RISC-V CPU Idle Support

[linux-block.git] / arch / riscv / Kconfig

# SPDX-License-Identifier: GPL-2.0-only
#
# For a description of the syntax of this configuration file,
# see Documentation/kbuild/kconfig-language.rst.
#

config 64BIT
        bool

config 32BIT
        bool

config RISCV
        def_bool y
        select ARCH_CLOCKSOURCE_INIT
        select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
        select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
        select ARCH_HAS_BINFMT_FLAT
        select ARCH_HAS_CURRENT_STACK_POINTER
        select ARCH_HAS_DEBUG_VM_PGTABLE
        select ARCH_HAS_DEBUG_VIRTUAL if MMU
        select ARCH_HAS_DEBUG_WX
        select ARCH_HAS_FORTIFY_SOURCE
        select ARCH_HAS_GCOV_PROFILE_ALL
        select ARCH_HAS_GIGANTIC_PAGE
        select ARCH_HAS_KCOV
        select ARCH_HAS_MMIOWB
        select ARCH_HAS_PTE_SPECIAL
        select ARCH_HAS_SET_DIRECT_MAP if MMU
        select ARCH_HAS_SET_MEMORY if MMU
        select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
        select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
        select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
        select ARCH_HAS_UBSAN_SANITIZE_ALL
        select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
        select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
        select ARCH_STACKWALK
        select ARCH_SUPPORTS_ATOMIC_RMW
        select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
        select ARCH_SUPPORTS_HUGETLBFS if MMU
        select ARCH_USE_MEMTEST
        select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
        select ARCH_WANT_FRAME_POINTERS
        select ARCH_WANT_GENERAL_HUGETLB
        select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
        select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
        select BUILDTIME_TABLE_SORT if MMU
        select CLONE_BACKWARDS
        select CLINT_TIMER if !MMU
        select COMMON_CLK
        select CPU_PM if CPU_IDLE
        select EDAC_SUPPORT
        select GENERIC_ARCH_TOPOLOGY if SMP
        select GENERIC_ATOMIC64 if !64BIT
        select GENERIC_CLOCKEVENTS_BROADCAST if SMP
        select GENERIC_EARLY_IOREMAP
        select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
        select GENERIC_IDLE_POLL_SETUP
        select GENERIC_IOREMAP if MMU
        select GENERIC_IRQ_MULTI_HANDLER
        select GENERIC_IRQ_SHOW
        select GENERIC_IRQ_SHOW_LEVEL
        select GENERIC_LIB_DEVMEM_IS_ALLOWED
        select GENERIC_PCI_IOMAP
        select GENERIC_PTDUMP if MMU
        select GENERIC_SCHED_CLOCK
        select GENERIC_SMP_IDLE_THREAD
        select GENERIC_TIME_VSYSCALL if MMU && 64BIT
        select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
        select HAVE_ARCH_AUDITSYSCALL
        select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
        select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
        select HAVE_ARCH_KASAN if MMU && 64BIT
        select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
        select HAVE_ARCH_KFENCE if MMU && 64BIT
        select HAVE_ARCH_KGDB if !XIP_KERNEL
        select HAVE_ARCH_KGDB_QXFER_PKT
        select HAVE_ARCH_MMAP_RND_BITS if MMU
        select HAVE_ARCH_SECCOMP_FILTER
        select HAVE_ARCH_TRACEHOOK
        select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
        select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
        select HAVE_ARCH_THREAD_STRUCT_WHITELIST
        select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
        select HAVE_ASM_MODVERSIONS
        select HAVE_CONTEXT_TRACKING
        select HAVE_DEBUG_KMEMLEAK
        select HAVE_DMA_CONTIGUOUS if MMU
        select HAVE_EBPF_JIT if MMU
        select HAVE_FUNCTION_ERROR_INJECTION
        select HAVE_GCC_PLUGINS
        select HAVE_GENERIC_VDSO if MMU && 64BIT
        select HAVE_IRQ_TIME_ACCOUNTING
        select HAVE_KPROBES if !XIP_KERNEL
        select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
        select HAVE_KRETPROBES if !XIP_KERNEL
        select HAVE_MOVE_PMD
        select HAVE_MOVE_PUD
        select HAVE_PCI
        select HAVE_PERF_EVENTS
        select HAVE_PERF_REGS
        select HAVE_PERF_USER_STACK_DUMP
        select HAVE_REGS_AND_STACK_ACCESS_API
        select HAVE_FUNCTION_ARG_ACCESS_API
        select HAVE_STACKPROTECTOR
        select HAVE_SYSCALL_TRACEPOINTS
        select HAVE_RSEQ
        select IRQ_DOMAIN
        select IRQ_FORCED_THREADING
        select MODULES_USE_ELF_RELA if MODULES
        select MODULE_SECTIONS if MODULES
        select OF
        select OF_EARLY_FLATTREE
        select OF_IRQ
        select PCI_DOMAINS_GENERIC if PCI
        select PCI_MSI if PCI
        select RISCV_INTC
        select RISCV_TIMER if RISCV_SBI
        select SPARSE_IRQ
        select SYSCTL_EXCEPTION_TRACE
        select THREAD_INFO_IN_TASK
        select TRACE_IRQFLAGS_SUPPORT
        select UACCESS_MEMCPY if !MMU
        select ZONE_DMA32 if 64BIT

