xref: /linux/arch/riscv/Kconfig (revision 0340dc4c82590d8735c58cf904a8aa1173273ab5)
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
7config 64BIT
8	bool
9
10config 32BIT
11	bool
12
13config RISCV
14	def_bool y
15	select ACPI_GENERIC_GSI if ACPI
16	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
17	select ARCH_DMA_DEFAULT_COHERENT
18	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
19	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
20	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
21	select ARCH_HAS_BINFMT_FLAT
22	select ARCH_HAS_CURRENT_STACK_POINTER
23	select ARCH_HAS_DEBUG_VIRTUAL if MMU
24	select ARCH_HAS_DEBUG_VM_PGTABLE
25	select ARCH_HAS_DEBUG_WX
26	select ARCH_HAS_FORTIFY_SOURCE
27	select ARCH_HAS_GCOV_PROFILE_ALL
28	select ARCH_HAS_GIGANTIC_PAGE
29	select ARCH_HAS_KCOV
30	select ARCH_HAS_MEMBARRIER_CALLBACKS
31	select ARCH_HAS_MEMBARRIER_SYNC_CORE
32	select ARCH_HAS_MMIOWB
33	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
34	select ARCH_HAS_PMEM_API
35	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
36	select ARCH_HAS_PTE_SPECIAL
37	select ARCH_HAS_SET_DIRECT_MAP if MMU
38	select ARCH_HAS_SET_MEMORY if MMU
39	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
40	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
41	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
42	select ARCH_HAS_SYSCALL_WRAPPER
43	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
44	select ARCH_HAS_UBSAN
45	select ARCH_HAS_VDSO_DATA
46	select ARCH_KEEP_MEMBLOCK if ACPI
47	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
48	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
49	select ARCH_STACKWALK
50	select ARCH_SUPPORTS_ATOMIC_RMW
51	select ARCH_SUPPORTS_CFI_CLANG
52	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
53	select ARCH_SUPPORTS_HUGETLBFS if MMU
54	# LLD >= 14: https://github.com/llvm/llvm-project/issues/50505
55	select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000
56	select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000
57	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
58	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
59	select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
60	select ARCH_USE_MEMTEST
61	select ARCH_USE_QUEUED_RWLOCKS
62	select ARCH_USES_CFI_TRAPS if CFI_CLANG
63	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP && MMU
64	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
65	select ARCH_WANT_FRAME_POINTERS
66	select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
67	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
68	select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
69	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
70	select ARCH_WANTS_NO_INSTR
71	select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
72	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
73	select BUILDTIME_TABLE_SORT if MMU
74	select CLINT_TIMER if !MMU
75	select CLONE_BACKWARDS
76	select COMMON_CLK
77	select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
78	select EDAC_SUPPORT
79	select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
80	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
81	select GENERIC_ARCH_TOPOLOGY
82	select GENERIC_ATOMIC64 if !64BIT
83	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
84	select GENERIC_CPU_DEVICES
85	select GENERIC_EARLY_IOREMAP
86	select GENERIC_ENTRY
87	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
88	select GENERIC_IDLE_POLL_SETUP
89	select GENERIC_IOREMAP if MMU
90	select GENERIC_IRQ_IPI if SMP
91	select GENERIC_IRQ_IPI_MUX if SMP
92	select GENERIC_IRQ_MULTI_HANDLER
93	select GENERIC_IRQ_SHOW
94	select GENERIC_IRQ_SHOW_LEVEL
95	select GENERIC_LIB_DEVMEM_IS_ALLOWED
96	select GENERIC_PCI_IOMAP
97	select GENERIC_PTDUMP if MMU
98	select GENERIC_SCHED_CLOCK
99	select GENERIC_SMP_IDLE_THREAD
100	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
101	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
102	select HARDIRQS_SW_RESEND
103	select HAS_IOPORT if MMU
104	select HAVE_ARCH_AUDITSYSCALL
105	select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
106	select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL
107	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
108	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
109	select HAVE_ARCH_KASAN if MMU && 64BIT
110	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
111	select HAVE_ARCH_KFENCE if MMU && 64BIT
112	select HAVE_ARCH_KGDB if !XIP_KERNEL
113	select HAVE_ARCH_KGDB_QXFER_PKT
114	select HAVE_ARCH_MMAP_RND_BITS if MMU
115	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
