1 # SPDX-License-Identifier: GPL-2.0-only
3 # For a description of the syntax of this configuration file,
4 # see Documentation/kbuild/kconfig-language.rst.
15 select ACPI_GENERIC_GSI if ACPI
16 select ACPI_MCFG if (ACPI && PCI)
17 select ACPI_PPTT if ACPI
18 select ACPI_REDUCED_HARDWARE_ONLY if ACPI
19 select ACPI_SPCR_TABLE if ACPI
20 select ARCH_DMA_DEFAULT_COHERENT
21 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
22 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM_VMEMMAP
23 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
24 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
25 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
26 select ARCH_HAS_BINFMT_FLAT
27 select ARCH_HAS_CRC32 if RISCV_ISA_ZBC
28 select ARCH_HAS_CURRENT_STACK_POINTER
29 select ARCH_HAS_DEBUG_VIRTUAL if MMU
30 select ARCH_HAS_DEBUG_VM_PGTABLE
31 select ARCH_HAS_DEBUG_WX
32 select ARCH_HAS_FAST_MULTIPLIER
33 select ARCH_HAS_FORTIFY_SOURCE
34 select ARCH_HAS_GCOV_PROFILE_ALL
35 select ARCH_HAS_GIGANTIC_PAGE
36 select ARCH_HAS_HW_PTE_YOUNG
38 select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU
39 select ARCH_HAS_MEMBARRIER_CALLBACKS
40 select ARCH_HAS_MEMBARRIER_SYNC_CORE
41 select ARCH_HAS_MMIOWB
42 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
43 select ARCH_HAS_PMEM_API
44 select ARCH_HAS_PREEMPT_LAZY
45 select ARCH_HAS_PREPARE_SYNC_CORE_CMD
46 select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU
47 select ARCH_HAS_PTE_SPECIAL
48 select ARCH_HAS_SET_DIRECT_MAP if MMU
49 select ARCH_HAS_SET_MEMORY if MMU
50 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
51 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
52 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
53 select ARCH_HAS_SYSCALL_WRAPPER
54 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
56 select ARCH_HAS_VDSO_TIME_DATA
57 select ARCH_KEEP_MEMBLOCK if ACPI
58 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU
59 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
60 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
62 select ARCH_SUPPORTS_ATOMIC_RMW
63 select ARCH_SUPPORTS_CFI_CLANG
64 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
65 select ARCH_SUPPORTS_HUGETLBFS if MMU
66 # LLD >= 14: https://github.com/llvm/llvm-project/issues/50505
67 select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000
68 select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000
69 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
70 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
71 select ARCH_SUPPORTS_RT
72 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
73 select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
74 select ARCH_USE_MEMTEST
75 select ARCH_USE_QUEUED_RWLOCKS
76 select ARCH_USE_SYM_ANNOTATIONS
77 select ARCH_USES_CFI_TRAPS if CFI_CLANG
78 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU
79 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
80 select ARCH_WANT_FRAME_POINTERS
81 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
82 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
83 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
84 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
85 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
86 select ARCH_WANTS_NO_INSTR
87 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
88 select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS
89 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
90 select BUILDTIME_TABLE_SORT if MMU
91 select CLINT_TIMER if RISCV_M_MODE
92 select CLONE_BACKWARDS
94 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
96 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
97 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
98 select GENERIC_ARCH_TOPOLOGY
99 select GENERIC_ATOMIC64 if !64BIT
100 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
101 select GENERIC_CPU_DEVICES
102 select GENERIC_CPU_VULNERABILITIES
103 select GENERIC_EARLY_IOREMAP
105 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
106 select GENERIC_IDLE_POLL_SETUP
107 select GENERIC_IOREMAP if MMU
108 select GENERIC_IRQ_IPI if SMP
109 select GENERIC_IRQ_IPI_MUX if SMP
110 select GENERIC_IRQ_MULTI_HANDLER
111 select GENERIC_IRQ_SHOW
112 select GENERIC_IRQ_SHOW_LEVEL
113 select GENERIC_LIB_DEVMEM_IS_ALLOWED
114 select GENERIC_PCI_IOMAP
115 select GENERIC_PTDUMP if MMU
116 select GENERIC_SCHED_CLOCK
117 select GENERIC_SMP_IDLE_THREAD
118 select GENERIC_TIME_VSYSCALL if MMU && 64BIT
119 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
120 select HARDIRQS_SW_RESEND
121 select HAS_IOPORT if MMU
122 select HAVE_ALIGNED_STRUCT_PAGE
123 select HAVE_ARCH_AUDITSYSCALL
124 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
125 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT
126 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
127 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
128 select HAVE_ARCH_KASAN if MMU && 64BIT
129 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
130 select HAVE_ARCH_KFENCE if MMU && 64BIT
131 select HAVE_ARCH_KGDB if !XIP_KERNEL
132 select HAVE_ARCH_KGDB_QXFER_PKT
