arch/riscv/Kconfig

   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
   7 config 64BIT
   8         bool
   9
  10 config 32BIT
  11         bool
  12
  13 config 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
  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_BATCHED_UNMAP_TLB_FLUSH if SMP && MMU
  57         select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
  58         select ARCH_WANT_FRAME_POINTERS
  59         select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
  60         select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
  61         select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
  62         select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
  63         select ARCH_WANTS_NO_INSTR
  64         select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
  65         select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
  66         select BUILDTIME_TABLE_SORT if MMU
  67         select CLINT_TIMER if !MMU
  68         select CLONE_BACKWARDS
  69         select COMMON_CLK
  70         select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
  71         select EDAC_SUPPORT
  72         select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
  73         select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
  74         select GENERIC_ARCH_TOPOLOGY
  75         select GENERIC_ATOMIC64 if !64BIT
  76         select GENERIC_CLOCKEVENTS_BROADCAST if SMP
  77         select GENERIC_CPU_DEVICES
  78         select GENERIC_EARLY_IOREMAP
  79         select GENERIC_ENTRY
  80         select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
  81         select GENERIC_IDLE_POLL_SETUP
  82         select GENERIC_IOREMAP if MMU
  83         select GENERIC_IRQ_IPI if SMP
  84         select GENERIC_IRQ_IPI_MUX if SMP
  85         select GENERIC_IRQ_MULTI_HANDLER
  86         select GENERIC_IRQ_SHOW
  87         select GENERIC_IRQ_SHOW_LEVEL
  88         select GENERIC_LIB_DEVMEM_IS_ALLOWED
  89         select GENERIC_PCI_IOMAP
  90         select GENERIC_PTDUMP if MMU
  91         select GENERIC_SCHED_CLOCK
  92         select GENERIC_SMP_IDLE_THREAD
  93         select GENERIC_TIME_VSYSCALL if MMU && 64BIT
  94         select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
  95         select HARDIRQS_SW_RESEND
  96         select HAS_IOPORT if MMU
  97         select HAVE_ARCH_AUDITSYSCALL
  98         select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
  99         select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL
 100         select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
 101         select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
 102         select HAVE_ARCH_KASAN if MMU && 64BIT
 103         select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
 104         select HAVE_ARCH_KFENCE if MMU && 64BIT
 105         select HAVE_ARCH_KGDB if !XIP_KERNEL
 106         select HAVE_ARCH_KGDB_QXFER_PKT
 107         select HAVE_ARCH_MMAP_RND_BITS if MMU
 108         select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
 109         select HAVE_ARCH_SECCOMP_FILTER
 110         select HAVE_ARCH_THREAD_STRUCT_WHITELIST
 111         select HAVE_ARCH_TRACEHOOK
 112         select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
 113         select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
 114         select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
 115         select HAVE_ASM_MODVERSIONS
 116         select HAVE_CONTEXT_TRACKING_USER
 117         select HAVE_DEBUG_KMEMLEAK
 118         select HAVE_DMA_CONTIGUOUS if MMU
 119         select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
 120         select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
 121         select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
 122         select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
 123         select HAVE_FUNCTION_GRAPH_TRACER
 124         select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
 125         select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
 126         select HAVE_EBPF_JIT if MMU
 127         select HAVE_FUNCTION_ARG_ACCESS_API
 128         select HAVE_FUNCTION_ERROR_INJECTION
 129         select HAVE_GCC_PLUGINS
 130         select HAVE_GENERIC_VDSO if MMU && 64BIT
 131         select HAVE_IRQ_TIME_ACCOUNTING
 132         select HAVE_KPROBES if !XIP_KERNEL
 133         select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
 134         select HAVE_KRETPROBES if !XIP_KERNEL
 135         # https://github.com/ClangBuiltLinux/linux/issues/1881
 136         select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
 137         select HAVE_MOVE_PMD
 138         select HAVE_MOVE_PUD
 139         select HAVE_PAGE_SIZE_4KB
 140         select HAVE_PCI
 141         select HAVE_PERF_EVENTS
 142         select HAVE_PERF_REGS
 143         select HAVE_PERF_USER_STACK_DUMP
 144         select HAVE_POSIX_CPU_TIMERS_TASK_WORK
 145         select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
 146         select HAVE_REGS_AND_STACK_ACCESS_API
 147         select HAVE_RETHOOK if !XIP_KERNEL
 148         select HAVE_RSEQ
 149         select HAVE_SAMPLE_FTRACE_DIRECT
 150         select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
 151         select HAVE_STACKPROTECTOR
