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         # even on 32-bit, physical (and DMA) addresses are > 32-bits
  16         select PHYS_ADDR_T_64BIT
  17         select OF
  18         select OF_EARLY_FLATTREE
  19         select OF_IRQ
  20         select ARCH_HAS_BINFMT_FLAT
  21         select ARCH_WANT_FRAME_POINTERS
  22         select CLONE_BACKWARDS
  23         select COMMON_CLK
  24         select GENERIC_CLOCKEVENTS
  25         select GENERIC_CPU_DEVICES
  26         select GENERIC_IRQ_SHOW
  27         select GENERIC_PCI_IOMAP
  28         select GENERIC_SCHED_CLOCK
  29         select GENERIC_STRNCPY_FROM_USER
  30         select GENERIC_STRNLEN_USER
  31         select GENERIC_SMP_IDLE_THREAD
  32         select GENERIC_ATOMIC64 if !64BIT
  33         select HAVE_ARCH_AUDITSYSCALL
  34         select HAVE_ASM_MODVERSIONS
  35         select HAVE_MEMBLOCK_NODE_MAP
  36         select HAVE_DMA_CONTIGUOUS
  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 HAVE_EBPF_JIT if 64BIT
  58         select EDAC_SUPPORT
  59         select ARCH_HAS_GIGANTIC_PAGE
  60         select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
  61         select SPARSEMEM_STATIC if 32BIT
  62         select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
  63         select HAVE_ARCH_MMAP_RND_BITS
  64
  65 config ARCH_MMAP_RND_BITS_MIN
  66         default 18 if 64BIT
  67         default 8
  68
  69 # max bits determined by the following formula:
  70 #  VA_BITS - PAGE_SHIFT - 3
  71 config ARCH_MMAP_RND_BITS_MAX
  72         default 24 if 64BIT # SV39 based
  73         default 17
  74
  75 config MMU
  76         def_bool y
  77
  78 config ZONE_DMA32
  79         bool
  80         default y if 64BIT
  81
  82 config VA_BITS
  83         int
  84         default 32 if 32BIT
  85         default 39 if 64BIT
  86
  87 config PA_BITS
  88         int
  89         default 34 if 32BIT
  90         default 56 if 64BIT
  91
  92 config PAGE_OFFSET
  93         hex
  94         default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
  95         default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
  96         default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
  97
  98 config ARCH_FLATMEM_ENABLE
  99         def_bool y
 100
 101 config ARCH_SPARSEMEM_ENABLE
 102         def_bool y
 103         select SPARSEMEM_VMEMMAP_ENABLE
 104
 105 config ARCH_SELECT_MEMORY_MODEL
 106         def_bool ARCH_SPARSEMEM_ENABLE
 107
 108 config ARCH_WANT_GENERAL_HUGETLB
 109         def_bool y
 110
 111 config SYS_SUPPORTS_HUGETLBFS
 112         def_bool y
 113
 114 config STACKTRACE_SUPPORT
 115         def_bool y
 116
 117 config TRACE_IRQFLAGS_SUPPORT
 118         def_bool y
 119
 120 config GENERIC_BUG
 121         def_bool y
 122         depends on BUG
 123         select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
 124
 125 config GENERIC_BUG_RELATIVE_POINTERS
 126         bool
 127
 128 config GENERIC_CALIBRATE_DELAY
 129         def_bool y
 130
 131 config GENERIC_CSUM
 132         def_bool y
 133
 134 config GENERIC_HWEIGHT
 135         def_bool y
 136
 137 config FIX_EARLYCON_MEM
 138         def_bool y
 139
 140 config PGTABLE_LEVELS
 141         int
 142         default 3 if 64BIT
 143         default 2
 144
 145 source "arch/riscv/Kconfig.socs"
 146
 147 menu "Platform type"
 148
 149 choice
 150         prompt "Base ISA"
 151         default ARCH_RV64I
 152         help
 153           This selects the base ISA that this kernel will target and must match
 154           the target platform.
 155
 156 config ARCH_RV32I
 157         bool "RV32I"
 158         select 32BIT
 159         select GENERIC_LIB_ASHLDI3
 160         select GENERIC_LIB_ASHRDI3
 161         select GENERIC_LIB_LSHRDI3
 162         select GENERIC_LIB_UCMPDI2
 163
 164 config ARCH_RV64I
 165         bool "RV64I"
 166         select 64BIT
 167         select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
 168         select HAVE_FUNCTION_TRACER
 169         select HAVE_FUNCTION_GRAPH_TRACER
 170         select HAVE_FTRACE_MCOUNT_RECORD
 171         select HAVE_DYNAMIC_FTRACE
 172         select HAVE_DYNAMIC_FTRACE_WITH_REGS
 173         select SWIOTLB
 174
 175 endchoice
 176
 177 # We must be able to map all physical memory into the kernel, but the compiler
 178 # is still a bit more efficient when generating code if it's setup in a manner
 179 # such that it can only map 2GiB of memory.