133 select HAVE_ARCH_MMAP_RND_BITS if MMU
134 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
135 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
136 select HAVE_ARCH_SECCOMP_FILTER
137 select HAVE_ARCH_STACKLEAK
138 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
139 select HAVE_ARCH_TRACEHOOK
140 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
141 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
142 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
143 select HAVE_ASM_MODVERSIONS
144 select HAVE_CONTEXT_TRACKING_USER
145 select HAVE_DEBUG_KMEMLEAK
146 select HAVE_DMA_CONTIGUOUS if MMU
147 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
148 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
149 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
150 select HAVE_FTRACE_GRAPH_FUNC
151 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
152 select HAVE_FUNCTION_GRAPH_TRACER
153 select HAVE_FUNCTION_GRAPH_FREGS
154 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
155 select HAVE_EBPF_JIT if MMU
156 select HAVE_GUP_FAST if MMU
157 select HAVE_FUNCTION_ARG_ACCESS_API
158 select HAVE_FUNCTION_ERROR_INJECTION
159 select HAVE_GCC_PLUGINS
160 select HAVE_GENERIC_VDSO if MMU && 64BIT
161 select HAVE_IRQ_TIME_ACCOUNTING
162 select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT
163 select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT
164 select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT
165 select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT
166 select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT
167 select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT
168 select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT
169 select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT
170 select HAVE_KPROBES if !XIP_KERNEL
171 select HAVE_KRETPROBES if !XIP_KERNEL
172 # https://github.com/ClangBuiltLinux/linux/issues/1881
173 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
176 select HAVE_PAGE_SIZE_4KB
178 select HAVE_PERF_EVENTS
179 select HAVE_PERF_REGS
180 select HAVE_PERF_USER_STACK_DUMP
181 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
182 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
183 select HAVE_REGS_AND_STACK_ACCESS_API
184 select HAVE_RETHOOK if !XIP_KERNEL
186 select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG
187 select HAVE_SAMPLE_FTRACE_DIRECT
188 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
189 select HAVE_STACKPROTECTOR
190 select HAVE_SYSCALL_TRACEPOINTS
191 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
193 select IRQ_FORCED_THREADING
194 select KASAN_VMALLOC if KASAN
195 select LOCK_MM_AND_FIND_VMA
196 select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU
197 select MODULES_USE_ELF_RELA if MODULES
199 select OF_EARLY_FLATTREE
201 select PCI_DOMAINS_GENERIC if PCI
202 select PCI_ECAM if (ACPI && PCI)
203 select PCI_MSI if PCI
204 select RISCV_ALTERNATIVE if !XIP_KERNEL
208 select RISCV_TIMER if RISCV_SBI
211 select SYSCTL_EXCEPTION_TRACE
212 select THREAD_INFO_IN_TASK
213 select TRACE_IRQFLAGS_SUPPORT
214 select UACCESS_MEMCPY if !MMU
215 select USER_STACKTRACE_SUPPORT
216 select ZONE_DMA32 if 64BIT
218 config RUSTC_SUPPORTS_RISCV
221 # Shadow call stack requires rustc version 1.82+ due to use of the
222 # -Zsanitizer=shadow-call-stack flag.
223 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200
225 config CLANG_SUPPORTS_DYNAMIC_FTRACE
227 # https://github.com/ClangBuiltLinux/linux/issues/1817
228 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
230 config GCC_SUPPORTS_DYNAMIC_FTRACE
232 depends on $(cc-option,-fpatchable-function-entry=8)
234 config HAVE_SHADOW_CALL_STACK
235 def_bool $(cc-option,-fsanitize=shadow-call-stack)
236 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
237 depends on $(ld-option,--no-relax-gp)
239 config RISCV_USE_LINKER_RELAXATION
241 # https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
242 depends on !LD_IS_LLD || LLD_VERSION >= 150000
244 # https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
245 config ARCH_HAS_BROKEN_DWARF5
247 depends on RISCV_USE_LINKER_RELAXATION
248 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
249 depends on AS_IS_LLVM && AS_VERSION < 180000
250 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
251 depends on LD_IS_LLD && LLD_VERSION < 180000
253 config ARCH_MMAP_RND_BITS_MIN
257 config ARCH_MMAP_RND_COMPAT_BITS_MIN
260 # max bits determined by the following formula:
261 # VA_BITS - PAGE_SHIFT - 3
262 config ARCH_MMAP_RND_BITS_MAX
263 default 24 if 64BIT # SV39 based
266 config ARCH_MMAP_RND_COMPAT_BITS_MAX
269 # set if we run in machine mode, cleared if we run in supervisor mode
271 bool "Build a kernel that runs in machine mode"
275 Select this option if you want to run the kernel in M-mode,
276 without the assistance of any other firmware.
278 # set if we are running in S-mode and can use SBI calls
281 depends on !RISCV_M_MODE
285 bool "MMU-based Paged Memory Management Support"
288 Select if you want MMU-based virtualised addressing space
289 support by paged memory management. If unsure, say 'Y'.
