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_MMIOWB
31	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
32	select ARCH_HAS_PMEM_API
33	select ARCH_HAS_PTE_SPECIAL
34	select ARCH_HAS_SET_DIRECT_MAP if MMU
35	select ARCH_HAS_SET_MEMORY if MMU
36	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
37	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
38	select ARCH_HAS_SYSCALL_WRAPPER
39	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
40	select ARCH_HAS_UBSAN_SANITIZE_ALL
41	select ARCH_HAS_VDSO_DATA
42	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
43	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
44	select ARCH_STACKWALK
45	select ARCH_SUPPORTS_ATOMIC_RMW
46	select ARCH_SUPPORTS_CFI_CLANG
47	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
48	select ARCH_SUPPORTS_HUGETLBFS if MMU
49	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
50	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
51	select ARCH_USE_MEMTEST
52	select ARCH_USE_QUEUED_RWLOCKS
53	select ARCH_USES_CFI_TRAPS if CFI_CLANG
54	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
55	select ARCH_WANT_FRAME_POINTERS
56	select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
57	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
58	select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
59	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
60	select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
61	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
62	select BUILDTIME_TABLE_SORT if MMU
63	select CLINT_TIMER if !MMU
64	select CLONE_BACKWARDS
65	select COMMON_CLK
66	select CPU_PM if CPU_IDLE || HIBERNATION
67	select EDAC_SUPPORT
68	select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
69	select GENERIC_ARCH_TOPOLOGY
70	select GENERIC_ATOMIC64 if !64BIT
71	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
72	select GENERIC_EARLY_IOREMAP
73	select GENERIC_ENTRY
74	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
75	select GENERIC_IDLE_POLL_SETUP
76	select GENERIC_IOREMAP if MMU
77	select GENERIC_IRQ_IPI if SMP
78	select GENERIC_IRQ_IPI_MUX if SMP
79	select GENERIC_IRQ_MULTI_HANDLER
80	select GENERIC_IRQ_SHOW
81	select GENERIC_IRQ_SHOW_LEVEL
82	select GENERIC_LIB_DEVMEM_IS_ALLOWED
83	select GENERIC_PCI_IOMAP
84	select GENERIC_PTDUMP if MMU
85	select GENERIC_SCHED_CLOCK
86	select GENERIC_SMP_IDLE_THREAD
87	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
88	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
89	select HARDIRQS_SW_RESEND
90	select HAS_IOPORT if MMU
91	select HAVE_ARCH_AUDITSYSCALL
92	select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
93	select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL
94	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
95	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
96	select HAVE_ARCH_KASAN if MMU && 64BIT
97	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
98	select HAVE_ARCH_KFENCE if MMU && 64BIT
99	select HAVE_ARCH_KGDB if !XIP_KERNEL
100	select HAVE_ARCH_KGDB_QXFER_PKT
101	select HAVE_ARCH_MMAP_RND_BITS if MMU
102	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
103	select HAVE_ARCH_SECCOMP_FILTER
104	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
105	select HAVE_ARCH_TRACEHOOK
106	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
107	select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