116	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
117	select HAVE_ARCH_SECCOMP_FILTER
118	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
119	select HAVE_ARCH_TRACEHOOK
120	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
121	select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
122	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
123	select HAVE_ASM_MODVERSIONS
124	select HAVE_CONTEXT_TRACKING_USER
125	select HAVE_DEBUG_KMEMLEAK
126	select HAVE_DMA_CONTIGUOUS if MMU
127	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
128	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
129	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
130	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
131	select HAVE_FUNCTION_GRAPH_TRACER
132	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
133	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
134	select HAVE_EBPF_JIT if MMU
135	select HAVE_FAST_GUP if MMU
136	select HAVE_FUNCTION_ARG_ACCESS_API
137	select HAVE_FUNCTION_ERROR_INJECTION
138	select HAVE_GCC_PLUGINS
139	select HAVE_GENERIC_VDSO if MMU && 64BIT
140	select HAVE_IRQ_TIME_ACCOUNTING
141	select HAVE_KPROBES if !XIP_KERNEL
142	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
143	select HAVE_KRETPROBES if !XIP_KERNEL
144	# https://github.com/ClangBuiltLinux/linux/issues/1881
145	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
146	select HAVE_MOVE_PMD
147	select HAVE_MOVE_PUD
148	select HAVE_PAGE_SIZE_4KB
149	select HAVE_PCI
150	select HAVE_PERF_EVENTS
151	select HAVE_PERF_REGS
152	select HAVE_PERF_USER_STACK_DUMP
153	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
154	select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
155	select HAVE_REGS_AND_STACK_ACCESS_API
156	select HAVE_RETHOOK if !XIP_KERNEL
157	select HAVE_RSEQ
158	select HAVE_SAMPLE_FTRACE_DIRECT
159	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
160	select HAVE_STACKPROTECTOR
161	select HAVE_SYSCALL_TRACEPOINTS
162	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
163	select IRQ_DOMAIN
164	select IRQ_FORCED_THREADING
165	select KASAN_VMALLOC if KASAN
166	select LOCK_MM_AND_FIND_VMA
167	select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU
168	select MODULES_USE_ELF_RELA if MODULES
169	select MODULE_SECTIONS if MODULES
170	select OF
171	select OF_EARLY_FLATTREE
172	select OF_IRQ
173	select PCI_DOMAINS_GENERIC if PCI
174	select PCI_MSI if PCI
175	select RISCV_ALTERNATIVE if !XIP_KERNEL
176	select RISCV_INTC
177	select RISCV_TIMER if RISCV_SBI
178	select SIFIVE_PLIC
179	select SPARSE_IRQ
180	select SYSCTL_EXCEPTION_TRACE
181	select THREAD_INFO_IN_TASK
182	select TRACE_IRQFLAGS_SUPPORT
183	select UACCESS_MEMCPY if !MMU
184	select ZONE_DMA32 if 64BIT
185
186config CLANG_SUPPORTS_DYNAMIC_FTRACE
187	def_bool CC_IS_CLANG
188	# https://github.com/ClangBuiltLinux/linux/issues/1817
189	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
190
191config GCC_SUPPORTS_DYNAMIC_FTRACE
192	def_bool CC_IS_GCC
193	depends on $(cc-option,-fpatchable-function-entry=8)
194
195config HAVE_SHADOW_CALL_STACK
196	def_bool $(cc-option,-fsanitize=shadow-call-stack)
197	# https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
198	depends on $(ld-option,--no-relax-gp)
199
200config RISCV_USE_LINKER_RELAXATION
201	def_bool y
202	# https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
203	depends on !LD_IS_LLD || LLD_VERSION >= 150000
204
205# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
206config ARCH_HAS_BROKEN_DWARF5
207	def_bool y
208	depends on RISCV_USE_LINKER_RELAXATION
209	# https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
210	depends on AS_IS_LLVM && AS_VERSION < 180000
211	# https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
212	depends on LD_IS_LLD && LLD_VERSION < 180000
213
214config ARCH_MMAP_RND_BITS_MIN
215	default 18 if 64BIT
216	default 8
217
218config ARCH_MMAP_RND_COMPAT_BITS_MIN
219	default 8
220
221# max bits determined by the following formula:
222#  VA_BITS - PAGE_SHIFT - 3
223config ARCH_MMAP_RND_BITS_MAX
224	default 24 if 64BIT # SV39 based
225	default 17
226
227config ARCH_MMAP_RND_COMPAT_BITS_MAX
228	default 17
229
230# set if we run in machine mode, cleared if we run in supervisor mode
231config RISCV_M_MODE
232	bool
233	default !MMU
234
235# set if we are running in S-mode and can use SBI calls
236config RISCV_SBI
237	bool
238	depends on !RISCV_M_MODE
239	default y
240
241config MMU
242	bool "MMU-based Paged Memory Management Support"
243	default y
244	help
245	  Select if you want MMU-based virtualised addressing space
246	  support by paged memory management. If unsure, say 'Y'.