 152         select HAVE_SYSCALL_TRACEPOINTS
 153         select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
 154         select IRQ_DOMAIN
 155         select IRQ_FORCED_THREADING
 156         select KASAN_VMALLOC if KASAN
 157         select LOCK_MM_AND_FIND_VMA
 158         select MODULES_USE_ELF_RELA if MODULES
 159         select MODULE_SECTIONS if MODULES
 160         select OF
 161         select OF_EARLY_FLATTREE
 162         select OF_IRQ
 163         select PCI_DOMAINS_GENERIC if PCI
 164         select PCI_MSI if PCI
 165         select RISCV_ALTERNATIVE if !XIP_KERNEL
 166         select RISCV_INTC
 167         select RISCV_TIMER if RISCV_SBI
 168         select SIFIVE_PLIC
 169         select SPARSE_IRQ
 170         select SYSCTL_EXCEPTION_TRACE
 171         select THREAD_INFO_IN_TASK
 172         select TRACE_IRQFLAGS_SUPPORT
 173         select UACCESS_MEMCPY if !MMU
 174         select ZONE_DMA32 if 64BIT
 175
 176 config CLANG_SUPPORTS_DYNAMIC_FTRACE
 177         def_bool CC_IS_CLANG
 178         # https://github.com/llvm/llvm-project/commit/6ab8927931851bb42b2c93a00801dc499d7d9b1e
 179         depends on CLANG_VERSION >= 130000
 180         # https://github.com/ClangBuiltLinux/linux/issues/1817
 181         depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
 182
 183 config GCC_SUPPORTS_DYNAMIC_FTRACE
 184         def_bool CC_IS_GCC
 185         depends on $(cc-option,-fpatchable-function-entry=8)
 186
 187 config HAVE_SHADOW_CALL_STACK
 188         def_bool $(cc-option,-fsanitize=shadow-call-stack)
 189         # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
 190         depends on $(ld-option,--no-relax-gp)
 191
 192 config RISCV_USE_LINKER_RELAXATION
 193         def_bool y
 194         # https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
 195         depends on !LD_IS_LLD || LLD_VERSION >= 150000
 196
 197 # https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
 198 config ARCH_HAS_BROKEN_DWARF5
 199         def_bool y
 200         depends on RISCV_USE_LINKER_RELAXATION
 201         # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
 202         depends on AS_IS_LLVM && AS_VERSION < 180000
 203         # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
 204         depends on LD_IS_LLD && LLD_VERSION < 180000
 205
 206 config ARCH_MMAP_RND_BITS_MIN
 207         default 18 if 64BIT
 208         default 8
 209
 210 config ARCH_MMAP_RND_COMPAT_BITS_MIN
 211         default 8
 212
 213 # max bits determined by the following formula:
 214 #  VA_BITS - PAGE_SHIFT - 3
 215 config ARCH_MMAP_RND_BITS_MAX
 216         default 24 if 64BIT # SV39 based
 217         default 17
 218
 219 config ARCH_MMAP_RND_COMPAT_BITS_MAX
 220         default 17
 221
 222 # set if we run in machine mode, cleared if we run in supervisor mode
 223 config RISCV_M_MODE
 224         bool
 225         default !MMU
 226
 227 # set if we are running in S-mode and can use SBI calls
 228 config RISCV_SBI
 229         bool
 230         depends on !RISCV_M_MODE
 231         default y
 232
 233 config MMU
 234         bool "MMU-based Paged Memory Management Support"
 235         default y
 236         help
 237           Select if you want MMU-based virtualised addressing space
 238           support by paged memory management. If unsure, say 'Y'.
 239
 240 config PAGE_OFFSET
 241         hex
 242         default 0xC0000000 if 32BIT && MMU
 243         default 0x80000000 if !MMU
 244         default 0xff60000000000000 if 64BIT
 245
 246 config KASAN_SHADOW_OFFSET
 247         hex
 248         depends on KASAN_GENERIC
 249         default 0xdfffffff00000000 if 64BIT
 250         default 0xffffffff if 32BIT
 251
 252 config ARCH_FLATMEM_ENABLE
 253         def_bool !NUMA
 254
 255 config ARCH_SPARSEMEM_ENABLE
 256         def_bool y
 257         depends on MMU
 258         select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
 259         select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
 260
 261 config ARCH_SELECT_MEMORY_MODEL
 262         def_bool ARCH_SPARSEMEM_ENABLE
 263
 264 config ARCH_SUPPORTS_UPROBES
 265         def_bool y
 266
 267 config STACKTRACE_SUPPORT
 268         def_bool y
 269
 270 config GENERIC_BUG
 271         def_bool y
 272         depends on BUG
 273         select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
 274
 275 config GENERIC_BUG_RELATIVE_POINTERS
 276         bool
 277
 278 config GENERIC_CALIBRATE_DELAY
 279         def_bool y
 280
 281 config GENERIC_CSUM
 282         def_bool y
 283
 284 config GENERIC_HWEIGHT
 285         def_bool y
 286
 287 config FIX_EARLYCON_MEM
 288         def_bool MMU
 289
 290 config PGTABLE_LEVELS
 291         int
 292         default 5 if 64BIT
 293         default 2
 294
 295 config LOCKDEP_SUPPORT
 296         def_bool y
 297
 298 config RISCV_DMA_NONCOHERENT
 299         bool
 300         select ARCH_HAS_DMA_PREP_COHERENT
 301         select ARCH_HAS_SETUP_DMA_OPS
 302         select ARCH_HAS_SYNC_DMA_FOR_CPU
 303         select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 304         select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
 305
 306 config RISCV_NONSTANDARD_CACHE_OPS
 307         bool
 308         help
 309           This enables function pointer support for non-standard noncoherent
 310           systems to handle cache management.
