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 OF
  16         select OF_EARLY_FLATTREE
  17         select OF_IRQ
  18         select ARCH_HAS_BINFMT_FLAT
  19         select ARCH_WANT_FRAME_POINTERS
  20         select CLONE_BACKWARDS
  21         select COMMON_CLK
  22         select GENERIC_CLOCKEVENTS
  23         select GENERIC_IRQ_SHOW
  24         select GENERIC_PCI_IOMAP
  25         select GENERIC_SCHED_CLOCK
  26         select GENERIC_STRNCPY_FROM_USER if MMU
  27         select GENERIC_STRNLEN_USER if MMU
  28         select GENERIC_SMP_IDLE_THREAD
  29         select GENERIC_ATOMIC64 if !64BIT
  30         select GENERIC_IOREMAP
  31         select GENERIC_PTDUMP if MMU
  32         select HAVE_ARCH_AUDITSYSCALL
  33         select HAVE_ARCH_SECCOMP_FILTER
  34         select HAVE_ASM_MODVERSIONS
  35         select HAVE_MEMBLOCK_NODE_MAP
  36         select HAVE_DMA_CONTIGUOUS if MMU
  37         select HAVE_FUTEX_CMPXCHG if FUTEX
  38         select HAVE_PERF_EVENTS
  39         select HAVE_PERF_REGS
  40         select HAVE_PERF_USER_STACK_DUMP
  41         select HAVE_SYSCALL_TRACEPOINTS
  42         select IRQ_DOMAIN
  43         select SPARSE_IRQ
  44         select SYSCTL_EXCEPTION_TRACE
  45         select HAVE_ARCH_TRACEHOOK
  46         select HAVE_PCI
  47         select MODULES_USE_ELF_RELA if MODULES
  48         select MODULE_SECTIONS if MODULES
  49         select THREAD_INFO_IN_TASK
  50         select PCI_DOMAINS_GENERIC if PCI
  51         select PCI_MSI if PCI
  52         select RISCV_TIMER
  53         select GENERIC_IRQ_MULTI_HANDLER
  54         select GENERIC_ARCH_TOPOLOGY if SMP
  55         select ARCH_HAS_PTE_SPECIAL
  56         select ARCH_HAS_MMIOWB
  57         select ARCH_HAS_DEBUG_VIRTUAL if MMU
  58         select HAVE_EBPF_JIT if MMU
  59         select EDAC_SUPPORT
  60         select ARCH_HAS_GIGANTIC_PAGE
  61         select ARCH_HAS_SET_DIRECT_MAP
  62         select ARCH_HAS_SET_MEMORY
  63         select ARCH_HAS_STRICT_KERNEL_RWX if MMU
  64         select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
  65         select SPARSEMEM_STATIC if 32BIT
  66         select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
  67         select HAVE_ARCH_MMAP_RND_BITS if MMU
  68         select ARCH_HAS_GCOV_PROFILE_ALL
  69         select HAVE_COPY_THREAD_TLS
  70         select HAVE_ARCH_KASAN if MMU && 64BIT
  71
  72 config ARCH_MMAP_RND_BITS_MIN
  73         default 18 if 64BIT
  74         default 8
  75
  76 # max bits determined by the following formula:
  77 #  VA_BITS - PAGE_SHIFT - 3
  78 config ARCH_MMAP_RND_BITS_MAX
  79         default 24 if 64BIT # SV39 based
  80         default 17
  81
  82 # set if we run in machine mode, cleared if we run in supervisor mode
  83 config RISCV_M_MODE
  84         bool
  85         default !MMU
  86
  87 # set if we are running in S-mode and can use SBI calls
  88 config RISCV_SBI
  89         bool
  90         depends on !RISCV_M_MODE
  91         default y
  92
  93 config MMU
  94         bool "MMU-based Paged Memory Management Support"
  95         default y
  96         help
  97           Select if you want MMU-based virtualised addressing space
  98           support by paged memory management. If unsure, say 'Y'.