293 default 0x80000000 if !MMU && RISCV_M_MODE
294 default 0x80200000 if !MMU
295 default 0xc0000000 if 32BIT
296 default 0xff60000000000000 if 64BIT
298 config KASAN_SHADOW_OFFSET
300 depends on KASAN_GENERIC
301 default 0xdfffffff00000000 if 64BIT
302 default 0xffffffff if 32BIT
304 config ARCH_FLATMEM_ENABLE
307 config ARCH_SPARSEMEM_ENABLE
310 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
311 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
313 config ARCH_SELECT_MEMORY_MODEL
314 def_bool ARCH_SPARSEMEM_ENABLE
316 config ARCH_SUPPORTS_UPROBES
319 config STACKTRACE_SUPPORT
325 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
327 config GENERIC_BUG_RELATIVE_POINTERS
330 config GENERIC_CALIBRATE_DELAY
336 config GENERIC_HWEIGHT
339 config FIX_EARLYCON_MEM
342 config ILLEGAL_POINTER_VALUE
345 default 0xdead000000000000 if 64BIT
347 config PGTABLE_LEVELS
352 config LOCKDEP_SUPPORT
355 config RISCV_DMA_NONCOHERENT
357 select ARCH_HAS_DMA_PREP_COHERENT
358 select ARCH_HAS_SETUP_DMA_OPS
359 select ARCH_HAS_SYNC_DMA_FOR_CPU
360 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
361 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
363 config RISCV_NONSTANDARD_CACHE_OPS
366 This enables function pointer support for non-standard noncoherent
367 systems to handle cache management.
370 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
372 config AS_HAS_OPTION_ARCH
373 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4
375 depends on $(as-instr, .option arch$(comma) +m)
377 source "arch/riscv/Kconfig.socs"
378 source "arch/riscv/Kconfig.errata"
383 bool "Allow configurations that result in non-portable kernels"
385 RISC-V kernel binaries are compatible between all known systems
386 whenever possible, but there are some use cases that can only be
387 satisfied by configurations that result in kernel binaries that are
388 not portable between systems.
390 Selecting N does not guarantee kernels will be portable to all known
391 systems. Selecting any of the options guarded by NONPORTABLE will
392 result in kernel binaries that are unlikely to be portable between
401 This selects the base ISA that this kernel will target and must match
406 depends on NONPORTABLE
408 select GENERIC_LIB_ASHLDI3
409 select GENERIC_LIB_ASHRDI3
410 select GENERIC_LIB_LSHRDI3
411 select GENERIC_LIB_UCMPDI2
416 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
417 select SWIOTLB if MMU
421 # We must be able to map all physical memory into the kernel, but the compiler
422 # is still a bit more efficient when generating code if it's setup in a manner
423 # such that it can only map 2GiB of memory.
425 prompt "Kernel Code Model"
426 default CMODEL_MEDLOW if 32BIT
427 default CMODEL_MEDANY if 64BIT
430 bool "medium low code model"
432 bool "medium any code model"
435 config MODULE_SECTIONS
437 select HAVE_MOD_ARCH_SPECIFIC
440 bool "Symmetric Multi-Processing"
442 This enables support for systems with more than one CPU. If
443 you say N here, the kernel will run on single and
444 multiprocessor machines, but will use only one CPU of a
445 multiprocessor machine. If you say Y here, the kernel will run
446 on many, but not all, single processor machines. On a single
447 processor machine, the kernel will run faster if you say N
450 If you don't know what to do here, say N.
453 bool "Multi-core scheduler support"
456 Multi-core scheduler support improves the CPU scheduler's decision
457 making when dealing with multi-core CPU chips at a cost of slightly
458 increased overhead in some places. If unsure say N here.
461 int "Maximum number of CPUs (2-512)"
463 range 2 512 if !RISCV_SBI_V01
464 range 2 32 if RISCV_SBI_V01 && 32BIT
465 range 2 64 if RISCV_SBI_V01 && 64BIT
466 default "32" if 32BIT
467 default "64" if 64BIT
470 bool "Support for hot-pluggable CPUs"
472 select GENERIC_IRQ_MIGRATION
475 Say Y here to experiment with turning CPUs off and on. CPUs
476 can be controlled through /sys/devices/system/cpu.
478 Say N if you want to disable CPU hotplug.
489 # Common NUMA Features
491 bool "NUMA Memory Allocation and Scheduler Support"
492 depends on SMP && MMU
493 select ARCH_SUPPORTS_NUMA_BALANCING
494 select GENERIC_ARCH_NUMA
495 select HAVE_SETUP_PER_CPU_AREA
496 select NEED_PER_CPU_EMBED_FIRST_CHUNK
497 select NEED_PER_CPU_PAGE_FIRST_CHUNK
499 select USE_PERCPU_NUMA_NODE_ID
501 Enable NUMA (Non-Uniform Memory Access) support.
503 The kernel will try to allocate memory used by a CPU on the
504 local memory of the CPU and add some more NUMA awareness to the kernel.