 311
 312 config AS_HAS_INSN
 313         def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
 314
 315 config AS_HAS_OPTION_ARCH
 316         # https://reviews.llvm.org/D123515
 317         def_bool y
 318         depends on $(as-instr, .option arch$(comma) +m)
 319
 320 source "arch/riscv/Kconfig.socs"
 321 source "arch/riscv/Kconfig.errata"
 322
 323 menu "Platform type"
 324
 325 config NONPORTABLE
 326         bool "Allow configurations that result in non-portable kernels"
 327         help
 328           RISC-V kernel binaries are compatible between all known systems
 329           whenever possible, but there are some use cases that can only be
 330           satisfied by configurations that result in kernel binaries that are
 331           not portable between systems.
 332
 333           Selecting N does not guarantee kernels will be portable to all known
 334           systems.  Selecting any of the options guarded by NONPORTABLE will
 335           result in kernel binaries that are unlikely to be portable between
 336           systems.
 337
 338           If unsure, say N.
 339
 340 choice
 341         prompt "Base ISA"
 342         default ARCH_RV64I
 343         help
 344           This selects the base ISA that this kernel will target and must match
 345           the target platform.
 346
 347 config ARCH_RV32I
 348         bool "RV32I"
 349         depends on NONPORTABLE
 350         select 32BIT
 351         select GENERIC_LIB_ASHLDI3
 352         select GENERIC_LIB_ASHRDI3
 353         select GENERIC_LIB_LSHRDI3
 354         select GENERIC_LIB_UCMPDI2
 355
 356 config ARCH_RV64I
 357         bool "RV64I"
 358         select 64BIT
 359         select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
 360         select SWIOTLB if MMU
 361
 362 endchoice
 363
 364 # We must be able to map all physical memory into the kernel, but the compiler
 365 # is still a bit more efficient when generating code if it's setup in a manner
 366 # such that it can only map 2GiB of memory.
 367 choice
 368         prompt "Kernel Code Model"
 369         default CMODEL_MEDLOW if 32BIT
 370         default CMODEL_MEDANY if 64BIT
 371
 372         config CMODEL_MEDLOW
 373                 bool "medium low code model"
 374         config CMODEL_MEDANY
 375                 bool "medium any code model"
 376 endchoice
 377
 378 config MODULE_SECTIONS
 379         bool
 380         select HAVE_MOD_ARCH_SPECIFIC
 381
 382 config SMP
 383         bool "Symmetric Multi-Processing"
 384         help
 385           This enables support for systems with more than one CPU.  If
 386           you say N here, the kernel will run on single and
 387           multiprocessor machines, but will use only one CPU of a
 388           multiprocessor machine. If you say Y here, the kernel will run
 389           on many, but not all, single processor machines. On a single
 390           processor machine, the kernel will run faster if you say N
 391           here.
 392
 393           If you don't know what to do here, say N.
 394
 395 config SCHED_MC
 396         bool "Multi-core scheduler support"
 397         depends on SMP
 398         help
 399           Multi-core scheduler support improves the CPU scheduler's decision
 400           making when dealing with multi-core CPU chips at a cost of slightly
 401           increased overhead in some places. If unsure say N here.
 402
 403 config NR_CPUS
 404         int "Maximum number of CPUs (2-512)"
 405         depends on SMP
 406         range 2 512 if !RISCV_SBI_V01
 407         range 2 32 if RISCV_SBI_V01 && 32BIT
 408         range 2 64 if RISCV_SBI_V01 && 64BIT
 409         default "32" if 32BIT
 410         default "64" if 64BIT
 411
 412 config HOTPLUG_CPU
 413         bool "Support for hot-pluggable CPUs"
 414         depends on SMP
 415         select GENERIC_IRQ_MIGRATION
 416         help
 417
 418           Say Y here to experiment with turning CPUs off and on.  CPUs
 419           can be controlled through /sys/devices/system/cpu.
