xref: /linux-6.15/arch/riscv/Kconfig (revision 03dc00a2)
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_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
37	select ARCH_HAS_KCOV
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
55	select ARCH_HAS_UBSAN
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
61	select ARCH_STACKWALK
62	select ARCH_SUPPORTS_ATOMIC_RMW
63	select ARCH_SUPPORTS_CFI_CLANG
64	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
65	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
66	select ARCH_SUPPORTS_HUGETLBFS if MMU
67	# LLD >= 14: https://github.com/llvm/llvm-project/issues/50505
68	select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000
69	select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000
70	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
71	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
72	select ARCH_SUPPORTS_RT
73	select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
74	select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
75	select ARCH_USE_MEMTEST
76	select ARCH_USE_QUEUED_RWLOCKS
77	select ARCH_USE_SYM_ANNOTATIONS
78	select ARCH_USES_CFI_TRAPS if CFI_CLANG
79	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU
80	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
81	select ARCH_WANT_FRAME_POINTERS
82	select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
83	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
84	select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
85	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
86	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
87	select ARCH_WANTS_NO_INSTR
88	select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
89	select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS
90	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
91	select BUILDTIME_TABLE_SORT if MMU
92	select CLINT_TIMER if RISCV_M_MODE
93	select CLONE_BACKWARDS
94	select COMMON_CLK
95	select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
96	select EDAC_SUPPORT
97	select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
98	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
99	select GENERIC_ARCH_TOPOLOGY
100	select GENERIC_ATOMIC64 if !64BIT
101	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
102	select GENERIC_CPU_DEVICES
103	select GENERIC_CPU_VULNERABILITIES
104	select GENERIC_EARLY_IOREMAP
105	select GENERIC_ENTRY
106	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
107	select GENERIC_IDLE_POLL_SETUP
108	select GENERIC_IOREMAP if MMU
109	select GENERIC_IRQ_IPI if SMP
110	select GENERIC_IRQ_IPI_MUX if SMP
111	select GENERIC_IRQ_MULTI_HANDLER
112	select GENERIC_IRQ_SHOW
113	select GENERIC_IRQ_SHOW_LEVEL
114	select GENERIC_LIB_DEVMEM_IS_ALLOWED
115	select GENERIC_PCI_IOMAP
116	select GENERIC_PTDUMP if MMU
117	select GENERIC_SCHED_CLOCK
118	select GENERIC_SMP_IDLE_THREAD
119	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
120	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
121	select HARDIRQS_SW_RESEND
122	select HAS_IOPORT if MMU
123	select HAVE_ALIGNED_STRUCT_PAGE
124	select HAVE_ARCH_AUDITSYSCALL
125	select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
126	select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT
127	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
128	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
129	select HAVE_ARCH_KASAN if MMU && 64BIT
130	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
131	select HAVE_ARCH_KFENCE if MMU && 64BIT
132	select HAVE_ARCH_KGDB if !XIP_KERNEL
133	select HAVE_ARCH_KGDB_QXFER_PKT
134	select HAVE_ARCH_MMAP_RND_BITS if MMU
135	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
136	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
137	select HAVE_ARCH_SECCOMP_FILTER
138	select HAVE_ARCH_STACKLEAK
139	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
140	select HAVE_ARCH_TRACEHOOK
141	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
142	select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
143	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
144	select HAVE_ASM_MODVERSIONS
145	select HAVE_CONTEXT_TRACKING_USER
146	select HAVE_DEBUG_KMEMLEAK
147	select HAVE_DMA_CONTIGUOUS if MMU
148	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
149	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
150	select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
151	select HAVE_FTRACE_GRAPH_FUNC
152	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
153	select HAVE_FUNCTION_GRAPH_TRACER