108	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
109	select HAVE_ASM_MODVERSIONS
110	select HAVE_CONTEXT_TRACKING_USER
111	select HAVE_DEBUG_KMEMLEAK
112	select HAVE_DMA_CONTIGUOUS if MMU
113	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
114	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
115	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
116	select HAVE_FUNCTION_GRAPH_TRACER
117	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
118	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
119	select HAVE_EBPF_JIT if MMU
120	select HAVE_FUNCTION_ARG_ACCESS_API
121	select HAVE_FUNCTION_ERROR_INJECTION
122	select HAVE_GCC_PLUGINS
123	select HAVE_GENERIC_VDSO if MMU && 64BIT
124	select HAVE_IRQ_TIME_ACCOUNTING
125	select HAVE_KPROBES if !XIP_KERNEL
126	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
127	select HAVE_KRETPROBES if !XIP_KERNEL
128	# https://github.com/ClangBuiltLinux/linux/issues/1881
129	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
130	select HAVE_MOVE_PMD
131	select HAVE_MOVE_PUD
132	select HAVE_PCI
133	select HAVE_PERF_EVENTS
134	select HAVE_PERF_REGS
135	select HAVE_PERF_USER_STACK_DUMP
136	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
137	select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
138	select HAVE_REGS_AND_STACK_ACCESS_API
139	select HAVE_RETHOOK if !XIP_KERNEL
140	select HAVE_RSEQ
141	select HAVE_STACKPROTECTOR
142	select HAVE_SYSCALL_TRACEPOINTS
143	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
144	select IRQ_DOMAIN
145	select IRQ_FORCED_THREADING
146	select KASAN_VMALLOC if KASAN
147	select LOCK_MM_AND_FIND_VMA
148	select MODULES_USE_ELF_RELA if MODULES
149	select MODULE_SECTIONS if MODULES
150	select OF
151	select OF_EARLY_FLATTREE
152	select OF_IRQ
153	select PCI_DOMAINS_GENERIC if PCI
154	select PCI_MSI if PCI
155	select RISCV_ALTERNATIVE if !XIP_KERNEL
156	select RISCV_INTC
157	select RISCV_TIMER if RISCV_SBI
158	select SIFIVE_PLIC
159	select SPARSE_IRQ
160	select SYSCTL_EXCEPTION_TRACE
161	select THREAD_INFO_IN_TASK
162	select TRACE_IRQFLAGS_SUPPORT
163	select UACCESS_MEMCPY if !MMU
164	select ZONE_DMA32 if 64BIT
165
166config CLANG_SUPPORTS_DYNAMIC_FTRACE
167	def_bool CC_IS_CLANG
168	# https://github.com/llvm/llvm-project/commit/6ab8927931851bb42b2c93a00801dc499d7d9b1e
169	depends on CLANG_VERSION >= 130000
170	# https://github.com/ClangBuiltLinux/linux/issues/1817
171	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
172
173config GCC_SUPPORTS_DYNAMIC_FTRACE
174	def_bool CC_IS_GCC
175	depends on $(cc-option,-fpatchable-function-entry=8)
176
177config ARCH_MMAP_RND_BITS_MIN
178	default 18 if 64BIT
179	default 8
180
181config ARCH_MMAP_RND_COMPAT_BITS_MIN
182	default 8
183
184# max bits determined by the following formula:
185#  VA_BITS - PAGE_SHIFT - 3
186config ARCH_MMAP_RND_BITS_MAX
187	default 24 if 64BIT # SV39 based
188	default 17
189
190config ARCH_MMAP_RND_COMPAT_BITS_MAX
191	default 17
192
193# set if we run in machine mode, cleared if we run in supervisor mode
194config RISCV_M_MODE
195	bool
196	default !MMU
197
198# set if we are running in S-mode and can use SBI calls
199config RISCV_SBI
200	bool
201	depends on !RISCV_M_MODE
202	default y
203
204config MMU
205	bool "MMU-based Paged Memory Management Support"
206	default y
207	help
208	  Select if you want MMU-based virtualised addressing space
209	  support by paged memory management. If unsure, say 'Y'.