 420
 421           Say N if you want to disable CPU hotplug.
 422
 423 choice
 424         prompt "CPU Tuning"
 425         default TUNE_GENERIC
 426
 427 config TUNE_GENERIC
 428         bool "generic"
 429
 430 endchoice
 431
 432 # Common NUMA Features
 433 config NUMA
 434         bool "NUMA Memory Allocation and Scheduler Support"
 435         depends on SMP && MMU
 436         select ARCH_SUPPORTS_NUMA_BALANCING
 437         select GENERIC_ARCH_NUMA
 438         select HAVE_SETUP_PER_CPU_AREA
 439         select NEED_PER_CPU_EMBED_FIRST_CHUNK
 440         select NEED_PER_CPU_PAGE_FIRST_CHUNK
 441         select OF_NUMA
 442         select USE_PERCPU_NUMA_NODE_ID
 443         help
 444           Enable NUMA (Non-Uniform Memory Access) support.
 445
 446           The kernel will try to allocate memory used by a CPU on the
 447           local memory of the CPU and add some more NUMA awareness to the kernel.
 448
 449 config NODES_SHIFT
 450         int "Maximum NUMA Nodes (as a power of 2)"
 451         range 1 10
 452         default "2"
 453         depends on NUMA
 454         help
 455           Specify the maximum number of NUMA Nodes available on the target
 456           system.  Increases memory reserved to accommodate various tables.
 457
 458 config RISCV_ALTERNATIVE
 459         bool
 460         depends on !XIP_KERNEL
 461         help
 462           This Kconfig allows the kernel to automatically patch the
 463           erratum or cpufeature required by the execution platform at run
 464           time. The code patching overhead is minimal, as it's only done
 465           once at boot and once on each module load.
 466
 467 config RISCV_ALTERNATIVE_EARLY
 468         bool
 469         depends on RISCV_ALTERNATIVE
 470         help
 471           Allows early patching of the kernel for special errata
 472
 473 config RISCV_ISA_C
 474         bool "Emit compressed instructions when building Linux"
 475         default y
 476         help
 477           Adds "C" to the ISA subsets that the toolchain is allowed to emit
 478           when building Linux, which results in compressed instructions in the
 479           Linux binary.
 480
 481           If you don't know what to do here, say Y.
 482
 483 config RISCV_ISA_SVNAPOT
 484         bool "Svnapot extension support for supervisor mode NAPOT pages"
 485         depends on 64BIT && MMU
 486         depends on RISCV_ALTERNATIVE
 487         default y
 488         help
 489           Allow kernel to detect the Svnapot ISA-extension dynamically at boot
 490           time and enable its usage.
 491
 492           The Svnapot extension is used to mark contiguous PTEs as a range
 493           of contiguous virtual-to-physical translations for a naturally
 494           aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
 495           size. When HUGETLBFS is also selected this option unconditionally
 496           allocates some memory for each NAPOT page size supported by the kernel.
 497           When optimizing for low memory consumption and for platforms without
 498           the Svnapot extension, it may be better to say N here.
 499
 500           If you don't know what to do here, say Y.
 501
 502 config RISCV_ISA_SVPBMT
 503         bool "Svpbmt extension support for supervisor mode page-based memory types"
 504         depends on 64BIT && MMU
 505         depends on RISCV_ALTERNATIVE
 506         default y
 507         help
 508            Adds support to dynamically detect the presence of the Svpbmt
 509            ISA-extension (Supervisor-mode: page-based memory types) and
 510            enable its usage.
 511
 512            The memory type for a page contains a combination of attributes
 513            that indicate the cacheability, idempotency, and ordering
 514            properties for access to that page.
 515
 516            The Svpbmt extension is only available on 64-bit cpus.
 517
 518            If you don't know what to do here, say Y.
 519
 520 config TOOLCHAIN_HAS_V
 521         bool
 522         default y
 523         depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv)
 524         depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv)
 525         depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
 526         depends on AS_HAS_OPTION_ARCH
 527
 528 config RISCV_ISA_V
 529         bool "VECTOR extension support"
 530         depends on TOOLCHAIN_HAS_V
 531         depends on FPU
 532         select DYNAMIC_SIGFRAME
 533         default y
 534         help
 535           Say N here if you want to disable all vector related procedure
 536           in the kernel.
