE 930 bool "Build a relocatable kernel" 931 depends on MMU && 64BIT && !XIP_KERNEL 932 select MODULE_SECTIONS if MODULES 933 help 934 This builds a kernel as a Position Independent Executable (PIE), 935 which retains all relocation metadata required to relocate the 936 kernel binary at runtime to a different virtual address than the 937 address it was linked at. 938 Since RISCV uses the RELA relocation format, this requires a 939 relocation pass at runtime even if the kernel is loaded at the 940 same address it was linked at. 941 942 If unsure, say N. 943 944config RANDOMIZE_BASE 945 bool "Randomize the address of the kernel image" 946 select RELOCATABLE 947 depends on MMU && 64BIT && !XIP_KERNEL 948 help 949 Randomizes the virtual address at which the kernel image is 950 loaded, as a security feature that deters exploit attempts 951 relying on knowledge of the location of kernel internals. 952 953 It is the bootloader's job to provide entropy, by passing a 954 random u64 value in /chosen/kaslr-seed at kernel entry. 955 956 When booting via the UEFI stub, it will invoke the firmware's 957 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 958 to the kernel proper. In addition, it will randomise the physical 959 location of the kernel Image as well. 960 961 If unsure, say N. 962 963endmenu # "Kernel features" 964 965menu "Boot options" 966 967config CMDLINE 968 string "Built-in kernel command line" 969 help 970 For most platforms, the arguments for the kernel's command line 971 are provided at run-time, during boot. However, there are cases 972 where either no arguments are being provided or the provided 973 arguments are insufficient or even invalid. 974 975 When that occurs, it is possible to define a built-in command 976 line here and choose how the kernel should use it later on. 977 978choice 979 prompt "Built-in command line usage" 980 depends on CMDLINE != "" 981 default CMDLINE_FALLBACK 982 help 983 Choose how the kernel will handle the provided built-in command 984 line. 985 986config CMDLINE_FALLBACK 987 bool "Use bootloader kernel arguments if available" 988 help 989 Use the built-in command line as fallback in case we get nothing 990 during boot. This is the default behaviour. 991 992config CMDLINE_EXTEND 993 bool "Extend bootloader kernel arguments" 994 help 995 The command-line arguments provided during boot will be 996 appended to the built-in command line. This is useful in 997 cases where the provided arguments are insufficient and 998 you don't want to or cannot modify them. 999 1000config CMDLINE_FORCE 1001 bool "Always use the default kernel command string" 1002 help 1003 Always use the built-in command line, even if we get one during 1004 boot. This is useful in case you need to override the provided 1005 command line on systems where you don't have or want control 1006 over it. 1007 1008endchoice 1009 1010config EFI_STUB 1011 bool 1012 1013config EFI 1014 bool "UEFI runtime support" 1015 depends on OF && !XIP_KERNEL 1016 depends on MMU 1017 default y 1018 select ARCH_SUPPORTS_ACPI if 64BIT 1019 select EFI_GENERIC_STUB 1020 select EFI_PARAMS_FROM_FDT 1021 select EFI_RUNTIME_WRAPPERS 1022 select EFI_STUB 1023 select LIBFDT 1024 select RISCV_ISA_C 1025 select UCS2_STRING 1026 help 1027 This option provides support for runtime services provided 1028 by UEFI firmware (such as non-volatile variables, realtime 1029 clock, and platform reset). A UEFI stub is also provided to 1030 allow the kernel to be booted as an EFI application. This 1031 is only useful on systems that have UEFI firmware. 1032 1033config DMI 1034 bool "Enable support for SMBIOS (DMI) tables" 1035 depends on EFI 1036 default y 1037 help 1038 This enables SMBIOS/DMI feature for systems. 1039 1040 This option is only useful on systems that have UEFI firmware. 1041 However, even with this option, the resultant kernel should 1042 continue to boot on existing non-UEFI platforms. 