210
211config PAGE_OFFSET
212	hex
213	default 0xC0000000 if 32BIT && MMU
214	default 0x80000000 if !MMU
215	default 0xff60000000000000 if 64BIT
216
217config KASAN_SHADOW_OFFSET
218	hex
219	depends on KASAN_GENERIC
220	default 0xdfffffff00000000 if 64BIT
221	default 0xffffffff if 32BIT
222
223config ARCH_FLATMEM_ENABLE
224	def_bool !NUMA
225
226config ARCH_SPARSEMEM_ENABLE
227	def_bool y
228	depends on MMU
229	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
230	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
231
232config ARCH_SELECT_MEMORY_MODEL
233	def_bool ARCH_SPARSEMEM_ENABLE
234
235config ARCH_SUPPORTS_UPROBES
236	def_bool y
237
238config STACKTRACE_SUPPORT
239	def_bool y
240
241config GENERIC_BUG
242	def_bool y
243	depends on BUG
244	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
245
246config GENERIC_BUG_RELATIVE_POINTERS
247	bool
248
249config GENERIC_CALIBRATE_DELAY
250	def_bool y
251
252config GENERIC_CSUM
253	def_bool y
254
255config GENERIC_HWEIGHT
256	def_bool y
257
258config FIX_EARLYCON_MEM
259	def_bool MMU
260
261config PGTABLE_LEVELS
262	int
263	default 5 if 64BIT
264	default 2
265
266config LOCKDEP_SUPPORT
267	def_bool y
268
269config RISCV_DMA_NONCOHERENT
270	bool
271	select ARCH_HAS_DMA_PREP_COHERENT
272	select ARCH_HAS_SETUP_DMA_OPS
273	select ARCH_HAS_SYNC_DMA_FOR_CPU
274	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
275	select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
276
277config RISCV_NONSTANDARD_CACHE_OPS
278	bool
279	help
280	  This enables function pointer support for non-standard noncoherent
281	  systems to handle cache management.
282
283config AS_HAS_INSN
284	def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
285
286config AS_HAS_OPTION_ARCH
287	# https://reviews.llvm.org/D123515
288	def_bool y
289	depends on $(as-instr, .option arch$(comma) +m)
290
291source "arch/riscv/Kconfig.socs"
292source "arch/riscv/Kconfig.errata"
293
294menu "Platform type"
295
296config NONPORTABLE
297	bool "Allow configurations that result in non-portable kernels"
298	help
299	  RISC-V kernel binaries are compatible between all known systems
300	  whenever possible, but there are some use cases that can only be
301	  satisfied by configurations that result in kernel binaries that are
302	  not portable between systems.
303
304	  Selecting N does not guarantee kernels will be portable to all known
305	  systems.  Selecting any of the options guarded by NONPORTABLE will
306	  result in kernel binaries that are unlikely to be portable between
307	  systems.
308
309	  If unsure, say N.
310
311choice
312	prompt "Base ISA"
313	default ARCH_RV64I
314	help
315	  This selects the base ISA that this kernel will target and must match
316	  the target platform.
317
318config ARCH_RV32I
319	bool "RV32I"
320	depends on NONPORTABLE
321	select 32BIT
322	select GENERIC_LIB_ASHLDI3
323	select GENERIC_LIB_ASHRDI3
324	select GENERIC_LIB_LSHRDI3
325	select GENERIC_LIB_UCMPDI2
326
327config ARCH_RV64I
328	bool "RV64I"
329	select 64BIT
330	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
331	select SWIOTLB if MMU
332
333endchoice
334
335# We must be able to map all physical memory into the kernel, but the compiler
336# is still a bit more efficient when generating code if it's setup in a manner
337# such that it can only map 2GiB of memory.
338choice
339	prompt "Kernel Code Model"
340	default CMODEL_MEDLOW if 32BIT
341	default CMODEL_MEDANY if 64BIT
342
343	config CMODEL_MEDLOW
344		bool "medium low code model"
345	config CMODEL_MEDANY
346		bool "medium any code model"
347endchoice
348
349config MODULE_SECTIONS
350	bool
351	select HAVE_MOD_ARCH_SPECIFIC
352
353config SMP
354	bool "Symmetric Multi-Processing"
355	help
356	  This enables support for systems with more than one CPU.  If
357	  you say N here, the kernel will run on single and
358	  multiprocessor machines, but will use only one CPU of a
359	  multiprocessor machine. If you say Y here, the kernel will run
360	  on many, but not all, single processor machines. On a single
361	  processor machine, the kernel will run faster if you say N
362	  here.