154	select HAVE_FUNCTION_GRAPH_FREGS
155	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
156	select HAVE_EBPF_JIT if MMU
157	select HAVE_GUP_FAST if MMU
158	select HAVE_FUNCTION_ARG_ACCESS_API
159	select HAVE_FUNCTION_ERROR_INJECTION
160	select HAVE_GCC_PLUGINS
161	select HAVE_GENERIC_VDSO if MMU && 64BIT
162	select HAVE_IRQ_TIME_ACCOUNTING
163	select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT
164	select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT
165	select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT
166	select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT
167	select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT
168	select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT
169	select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT
170	select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT
171	select HAVE_KPROBES if !XIP_KERNEL
172	select HAVE_KRETPROBES if !XIP_KERNEL
173	# https://github.com/ClangBuiltLinux/linux/issues/1881
174	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
175	select HAVE_MOVE_PMD
176	select HAVE_MOVE_PUD
177	select HAVE_PAGE_SIZE_4KB
178	select HAVE_PCI
179	select HAVE_PERF_EVENTS
180	select HAVE_PERF_REGS
181	select HAVE_PERF_USER_STACK_DUMP
182	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
183	select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
184	select HAVE_REGS_AND_STACK_ACCESS_API
185	select HAVE_RETHOOK if !XIP_KERNEL
186	select HAVE_RSEQ
187	select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG
188	select HAVE_SAMPLE_FTRACE_DIRECT
189	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
190	select HAVE_STACKPROTECTOR
191	select HAVE_SYSCALL_TRACEPOINTS
192	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
193	select IRQ_DOMAIN
194	select IRQ_FORCED_THREADING
195	select KASAN_VMALLOC if KASAN
196	select LOCK_MM_AND_FIND_VMA
197	select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU
198	select MODULES_USE_ELF_RELA if MODULES
199	select OF
200	select OF_EARLY_FLATTREE
201	select OF_IRQ
202	select PCI_DOMAINS_GENERIC if PCI
203	select PCI_ECAM if (ACPI && PCI)
204	select PCI_MSI if PCI
205	select RISCV_ALTERNATIVE if !XIP_KERNEL
206	select RISCV_APLIC
207	select RISCV_IMSIC
208	select RISCV_INTC
209	select RISCV_TIMER if RISCV_SBI
210	select SIFIVE_PLIC
211	select SPARSE_IRQ
212	select SYSCTL_EXCEPTION_TRACE
213	select THREAD_INFO_IN_TASK
214	select TRACE_IRQFLAGS_SUPPORT
215	select UACCESS_MEMCPY if !MMU
216	select USER_STACKTRACE_SUPPORT
217	select ZONE_DMA32 if 64BIT
218
219config RUSTC_SUPPORTS_RISCV
220	def_bool y
221	depends on 64BIT
222	# Shadow call stack requires rustc version 1.82+ due to use of the
223	# -Zsanitizer=shadow-call-stack flag.
224	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200
225
226config CLANG_SUPPORTS_DYNAMIC_FTRACE
227	def_bool CC_IS_CLANG
228	# https://github.com/ClangBuiltLinux/linux/issues/1817
229	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
230
231config GCC_SUPPORTS_DYNAMIC_FTRACE
232	def_bool CC_IS_GCC
233	depends on $(cc-option,-fpatchable-function-entry=8)
234
235config HAVE_SHADOW_CALL_STACK
236	def_bool $(cc-option,-fsanitize=shadow-call-stack)
237	# https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
238	depends on $(ld-option,--no-relax-gp)
239
240config RISCV_USE_LINKER_RELAXATION
241	def_bool y
242	# https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
243	depends on !LD_IS_LLD || LLD_VERSION >= 150000
244
245# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
246config ARCH_HAS_BROKEN_DWARF5
247	def_bool y
248	depends on RISCV_USE_LINKER_RELAXATION
249	# https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
250	depends on AS_IS_LLVM && AS_VERSION < 180000
251	# https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
252	depends on LD_IS_LLD && LLD_VERSION < 180000
253
254config ARCH_MMAP_RND_BITS_MIN
255	default 18 if 64BIT
256	default 8
257
258config ARCH_MMAP_RND_COMPAT_BITS_MIN
259	default 8
260
261# max bits determined by the following formula:
262#  VA_BITS - PAGE_SHIFT - 3
263config ARCH_MMAP_RND_BITS_MAX
264	default 24 if 64BIT # SV39 based
265	default 17
266
267config ARCH_MMAP_RND_COMPAT_BITS_MAX
268	default 17
269
270# set if we run in machine mode, cleared if we run in supervisor mode
271config RISCV_M_MODE
272	bool "Build a kernel that runs in machine mode"
273	depends on !MMU
274	default y
275	help
276	  Select this option if you want to run the kernel in M-mode,
277	  without the assistance of any other firmware.