247
248config PAGE_OFFSET
249	hex
250	default 0xC0000000 if 32BIT && MMU
251	default 0x80000000 if !MMU
252	default 0xff60000000000000 if 64BIT
253
254config KASAN_SHADOW_OFFSET
255	hex
256	depends on KASAN_GENERIC
257	default 0xdfffffff00000000 if 64BIT
258	default 0xffffffff if 32BIT
259
260config ARCH_FLATMEM_ENABLE
261	def_bool !NUMA
262
263config ARCH_SPARSEMEM_ENABLE
264	def_bool y
265	depends on MMU
266	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
267	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
268
269config ARCH_SELECT_MEMORY_MODEL
270	def_bool ARCH_SPARSEMEM_ENABLE
271
272config ARCH_SUPPORTS_UPROBES
273	def_bool y
274
275config STACKTRACE_SUPPORT
276	def_bool y
277
278config GENERIC_BUG
279	def_bool y
280	depends on BUG
281	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
282
283config GENERIC_BUG_RELATIVE_POINTERS
284	bool
285
286config GENERIC_CALIBRATE_DELAY
287	def_bool y
288
289config GENERIC_CSUM
290	def_bool y
291
292config GENERIC_HWEIGHT
293	def_bool y
294
295config FIX_EARLYCON_MEM
296	def_bool MMU
297
298config PGTABLE_LEVELS
299	int
300	default 5 if 64BIT
301	default 2
302
303config LOCKDEP_SUPPORT
304	def_bool y
305
306config RISCV_DMA_NONCOHERENT
307	bool
308	select ARCH_HAS_DMA_PREP_COHERENT
309	select ARCH_HAS_SETUP_DMA_OPS
310	select ARCH_HAS_SYNC_DMA_FOR_CPU
311	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
312	select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
313
314config RISCV_NONSTANDARD_CACHE_OPS
315	bool
316	help
317	  This enables function pointer support for non-standard noncoherent
318	  systems to handle cache management.
319
320config AS_HAS_INSN
321	def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
322
323config AS_HAS_OPTION_ARCH
324	# https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4
325	def_bool y
326	depends on $(as-instr, .option arch$(comma) +m)
327
328source "arch/riscv/Kconfig.socs"
329source "arch/riscv/Kconfig.errata"
330
331menu "Platform type"
332
333config NONPORTABLE
334	bool "Allow configurations that result in non-portable kernels"
335	help
336	  RISC-V kernel binaries are compatible between all known systems
337	  whenever possible, but there are some use cases that can only be
338	  satisfied by configurations that result in kernel binaries that are
339	  not portable between systems.
340
341	  Selecting N does not guarantee kernels will be portable to all known
342	  systems.  Selecting any of the options guarded by NONPORTABLE will
343	  result in kernel binaries that are unlikely to be portable between
344	  systems.
345
346	  If unsure, say N.
347
348choice
349	prompt "Base ISA"
350	default ARCH_RV64I
351	help
352	  This selects the base ISA that this kernel will target and must match
353	  the target platform.
354
355config ARCH_RV32I
356	bool "RV32I"
357	depends on NONPORTABLE
358	select 32BIT
359	select GENERIC_LIB_ASHLDI3
360	select GENERIC_LIB_ASHRDI3
361	select GENERIC_LIB_LSHRDI3
362	select GENERIC_LIB_UCMPDI2
363
364config ARCH_RV64I
365	bool "RV64I"
366	select 64BIT
367	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
368	select SWIOTLB if MMU
369
370endchoice
371
372# We must be able to map all physical memory into the kernel, but the compiler
373# is still a bit more efficient when generating code if it's setup in a manner
374# such that it can only map 2GiB of memory.
375choice
376	prompt "Kernel Code Model"
377	default CMODEL_MEDLOW if 32BIT
378	default CMODEL_MEDANY if 64BIT
379
380	config CMODEL_MEDLOW
381		bool "medium low code model"
382	config CMODEL_MEDANY
383		bool "medium any code model"
384endchoice
385
386config MODULE_SECTIONS
387	bool
388	select HAVE_MOD_ARCH_SPECIFIC
389
390config SMP
391	bool "Symmetric Multi-Processing"
392	help
393	  This enables support for systems with more than one CPU.  If
394	  you say N here, the kernel will run on single and
395	  multiprocessor machines, but will use only one CPU of a
396	  multiprocessor machine. If you say Y here, the kernel will run
397	  on many, but not all, single processor machines. On a single
398	  processor machine, the kernel will run faster if you say N
399	  here.
400
401	  If you don't know what to do here, say N.
402
403config SCHED_MC
404	bool "Multi-core scheduler support"
405	depends on SMP
406	help
407	  Multi-core scheduler support improves the CPU scheduler's decision
408	  making when dealing with multi-core CPU chips at a cost of slightly
409	  increased overhead in some places. If unsure say N here.