363
364	  If you don't know what to do here, say N.
365
366config SCHED_MC
367	bool "Multi-core scheduler support"
368	depends on SMP
369	help
370	  Multi-core scheduler support improves the CPU scheduler's decision
371	  making when dealing with multi-core CPU chips at a cost of slightly
372	  increased overhead in some places. If unsure say N here.
373
374config NR_CPUS
375	int "Maximum number of CPUs (2-512)"
376	depends on SMP
377	range 2 512 if !RISCV_SBI_V01
378	range 2 32 if RISCV_SBI_V01 && 32BIT
379	range 2 64 if RISCV_SBI_V01 && 64BIT
380	default "32" if 32BIT
381	default "64" if 64BIT
382
383config HOTPLUG_CPU
384	bool "Support for hot-pluggable CPUs"
385	depends on SMP
386	select GENERIC_IRQ_MIGRATION
387	help
388
389	  Say Y here to experiment with turning CPUs off and on.  CPUs
390	  can be controlled through /sys/devices/system/cpu.
391
392	  Say N if you want to disable CPU hotplug.
393
394choice
395	prompt "CPU Tuning"
396	default TUNE_GENERIC
397
398config TUNE_GENERIC
399	bool "generic"
400
401endchoice
402
403# Common NUMA Features
404config NUMA
405	bool "NUMA Memory Allocation and Scheduler Support"
406	depends on SMP && MMU
407	select ARCH_SUPPORTS_NUMA_BALANCING
408	select GENERIC_ARCH_NUMA
409	select NEED_PER_CPU_EMBED_FIRST_CHUNK
410	select OF_NUMA
411	select USE_PERCPU_NUMA_NODE_ID
412	help
413	  Enable NUMA (Non-Uniform Memory Access) support.
414
415	  The kernel will try to allocate memory used by a CPU on the
416	  local memory of the CPU and add some more NUMA awareness to the kernel.
417
418config NODES_SHIFT
419	int "Maximum NUMA Nodes (as a power of 2)"
420	range 1 10
421	default "2"
422	depends on NUMA
423	help
424	  Specify the maximum number of NUMA Nodes available on the target
425	  system.  Increases memory reserved to accommodate various tables.
426
427config RISCV_ALTERNATIVE
428	bool
429	depends on !XIP_KERNEL
430	help
431	  This Kconfig allows the kernel to automatically patch the
432	  erratum or cpufeature required by the execution platform at run
433	  time. The code patching overhead is minimal, as it's only done
434	  once at boot and once on each module load.
435
436config RISCV_ALTERNATIVE_EARLY
437	bool
438	depends on RISCV_ALTERNATIVE
439	help
440	  Allows early patching of the kernel for special errata
441
442config RISCV_ISA_C
443	bool "Emit compressed instructions when building Linux"
444	default y
445	help
446	  Adds "C" to the ISA subsets that the toolchain is allowed to emit
447	  when building Linux, which results in compressed instructions in the
448	  Linux binary.
449
450	  If you don't know what to do here, say Y.
451
452config RISCV_ISA_SVNAPOT
453	bool "Svnapot extension support for supervisor mode NAPOT pages"
454	depends on 64BIT && MMU
455	depends on RISCV_ALTERNATIVE
456	default y
457	help
458	  Allow kernel to detect the Svnapot ISA-extension dynamically at boot
459	  time and enable its usage.
460
461	  The Svnapot extension is used to mark contiguous PTEs as a range
462	  of contiguous virtual-to-physical translations for a naturally
463	  aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
464	  size. When HUGETLBFS is also selected this option unconditionally
465	  allocates some memory for each NAPOT page size supported by the kernel.
466	  When optimizing for low memory consumption and for platforms without
467	  the Svnapot extension, it may be better to say N here.