278
279# set if we are running in S-mode and can use SBI calls
280config RISCV_SBI
281	bool
282	depends on !RISCV_M_MODE
283	default y
284
285config MMU
286	bool "MMU-based Paged Memory Management Support"
287	default y
288	help
289	  Select if you want MMU-based virtualised addressing space
290	  support by paged memory management. If unsure, say 'Y'.
291
292config PAGE_OFFSET
293	hex
294	default 0x80000000 if !MMU && RISCV_M_MODE
295	default 0x80200000 if !MMU
296	default 0xc0000000 if 32BIT
297	default 0xff60000000000000 if 64BIT
298
299config KASAN_SHADOW_OFFSET
300	hex
301	depends on KASAN_GENERIC
302	default 0xdfffffff00000000 if 64BIT
303	default 0xffffffff if 32BIT
304
305config ARCH_FLATMEM_ENABLE
306	def_bool !NUMA
307
308config ARCH_SPARSEMEM_ENABLE
309	def_bool y
310	depends on MMU
311	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
312	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
313
314config ARCH_SELECT_MEMORY_MODEL
315	def_bool ARCH_SPARSEMEM_ENABLE
316
317config ARCH_SUPPORTS_UPROBES
318	def_bool y
319
320config STACKTRACE_SUPPORT
321	def_bool y
322
323config GENERIC_BUG
324	def_bool y
325	depends on BUG
326	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
327
328config GENERIC_BUG_RELATIVE_POINTERS
329	bool
330
331config GENERIC_CALIBRATE_DELAY
332	def_bool y
333
334config GENERIC_CSUM
335	def_bool y
336
337config GENERIC_HWEIGHT
338	def_bool y
339
340config FIX_EARLYCON_MEM
341	def_bool MMU
342
343config ILLEGAL_POINTER_VALUE
344	hex
345	default 0 if 32BIT
346	default 0xdead000000000000 if 64BIT
347
348config PGTABLE_LEVELS
349	int
350	default 5 if 64BIT
351	default 2
352
353config LOCKDEP_SUPPORT
354	def_bool y
355
356config RISCV_DMA_NONCOHERENT
357	bool
358	select ARCH_HAS_DMA_PREP_COHERENT
359	select ARCH_HAS_SETUP_DMA_OPS
360	select ARCH_HAS_SYNC_DMA_FOR_CPU
361	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
362	select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
363
364config RISCV_NONSTANDARD_CACHE_OPS
365	bool
366	help
367	  This enables function pointer support for non-standard noncoherent
368	  systems to handle cache management.
369
370config AS_HAS_INSN
371	def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
372
373config AS_HAS_OPTION_ARCH
374	# https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4
375	def_bool y
376	depends on $(as-instr, .option arch$(comma) +m)
377
378source "arch/riscv/Kconfig.socs"
379source "arch/riscv/Kconfig.errata"
380
381menu "Platform type"
382
383config NONPORTABLE
384	bool "Allow configurations that result in non-portable kernels"
385	help
386	  RISC-V kernel binaries are compatible between all known systems
387	  whenever possible, but there are some use cases that can only be
388	  satisfied by configurations that result in kernel binaries that are
389	  not portable between systems.