410
411config NR_CPUS
412	int "Maximum number of CPUs (2-512)"
413	depends on SMP
414	range 2 512 if !RISCV_SBI_V01
415	range 2 32 if RISCV_SBI_V01 && 32BIT
416	range 2 64 if RISCV_SBI_V01 && 64BIT
417	default "32" if 32BIT
418	default "64" if 64BIT
419
420config HOTPLUG_CPU
421	bool "Support for hot-pluggable CPUs"
422	depends on SMP
423	select GENERIC_IRQ_MIGRATION
424	help
425
426	  Say Y here to experiment with turning CPUs off and on.  CPUs
427	  can be controlled through /sys/devices/system/cpu.
428
429	  Say N if you want to disable CPU hotplug.
430
431choice
432	prompt "CPU Tuning"
433	default TUNE_GENERIC
434
435config TUNE_GENERIC
436	bool "generic"
437
438endchoice
439
440# Common NUMA Features
441config NUMA
442	bool "NUMA Memory Allocation and Scheduler Support"
443	depends on SMP && MMU
444	select ARCH_SUPPORTS_NUMA_BALANCING
445	select GENERIC_ARCH_NUMA
446	select HAVE_SETUP_PER_CPU_AREA
447	select NEED_PER_CPU_EMBED_FIRST_CHUNK
448	select NEED_PER_CPU_PAGE_FIRST_CHUNK
449	select OF_NUMA
450	select USE_PERCPU_NUMA_NODE_ID
451	help
452	  Enable NUMA (Non-Uniform Memory Access) support.
453
454	  The kernel will try to allocate memory used by a CPU on the
455	  local memory of the CPU and add some more NUMA awareness to the kernel.
456
457config NODES_SHIFT
458	int "Maximum NUMA Nodes (as a power of 2)"
459	range 1 10
460	default "2"
461	depends on NUMA
462	help
463	  Specify the maximum number of NUMA Nodes available on the target
464	  system.  Increases memory reserved to accommodate various tables.
465
466config RISCV_ALTERNATIVE
467	bool
468	depends on !XIP_KERNEL
469	help
470	  This Kconfig allows the kernel to automatically patch the
471	  erratum or cpufeature required by the execution platform at run
472	  time. The code patching overhead is minimal, as it's only done
473	  once at boot and once on each module load.
474
475config RISCV_ALTERNATIVE_EARLY
476	bool
477	depends on RISCV_ALTERNATIVE
478	help
479	  Allows early patching of the kernel for special errata
480
481config RISCV_ISA_C
482	bool "Emit compressed instructions when building Linux"
483	default y
484	help
485	  Adds "C" to the ISA subsets that the toolchain is allowed to emit
486	  when building Linux, which results in compressed instructions in the
487	  Linux binary.
488
489	  If you don't know what to do here, say Y.
490
491config RISCV_ISA_SVNAPOT
492	bool "Svnapot extension support for supervisor mode NAPOT pages"
493	depends on 64BIT && MMU
494	depends on RISCV_ALTERNATIVE
495	default y
496	help
497	  Allow kernel to detect the Svnapot ISA-extension dynamically at boot
498	  time and enable its usage.
499
500	  The Svnapot extension is used to mark contiguous PTEs as a range
501	  of contiguous virtual-to-physical translations for a naturally
502	  aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
503	  size. When HUGETLBFS is also selected this option unconditionally
504	  allocates some memory for each NAPOT page size supported by the kernel.
505	  When optimizing for low memory consumption and for platforms without
506	  the Svnapot extension, it may be better to say N here.
507
508	  If you don't know what to do here, say Y.
509
510config RISCV_ISA_SVPBMT
511	bool "Svpbmt extension support for supervisor mode page-based memory types"
512	depends on 64BIT && MMU
513	depends on RISCV_ALTERNATIVE
514	default y
515	help
516	   Adds support to dynamically detect the presence of the Svpbmt
517	   ISA-extension (Supervisor-mode: page-based memory types) and
518	   enable its usage.
519
520	   The memory type for a page contains a combination of attributes
521	   that indicate the cacheability, idempotency, and ordering
522	   properties for access to that page.
523
524	   The Svpbmt extension is only available on 64-bit cpus.
525
526	   If you don't know what to do here, say Y.
527
528config TOOLCHAIN_HAS_V
529	bool
530	default y
531	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv)
532	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv)
533	depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
534	depends on AS_HAS_OPTION_ARCH
535
536config RISCV_ISA_V
537	bool "VECTOR extension support"
538	depends on TOOLCHAIN_HAS_V
539	depends on FPU
540	select DYNAMIC_SIGFRAME
541	default y
542	help
543	  Say N here if you want to disable all vector related procedure
544	  in the kernel.