507 int "Maximum NUMA Nodes (as a power of 2)"
512 Specify the maximum number of NUMA Nodes available on the target
513 system. Increases memory reserved to accommodate various tables.
516 prompt "RISC-V spinlock type"
517 default RISCV_COMBO_SPINLOCKS
519 config RISCV_TICKET_SPINLOCKS
520 bool "Using ticket spinlock"
522 config RISCV_QUEUED_SPINLOCKS
523 bool "Using queued spinlock"
524 depends on SMP && MMU && NONPORTABLE
525 select ARCH_USE_QUEUED_SPINLOCKS
527 The queued spinlock implementation requires the forward progress
528 guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or
529 LR/SC with Ziccrse provide such guarantee.
531 Select this if and only if Zabha or Ziccrse is available on your
532 platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms
533 without one of those extensions.
535 If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks
536 when supported and otherwise ticket spinlocks.
538 config RISCV_COMBO_SPINLOCKS
539 bool "Using combo spinlock"
540 depends on SMP && MMU
541 select ARCH_USE_QUEUED_SPINLOCKS
543 Embed both queued spinlock and ticket lock so that the spinlock
544 implementation can be chosen at runtime.
548 config RISCV_ALTERNATIVE
550 depends on !XIP_KERNEL
552 This Kconfig allows the kernel to automatically patch the
553 erratum or cpufeature required by the execution platform at run
554 time. The code patching overhead is minimal, as it's only done
555 once at boot and once on each module load.
557 config RISCV_ALTERNATIVE_EARLY
559 depends on RISCV_ALTERNATIVE
561 Allows early patching of the kernel for special errata
564 bool "Emit compressed instructions when building Linux"
567 Adds "C" to the ISA subsets that the toolchain is allowed to emit
568 when building Linux, which results in compressed instructions in the
571 If you don't know what to do here, say Y.
573 config RISCV_ISA_SUPM
574 bool "Supm extension for userspace pointer masking"
578 Add support for pointer masking in userspace (Supm) when the
579 underlying hardware extension (Smnpm or Ssnpm) is detected at boot.
581 If this option is disabled, userspace will be unable to use
582 the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API.
584 config RISCV_ISA_SVNAPOT
585 bool "Svnapot extension support for supervisor mode NAPOT pages"
586 depends on 64BIT && MMU
587 depends on RISCV_ALTERNATIVE
590 Allow kernel to detect the Svnapot ISA-extension dynamically at boot
591 time and enable its usage.
593 The Svnapot extension is used to mark contiguous PTEs as a range
594 of contiguous virtual-to-physical translations for a naturally
595 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
596 size. When HUGETLBFS is also selected this option unconditionally
597 allocates some memory for each NAPOT page size supported by the kernel.
598 When optimizing for low memory consumption and for platforms without
599 the Svnapot extension, it may be better to say N here.
601 If you don't know what to do here, say Y.
603 config RISCV_ISA_SVPBMT
604 bool "Svpbmt extension support for supervisor mode page-based memory types"
605 depends on 64BIT && MMU
606 depends on RISCV_ALTERNATIVE
609 Adds support to dynamically detect the presence of the Svpbmt
610 ISA-extension (Supervisor-mode: page-based memory types) and
613 The memory type for a page contains a combination of attributes
614 that indicate the cacheability, idempotency, and ordering
615 properties for access to that page.
617 The Svpbmt extension is only available on 64-bit cpus.
619 If you don't know what to do here, say Y.
621 config TOOLCHAIN_HAS_V
624 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv)
625 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv)
626 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
627 depends on AS_HAS_OPTION_ARCH
630 bool "VECTOR extension support"
631 depends on TOOLCHAIN_HAS_V
633 select DYNAMIC_SIGFRAME
636 Say N here if you want to disable all vector related procedure
639 If you don't know what to do here, say Y.
641 config RISCV_ISA_V_DEFAULT_ENABLE
642 bool "Enable userspace Vector by default"
643 depends on RISCV_ISA_V
646 Say Y here if you want to enable Vector in userspace by default.
647 Otherwise, userspace has to make explicit prctl() call to enable
648 Vector, or enable it via the sysctl interface.
650 If you don't know what to do here, say Y.
652 config RISCV_ISA_V_UCOPY_THRESHOLD
653 int "Threshold size for vectorized user copies"
654 depends on RISCV_ISA_V
657 Prefer using vectorized copy_to_user()/copy_from_user() when the
658 workload size exceeds this value.
660 config RISCV_ISA_V_PREEMPTIVE
661 bool "Run kernel-mode Vector with kernel preemption"
662 depends on PREEMPTION
663 depends on RISCV_ISA_V
666 Usually, in-kernel SIMD routines are run with preemption disabled.
667 Functions which envoke long running SIMD thus must yield core's
668 vector unit to prevent blocking other tasks for too long.
670 This config allows kernel to run SIMD without explicitly disable
671 preemption. Enabling this config will result in higher memory
672 consumption due to the allocation of per-task's kernel Vector context.