390
391	  Selecting N does not guarantee kernels will be portable to all known
392	  systems.  Selecting any of the options guarded by NONPORTABLE will
393	  result in kernel binaries that are unlikely to be portable between
394	  systems.
395
396	  If unsure, say N.
397
398choice
399	prompt "Base ISA"
400	default ARCH_RV64I
401	help
402	  This selects the base ISA that this kernel will target and must match
403	  the target platform.
404
405config ARCH_RV32I
406	bool "RV32I"
407	depends on NONPORTABLE
408	select 32BIT
409	select GENERIC_LIB_ASHLDI3
410	select GENERIC_LIB_ASHRDI3
411	select GENERIC_LIB_LSHRDI3
412	select GENERIC_LIB_UCMPDI2
413
414config ARCH_RV64I
415	bool "RV64I"
416	select 64BIT
417	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
418	select SWIOTLB if MMU
419
420endchoice
421
422# We must be able to map all physical memory into the kernel, but the compiler
423# is still a bit more efficient when generating code if it's setup in a manner
424# such that it can only map 2GiB of memory.
425choice
426	prompt "Kernel Code Model"
427	default CMODEL_MEDLOW if 32BIT
428	default CMODEL_MEDANY if 64BIT
429
430	config CMODEL_MEDLOW
431		bool "medium low code model"
432	config CMODEL_MEDANY
433		bool "medium any code model"
434endchoice
435
436config MODULE_SECTIONS
437	bool
438	select HAVE_MOD_ARCH_SPECIFIC
439
440config SMP
441	bool "Symmetric Multi-Processing"
442	help
443	  This enables support for systems with more than one CPU.  If
444	  you say N here, the kernel will run on single and
445	  multiprocessor machines, but will use only one CPU of a
446	  multiprocessor machine. If you say Y here, the kernel will run
447	  on many, but not all, single processor machines. On a single
448	  processor machine, the kernel will run faster if you say N
449	  here.
450
451	  If you don't know what to do here, say N.
452
453config SCHED_MC
454	bool "Multi-core scheduler support"
455	depends on SMP
456	help
457	  Multi-core scheduler support improves the CPU scheduler's decision
458	  making when dealing with multi-core CPU chips at a cost of slightly
459	  increased overhead in some places. If unsure say N here.
460
461config NR_CPUS
462	int "Maximum number of CPUs (2-512)"
463	depends on SMP
464	range 2 512 if !RISCV_SBI_V01
465	range 2 32 if RISCV_SBI_V01 && 32BIT
466	range 2 64 if RISCV_SBI_V01 && 64BIT
467	default "32" if 32BIT
468	default "64" if 64BIT
469
470config HOTPLUG_CPU
471	bool "Support for hot-pluggable CPUs"
472	depends on SMP
473	select GENERIC_IRQ_MIGRATION
474	help
475
476	  Say Y here to experiment with turning CPUs off and on.  CPUs
477	  can be controlled through /sys/devices/system/cpu.
478
479	  Say N if you want to disable CPU hotplug.
480
481choice
482	prompt "CPU Tuning"
483	default TUNE_GENERIC
484
485config TUNE_GENERIC
486	bool "generic"
487
488endchoice
489
490# Common NUMA Features
491config NUMA
492	bool "NUMA Memory Allocation and Scheduler Support"
493	depends on SMP && MMU
494	select ARCH_SUPPORTS_NUMA_BALANCING
495	select GENERIC_ARCH_NUMA
496	select HAVE_SETUP_PER_CPU_AREA
497	select NEED_PER_CPU_EMBED_FIRST_CHUNK
498	select NEED_PER_CPU_PAGE_FIRST_CHUNK
499	select OF_NUMA
500	select USE_PERCPU_NUMA_NODE_ID
501	help
502	  Enable NUMA (Non-Uniform Memory Access) support.
503
504	  The kernel will try to allocate memory used by a CPU on the
505	  local memory of the CPU and add some more NUMA awareness to the kernel.