 537
 538           If you don't know what to do here, say Y.
 539
 540 config RISCV_ISA_V_DEFAULT_ENABLE
 541         bool "Enable userspace Vector by default"
 542         depends on RISCV_ISA_V
 543         default y
 544         help
 545           Say Y here if you want to enable Vector in userspace by default.
 546           Otherwise, userspace has to make explicit prctl() call to enable
 547           Vector, or enable it via the sysctl interface.
 548
 549           If you don't know what to do here, say Y.
 550
 551 config RISCV_ISA_V_UCOPY_THRESHOLD
 552         int "Threshold size for vectorized user copies"
 553         depends on RISCV_ISA_V
 554         default 768
 555         help
 556           Prefer using vectorized copy_to_user()/copy_from_user() when the
 557           workload size exceeds this value.
 558
 559 config RISCV_ISA_V_PREEMPTIVE
 560         bool "Run kernel-mode Vector with kernel preemption"
 561         depends on PREEMPTION
 562         depends on RISCV_ISA_V
 563         default y
 564         help
 565           Usually, in-kernel SIMD routines are run with preemption disabled.
 566           Functions which envoke long running SIMD thus must yield core's
 567           vector unit to prevent blocking other tasks for too long.
 568
 569           This config allows kernel to run SIMD without explicitly disable
 570           preemption. Enabling this config will result in higher memory
 571           consumption due to the allocation of per-task's kernel Vector context.
 572
 573 config TOOLCHAIN_HAS_ZBB
 574         bool
 575         default y
 576         depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
 577         depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
 578         depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
 579         depends on AS_HAS_OPTION_ARCH
 580
 581 config RISCV_ISA_ZBB
 582         bool "Zbb extension support for bit manipulation instructions"
 583         depends on TOOLCHAIN_HAS_ZBB
 584         depends on MMU
 585         depends on RISCV_ALTERNATIVE
 586         default y
 587         help
 588            Adds support to dynamically detect the presence of the ZBB
 589            extension (basic bit manipulation) and enable its usage.
 590
 591            The Zbb extension provides instructions to accelerate a number
 592            of bit-specific operations (count bit population, sign extending,
 593            bitrotation, etc).
 594
 595            If you don't know what to do here, say Y.
 596
 597 config RISCV_ISA_ZICBOM
 598         bool "Zicbom extension support for non-coherent DMA operation"
 599         depends on MMU
 600         depends on RISCV_ALTERNATIVE
 601         default y
 602         select RISCV_DMA_NONCOHERENT
 603         select DMA_DIRECT_REMAP
 604         help
 605            Adds support to dynamically detect the presence of the ZICBOM
 606            extension (Cache Block Management Operations) and enable its
 607            usage.
 608
 609            The Zicbom extension can be used to handle for example
 610            non-coherent DMA support on devices that need it.
 611
 612            If you don't know what to do here, say Y.
 613
 614 config RISCV_ISA_ZICBOZ
 615         bool "Zicboz extension support for faster zeroing of memory"
 616         depends on MMU
 617         depends on RISCV_ALTERNATIVE
 618         default y
 619         help
 620            Enable the use of the Zicboz extension (cbo.zero instruction)
 621            when available.
 622
 623            The Zicboz extension is used for faster zeroing of memory.
 624
 625            If you don't know what to do here, say Y.
 626
 627 config TOOLCHAIN_HAS_ZIHINTPAUSE
 628         bool
 629         default y
 630         depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
 631         depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
 632         depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
 633
 634 config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
 635         def_bool y
 636         # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
 637         # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
 638         depends on AS_IS_GNU && AS_VERSION >= 23600
 639         help
 640           Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
 641           20191213 version, which moves some instructions from the I extension to
 642           the Zicsr and Zifencei extensions. This requires explicitly specifying
 643           Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
 644           and Zifencei are supported in binutils from version 2.36 onwards.
 645           To make life easier, and avoid forcing toolchains that default to a
 646           newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
 647           For clang < 17 or GCC < 11.3.0, for which this is not possible or need
 648           special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
 649
 650 config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
 651         def_bool y
 652         depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
 653         # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
 654         # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
 655         depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
 656         help
 657           Certain versions of clang and GCC do not support zicsr and zifencei via
 658           -march. This option causes an older ISA spec compatible with these older
 659           versions of clang and GCC to be passed to GAS, which has the same result
 660           as passing zicsr and zifencei to -march.
 661
 662 config FPU
 663         bool "FPU support"
 664         default y
 665         help
 666           Say N here if you want to disable all floating-point related procedure
 667           in the kernel.
 668
 669           If you don't know what to do here, say Y.
 670
 671 config IRQ_STACKS
 672         bool "Independent irq & softirq stacks" if EXPERT
 673         default y
 674         select HAVE_IRQ_EXIT_ON_IRQ_STACK
 675         select HAVE_SOFTIRQ_ON_OWN_STACK
 676         help
 677           Add independent irq & softirq stacks for percpu to prevent kernel stack
 678           overflows. We may save some memory footprint by disabling IRQ_STACKS.