674 config RISCV_ISA_ZAWRS
675 bool "Zawrs extension support for more efficient busy waiting"
676 depends on RISCV_ALTERNATIVE
679 The Zawrs extension defines instructions to be used in polling loops
680 which allow a hart to enter a low-power state or to trap to the
681 hypervisor while waiting on a store to a memory location. Enable the
682 use of these instructions in the kernel when the Zawrs extension is
685 config TOOLCHAIN_HAS_ZABHA
688 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha)
689 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha)
690 depends on AS_HAS_OPTION_ARCH
692 config RISCV_ISA_ZABHA
693 bool "Zabha extension support for atomic byte/halfword operations"
694 depends on TOOLCHAIN_HAS_ZABHA
695 depends on RISCV_ALTERNATIVE
698 Enable the use of the Zabha ISA-extension to implement kernel
699 byte/halfword atomic memory operations when it is detected at boot.
701 If you don't know what to do here, say Y.
703 config TOOLCHAIN_HAS_ZACAS
706 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas)
707 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas)
708 depends on AS_HAS_OPTION_ARCH
710 config RISCV_ISA_ZACAS
711 bool "Zacas extension support for atomic CAS"
712 depends on TOOLCHAIN_HAS_ZACAS
713 depends on RISCV_ALTERNATIVE
716 Enable the use of the Zacas ISA-extension to implement kernel atomic
717 cmpxchg operations when it is detected at boot.
719 If you don't know what to do here, say Y.
721 config TOOLCHAIN_HAS_ZBB
724 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
725 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
726 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
727 depends on AS_HAS_OPTION_ARCH
729 # This symbol indicates that the toolchain supports all v1.0 vector crypto
730 # extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once.
731 # binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb.
732 config TOOLCHAIN_HAS_VECTOR_CRYPTO
733 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
734 depends on AS_HAS_OPTION_ARCH
737 bool "Zba extension support for bit manipulation instructions"
740 Add support for enabling optimisations in the kernel when the Zba
741 extension is detected at boot.
743 The Zba extension provides instructions to accelerate the generation
744 of addresses that index into arrays of basic data types.
746 If you don't know what to do here, say Y.
749 bool "Zbb extension support for bit manipulation instructions"
750 depends on TOOLCHAIN_HAS_ZBB
751 depends on RISCV_ALTERNATIVE
754 Adds support to dynamically detect the presence of the ZBB
755 extension (basic bit manipulation) and enable its usage.
757 The Zbb extension provides instructions to accelerate a number
758 of bit-specific operations (count bit population, sign extending,
761 If you don't know what to do here, say Y.
763 config TOOLCHAIN_HAS_ZBC
766 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
767 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
768 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
769 depends on AS_HAS_OPTION_ARCH
772 bool "Zbc extension support for carry-less multiplication instructions"
773 depends on TOOLCHAIN_HAS_ZBC
775 depends on RISCV_ALTERNATIVE
778 Adds support to dynamically detect the presence of the Zbc
779 extension (carry-less multiplication) and enable its usage.
781 The Zbc extension could accelerate CRC (cyclic redundancy check)
784 If you don't know what to do here, say Y.
786 config RISCV_ISA_ZICBOM
787 bool "Zicbom extension support for non-coherent DMA operation"
789 depends on RISCV_ALTERNATIVE
791 select RISCV_DMA_NONCOHERENT
792 select DMA_DIRECT_REMAP
794 Adds support to dynamically detect the presence of the ZICBOM
795 extension (Cache Block Management Operations) and enable its
798 The Zicbom extension can be used to handle for example
799 non-coherent DMA support on devices that need it.
801 If you don't know what to do here, say Y.
803 config RISCV_ISA_ZICBOZ
804 bool "Zicboz extension support for faster zeroing of memory"
805 depends on RISCV_ALTERNATIVE
808 Enable the use of the Zicboz extension (cbo.zero instruction)
811 The Zicboz extension is used for faster zeroing of memory.
813 If you don't know what to do here, say Y.
815 config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
817 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
818 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
819 depends on AS_IS_GNU && AS_VERSION >= 23600
821 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
822 20191213 version, which moves some instructions from the I extension to
823 the Zicsr and Zifencei extensions. This requires explicitly specifying
824 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
825 and Zifencei are supported in binutils from version 2.36 onwards.
826 To make life easier, and avoid forcing toolchains that default to a
827 newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
828 For clang < 17 or GCC < 11.3.0, for which this is not possible or need
829 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
831 config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
833 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
834 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
835 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
836 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
838 Certain versions of clang and GCC do not support zicsr and zifencei via
839 -march. This option causes an older ISA spec compatible with these older
840 versions of clang and GCC to be passed to GAS, which has the same result
841 as passing zicsr and zifencei to -march.
