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
  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         def_bool y
 140
 141 config STACKTRACE_SUPPORT
 142         def_bool y
 143
 144 config TRACE_IRQFLAGS_SUPPORT
 145         def_bool y
 146
 147 config GENERIC_BUG
 148         def_bool y
 149         depends on BUG
 150         select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
 151
 152 config GENERIC_BUG_RELATIVE_POINTERS
 153         bool
 154
 155 config GENERIC_CALIBRATE_DELAY
 156         def_bool y
 157
 158 config GENERIC_CSUM
 159         def_bool y
 160
 161 config GENERIC_HWEIGHT
 162         def_bool y
 163
 164 config FIX_EARLYCON_MEM
 165         def_bool MMU
 166
 167 config PGTABLE_LEVELS
 168         int
 169         default 3 if 64BIT
 170         default 2
 171
 172 source "arch/riscv/Kconfig.socs"
 173
 174 menu "Platform type"
 175
 176 choice
 177         prompt "Base ISA"
 178         default ARCH_RV64I
 179         help
 180           This selects the base ISA that this kernel will target and must match
 181           the target platform.
 182
 183 config ARCH_RV32I
 184         bool "RV32I"
 185         select 32BIT
 186         select GENERIC_LIB_ASHLDI3
 187         select GENERIC_LIB_ASHRDI3
 188         select GENERIC_LIB_LSHRDI3
 189         select GENERIC_LIB_UCMPDI2
 190         select MMU
 191
 192 config ARCH_RV64I
 193         bool "RV64I"
 194         select 64BIT
 195         select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
 196         select HAVE_FUNCTION_TRACER
 197         select HAVE_FUNCTION_GRAPH_TRACER
 198         select HAVE_FTRACE_MCOUNT_RECORD
 199         select HAVE_DYNAMIC_FTRACE if MMU
 200         select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
 201         select SWIOTLB if MMU
 202
 203 endchoice
 204
 205 # We must be able to map all physical memory into the kernel, but the compiler
 206 # is still a bit more efficient when generating code if it's setup in a manner
 207 # such that it can only map 2GiB of memory.
 208 choice
 209         prompt "Kernel Code Model"
 210         default CMODEL_MEDLOW if 32BIT
 211         default CMODEL_MEDANY if 64BIT
 212
 213         config CMODEL_MEDLOW
 214                 bool "medium low code model"
 215         config CMODEL_MEDANY
 216                 bool "medium any code model"
 217 endchoice
 218
 219 config MODULE_SECTIONS
 220         bool
 221         select HAVE_MOD_ARCH_SPECIFIC
 222
 223 choice
 224         prompt "Maximum Physical Memory"
 225         default MAXPHYSMEM_2GB if 32BIT
 226         default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
 227         default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
 228
 229         config MAXPHYSMEM_2GB
 230                 bool "2GiB"
 231         config MAXPHYSMEM_128GB
 232                 depends on 64BIT && CMODEL_MEDANY
 233                 bool "128GiB"
 234 endchoice
 235
 236
 237 config SMP
 238         bool "Symmetric Multi-Processing"
 239         help
 240           This enables support for systems with more than one CPU.  If
 241           you say N here, the kernel will run on single and
 242           multiprocessor machines, but will use only one CPU of a
 243           multiprocessor machine. If you say Y here, the kernel will run
 244           on many, but not all, single processor machines. On a single
 245           processor machine, the kernel will run faster if you say N
 246           here.
 247
 248           If you don't know what to do here, say N.
 249
 250 config NR_CPUS
 251         int "Maximum number of CPUs (2-32)"
 252         range 2 32
 253         depends on SMP
 254         default "8"
 255
 256 config HOTPLUG_CPU
 257         bool "Support for hot-pluggable CPUs"
 258         depends on SMP
 259         select GENERIC_IRQ_MIGRATION
 260         help
 261
 262           Say Y here to experiment with turning CPUs off and on.  CPUs
 263           can be controlled through /sys/devices/system/cpu.