468
469	  If you don't know what to do here, say Y.
470
471config RISCV_ISA_SVPBMT
472	bool "Svpbmt extension support for supervisor mode page-based memory types"
473	depends on 64BIT && MMU
474	depends on RISCV_ALTERNATIVE
475	default y
476	help
477	   Adds support to dynamically detect the presence of the Svpbmt
478	   ISA-extension (Supervisor-mode: page-based memory types) and
479	   enable its usage.
480
481	   The memory type for a page contains a combination of attributes
482	   that indicate the cacheability, idempotency, and ordering
483	   properties for access to that page.
484
485	   The Svpbmt extension is only available on 64-bit cpus.
486
487	   If you don't know what to do here, say Y.
488
489config TOOLCHAIN_HAS_V
490	bool
491	default y
492	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv)
493	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv)
494	depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
495	depends on AS_HAS_OPTION_ARCH
496
497config RISCV_ISA_V
498	bool "VECTOR extension support"
499	depends on TOOLCHAIN_HAS_V
500	depends on FPU
501	select DYNAMIC_SIGFRAME
502	default y
503	help
504	  Say N here if you want to disable all vector related procedure
505	  in the kernel.
506
507	  If you don't know what to do here, say Y.
508
509config RISCV_ISA_V_DEFAULT_ENABLE
510	bool "Enable userspace Vector by default"
511	depends on RISCV_ISA_V
512	default y
513	help
514	  Say Y here if you want to enable Vector in userspace by default.
515	  Otherwise, userspace has to make explicit prctl() call to enable
516	  Vector, or enable it via the sysctl interface.
517
518	  If you don't know what to do here, say Y.
519
520config TOOLCHAIN_HAS_ZBB
521	bool
522	default y
523	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
524	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
525	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
526	depends on AS_HAS_OPTION_ARCH
527
528config RISCV_ISA_ZBB
529	bool "Zbb extension support for bit manipulation instructions"
530	depends on TOOLCHAIN_HAS_ZBB
531	depends on MMU
532	depends on RISCV_ALTERNATIVE
533	default y
534	help
535	   Adds support to dynamically detect the presence of the ZBB
536	   extension (basic bit manipulation) and enable its usage.
537
538	   The Zbb extension provides instructions to accelerate a number
539	   of bit-specific operations (count bit population, sign extending,
540	   bitrotation, etc).
541
542	   If you don't know what to do here, say Y.
543
544config RISCV_ISA_ZICBOM
545	bool "Zicbom extension support for non-coherent DMA operation"
546	depends on MMU
547	depends on RISCV_ALTERNATIVE
548	default y
549	select RISCV_DMA_NONCOHERENT
550	select DMA_DIRECT_REMAP
551	help
552	   Adds support to dynamically detect the presence of the ZICBOM
553	   extension (Cache Block Management Operations) and enable its
554	   usage.
555
556	   The Zicbom extension can be used to handle for example
557	   non-coherent DMA support on devices that need it.
558
559	   If you don't know what to do here, say Y.
560
561config RISCV_ISA_ZICBOZ
562	bool "Zicboz extension support for faster zeroing of memory"
563	depends on MMU
564	depends on RISCV_ALTERNATIVE
565	default y
566	help
567	   Enable the use of the Zicboz extension (cbo.zero instruction)
568	   when available.
569
570	   The Zicboz extension is used for faster zeroing of memory.
571
572	   If you don't know what to do here, say Y.
573
574config TOOLCHAIN_HAS_ZIHINTPAUSE
575	bool
576	default y
577	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause)
578	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause)
579	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600
580
581config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
582	def_bool y
583	# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
584	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
585	depends on AS_IS_GNU && AS_VERSION >= 23600
586	help
587	  Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
588	  20191213 version, which moves some instructions from the I extension to
589	  the Zicsr and Zifencei extensions. This requires explicitly specifying
590	  Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
591	  and Zifencei are supported in binutils from version 2.36 onwards.
