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