  99
 100 config ZONE_DMA32
 101         bool
 102         default y if 64BIT
 103
 104 config VA_BITS
 105         int
 106         default 32 if 32BIT
 107         default 39 if 64BIT
 108
 109 config PA_BITS
 110         int
 111         default 34 if 32BIT
 112         default 56 if 64BIT
 113
 114 config PAGE_OFFSET
 115         hex
 116         default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
 117         default 0x80000000 if 64BIT && !MMU
 118         default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
 119         default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
 120
 121 config ARCH_FLATMEM_ENABLE
 122         def_bool y
 123
 124 config ARCH_SPARSEMEM_ENABLE
 125         def_bool y
 126         depends on MMU
 127         select SPARSEMEM_VMEMMAP_ENABLE
 128
 129 config ARCH_SELECT_MEMORY_MODEL
 130         def_bool ARCH_SPARSEMEM_ENABLE
 131
 132 config ARCH_WANT_GENERAL_HUGETLB
 133         def_bool y
 134
 135 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 136         def_bool y
 137
 138 config SYS_SUPPORTS_HUGETLBFS
 139         depends on MMU
 140         def_bool y
 141
 142 config STACKTRACE_SUPPORT
 143         def_bool y
 144
 145 config TRACE_IRQFLAGS_SUPPORT
 146         def_bool y
 147
 148 config GENERIC_BUG
 149         def_bool y
 150         depends on BUG
 151         select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
 152
 153 config GENERIC_BUG_RELATIVE_POINTERS
 154         bool
 155
 156 config GENERIC_CALIBRATE_DELAY
 157         def_bool y
 158
 159 config GENERIC_CSUM
 160         def_bool y
 161
 162 config GENERIC_HWEIGHT
 163         def_bool y
 164
 165 config FIX_EARLYCON_MEM
 166         def_bool MMU
 167
 168 config PGTABLE_LEVELS
 169         int
 170         default 3 if 64BIT
 171         default 2
 172
 173 source "arch/riscv/Kconfig.socs"
 174
 175 menu "Platform type"
 176
 177 choice
 178         prompt "Base ISA"
 179         default ARCH_RV64I
 180         help
 181           This selects the base ISA that this kernel will target and must match
 182           the target platform.
 183
 184 config ARCH_RV32I
 185         bool "RV32I"
 186         select 32BIT
 187         select GENERIC_LIB_ASHLDI3
 188         select GENERIC_LIB_ASHRDI3
 189         select GENERIC_LIB_LSHRDI3
 190         select GENERIC_LIB_UCMPDI2
 191         select MMU
 192
 193 config ARCH_RV64I
 194         bool "RV64I"
 195         select 64BIT
 196         select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
 197         select HAVE_FUNCTION_TRACER
 198         select HAVE_FUNCTION_GRAPH_TRACER
 199         select HAVE_FTRACE_MCOUNT_RECORD
 200         select HAVE_DYNAMIC_FTRACE if MMU
 201         select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
 202         select SWIOTLB if MMU
 203
 204 endchoice
 205
 206 # We must be able to map all physical memory into the kernel, but the compiler
 207 # is still a bit more efficient when generating code if it's setup in a manner
 208 # such that it can only map 2GiB of memory.
 209 choice
 210         prompt "Kernel Code Model"
 211         default CMODEL_MEDLOW if 32BIT
 212         default CMODEL_MEDANY if 64BIT
 213
 214         config CMODEL_MEDLOW
 215                 bool "medium low code model"
 216         config CMODEL_MEDANY
 217                 bool "medium any code model"
 218 endchoice
 219
 220 config MODULE_SECTIONS
 221         bool
 222         select HAVE_MOD_ARCH_SPECIFIC
 223
 224 choice
 225         prompt "Maximum Physical Memory"
 226         default MAXPHYSMEM_2GB if 32BIT
 227         default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
 228         default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
 229
 230         config MAXPHYSMEM_2GB
 231                 bool "2GiB"
 232         config MAXPHYSMEM_128GB
 233                 depends on 64BIT && CMODEL_MEDANY
 234                 bool "128GiB"
 235 endchoice
 236
 237
 238 config SMP
 239         bool "Symmetric Multi-Processing"
 240         help
 241           This enables support for systems with more than one CPU.  If
 242           you say N here, the kernel will run on single and
 243           multiprocessor machines, but will use only one CPU of a
 244           multiprocessor machine. If you say Y here, the kernel will run
 245           on many, but not all, single processor machines. On a single
 246           processor machine, the kernel will run faster if you say N
 247           here.