 679
 680 config THREAD_SIZE_ORDER
 681         int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
 682         range 0 4
 683         default 1 if 32BIT && !KASAN
 684         default 3 if 64BIT && KASAN
 685         default 2
 686         help
 687           Specify the Pages of thread stack size (from 4KB to 64KB), which also
 688           affects irq stack size, which is equal to thread stack size.
 689
 690 config RISCV_MISALIGNED
 691         bool "Support misaligned load/store traps for kernel and userspace"
 692         select SYSCTL_ARCH_UNALIGN_ALLOW
 693         default y
 694         help
 695           Say Y here if you want the kernel to embed support for misaligned
 696           load/store for both kernel and userspace. When disable, misaligned
 697           accesses will generate SIGBUS in userspace and panic in kernel.
 698
 699 config RISCV_EFFICIENT_UNALIGNED_ACCESS
 700         bool "Assume the CPU supports fast unaligned memory accesses"
 701         depends on NONPORTABLE
 702         select DCACHE_WORD_ACCESS if MMU
 703         select HAVE_EFFICIENT_UNALIGNED_ACCESS
 704         help
 705           Say Y here if you want the kernel to assume that the CPU supports
 706           efficient unaligned memory accesses.  When enabled, this option
 707           improves the performance of the kernel on such CPUs.  However, the
 708           kernel will run much more slowly, or will not be able to run at all,
 709           on CPUs that do not support efficient unaligned memory accesses.
 710
 711           If unsure what to do here, say N.
 712
 713 endmenu # "Platform type"
 714
 715 menu "Kernel features"
 716
 717 source "kernel/Kconfig.hz"
 718
 719 config RISCV_SBI_V01
 720         bool "SBI v0.1 support"
 721         depends on RISCV_SBI
 722         help
 723           This config allows kernel to use SBI v0.1 APIs. This will be
 724           deprecated in future once legacy M-mode software are no longer in use.
 725
 726 config RISCV_BOOT_SPINWAIT
 727         bool "Spinwait booting method"
 728         depends on SMP
 729         default y if RISCV_SBI_V01 || RISCV_M_MODE
 730         help
 731           This enables support for booting Linux via spinwait method. In the
 732           spinwait method, all cores randomly jump to Linux. One of the cores
 733           gets chosen via lottery and all other keep spinning on a percpu
 734           variable. This method cannot support CPU hotplug and sparse hartid
 735           scheme. It should be only enabled for M-mode Linux or platforms relying
 736           on older firmware without SBI HSM extension. All other platforms should
 737           rely on ordered booting via SBI HSM extension which gets chosen
 738           dynamically at runtime if the firmware supports it.
 739
 740           Since spinwait is incompatible with sparse hart IDs, it requires
 741           NR_CPUS be large enough to contain the physical hart ID of the first
 742           hart to enter Linux.
 743
 744           If unsure what to do here, say N.
 745
 746 config ARCH_SUPPORTS_KEXEC
 747         def_bool y
 748
 749 config ARCH_SELECTS_KEXEC
 750         def_bool y
 751         depends on KEXEC
 752         select HOTPLUG_CPU if SMP
 753
 754 config ARCH_SUPPORTS_KEXEC_FILE
 755         def_bool 64BIT
 756
 757 config ARCH_SELECTS_KEXEC_FILE
 758         def_bool y
 759         depends on KEXEC_FILE
 760         select HAVE_IMA_KEXEC if IMA
 761         select KEXEC_ELF
 762
 763 config ARCH_SUPPORTS_KEXEC_PURGATORY
 764         def_bool ARCH_SUPPORTS_KEXEC_FILE
 765
 766 config ARCH_SUPPORTS_CRASH_DUMP
 767         def_bool y
 768
 769 config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
 770         def_bool CRASH_RESERVE
 771
 772 config COMPAT
 773         bool "Kernel support for 32-bit U-mode"
 774         default 64BIT
 775         depends on 64BIT && MMU
 776         help
 777           This option enables support for a 32-bit U-mode running under a 64-bit
 778           kernel at S-mode. riscv32-specific components such as system calls,
 779           the user helper functions (vdso), signal rt_frame functions and the
 780           ptrace interface are handled appropriately by the kernel.
 781
 782           If you want to execute 32-bit userspace applications, say Y.
 783
 784 config PARAVIRT
 785         bool "Enable paravirtualization code"
 786         depends on RISCV_SBI
 787         help
 788           This changes the kernel so it can modify itself when it is run
 789           under a hypervisor, potentially improving performance significantly
 790           over full virtualization.