847 Say N here if you want to disable all floating-point related procedure
850 If you don't know what to do here, say Y.
853 bool "Independent irq & softirq stacks" if EXPERT
855 select HAVE_IRQ_EXIT_ON_IRQ_STACK
856 select HAVE_SOFTIRQ_ON_OWN_STACK
858 Add independent irq & softirq stacks for percpu to prevent kernel stack
859 overflows. We may save some memory footprint by disabling IRQ_STACKS.
861 config THREAD_SIZE_ORDER
862 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
867 Specify the Pages of thread stack size (from 4KB to 64KB), which also
868 affects irq stack size, which is equal to thread stack size.
870 config RISCV_MISALIGNED
873 Embed support for detecting and emulating misaligned
874 scalar or vector loads and stores.
876 config RISCV_SCALAR_MISALIGNED
878 select RISCV_MISALIGNED
879 select SYSCTL_ARCH_UNALIGN_ALLOW
881 Embed support for emulating misaligned loads and stores.
883 config RISCV_VECTOR_MISALIGNED
885 select RISCV_MISALIGNED
886 depends on RISCV_ISA_V
888 Enable detecting support for vector misaligned loads and stores.
891 prompt "Unaligned Accesses Support"
892 default RISCV_PROBE_UNALIGNED_ACCESS
894 This determines the level of support for unaligned accesses. This
895 information is used by the kernel to perform optimizations. It is also
896 exposed to user space via the hwprobe syscall. The hardware will be
897 probed at boot by default.
899 config RISCV_PROBE_UNALIGNED_ACCESS
900 bool "Probe for hardware unaligned access support"
901 select RISCV_SCALAR_MISALIGNED
903 During boot, the kernel will run a series of tests to determine the
904 speed of unaligned accesses. This probing will dynamically determine
905 the speed of unaligned accesses on the underlying system. If unaligned
906 memory accesses trap into the kernel as they are not supported by the
907 system, the kernel will emulate the unaligned accesses to preserve the
910 config RISCV_EMULATED_UNALIGNED_ACCESS
911 bool "Emulate unaligned access where system support is missing"
912 select RISCV_SCALAR_MISALIGNED
914 If unaligned memory accesses trap into the kernel as they are not
915 supported by the system, the kernel will emulate the unaligned
916 accesses to preserve the UABI. When the underlying system does support
917 unaligned accesses, the unaligned accesses are assumed to be slow.
919 config RISCV_SLOW_UNALIGNED_ACCESS
920 bool "Assume the system supports slow unaligned memory accesses"
921 depends on NONPORTABLE
923 Assume that the system supports slow unaligned memory accesses. The
924 kernel and userspace programs may not be able to run at all on systems
925 that do not support unaligned memory accesses.
927 config RISCV_EFFICIENT_UNALIGNED_ACCESS
928 bool "Assume the system supports fast unaligned memory accesses"
929 depends on NONPORTABLE
930 select DCACHE_WORD_ACCESS if MMU
931 select HAVE_EFFICIENT_UNALIGNED_ACCESS
933 Assume that the system supports fast unaligned memory accesses. When
934 enabled, this option improves the performance of the kernel on such
935 systems. However, the kernel and userspace programs will run much more
936 slowly, or will not be able to run at all, on systems that do not
937 support efficient unaligned memory accesses.
942 prompt "Vector unaligned Accesses Support"
943 depends on RISCV_ISA_V
944 default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
946 This determines the level of support for vector unaligned accesses. This
947 information is used by the kernel to perform optimizations. It is also
948 exposed to user space via the hwprobe syscall. The hardware will be
949 probed at boot by default.
951 config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
952 bool "Probe speed of vector unaligned accesses"
953 select RISCV_VECTOR_MISALIGNED
954 depends on RISCV_ISA_V
956 During boot, the kernel will run a series of tests to determine the
957 speed of vector unaligned accesses if they are supported. This probing
958 will dynamically determine the speed of vector unaligned accesses on
959 the underlying system if they are supported.
961 config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
962 bool "Assume the system supports slow vector unaligned memory accesses"
963 depends on NONPORTABLE
965 Assume that the system supports slow vector unaligned memory accesses. The
966 kernel and userspace programs may not be able to run at all on systems
967 that do not support unaligned memory accesses.
969 config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
970 bool "Assume the system supports fast vector unaligned memory accesses"
971 depends on NONPORTABLE
973 Assume that the system supports fast vector unaligned memory accesses. When
974 enabled, this option improves the performance of the kernel on such
975 systems. However, the kernel and userspace programs will run much more
976 slowly, or will not be able to run at all, on systems that do not
977 support efficient unaligned memory accesses.
981 source "arch/riscv/Kconfig.vendor"
983 endmenu # "Platform type"
985 menu "Kernel features"
987 source "kernel/Kconfig.hz"
990 bool "SBI v0.1 support"
993 This config allows kernel to use SBI v0.1 APIs. This will be
994 deprecated in future once legacy M-mode software are no longer in use.