1043 1044config CC_HAVE_STACKPROTECTOR_TLS 1045 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 1046 1047config STACKPROTECTOR_PER_TASK 1048 def_bool y 1049 depends on !RANDSTRUCT 1050 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 1051 1052config PHYS_RAM_BASE_FIXED 1053 bool "Explicitly specified physical RAM address" 1054 depends on NONPORTABLE 1055 default n 1056 1057config PHYS_RAM_BASE 1058 hex "Platform Physical RAM address" 1059 depends on PHYS_RAM_BASE_FIXED 1060 default "0x80000000" 1061 help 1062 This is the physical address of RAM in the system. It has to be 1063 explicitly specified to run early relocations of read-write data 1064 from flash to RAM. 1065 1066config XIP_KERNEL 1067 bool "Kernel Execute-In-Place from ROM" 1068 depends on MMU && SPARSEMEM && NONPORTABLE 1069 # This prevents XIP from being enabled by all{yes,mod}config, which 1070 # fail to build since XIP doesn't support large kernels. 1071 depends on !COMPILE_TEST 1072 select PHYS_RAM_BASE_FIXED 1073 help 1074 Execute-In-Place allows the kernel to run from non-volatile storage 1075 directly addressable by the CPU, such as NOR flash. This saves RAM 1076 space since the text section of the kernel is not loaded from flash 1077 to RAM. Read-write sections, such as the data section and stack, 1078 are still copied to RAM. The XIP kernel is not compressed since 1079 it has to run directly from flash, so it will take more space to 1080 store it. The flash address used to link the kernel object files, 1081 and for storing it, is configuration dependent. Therefore, if you 1082 say Y here, you must know the proper physical address where to 1083 store the kernel image depending on your own flash memory usage. 1084 1085 Also note that the make target becomes "make xipImage" rather than 1086 "make zImage" or "make Image". The final kernel binary to put in 1087 ROM memory will be arch/riscv/boot/xipImage. 1088 1089 SPARSEMEM is required because the kernel text and rodata that are 1090 flash resident are not backed by memmap, then any attempt to get 1091 a struct page on those regions will trigger a fault. 1092 1093 If unsure, say N. 1094 1095config XIP_PHYS_ADDR 1096 hex "XIP Kernel Physical Location" 1097 depends on XIP_KERNEL 1098 default "0x21000000" 1099 help 1100 This is the physical address in your flash memory the kernel will 1101 be linked for and stored to. This address is dependent on your 1102 own flash usage. 1103 1104config RISCV_ISA_FALLBACK 1105 bool "Permit falling back to parsing riscv,isa for extension support by default" 1106 default y 1107 help 1108 Parsing the "riscv,isa" devicetree property has been deprecated and 1109 replaced by a list of explicitly defined strings. For compatibility 1110 with existing platforms, the kernel will fall back to parsing the 1111 "riscv,isa" property if the replacements are not found. 1112 1113 Selecting N here will result in a kernel that does not use the 1114 fallback, unless the commandline "riscv_isa_fallback" parameter is 1115 present. 1116 1117 Please see the dt-binding, located at 1118 Documentation/devicetree/bindings/riscv/extensions.yaml for details 1119 on the replacement properties, "riscv,isa-base" and 1120 "riscv,isa-extensions". 1121 1122config BUILTIN_DTB 1123 bool "Built-in device tree" 1124 depends on OF && NONPORTABLE 1125 help 1126 Build a device tree into the Linux image. 1127 This option should be selected if no bootloader is being used. 1128 If unsure, say N. 1129 1130 1131config BUILTIN_DTB_SOURCE 1132 string "Built-in device tree source" 1133 depends on BUILTIN_DTB 1134 help 1135 DTS file path (without suffix, relative to arch/riscv/boot/dts) 1136 for the DTS file that will be used to produce the DTB linked into the 1137 kernel. 1138 1139endmenu # "Boot options" 1140 1141config PORTABLE 1142 bool 1143 default !NONPORTABLE 1144 select EFI 1145 select MMU 1146 select OF 1147 1148config ARCH_PROC_KCORE_TEXT 1149 def_bool y 1150 1151menu "Power management options" 1152 1153source "kernel/power/Kconfig" 1154 1155config ARCH_HIBERNATION_POSSIBLE 1156 def_bool y 1157 1158config ARCH_HIBERNATION_HEADER 1159 def_bool HIBERNATION 1160 1161config ARCH_SUSPEND_POSSIBLE 1162 def_bool y 1163 1164endmenu # "Power management options" 1165 1166menu "CPU Power Management" 1167 1168source "drivers/cpuidle/Kconfig" 1169 1170source "drivers/cpufreq/Kconfig" 1171 1172endmenu # "CPU Power Management" 1173 1174source "arch/riscv/kvm/Kconfig" 1175 1176source "drivers/acpi/Kconfig" 1177