545
546	  If you don't know what to do here, say Y.
547
548config RISCV_ISA_V_DEFAULT_ENABLE
549	bool "Enable userspace Vector by default"
550	depends on RISCV_ISA_V
551	default y
552	help
553	  Say Y here if you want to enable Vector in userspace by default.
554	  Otherwise, userspace has to make explicit prctl() call to enable
555	  Vector, or enable it via the sysctl interface.
556
557	  If you don't know what to do here, say Y.
558
559config RISCV_ISA_V_UCOPY_THRESHOLD
560	int "Threshold size for vectorized user copies"
561	depends on RISCV_ISA_V
562	default 768
563	help
564	  Prefer using vectorized copy_to_user()/copy_from_user() when the
565	  workload size exceeds this value.
566
567config RISCV_ISA_V_PREEMPTIVE
568	bool "Run kernel-mode Vector with kernel preemption"
569	depends on PREEMPTION
570	depends on RISCV_ISA_V
571	default y
572	help
573	  Usually, in-kernel SIMD routines are run with preemption disabled.
574	  Functions which envoke long running SIMD thus must yield core's
575	  vector unit to prevent blocking other tasks for too long.
576
577	  This config allows kernel to run SIMD without explicitly disable
578	  preemption. Enabling this config will result in higher memory
579	  consumption due to the allocation of per-task's kernel Vector context.
580
581config TOOLCHAIN_HAS_ZBB
582	bool
583	default y
584	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
585	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
586	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
587	depends on AS_HAS_OPTION_ARCH
588
589# This symbol indicates that the toolchain supports all v1.0 vector crypto
590# extensions, including Zvk*, Zvbb, and Zvbc.  LLVM added all of these at once.
591# binutils added all except Zvkb, then added Zvkb.  So we just check for Zvkb.
592config TOOLCHAIN_HAS_VECTOR_CRYPTO
593	def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
594	depends on AS_HAS_OPTION_ARCH
595
596config RISCV_ISA_ZBB
597	bool "Zbb extension support for bit manipulation instructions"
598	depends on TOOLCHAIN_HAS_ZBB
599	depends on MMU
600	depends on RISCV_ALTERNATIVE
601	default y
602	help
603	   Adds support to dynamically detect the presence of the ZBB
604	   extension (basic bit manipulation) and enable its usage.
605
606	   The Zbb extension provides instructions to accelerate a number
607	   of bit-specific operations (count bit population, sign extending,
608	   bitrotation, etc).
609
610	   If you don't know what to do here, say Y.
611
612config RISCV_ISA_ZICBOM
613	bool "Zicbom extension support for non-coherent DMA operation"
614	depends on MMU
615	depends on RISCV_ALTERNATIVE
616	default y
617	select RISCV_DMA_NONCOHERENT
618	select DMA_DIRECT_REMAP
619	help
620	   Adds support to dynamically detect the presence of the ZICBOM
621	   extension (Cache Block Management Operations) and enable its
622	   usage.
623
624	   The Zicbom extension can be used to handle for example
625	   non-coherent DMA support on devices that need it.
626
627	   If you don't know what to do here, say Y.
628
629config RISCV_ISA_ZICBOZ
630	bool "Zicboz extension support for faster zeroing of memory"
631	depends on MMU
632	depends on RISCV_ALTERNATIVE
633	default y
634	help
635	   Enable the use of the Zicboz extension (cbo.zero instruction)
636	   when available.
637
638	   The Zicboz extension is used for faster zeroing of memory.
639
640	   If you don't know what to do here, say Y.
641
642config TOOLCHAIN_HAS_ZIHINTPAUSE
643	bool
644	default y
645	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
646	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
647	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
648
649config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
650	def_bool y
651	# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
652	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
653	depends on AS_IS_GNU && AS_VERSION >= 23600
654	help
655	  Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
656	  20191213 version, which moves some instructions from the I extension to
657	  the Zicsr and Zifencei extensions. This requires explicitly specifying
658	  Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
659	  and Zifencei are supported in binutils from version 2.36 onwards.
660	  To make life easier, and avoid forcing toolchains that default to a
661	  newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
662	  For clang < 17 or GCC < 11.3.0, for which this is not possible or need
663	  special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
664
665config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
666	def_bool y
667	depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
668	# https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
669	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
670	depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
671	help
672	  Certain versions of clang and GCC do not support zicsr and zifencei via
673	  -march. This option causes an older ISA spec compatible with these older
674	  versions of clang and GCC to be passed to GAS, which has the same result
675	  as passing zicsr and zifencei to -march.
676
677config FPU
678	bool "FPU support"
679	default y
680	help
681	  Say N here if you want to disable all floating-point related procedure
682	  in the kernel.
683
684	  If you don't know what to do here, say Y.
685
686config IRQ_STACKS
687	bool "Independent irq & softirq stacks" if EXPERT
688	default y
689	select HAVE_IRQ_EXIT_ON_IRQ_STACK
690	select HAVE_SOFTIRQ_ON_OWN_STACK
691	help
692	  Add independent irq & softirq stacks for percpu to prevent kernel stack
693	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
694
695config THREAD_SIZE_ORDER
696	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
697	range 0 4
698	default 1 if 32BIT && !KASAN
699	default 3 if 64BIT && KASAN
700	default 2
701	help
702	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
703	  affects irq stack size, which is equal to thread stack size.