config ARCH_MMAP_RND_BITS_MIN
        default 18 if 64BIT
        default 8

# max bits determined by the following formula:
#  VA_BITS - PAGE_SHIFT - 3
config ARCH_MMAP_RND_BITS_MAX
        default 24 if 64BIT # SV39 based
        default 17

# set if we run in machine mode, cleared if we run in supervisor mode
config RISCV_M_MODE
        bool
        default !MMU

# set if we are running in S-mode and can use SBI calls
config RISCV_SBI
        bool
        depends on !RISCV_M_MODE
        default y

config MMU
        bool "MMU-based Paged Memory Management Support"
        default y
        help
          Select if you want MMU-based virtualised addressing space
          support by paged memory management. If unsure, say 'Y'.

config PAGE_OFFSET
        hex
        default 0xC0000000 if 32BIT
        default 0x80000000 if 64BIT && !MMU
        default 0xff60000000000000 if 64BIT

config KASAN_SHADOW_OFFSET
        hex
        depends on KASAN_GENERIC
        default 0xdfffffff00000000 if 64BIT
        default 0xffffffff if 32BIT

config ARCH_FLATMEM_ENABLE
        def_bool !NUMA

config ARCH_SPARSEMEM_ENABLE
        def_bool y
        depends on MMU
        select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
        select SPARSEMEM_VMEMMAP_ENABLE if 64BIT

config ARCH_SELECT_MEMORY_MODEL
        def_bool ARCH_SPARSEMEM_ENABLE

config ARCH_SUPPORTS_UPROBES
        def_bool y

config STACKTRACE_SUPPORT
        def_bool y

config GENERIC_BUG
        def_bool y
        depends on BUG
        select GENERIC_BUG_RELATIVE_POINTERS if 64BIT

config GENERIC_BUG_RELATIVE_POINTERS
        bool

config GENERIC_CALIBRATE_DELAY
        def_bool y

config GENERIC_CSUM
        def_bool y

config GENERIC_HWEIGHT
        def_bool y

config FIX_EARLYCON_MEM
        def_bool MMU

config PGTABLE_LEVELS
        int
        default 5 if 64BIT
        default 2

config LOCKDEP_SUPPORT
        def_bool y

source "arch/riscv/Kconfig.socs"
source "arch/riscv/Kconfig.erratas"

menu "Platform type"

choice
        prompt "Base ISA"
        default ARCH_RV64I
        help
          This selects the base ISA that this kernel will target and must match
          the target platform.

config ARCH_RV32I
        bool "RV32I"
        select 32BIT
        select GENERIC_LIB_ASHLDI3
        select GENERIC_LIB_ASHRDI3
        select GENERIC_LIB_LSHRDI3
        select GENERIC_LIB_UCMPDI2
        select MMU

config ARCH_RV64I
        bool "RV64I"
        select 64BIT
        select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
        select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
        select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
        select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
        select HAVE_FUNCTION_GRAPH_TRACER
        select HAVE_FUNCTION_TRACER if !XIP_KERNEL
        select SWIOTLB if MMU

endchoice

# We must be able to map all physical memory into the kernel, but the compiler
# is still a bit more efficient when generating code if it's setup in a manner
# such that it can only map 2GiB of memory.
choice
        prompt "Kernel Code Model"
        default CMODEL_MEDLOW if 32BIT
        default CMODEL_MEDANY if 64BIT