 248
 249           If you don't know what to do here, say N.
 250
 251 config NR_CPUS
 252         int "Maximum number of CPUs (2-32)"
 253         range 2 32
 254         depends on SMP
 255         default "8"
 256
 257 config HOTPLUG_CPU
 258         bool "Support for hot-pluggable CPUs"
 259         depends on SMP
 260         select GENERIC_IRQ_MIGRATION
 261         help
 262
 263           Say Y here to experiment with turning CPUs off and on.  CPUs
 264           can be controlled through /sys/devices/system/cpu.
 265
 266           Say N if you want to disable CPU hotplug.
 267
 268 choice
 269         prompt "CPU Tuning"
 270         default TUNE_GENERIC
 271
 272 config TUNE_GENERIC
 273         bool "generic"
 274
 275 endchoice
 276
 277 config RISCV_ISA_C
 278         bool "Emit compressed instructions when building Linux"
 279         default y
 280         help
 281            Adds "C" to the ISA subsets that the toolchain is allowed to emit
 282            when building Linux, which results in compressed instructions in the
 283            Linux binary.
 284
 285            If you don't know what to do here, say Y.
 286
 287 menu "supported PMU type"
 288         depends on PERF_EVENTS
 289
 290 config RISCV_BASE_PMU
 291         bool "Base Performance Monitoring Unit"
 292         def_bool y
 293         help
 294           A base PMU that serves as a reference implementation and has limited
 295           feature of perf.  It can run on any RISC-V machines so serves as the
 296           fallback, but this option can also be disable to reduce kernel size.
 297
 298 endmenu
 299
 300 config FPU
 301         bool "FPU support"
 302         default y
 303         help
 304           Say N here if you want to disable all floating-point related procedure
 305           in the kernel.
 306
 307           If you don't know what to do here, say Y.
 308
 309 endmenu
 310
 311 menu "Kernel features"
 312
 313 source "kernel/Kconfig.hz"
 314
 315 config SECCOMP
 316         bool "Enable seccomp to safely compute untrusted bytecode"
 317         help
 318           This kernel feature is useful for number crunching applications
 319           that may need to compute untrusted bytecode during their
 320           execution. By using pipes or other transports made available to
 321           the process as file descriptors supporting the read/write
 322           syscalls, it's possible to isolate those applications in
 323           their own address space using seccomp. Once seccomp is
 324           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
 325           and the task is only allowed to execute a few safe syscalls
 326           defined by each seccomp mode.
 327
 328 config RISCV_SBI_V01
 329         bool "SBI v0.1 support"
 330         default y
 331         depends on RISCV_SBI
 332         help
 333           This config allows kernel to use SBI v0.1 APIs. This will be
 334           deprecated in future once legacy M-mode software are no longer in use.
 335 endmenu
 336
 337 menu "Boot options"
 338
 339 config CMDLINE
 340         string "Built-in kernel command line"
 341         help
 342           For most platforms, the arguments for the kernel's command line
 343           are provided at run-time, during boot. However, there are cases
 344           where either no arguments are being provided or the provided
 345           arguments are insufficient or even invalid.
 346
 347           When that occurs, it is possible to define a built-in command
 348           line here and choose how the kernel should use it later on.
 349
 350 choice
 351         prompt "Built-in command line usage" if CMDLINE != ""
 352         default CMDLINE_FALLBACK
 353         help
 354           Choose how the kernel will handle the provided built-in command
 355           line.
 356
 357 config CMDLINE_FALLBACK
 358         bool "Use bootloader kernel arguments if available"
 359         help
 360           Use the built-in command line as fallback in case we get nothing
 361           during boot. This is the default behaviour.
 362
 363 config CMDLINE_EXTEND
 364         bool "Extend bootloader kernel arguments"
 365         help
 366           The command-line arguments provided during boot will be
 367           appended to the built-in command line. This is useful in
 368           cases where the provided arguments are insufficient and
 369           you don't want to or cannot modify them.
 370
 371
 372 config CMDLINE_FORCE
 373         bool "Always use the default kernel command string"
 374         help
 375           Always use the built-in command line, even if we get one during
 376           boot. This is useful in case you need to override the provided
 377           command line on systems where you don't have or want control
 378           over it.
 379
 380 endchoice
 381
 382 endmenu
 383
 384 menu "Power management options"
 385
 386 source "kernel/power/Kconfig"
 387
 388 endmenu