704
705config RISCV_MISALIGNED
706	bool
707	select SYSCTL_ARCH_UNALIGN_ALLOW
708	help
709	  Embed support for emulating misaligned loads and stores.
710
711choice
712	prompt "Unaligned Accesses Support"
713	default RISCV_PROBE_UNALIGNED_ACCESS
714	help
715	  This determines the level of support for unaligned accesses. This
716	  information is used by the kernel to perform optimizations. It is also
717	  exposed to user space via the hwprobe syscall. The hardware will be
718	  probed at boot by default.
719
720config RISCV_PROBE_UNALIGNED_ACCESS
721	bool "Probe for hardware unaligned access support"
722	select RISCV_MISALIGNED
723	help
724	  During boot, the kernel will run a series of tests to determine the
725	  speed of unaligned accesses. This probing will dynamically determine
726	  the speed of unaligned accesses on the underlying system. If unaligned
727	  memory accesses trap into the kernel as they are not supported by the
728	  system, the kernel will emulate the unaligned accesses to preserve the
729	  UABI.
730
731config RISCV_EMULATED_UNALIGNED_ACCESS
732	bool "Emulate unaligned access where system support is missing"
733	select RISCV_MISALIGNED
734	help
735	  If unaligned memory accesses trap into the kernel as they are not
736	  supported by the system, the kernel will emulate the unaligned
737	  accesses to preserve the UABI. When the underlying system does support
738	  unaligned accesses, the unaligned accesses are assumed to be slow.
739
740config RISCV_SLOW_UNALIGNED_ACCESS
741	bool "Assume the system supports slow unaligned memory accesses"
742	depends on NONPORTABLE
743	help
744	  Assume that the system supports slow unaligned memory accesses. The
745	  kernel and userspace programs may not be able to run at all on systems
746	  that do not support unaligned memory accesses.
747
748config RISCV_EFFICIENT_UNALIGNED_ACCESS
749	bool "Assume the system supports fast unaligned memory accesses"
750	depends on NONPORTABLE
751	select DCACHE_WORD_ACCESS if MMU
752	select HAVE_EFFICIENT_UNALIGNED_ACCESS
753	help
754	  Assume that the system supports fast unaligned memory accesses. When
755	  enabled, this option improves the performance of the kernel on such
756	  systems. However, the kernel and userspace programs will run much more
757	  slowly, or will not be able to run at all, on systems that do not
758	  support efficient unaligned memory accesses.
759
760endchoice
761
762endmenu # "Platform type"
763
764menu "Kernel features"
765
766source "kernel/Kconfig.hz"
767
768config RISCV_SBI_V01
769	bool "SBI v0.1 support"
770	depends on RISCV_SBI
771	help
772	  This config allows kernel to use SBI v0.1 APIs. This will be
773	  deprecated in future once legacy M-mode software are no longer in use.
774
775config RISCV_BOOT_SPINWAIT
776	bool "Spinwait booting method"
777	depends on SMP
778	default y if RISCV_SBI_V01 || RISCV_M_MODE
779	help
780	  This enables support for booting Linux via spinwait method. In the
781	  spinwait method, all cores randomly jump to Linux. One of the cores
782	  gets chosen via lottery and all other keep spinning on a percpu
783	  variable. This method cannot support CPU hotplug and sparse hartid
784	  scheme. It should be only enabled for M-mode Linux or platforms relying
785	  on older firmware without SBI HSM extension. All other platforms should
786	  rely on ordered booting via SBI HSM extension which gets chosen
787	  dynamically at runtime if the firmware supports it.
788
789	  Since spinwait is incompatible with sparse hart IDs, it requires
790	  NR_CPUS be large enough to contain the physical hart ID of the first
791	  hart to enter Linux.
792
793	  If unsure what to do here, say N.
794
795config ARCH_SUPPORTS_KEXEC
796	def_bool y
797
798config ARCH_SELECTS_KEXEC
799	def_bool y
800	depends on KEXEC
801	select HOTPLUG_CPU if SMP
802
803config ARCH_SUPPORTS_KEXEC_FILE
804	def_bool 64BIT
805
806config ARCH_SELECTS_KEXEC_FILE
807	def_bool y
808	depends on KEXEC_FILE
809	select HAVE_IMA_KEXEC if IMA
810	select KEXEC_ELF
811
812config ARCH_SUPPORTS_KEXEC_PURGATORY
813	def_bool ARCH_SUPPORTS_KEXEC_FILE
814
815config ARCH_SUPPORTS_CRASH_DUMP
816	def_bool y
817
818config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
819	def_bool CRASH_RESERVE
820
821config COMPAT
822	bool "Kernel support for 32-bit U-mode"
823	default 64BIT
824	depends on 64BIT && MMU
825	help
826	  This option enables support for a 32-bit U-mode running under a 64-bit
827	  kernel at S-mode. riscv32-specific components such as system calls,
828	  the user helper functions (vdso), signal rt_frame functions and the
829	  ptrace interface are handled appropriately by the kernel.