 264
 265           Say N if you want to disable CPU hotplug.
 266
 267 choice
 268         prompt "CPU Tuning"
 269         default TUNE_GENERIC
 270
 271 config TUNE_GENERIC
 272         bool "generic"
 273
 274 endchoice
 275
 276 config RISCV_ISA_C
 277         bool "Emit compressed instructions when building Linux"
 278         default y
 279         help
 280            Adds "C" to the ISA subsets that the toolchain is allowed to emit
 281            when building Linux, which results in compressed instructions in the
 282            Linux binary.
 283
 284            If you don't know what to do here, say Y.
 285
 286 menu "supported PMU type"
 287         depends on PERF_EVENTS
 288
 289 config RISCV_BASE_PMU
 290         bool "Base Performance Monitoring Unit"
 291         def_bool y
 292         help
 293           A base PMU that serves as a reference implementation and has limited
 294           feature of perf.  It can run on any RISC-V machines so serves as the
 295           fallback, but this option can also be disable to reduce kernel size.
 296
 297 endmenu
 298
 299 config FPU
 300         bool "FPU support"
 301         default y
 302         help
 303           Say N here if you want to disable all floating-point related procedure
 304           in the kernel.
 305
 306           If you don't know what to do here, say Y.
 307
 308 endmenu
 309
 310 menu "Kernel features"
 311
 312 source "kernel/Kconfig.hz"
 313
 314 config SECCOMP
 315         bool "Enable seccomp to safely compute untrusted bytecode"
 316         help
 317           This kernel feature is useful for number crunching applications
 318           that may need to compute untrusted bytecode during their
 319           execution. By using pipes or other transports made available to
 320           the process as file descriptors supporting the read/write
 321           syscalls, it's possible to isolate those applications in
 322           their own address space using seccomp. Once seccomp is
 323           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
 324           and the task is only allowed to execute a few safe syscalls
 325           defined by each seccomp mode.
 326
 327 config RISCV_SBI_V01
 328         bool "SBI v0.1 support"
 329         default y
 330         depends on RISCV_SBI
 331         help
 332           This config allows kernel to use SBI v0.1 APIs. This will be
 333           deprecated in future once legacy M-mode software are no longer in use.
 334 endmenu
 335
 336 menu "Boot options"
 337
 338 config CMDLINE
 339         string "Built-in kernel command line"
 340         help
 341           For most platforms, the arguments for the kernel's command line
 342           are provided at run-time, during boot. However, there are cases
 343           where either no arguments are being provided or the provided
 344           arguments are insufficient or even invalid.
 345
 346           When that occurs, it is possible to define a built-in command
 347           line here and choose how the kernel should use it later on.
 348
 349 choice
 350         prompt "Built-in command line usage" if CMDLINE != ""
 351         default CMDLINE_FALLBACK
 352         help
 353           Choose how the kernel will handle the provided built-in command
 354           line.
 355
 356 config CMDLINE_FALLBACK
 357         bool "Use bootloader kernel arguments if available"
 358         help
 359           Use the built-in command line as fallback in case we get nothing
 360           during boot. This is the default behaviour.
 361
 362 config CMDLINE_EXTEND
 363         bool "Extend bootloader kernel arguments"
 364         help
 365           The command-line arguments provided during boot will be
 366           appended to the built-in command line. This is useful in
 367           cases where the provided arguments are insufficient and
 368           you don't want to or cannot modify them.
 369
 370
 371 config CMDLINE_FORCE
 372         bool "Always use the default kernel command string"
 373         help
 374           Always use the built-in command line, even if we get one during
 375           boot. This is useful in case you need to override the provided
 376           command line on systems where you don't have or want control
 377           over it.
 378
 379 endchoice
 380
 381 endmenu
 382
 383 menu "Power management options"
 384
 385 source "kernel/power/Kconfig"
 386
 387 endmenu