        config CMODEL_MEDLOW
                bool "medium low code model"
        config CMODEL_MEDANY
                bool "medium any code model"
endchoice

config MODULE_SECTIONS
        bool
        select HAVE_MOD_ARCH_SPECIFIC

config SMP
        bool "Symmetric Multi-Processing"
        help
          This enables support for systems with more than one CPU.  If
          you say N here, the kernel will run on single and
          multiprocessor machines, but will use only one CPU of a
          multiprocessor machine. If you say Y here, the kernel will run
          on many, but not all, single processor machines. On a single
          processor machine, the kernel will run faster if you say N
          here.

          If you don't know what to do here, say N.

config NR_CPUS
        int "Maximum number of CPUs (2-32)"
        range 2 32
        depends on SMP
        default "8"

config HOTPLUG_CPU
        bool "Support for hot-pluggable CPUs"
        depends on SMP
        select GENERIC_IRQ_MIGRATION
        help

          Say Y here to experiment with turning CPUs off and on.  CPUs
          can be controlled through /sys/devices/system/cpu.

          Say N if you want to disable CPU hotplug.

choice
        prompt "CPU Tuning"
        default TUNE_GENERIC

config TUNE_GENERIC
        bool "generic"

endchoice

# Common NUMA Features
config NUMA
        bool "NUMA Memory Allocation and Scheduler Support"
        depends on SMP && MMU
        select GENERIC_ARCH_NUMA
        select OF_NUMA
        select ARCH_SUPPORTS_NUMA_BALANCING
        select USE_PERCPU_NUMA_NODE_ID
        select NEED_PER_CPU_EMBED_FIRST_CHUNK
        help
          Enable NUMA (Non-Uniform Memory Access) support.

          The kernel will try to allocate memory used by a CPU on the
          local memory of the CPU and add some more NUMA awareness to the kernel.

config NODES_SHIFT
        int "Maximum NUMA Nodes (as a power of 2)"
        range 1 10
        default "2"
        depends on NUMA
        help
          Specify the maximum number of NUMA Nodes available on the target
          system.  Increases memory reserved to accommodate various tables.

config RISCV_ISA_C
        bool "Emit compressed instructions when building Linux"
        default y
        help
           Adds "C" to the ISA subsets that the toolchain is allowed to emit
           when building Linux, which results in compressed instructions in the
           Linux binary.

           If you don't know what to do here, say Y.

config FPU
        bool "FPU support"
        default y
        help
          Say N here if you want to disable all floating-point related procedure
          in the kernel.

          If you don't know what to do here, say Y.

endmenu

menu "Kernel features"

source "kernel/Kconfig.hz"

config RISCV_SBI_V01
        bool "SBI v0.1 support"
        depends on RISCV_SBI
        help
          This config allows kernel to use SBI v0.1 APIs. This will be
          deprecated in future once legacy M-mode software are no longer in use.

config RISCV_BOOT_SPINWAIT
        bool "Spinwait booting method"
        depends on SMP
        default y
        help
          This enables support for booting Linux via spinwait method. In the
          spinwait method, all cores randomly jump to Linux. One of the cores
          gets chosen via lottery and all other keep spinning on a percpu
          variable. This method cannot support CPU hotplug and sparse hartid
          scheme. It should be only enabled for M-mode Linux or platforms relying
          on older firmware without SBI HSM extension. All other platforms should
          rely on ordered booting via SBI HSM extension which gets chosen
          dynamically at runtime if the firmware supports it.

config KEXEC
        bool "Kexec system call"
        select KEXEC_CORE
        select HOTPLUG_CPU if SMP
        depends on MMU
        help
          kexec is a system call that implements the ability to shutdown your
          current kernel, and to start another kernel. It is like a reboot
          but it is independent of the system firmware. And like a reboot
          you can start any kernel with it, not just Linux.

          The name comes from the similarity to the exec system call.

config CRASH_DUMP
        bool "Build kdump crash kernel"
        help
          Generate crash dump after being started by kexec. This should
          be normally only set in special crash dump kernels which are
          loaded in the main kernel with kexec-tools into a specially
          reserved region and then later executed after a crash by
          kdump/kexec.