830
831	  If you want to execute 32-bit userspace applications, say Y.
832
833config PARAVIRT
834	bool "Enable paravirtualization code"
835	depends on RISCV_SBI
836	help
837	  This changes the kernel so it can modify itself when it is run
838	  under a hypervisor, potentially improving performance significantly
839	  over full virtualization.
840
841config PARAVIRT_TIME_ACCOUNTING
842	bool "Paravirtual steal time accounting"
843	depends on PARAVIRT
844	help
845	  Select this option to enable fine granularity task steal time
846	  accounting. Time spent executing other tasks in parallel with
847	  the current vCPU is discounted from the vCPU power. To account for
848	  that, there can be a small performance impact.
849
850	  If in doubt, say N here.
851
852config RELOCATABLE
853	bool "Build a relocatable kernel"
854	depends on MMU && 64BIT && !XIP_KERNEL
855	help
856          This builds a kernel as a Position Independent Executable (PIE),
857          which retains all relocation metadata required to relocate the
858          kernel binary at runtime to a different virtual address than the
859          address it was linked at.
860          Since RISCV uses the RELA relocation format, this requires a
861          relocation pass at runtime even if the kernel is loaded at the
862          same address it was linked at.
863
864          If unsure, say N.
865
866config RANDOMIZE_BASE
867        bool "Randomize the address of the kernel image"
868        select RELOCATABLE
869        depends on MMU && 64BIT && !XIP_KERNEL
870        help
871          Randomizes the virtual address at which the kernel image is
872          loaded, as a security feature that deters exploit attempts
873          relying on knowledge of the location of kernel internals.
874
875          It is the bootloader's job to provide entropy, by passing a
876          random u64 value in /chosen/kaslr-seed at kernel entry.
877
878          When booting via the UEFI stub, it will invoke the firmware's
879          EFI_RNG_PROTOCOL implementation (if available) to supply entropy
880          to the kernel proper. In addition, it will randomise the physical
881          location of the kernel Image as well.
882
883          If unsure, say N.
884
885endmenu # "Kernel features"
886
887menu "Boot options"
888
889config CMDLINE
890	string "Built-in kernel command line"
891	help
892	  For most platforms, the arguments for the kernel's command line
893	  are provided at run-time, during boot. However, there are cases
894	  where either no arguments are being provided or the provided
895	  arguments are insufficient or even invalid.
896
897	  When that occurs, it is possible to define a built-in command
898	  line here and choose how the kernel should use it later on.
899
900choice
901	prompt "Built-in command line usage" if CMDLINE != ""
902	default CMDLINE_FALLBACK
903	help
904	  Choose how the kernel will handle the provided built-in command
905	  line.
906
907config CMDLINE_FALLBACK
908	bool "Use bootloader kernel arguments if available"
909	help
910	  Use the built-in command line as fallback in case we get nothing
911	  during boot. This is the default behaviour.
912
913config CMDLINE_EXTEND
914	bool "Extend bootloader kernel arguments"
915	help
916	  The command-line arguments provided during boot will be
917	  appended to the built-in command line. This is useful in
918	  cases where the provided arguments are insufficient and
919	  you don't want to or cannot modify them.
920
921config CMDLINE_FORCE
922	bool "Always use the default kernel command string"
923	help
924	  Always use the built-in command line, even if we get one during
925	  boot. This is useful in case you need to override the provided
926	  command line on systems where you don't have or want control
927	  over it.
928
929endchoice
930
931config EFI_STUB
932	bool
933
934config EFI
935	bool "UEFI runtime support"
936	depends on OF && !XIP_KERNEL
937	depends on MMU
938	default y
939	select ARCH_SUPPORTS_ACPI if 64BIT
940	select EFI_GENERIC_STUB
941	select EFI_PARAMS_FROM_FDT
942	select EFI_RUNTIME_WRAPPERS
943	select EFI_STUB
944	select LIBFDT
945	select RISCV_ISA_C
946	select UCS2_STRING
947	help
948	  This option provides support for runtime services provided
949	  by UEFI firmware (such as non-volatile variables, realtime
950	  clock, and platform reset). A UEFI stub is also provided to
951	  allow the kernel to be booted as an EFI application. This
952	  is only useful on systems that have UEFI firmware.