592	  To make life easier, and avoid forcing toolchains that default to a
593	  newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
594	  For clang < 17 or GCC < 11.3.0, for which this is not possible or need
595	  special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
596
597config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
598	def_bool y
599	depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
600	# https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
601	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
602	depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
603	help
604	  Certain versions of clang and GCC do not support zicsr and zifencei via
605	  -march. This option causes an older ISA spec compatible with these older
606	  versions of clang and GCC to be passed to GAS, which has the same result
607	  as passing zicsr and zifencei to -march.
608
609config FPU
610	bool "FPU support"
611	default y
612	help
613	  Say N here if you want to disable all floating-point related procedure
614	  in the kernel.
615
616	  If you don't know what to do here, say Y.
617
618config IRQ_STACKS
619	bool "Independent irq & softirq stacks" if EXPERT
620	default y
621	select HAVE_IRQ_EXIT_ON_IRQ_STACK
622	select HAVE_SOFTIRQ_ON_OWN_STACK
623	help
624	  Add independent irq & softirq stacks for percpu to prevent kernel stack
625	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
626
627config THREAD_SIZE_ORDER
628	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
629	range 0 4
630	default 1 if 32BIT && !KASAN
631	default 3 if 64BIT && KASAN
632	default 2
633	help
634	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
635	  affects irq stack size, which is equal to thread stack size.
636
637endmenu # "Platform type"
638
639menu "Kernel features"
640
641source "kernel/Kconfig.hz"
642
643config RISCV_SBI_V01
644	bool "SBI v0.1 support"
645	depends on RISCV_SBI
646	help
647	  This config allows kernel to use SBI v0.1 APIs. This will be
648	  deprecated in future once legacy M-mode software are no longer in use.
649
650config RISCV_BOOT_SPINWAIT
651	bool "Spinwait booting method"
652	depends on SMP
653	default y if RISCV_SBI_V01 || RISCV_M_MODE
654	help
655	  This enables support for booting Linux via spinwait method. In the
656	  spinwait method, all cores randomly jump to Linux. One of the cores
657	  gets chosen via lottery and all other keep spinning on a percpu
658	  variable. This method cannot support CPU hotplug and sparse hartid
659	  scheme. It should be only enabled for M-mode Linux or platforms relying
660	  on older firmware without SBI HSM extension. All other platforms should
661	  rely on ordered booting via SBI HSM extension which gets chosen
662	  dynamically at runtime if the firmware supports it.
663
664	  Since spinwait is incompatible with sparse hart IDs, it requires
665	  NR_CPUS be large enough to contain the physical hart ID of the first
666	  hart to enter Linux.
667
668	  If unsure what to do here, say N.
669
670config ARCH_SUPPORTS_KEXEC
671	def_bool y
672
673config ARCH_SELECTS_KEXEC
674	def_bool y
675	depends on KEXEC
676	select HOTPLUG_CPU if SMP
677
678config ARCH_SUPPORTS_KEXEC_FILE
679	def_bool 64BIT
680
681config ARCH_SELECTS_KEXEC_FILE
682	def_bool y
683	depends on KEXEC_FILE
684	select HAVE_IMA_KEXEC if IMA
685	select KEXEC_ELF
686
687config ARCH_SUPPORTS_KEXEC_PURGATORY
688	def_bool ARCH_SUPPORTS_KEXEC_FILE
689
690config ARCH_SUPPORTS_CRASH_DUMP
691	def_bool y
692
693config COMPAT
694	bool "Kernel support for 32-bit U-mode"
695	default 64BIT
696	depends on 64BIT && MMU
697	help
698	  This option enables support for a 32-bit U-mode running under a 64-bit
699	  kernel at S-mode. riscv32-specific components such as system calls,
700	  the user helper functions (vdso), signal rt_frame functions and the
701	  ptrace interface are handled appropriately by the kernel.