          For more details see Documentation/admin-guide/kdump/kdump.rst

endmenu

menu "Boot options"

config CMDLINE
        string "Built-in kernel command line"
        help
          For most platforms, the arguments for the kernel's command line
          are provided at run-time, during boot. However, there are cases
          where either no arguments are being provided or the provided
          arguments are insufficient or even invalid.

          When that occurs, it is possible to define a built-in command
          line here and choose how the kernel should use it later on.

choice
        prompt "Built-in command line usage" if CMDLINE != ""
        default CMDLINE_FALLBACK
        help
          Choose how the kernel will handle the provided built-in command
          line.

config CMDLINE_FALLBACK
        bool "Use bootloader kernel arguments if available"
        help
          Use the built-in command line as fallback in case we get nothing
          during boot. This is the default behaviour.

config CMDLINE_EXTEND
        bool "Extend bootloader kernel arguments"
        help
          The command-line arguments provided during boot will be
          appended to the built-in command line. This is useful in
          cases where the provided arguments are insufficient and
          you don't want to or cannot modify them.


config CMDLINE_FORCE
        bool "Always use the default kernel command string"
        help
          Always use the built-in command line, even if we get one during
          boot. This is useful in case you need to override the provided
          command line on systems where you don't have or want control
          over it.

endchoice

config EFI_STUB
        bool

config EFI
        bool "UEFI runtime support"
        depends on OF && !XIP_KERNEL
        select LIBFDT
        select UCS2_STRING
        select EFI_PARAMS_FROM_FDT
        select EFI_STUB
        select EFI_GENERIC_STUB
        select EFI_RUNTIME_WRAPPERS
        select RISCV_ISA_C
        depends on MMU
        default y
        help
          This option provides support for runtime services provided
          by UEFI firmware (such as non-volatile variables, realtime
          clock, and platform reset). A UEFI stub is also provided to
          allow the kernel to be booted as an EFI application. This
          is only useful on systems that have UEFI firmware.

config CC_HAVE_STACKPROTECTOR_TLS
        def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)

config STACKPROTECTOR_PER_TASK
        def_bool y
        depends on !GCC_PLUGIN_RANDSTRUCT
        depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS

config PHYS_RAM_BASE_FIXED
        bool "Explicitly specified physical RAM address"
        default n

config PHYS_RAM_BASE
        hex "Platform Physical RAM address"
        depends on PHYS_RAM_BASE_FIXED
        default "0x80000000"
        help
          This is the physical address of RAM in the system. It has to be
          explicitly specified to run early relocations of read-write data
          from flash to RAM.

config XIP_KERNEL
        bool "Kernel Execute-In-Place from ROM"
        depends on MMU && SPARSEMEM
        # This prevents XIP from being enabled by all{yes,mod}config, which
        # fail to build since XIP doesn't support large kernels.
        depends on !COMPILE_TEST
        select PHYS_RAM_BASE_FIXED
        help
          Execute-In-Place allows the kernel to run from non-volatile storage
          directly addressable by the CPU, such as NOR flash. This saves RAM
          space since the text section of the kernel is not loaded from flash
          to RAM.  Read-write sections, such as the data section and stack,
          are still copied to RAM.  The XIP kernel is not compressed since
          it has to run directly from flash, so it will take more space to
          store it.  The flash address used to link the kernel object files,
          and for storing it, is configuration dependent. Therefore, if you
          say Y here, you must know the proper physical address where to
          store the kernel image depending on your own flash memory usage.

          Also note that the make target becomes "make xipImage" rather than
          "make zImage" or "make Image".  The final kernel binary to put in
          ROM memory will be arch/riscv/boot/xipImage.

          SPARSEMEM is required because the kernel text and rodata that are
          flash resident are not backed by memmap, then any attempt to get
          a struct page on those regions will trigger a fault.

          If unsure, say N.

config XIP_PHYS_ADDR
        hex "XIP Kernel Physical Location"
        depends on XIP_KERNEL
        default "0x21000000"
        help
          This is the physical address in your flash memory the kernel will
          be linked for and stored to.  This address is dependent on your
          own flash usage.

endmenu

config BUILTIN_DTB
        bool
        depends on OF
        default y if XIP_KERNEL

menu "Power management options"

source "kernel/power/Kconfig"

endmenu

menu "CPU Power Management"

source "drivers/cpuidle/Kconfig"

endmenu

source "arch/riscv/kvm/Kconfig"