 791
 792 config PARAVIRT_TIME_ACCOUNTING
 793         bool "Paravirtual steal time accounting"
 794         depends on PARAVIRT
 795         help
 796           Select this option to enable fine granularity task steal time
 797           accounting. Time spent executing other tasks in parallel with
 798           the current vCPU is discounted from the vCPU power. To account for
 799           that, there can be a small performance impact.
 800
 801           If in doubt, say N here.
 802
 803 config RELOCATABLE
 804         bool "Build a relocatable kernel"
 805         depends on MMU && 64BIT && !XIP_KERNEL
 806         help
 807           This builds a kernel as a Position Independent Executable (PIE),
 808           which retains all relocation metadata required to relocate the
 809           kernel binary at runtime to a different virtual address than the
 810           address it was linked at.
 811           Since RISCV uses the RELA relocation format, this requires a
 812           relocation pass at runtime even if the kernel is loaded at the
 813           same address it was linked at.
 814
 815           If unsure, say N.
 816
 817 config RANDOMIZE_BASE
 818         bool "Randomize the address of the kernel image"
 819         select RELOCATABLE
 820         depends on MMU && 64BIT && !XIP_KERNEL
 821         help
 822           Randomizes the virtual address at which the kernel image is
 823           loaded, as a security feature that deters exploit attempts
 824           relying on knowledge of the location of kernel internals.
 825
 826           It is the bootloader's job to provide entropy, by passing a
 827           random u64 value in /chosen/kaslr-seed at kernel entry.
 828
 829           When booting via the UEFI stub, it will invoke the firmware's
 830           EFI_RNG_PROTOCOL implementation (if available) to supply entropy
 831           to the kernel proper. In addition, it will randomise the physical
 832           location of the kernel Image as well.
 833
 834           If unsure, say N.
 835
 836 endmenu # "Kernel features"
 837
 838 menu "Boot options"
 839
 840 config CMDLINE
 841         string "Built-in kernel command line"
 842         help
 843           For most platforms, the arguments for the kernel's command line
 844           are provided at run-time, during boot. However, there are cases
 845           where either no arguments are being provided or the provided
 846           arguments are insufficient or even invalid.
 847
 848           When that occurs, it is possible to define a built-in command
 849           line here and choose how the kernel should use it later on.
 850
 851 choice
 852         prompt "Built-in command line usage" if CMDLINE != ""
 853         default CMDLINE_FALLBACK
 854         help
 855           Choose how the kernel will handle the provided built-in command
 856           line.
 857
 858 config CMDLINE_FALLBACK
 859         bool "Use bootloader kernel arguments if available"
 860         help
 861           Use the built-in command line as fallback in case we get nothing
 862           during boot. This is the default behaviour.
 863
 864 config CMDLINE_EXTEND
 865         bool "Extend bootloader kernel arguments"
 866         help
 867           The command-line arguments provided during boot will be
 868           appended to the built-in command line. This is useful in
 869           cases where the provided arguments are insufficient and
 870           you don't want to or cannot modify them.
 871
 872 config CMDLINE_FORCE
 873         bool "Always use the default kernel command string"
 874         help
 875           Always use the built-in command line, even if we get one during
 876           boot. This is useful in case you need to override the provided
 877           command line on systems where you don't have or want control
 878           over it.
 879
 880 endchoice
 881
 882 config EFI_STUB
 883         bool
 884
 885 config EFI
 886         bool "UEFI runtime support"
 887         depends on OF && !XIP_KERNEL
 888         depends on MMU
 889         default y
 890         select ARCH_SUPPORTS_ACPI if 64BIT
 891         select EFI_GENERIC_STUB
 892         select EFI_PARAMS_FROM_FDT
 893         select EFI_RUNTIME_WRAPPERS
 894         select EFI_STUB
 895         select LIBFDT
 896         select RISCV_ISA_C
 897         select UCS2_STRING
 898         help
 899           This option provides support for runtime services provided
 900           by UEFI firmware (such as non-volatile variables, realtime
 901           clock, and platform reset). A UEFI stub is also provided to
 902           allow the kernel to be booted as an EFI application. This
 903           is only useful on systems that have UEFI firmware.
 904
 905 config CC_HAVE_STACKPROTECTOR_TLS
 906         def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
 907
 908 config STACKPROTECTOR_PER_TASK
 909         def_bool y
 910         depends on !RANDSTRUCT
 911         depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
 912
 913 config PHYS_RAM_BASE_FIXED
 914         bool "Explicitly specified physical RAM address"
 915         depends on NONPORTABLE
 916         default n
 917
 918 config PHYS_RAM_BASE
 919         hex "Platform Physical RAM address"
 920         depends on PHYS_RAM_BASE_FIXED
 921         default "0x80000000"
 922         help
 923           This is the physical address of RAM in the system. It has to be
 924           explicitly specified to run early relocations of read-write data
 925           from flash to RAM.