996 config RISCV_BOOT_SPINWAIT
997 bool "Spinwait booting method"
999 default y if RISCV_SBI_V01 || RISCV_M_MODE
1001 This enables support for booting Linux via spinwait method. In the
1002 spinwait method, all cores randomly jump to Linux. One of the cores
1003 gets chosen via lottery and all other keep spinning on a percpu
1004 variable. This method cannot support CPU hotplug and sparse hartid
1005 scheme. It should be only enabled for M-mode Linux or platforms relying
1006 on older firmware without SBI HSM extension. All other platforms should
1007 rely on ordered booting via SBI HSM extension which gets chosen
1008 dynamically at runtime if the firmware supports it.
1010 Since spinwait is incompatible with sparse hart IDs, it requires
1011 NR_CPUS be large enough to contain the physical hart ID of the first
1012 hart to enter Linux.
1014 If unsure what to do here, say N.
1016 config ARCH_SUPPORTS_KEXEC
1019 config ARCH_SELECTS_KEXEC
1022 select HOTPLUG_CPU if SMP
1024 config ARCH_SUPPORTS_KEXEC_FILE
1027 config ARCH_SELECTS_KEXEC_FILE
1029 depends on KEXEC_FILE
1030 select HAVE_IMA_KEXEC if IMA
1033 config ARCH_SUPPORTS_KEXEC_PURGATORY
1034 def_bool ARCH_SUPPORTS_KEXEC_FILE
1036 config ARCH_SUPPORTS_CRASH_DUMP
1039 config ARCH_DEFAULT_CRASH_DUMP
1042 config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1043 def_bool CRASH_RESERVE
1046 bool "Kernel support for 32-bit U-mode"
1048 depends on 64BIT && MMU
1050 This option enables support for a 32-bit U-mode running under a 64-bit
1051 kernel at S-mode. riscv32-specific components such as system calls,
1052 the user helper functions (vdso), signal rt_frame functions and the
1053 ptrace interface are handled appropriately by the kernel.
1055 If you want to execute 32-bit userspace applications, say Y.
1058 bool "Enable paravirtualization code"
1059 depends on RISCV_SBI
1061 This changes the kernel so it can modify itself when it is run
1062 under a hypervisor, potentially improving performance significantly
1063 over full virtualization.
1065 config PARAVIRT_TIME_ACCOUNTING
1066 bool "Paravirtual steal time accounting"
1069 Select this option to enable fine granularity task steal time
1070 accounting. Time spent executing other tasks in parallel with
1071 the current vCPU is discounted from the vCPU power. To account for
1072 that, there can be a small performance impact.
1074 If in doubt, say N here.
1077 bool "Build a relocatable kernel"
1078 depends on MMU && 64BIT && !XIP_KERNEL
1079 select MODULE_SECTIONS if MODULES
1081 This builds a kernel as a Position Independent Executable (PIE),
1082 which retains all relocation metadata required to relocate the
1083 kernel binary at runtime to a different virtual address than the
1084 address it was linked at.
1085 Since RISCV uses the RELA relocation format, this requires a
1086 relocation pass at runtime even if the kernel is loaded at the
1087 same address it was linked at.
1091 config RANDOMIZE_BASE
1092 bool "Randomize the address of the kernel image"
1094 depends on MMU && 64BIT && !XIP_KERNEL
1096 Randomizes the virtual address at which the kernel image is
1097 loaded, as a security feature that deters exploit attempts
1098 relying on knowledge of the location of kernel internals.
1100 It is the bootloader's job to provide entropy, by passing a
1101 random u64 value in /chosen/kaslr-seed at kernel entry.
1103 When booting via the UEFI stub, it will invoke the firmware's
1104 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1105 to the kernel proper. In addition, it will randomise the physical
1106 location of the kernel Image as well.
1110 endmenu # "Kernel features"
1115 string "Built-in kernel command line"
1117 For most platforms, the arguments for the kernel's command line
1118 are provided at run-time, during boot. However, there are cases
1119 where either no arguments are being provided or the provided
1120 arguments are insufficient or even invalid.
1122 When that occurs, it is possible to define a built-in command
1123 line here and choose how the kernel should use it later on.
1126 prompt "Built-in command line usage"
1127 depends on CMDLINE != ""
1128 default CMDLINE_FALLBACK
1130 Choose how the kernel will handle the provided built-in command
1133 config CMDLINE_FALLBACK
1134 bool "Use bootloader kernel arguments if available"
1136 Use the built-in command line as fallback in case we get nothing
1137 during boot. This is the default behaviour.
1139 config CMDLINE_EXTEND
1140 bool "Extend bootloader kernel arguments"
1142 The command-line arguments provided during boot will be
1143 appended to the built-in command line. This is useful in
1144 cases where the provided arguments are insufficient and
1145 you don't want to or cannot modify them.