 180 choice
 181         prompt "Kernel Code Model"
 182         default CMODEL_MEDLOW if 32BIT
 183         default CMODEL_MEDANY if 64BIT
 184
 185         config CMODEL_MEDLOW
 186                 bool "medium low code model"
 187         config CMODEL_MEDANY
 188                 bool "medium any code model"
 189 endchoice
 190
 191 config MODULE_SECTIONS
 192         bool
 193         select HAVE_MOD_ARCH_SPECIFIC
 194
 195 choice
 196         prompt "Maximum Physical Memory"
 197         default MAXPHYSMEM_2GB if 32BIT
 198         default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
 199         default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
 200
 201         config MAXPHYSMEM_2GB
 202                 bool "2GiB"
 203         config MAXPHYSMEM_128GB
 204                 depends on 64BIT && CMODEL_MEDANY
 205                 bool "128GiB"
 206 endchoice
 207
 208
 209 config SMP
 210         bool "Symmetric Multi-Processing"
 211         help
 212           This enables support for systems with more than one CPU.  If
 213           you say N here, the kernel will run on single and
 214           multiprocessor machines, but will use only one CPU of a
 215           multiprocessor machine. If you say Y here, the kernel will run
 216           on many, but not all, single processor machines. On a single
 217           processor machine, the kernel will run faster if you say N
 218           here.
 219
 220           If you don't know what to do here, say N.
 221
 222 config NR_CPUS
 223         int "Maximum number of CPUs (2-32)"
 224         range 2 32
 225         depends on SMP
 226         default "8"
 227
 228 choice
 229         prompt "CPU Tuning"
 230         default TUNE_GENERIC
 231
 232 config TUNE_GENERIC
 233         bool "generic"
 234
 235 endchoice
 236
 237 config RISCV_ISA_C
 238         bool "Emit compressed instructions when building Linux"
 239         default y
 240         help
 241            Adds "C" to the ISA subsets that the toolchain is allowed to emit
 242            when building Linux, which results in compressed instructions in the
 243            Linux binary.
 244
 245            If you don't know what to do here, say Y.
 246
 247 menu "supported PMU type"
 248         depends on PERF_EVENTS
 249
 250 config RISCV_BASE_PMU
 251         bool "Base Performance Monitoring Unit"
 252         def_bool y
 253         help
 254           A base PMU that serves as a reference implementation and has limited
 255           feature of perf.  It can run on any RISC-V machines so serves as the
 256           fallback, but this option can also be disable to reduce kernel size.
 257
 258 endmenu
 259
 260 config FPU
 261         bool "FPU support"
 262         default y
 263         help
 264           Say N here if you want to disable all floating-point related procedure
 265           in the kernel.
 266
 267           If you don't know what to do here, say Y.
 268
 269 endmenu
 270
 271 menu "Kernel features"
 272
 273 source "kernel/Kconfig.hz"
 274
 275 endmenu
 276
 277 menu "Boot options"
 278
 279 config CMDLINE
 280         string "Built-in kernel command line"
 281         help
 282           For most platforms, the arguments for the kernel's command line
 283           are provided at run-time, during boot. However, there are cases
 284           where either no arguments are being provided or the provided
 285           arguments are insufficient or even invalid.
 286
 287           When that occurs, it is possible to define a built-in command
 288           line here and choose how the kernel should use it later on.
 289
 290 choice
 291         prompt "Built-in command line usage" if CMDLINE != ""
 292         default CMDLINE_FALLBACK
 293         help
 294           Choose how the kernel will handle the provided built-in command
 295           line.
 296
 297 config CMDLINE_FALLBACK
 298         bool "Use bootloader kernel arguments if available"
 299         help
 300           Use the built-in command line as fallback in case we get nothing
 301           during boot. This is the default behaviour.
 302
 303 config CMDLINE_EXTEND
 304         bool "Extend bootloader kernel arguments"
 305         help
 306           The command-line arguments provided during boot will be
 307           appended to the built-in command line. This is useful in
 308           cases where the provided arguments are insufficient and
 309           you don't want to or cannot modify them.
 310
 311
 312 config CMDLINE_FORCE
 313         bool "Always use the default kernel command string"
 314         help
 315           Always use the built-in command line, even if we get one during
 316           boot. This is useful in case you need to override the provided
 317           command line on systems where you don't have or want control
 318           over it.
 319
 320 endchoice
 321
 322 endmenu
 323
 324 menu "Power management options"
 325
 326 source "kernel/power/Kconfig"
 327
 328 endmenu