702
703	  If you want to execute 32-bit userspace applications, say Y.
704
705config RELOCATABLE
706	bool "Build a relocatable kernel"
707	depends on MMU && 64BIT && !XIP_KERNEL
708	help
709          This builds a kernel as a Position Independent Executable (PIE),
710          which retains all relocation metadata required to relocate the
711          kernel binary at runtime to a different virtual address than the
712          address it was linked at.
713          Since RISCV uses the RELA relocation format, this requires a
714          relocation pass at runtime even if the kernel is loaded at the
715          same address it was linked at.
716
717          If unsure, say N.
718
719config RANDOMIZE_BASE
720        bool "Randomize the address of the kernel image"
721        select RELOCATABLE
722        depends on MMU && 64BIT && !XIP_KERNEL
723        help
724          Randomizes the virtual address at which the kernel image is
725          loaded, as a security feature that deters exploit attempts
726          relying on knowledge of the location of kernel internals.
727
728          It is the bootloader's job to provide entropy, by passing a
729          random u64 value in /chosen/kaslr-seed at kernel entry.
730
731          When booting via the UEFI stub, it will invoke the firmware's
732          EFI_RNG_PROTOCOL implementation (if available) to supply entropy
733          to the kernel proper. In addition, it will randomise the physical
734          location of the kernel Image as well.
735
736          If unsure, say N.
737
738endmenu # "Kernel features"
739
740menu "Boot options"
741
742config CMDLINE
743	string "Built-in kernel command line"
744	help
745	  For most platforms, the arguments for the kernel's command line
746	  are provided at run-time, during boot. However, there are cases
747	  where either no arguments are being provided or the provided
748	  arguments are insufficient or even invalid.
749
750	  When that occurs, it is possible to define a built-in command
751	  line here and choose how the kernel should use it later on.
752
753choice
754	prompt "Built-in command line usage" if CMDLINE != ""
755	default CMDLINE_FALLBACK
756	help
757	  Choose how the kernel will handle the provided built-in command
758	  line.
759
760config CMDLINE_FALLBACK
761	bool "Use bootloader kernel arguments if available"
762	help
763	  Use the built-in command line as fallback in case we get nothing
764	  during boot. This is the default behaviour.
765
766config CMDLINE_EXTEND
767	bool "Extend bootloader kernel arguments"
768	help
769	  The command-line arguments provided during boot will be
770	  appended to the built-in command line. This is useful in
771	  cases where the provided arguments are insufficient and
772	  you don't want to or cannot modify them.
773
774config CMDLINE_FORCE
775	bool "Always use the default kernel command string"
776	help
777	  Always use the built-in command line, even if we get one during
778	  boot. This is useful in case you need to override the provided
779	  command line on systems where you don't have or want control
780	  over it.
781
782endchoice
783
784config EFI_STUB
785	bool
786
787config EFI
788	bool "UEFI runtime support"
789	depends on OF && !XIP_KERNEL
790	depends on MMU
791	default y
792	select ARCH_SUPPORTS_ACPI if 64BIT
793	select EFI_GENERIC_STUB
794	select EFI_PARAMS_FROM_FDT
795	select EFI_RUNTIME_WRAPPERS
796	select EFI_STUB
797	select LIBFDT
798	select RISCV_ISA_C
799	select UCS2_STRING
800	help
801	  This option provides support for runtime services provided
802	  by UEFI firmware (such as non-volatile variables, realtime
803	  clock, and platform reset). A UEFI stub is also provided to
804	  allow the kernel to be booted as an EFI application. This
805	  is only useful on systems that have UEFI firmware.
806
807config CC_HAVE_STACKPROTECTOR_TLS
808	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
809
810config STACKPROTECTOR_PER_TASK
811	def_bool y
812	depends on !RANDSTRUCT
813	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
814
815config PHYS_RAM_BASE_FIXED
816	bool "Explicitly specified physical RAM address"
817	depends on NONPORTABLE
818	default n
819
820config PHYS_RAM_BASE
821	hex "Platform Physical RAM address"
822	depends on PHYS_RAM_BASE_FIXED
823	default "0x80000000"
824	help
825	  This is the physical address of RAM in the system. It has to be
826	  explicitly specified to run early relocations of read-write data
827	  from flash to RAM.