953
954config CC_HAVE_STACKPROTECTOR_TLS
955	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
956
957config STACKPROTECTOR_PER_TASK
958	def_bool y
959	depends on !RANDSTRUCT
960	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
961
962config PHYS_RAM_BASE_FIXED
963	bool "Explicitly specified physical RAM address"
964	depends on NONPORTABLE
965	default n
966
967config PHYS_RAM_BASE
968	hex "Platform Physical RAM address"
969	depends on PHYS_RAM_BASE_FIXED
970	default "0x80000000"
971	help
972	  This is the physical address of RAM in the system. It has to be
973	  explicitly specified to run early relocations of read-write data
974	  from flash to RAM.
975
976config XIP_KERNEL
977	bool "Kernel Execute-In-Place from ROM"
978	depends on MMU && SPARSEMEM && NONPORTABLE
979	# This prevents XIP from being enabled by all{yes,mod}config, which
980	# fail to build since XIP doesn't support large kernels.
981	depends on !COMPILE_TEST
982	select PHYS_RAM_BASE_FIXED
983	help
984	  Execute-In-Place allows the kernel to run from non-volatile storage
985	  directly addressable by the CPU, such as NOR flash. This saves RAM
986	  space since the text section of the kernel is not loaded from flash
987	  to RAM.  Read-write sections, such as the data section and stack,
988	  are still copied to RAM.  The XIP kernel is not compressed since
989	  it has to run directly from flash, so it will take more space to
990	  store it.  The flash address used to link the kernel object files,
991	  and for storing it, is configuration dependent. Therefore, if you
992	  say Y here, you must know the proper physical address where to
993	  store the kernel image depending on your own flash memory usage.
994
995	  Also note that the make target becomes "make xipImage" rather than
996	  "make zImage" or "make Image".  The final kernel binary to put in
997	  ROM memory will be arch/riscv/boot/xipImage.
998
999	  SPARSEMEM is required because the kernel text and rodata that are
1000	  flash resident are not backed by memmap, then any attempt to get
1001	  a struct page on those regions will trigger a fault.
1002
1003	  If unsure, say N.
1004
1005config XIP_PHYS_ADDR
1006	hex "XIP Kernel Physical Location"
1007	depends on XIP_KERNEL
1008	default "0x21000000"
1009	help
1010	  This is the physical address in your flash memory the kernel will
1011	  be linked for and stored to.  This address is dependent on your
1012	  own flash usage.
1013
1014config RISCV_ISA_FALLBACK
1015	bool "Permit falling back to parsing riscv,isa for extension support by default"
1016	default y
1017	help
1018	  Parsing the "riscv,isa" devicetree property has been deprecated and
1019	  replaced by a list of explicitly defined strings. For compatibility
1020	  with existing platforms, the kernel will fall back to parsing the
1021	  "riscv,isa" property if the replacements are not found.
1022
1023	  Selecting N here will result in a kernel that does not use the
1024	  fallback, unless the commandline "riscv_isa_fallback" parameter is
1025	  present.
1026
1027	  Please see the dt-binding, located at
1028	  Documentation/devicetree/bindings/riscv/extensions.yaml for details
1029	  on the replacement properties, "riscv,isa-base" and
1030	  "riscv,isa-extensions".
1031
1032config BUILTIN_DTB
1033	bool "Built-in device tree"
1034	depends on OF && NONPORTABLE
1035	help
1036	  Build a device tree into the Linux image.
1037	  This option should be selected if no bootloader is being used.
1038	  If unsure, say N.
1039
1040
1041config BUILTIN_DTB_SOURCE
1042	string "Built-in device tree source"
1043	depends on BUILTIN_DTB
1044	help
1045	  DTS file path (without suffix, relative to arch/riscv/boot/dts)
1046	  for the DTS file that will be used to produce the DTB linked into the
1047	  kernel.
1048
1049endmenu # "Boot options"
1050
1051config PORTABLE
1052	bool
1053	default !NONPORTABLE
1054	select EFI
1055	select MMU
1056	select OF
1057
1058config ARCH_PROC_KCORE_TEXT
1059	def_bool y
1060
1061menu "Power management options"
1062
1063source "kernel/power/Kconfig"
1064
1065config ARCH_HIBERNATION_POSSIBLE
1066	def_bool y
1067
1068config ARCH_HIBERNATION_HEADER
1069	def_bool HIBERNATION
1070
1071config ARCH_SUSPEND_POSSIBLE
1072	def_bool y
1073
1074endmenu # "Power management options"
1075
1076menu "CPU Power Management"
1077
1078source "drivers/cpuidle/Kconfig"
1079
1080source "drivers/cpufreq/Kconfig"
1081
1082endmenu # "CPU Power Management"
1083
1084source "arch/riscv/kvm/Kconfig"
1085
1086source "drivers/acpi/Kconfig"
1087