1147 config CMDLINE_FORCE
1148 bool "Always use the default kernel command string"
1150 Always use the built-in command line, even if we get one during
1151 boot. This is useful in case you need to override the provided
1152 command line on systems where you don't have or want control
1161 bool "UEFI runtime support"
1162 depends on OF && !XIP_KERNEL
1165 select ARCH_SUPPORTS_ACPI if 64BIT
1166 select EFI_GENERIC_STUB
1167 select EFI_PARAMS_FROM_FDT
1168 select EFI_RUNTIME_WRAPPERS
1174 This option provides support for runtime services provided
1175 by UEFI firmware (such as non-volatile variables, realtime
1176 clock, and platform reset). A UEFI stub is also provided to
1177 allow the kernel to be booted as an EFI application. This
1178 is only useful on systems that have UEFI firmware.
1181 bool "Enable support for SMBIOS (DMI) tables"
1185 This enables SMBIOS/DMI feature for systems.
1187 This option is only useful on systems that have UEFI firmware.
1188 However, even with this option, the resultant kernel should
1189 continue to boot on existing non-UEFI platforms.
1191 config CC_HAVE_STACKPROTECTOR_TLS
1192 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
1194 config STACKPROTECTOR_PER_TASK
1196 depends on !RANDSTRUCT
1197 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
1199 config PHYS_RAM_BASE_FIXED
1200 bool "Explicitly specified physical RAM address"
1201 depends on NONPORTABLE
1204 config PHYS_RAM_BASE
1205 hex "Platform Physical RAM address"
1206 depends on PHYS_RAM_BASE_FIXED
1207 default "0x80000000"
1209 This is the physical address of RAM in the system. It has to be
1210 explicitly specified to run early relocations of read-write data
1214 bool "Kernel Execute-In-Place from ROM"
1215 depends on MMU && SPARSEMEM && NONPORTABLE
1216 # This prevents XIP from being enabled by all{yes,mod}config, which
1217 # fail to build since XIP doesn't support large kernels.
1218 depends on !COMPILE_TEST
1219 select PHYS_RAM_BASE_FIXED
1221 Execute-In-Place allows the kernel to run from non-volatile storage
1222 directly addressable by the CPU, such as NOR flash. This saves RAM
1223 space since the text section of the kernel is not loaded from flash
1224 to RAM. Read-write sections, such as the data section and stack,
1225 are still copied to RAM. The XIP kernel is not compressed since
1226 it has to run directly from flash, so it will take more space to
1227 store it. The flash address used to link the kernel object files,
1228 and for storing it, is configuration dependent. Therefore, if you
1229 say Y here, you must know the proper physical address where to
1230 store the kernel image depending on your own flash memory usage.
1232 Also note that the make target becomes "make xipImage" rather than
1233 "make zImage" or "make Image". The final kernel binary to put in
1234 ROM memory will be arch/riscv/boot/xipImage.
1236 SPARSEMEM is required because the kernel text and rodata that are
1237 flash resident are not backed by memmap, then any attempt to get
1238 a struct page on those regions will trigger a fault.
1242 config XIP_PHYS_ADDR
1243 hex "XIP Kernel Physical Location"
1244 depends on XIP_KERNEL
1245 default "0x21000000"
1247 This is the physical address in your flash memory the kernel will
1248 be linked for and stored to. This address is dependent on your
1251 config RISCV_ISA_FALLBACK
1252 bool "Permit falling back to parsing riscv,isa for extension support by default"
1255 Parsing the "riscv,isa" devicetree property has been deprecated and
1256 replaced by a list of explicitly defined strings. For compatibility
1257 with existing platforms, the kernel will fall back to parsing the
1258 "riscv,isa" property if the replacements are not found.
1260 Selecting N here will result in a kernel that does not use the
1261 fallback, unless the commandline "riscv_isa_fallback" parameter is
1264 Please see the dt-binding, located at
1265 Documentation/devicetree/bindings/riscv/extensions.yaml for details
1266 on the replacement properties, "riscv,isa-base" and
1267 "riscv,isa-extensions".
1270 bool "Built-in device tree"
1271 depends on OF && NONPORTABLE
1273 Build a device tree into the Linux image.
1274 This option should be selected if no bootloader is being used.
1278 config BUILTIN_DTB_SOURCE
1279 string "Built-in device tree source"
1280 depends on BUILTIN_DTB
1282 DTS file path (without suffix, relative to arch/riscv/boot/dts)
1283 for the DTS file that will be used to produce the DTB linked into the
1286 endmenu # "Boot options"
1290 default !NONPORTABLE
1295 config ARCH_PROC_KCORE_TEXT
1298 menu "Power management options"
1300 source "kernel/power/Kconfig"
1302 config ARCH_HIBERNATION_POSSIBLE
1305 config ARCH_HIBERNATION_HEADER
1306 def_bool HIBERNATION
1308 config ARCH_SUSPEND_POSSIBLE
1311 endmenu # "Power management options"
1313 menu "CPU Power Management"
1315 source "drivers/cpuidle/Kconfig"
1317 source "drivers/cpufreq/Kconfig"
1319 endmenu # "CPU Power Management"
1321 source "arch/riscv/kvm/Kconfig"
1323 source "drivers/acpi/Kconfig"