 926
 927 config XIP_KERNEL
 928         bool "Kernel Execute-In-Place from ROM"
 929         depends on MMU && SPARSEMEM && NONPORTABLE
 930         # This prevents XIP from being enabled by all{yes,mod}config, which
 931         # fail to build since XIP doesn't support large kernels.
 932         depends on !COMPILE_TEST
 933         select PHYS_RAM_BASE_FIXED
 934         help
 935           Execute-In-Place allows the kernel to run from non-volatile storage
 936           directly addressable by the CPU, such as NOR flash. This saves RAM
 937           space since the text section of the kernel is not loaded from flash
 938           to RAM.  Read-write sections, such as the data section and stack,
 939           are still copied to RAM.  The XIP kernel is not compressed since
 940           it has to run directly from flash, so it will take more space to
 941           store it.  The flash address used to link the kernel object files,
 942           and for storing it, is configuration dependent. Therefore, if you
 943           say Y here, you must know the proper physical address where to
 944           store the kernel image depending on your own flash memory usage.
 945
 946           Also note that the make target becomes "make xipImage" rather than
 947           "make zImage" or "make Image".  The final kernel binary to put in
 948           ROM memory will be arch/riscv/boot/xipImage.
 949
 950           SPARSEMEM is required because the kernel text and rodata that are
 951           flash resident are not backed by memmap, then any attempt to get
 952           a struct page on those regions will trigger a fault.
 953
 954           If unsure, say N.
 955
 956 config XIP_PHYS_ADDR
 957         hex "XIP Kernel Physical Location"
 958         depends on XIP_KERNEL
 959         default "0x21000000"
 960         help
 961           This is the physical address in your flash memory the kernel will
 962           be linked for and stored to.  This address is dependent on your
 963           own flash usage.
 964
 965 config RISCV_ISA_FALLBACK
 966         bool "Permit falling back to parsing riscv,isa for extension support by default"
 967         default y
 968         help
 969           Parsing the "riscv,isa" devicetree property has been deprecated and
 970           replaced by a list of explicitly defined strings. For compatibility
 971           with existing platforms, the kernel will fall back to parsing the
 972           "riscv,isa" property if the replacements are not found.
 973
 974           Selecting N here will result in a kernel that does not use the
 975           fallback, unless the commandline "riscv_isa_fallback" parameter is
 976           present.
 977
 978           Please see the dt-binding, located at
 979           Documentation/devicetree/bindings/riscv/extensions.yaml for details
 980           on the replacement properties, "riscv,isa-base" and
 981           "riscv,isa-extensions".
 982
 983 config BUILTIN_DTB
 984         bool "Built-in device tree"
 985         depends on OF && NONPORTABLE
 986         help
 987           Build a device tree into the Linux image.
 988           This option should be selected if no bootloader is being used.
 989           If unsure, say N.
 990
 991
 992 config BUILTIN_DTB_SOURCE
 993         string "Built-in device tree source"
 994         depends on BUILTIN_DTB
 995         help
 996           DTS file path (without suffix, relative to arch/riscv/boot/dts)
 997           for the DTS file that will be used to produce the DTB linked into the
 998           kernel.
 999
1000 endmenu # "Boot options"
1001
1002 config PORTABLE
1003         bool
1004         default !NONPORTABLE
1005         select EFI
1006         select MMU
1007         select OF
1008
1009 config ARCH_PROC_KCORE_TEXT
1010         def_bool y
1011
1012 menu "Power management options"
1013
1014 source "kernel/power/Kconfig"
1015
1016 # Hibernation is only possible on systems where the SBI implementation has
1017 # marked its reserved memory as not accessible from, or does not run
1018 # from the same memory as, Linux
1019 config ARCH_HIBERNATION_POSSIBLE
1020         def_bool NONPORTABLE
1021
1022 config ARCH_HIBERNATION_HEADER
1023         def_bool HIBERNATION
1024
1025 config ARCH_SUSPEND_POSSIBLE
1026         def_bool y
1027
1028 endmenu # "Power management options"
1029
1030 menu "CPU Power Management"
1031
1032 source "drivers/cpuidle/Kconfig"
1033
1034 source "drivers/cpufreq/Kconfig"
1035
1036 endmenu # "CPU Power Management"
1037
1038 source "arch/riscv/kvm/Kconfig"
1039
1040 source "drivers/acpi/Kconfig"