828
829config XIP_KERNEL
830	bool "Kernel Execute-In-Place from ROM"
831	depends on MMU && SPARSEMEM && NONPORTABLE
832	# This prevents XIP from being enabled by all{yes,mod}config, which
833	# fail to build since XIP doesn't support large kernels.
834	depends on !COMPILE_TEST
835	select PHYS_RAM_BASE_FIXED
836	help
837	  Execute-In-Place allows the kernel to run from non-volatile storage
838	  directly addressable by the CPU, such as NOR flash. This saves RAM
839	  space since the text section of the kernel is not loaded from flash
840	  to RAM.  Read-write sections, such as the data section and stack,
841	  are still copied to RAM.  The XIP kernel is not compressed since
842	  it has to run directly from flash, so it will take more space to
843	  store it.  The flash address used to link the kernel object files,
844	  and for storing it, is configuration dependent. Therefore, if you
845	  say Y here, you must know the proper physical address where to
846	  store the kernel image depending on your own flash memory usage.
847
848	  Also note that the make target becomes "make xipImage" rather than
849	  "make zImage" or "make Image".  The final kernel binary to put in
850	  ROM memory will be arch/riscv/boot/xipImage.
851
852	  SPARSEMEM is required because the kernel text and rodata that are
853	  flash resident are not backed by memmap, then any attempt to get
854	  a struct page on those regions will trigger a fault.
855
856	  If unsure, say N.
857
858config XIP_PHYS_ADDR
859	hex "XIP Kernel Physical Location"
860	depends on XIP_KERNEL
861	default "0x21000000"
862	help
863	  This is the physical address in your flash memory the kernel will
864	  be linked for and stored to.  This address is dependent on your
865	  own flash usage.
866
867config RISCV_ISA_FALLBACK
868	bool "Permit falling back to parsing riscv,isa for extension support by default"
869	default y
870	help
871	  Parsing the "riscv,isa" devicetree property has been deprecated and
872	  replaced by a list of explicitly defined strings. For compatibility
873	  with existing platforms, the kernel will fall back to parsing the
874	  "riscv,isa" property if the replacements are not found.
875
876	  Selecting N here will result in a kernel that does not use the
877	  fallback, unless the commandline "riscv_isa_fallback" parameter is
878	  present.
879
880	  Please see the dt-binding, located at
881	  Documentation/devicetree/bindings/riscv/extensions.yaml for details
882	  on the replacement properties, "riscv,isa-base" and
883	  "riscv,isa-extensions".
884
885endmenu # "Boot options"
886
887config BUILTIN_DTB
888	bool
889	depends on OF && NONPORTABLE
890	default y if XIP_KERNEL
891
892config PORTABLE
893	bool
894	default !NONPORTABLE
895	select EFI
896	select MMU
897	select OF
898
899menu "Power management options"
900
901source "kernel/power/Kconfig"
902
903# Hibernation is only possible on systems where the SBI implementation has
904# marked its reserved memory as not accessible from, or does not run
905# from the same memory as, Linux
906config ARCH_HIBERNATION_POSSIBLE
907	def_bool NONPORTABLE
908
909config ARCH_HIBERNATION_HEADER
910	def_bool HIBERNATION
911
912config ARCH_SUSPEND_POSSIBLE
913	def_bool y
914
915endmenu # "Power management options"
916
917menu "CPU Power Management"
918
919source "drivers/cpuidle/Kconfig"
920
921source "drivers/cpufreq/Kconfig"
922
923endmenu # "CPU Power Management"
924
925source "arch/riscv/kvm/Kconfig"
926
927source "drivers/acpi/Kconfig"
928