506
507config NODES_SHIFT
508	int "Maximum NUMA Nodes (as a power of 2)"
509	range 1 10
510	default "2"
511	depends on NUMA
512	help
513	  Specify the maximum number of NUMA Nodes available on the target
514	  system.  Increases memory reserved to accommodate various tables.
515
516choice
517	prompt "RISC-V spinlock type"
518	default RISCV_COMBO_SPINLOCKS
519
520config RISCV_TICKET_SPINLOCKS
521	bool "Using ticket spinlock"
522
523config RISCV_QUEUED_SPINLOCKS
524	bool "Using queued spinlock"
525	depends on SMP && MMU && NONPORTABLE
526	select ARCH_USE_QUEUED_SPINLOCKS
527	help
528	  The queued spinlock implementation requires the forward progress
529	  guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or
530	  LR/SC with Ziccrse provide such guarantee.
531
532	  Select this if and only if Zabha or Ziccrse is available on your
533	  platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms
534	  without one of those extensions.
535
536	  If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks
537	  when supported and otherwise ticket spinlocks.
538
539config RISCV_COMBO_SPINLOCKS
540	bool "Using combo spinlock"
541	depends on SMP && MMU
542	select ARCH_USE_QUEUED_SPINLOCKS
543	help
544	  Embed both queued spinlock and ticket lock so that the spinlock
545	  implementation can be chosen at runtime.
546
547endchoice
548
549config RISCV_ALTERNATIVE
550	bool
551	depends on !XIP_KERNEL
552	help
553	  This Kconfig allows the kernel to automatically patch the
554	  erratum or cpufeature required by the execution platform at run
555	  time. The code patching overhead is minimal, as it's only done
556	  once at boot and once on each module load.
557
558config RISCV_ALTERNATIVE_EARLY
559	bool
560	depends on RISCV_ALTERNATIVE
561	help
562	  Allows early patching of the kernel for special errata
563
564config RISCV_ISA_C
565	bool "Emit compressed instructions when building Linux"
566	default y
567	help
568	  Adds "C" to the ISA subsets that the toolchain is allowed to emit
569	  when building Linux, which results in compressed instructions in the
570	  Linux binary. This option produces a kernel that will not run on
571	  systems that do not support compressed instructions.
572
573	  If you don't know what to do here, say Y.
574
575config RISCV_ISA_SUPM
576	bool "Supm extension for userspace pointer masking"
577	depends on 64BIT
578	default y
579	help
580	  Add support for pointer masking in userspace (Supm) when the
581	  underlying hardware extension (Smnpm or Ssnpm) is detected at boot.
582
583	  If this option is disabled, userspace will be unable to use
584	  the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API.
585
586config RISCV_ISA_SVNAPOT
587	bool "Svnapot extension support for supervisor mode NAPOT pages"
588	depends on 64BIT && MMU
589	depends on RISCV_ALTERNATIVE
590	default y
591	help
592	  Enable support for the Svnapot ISA-extension when it is detected
593	  at boot.
594
595	  The Svnapot extension is used to mark contiguous PTEs as a range
596	  of contiguous virtual-to-physical translations for a naturally
597	  aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
598	  size. When HUGETLBFS is also selected this option unconditionally
599	  allocates some memory for each NAPOT page size supported by the kernel.
600	  When optimizing for low memory consumption and for platforms without
601	  the Svnapot extension, it may be better to say N here.
602
603	  If you don't know what to do here, say Y.
604
605config RISCV_ISA_SVPBMT
606	bool "Svpbmt extension support for supervisor mode page-based memory types"
607	depends on 64BIT && MMU
608	depends on RISCV_ALTERNATIVE
609	default y
610	help
611	   Add support for the Svpbmt ISA-extension (Supervisor-mode:
612	   page-based memory types) in the kernel when it is detected at boot.
613
614	   The memory type for a page contains a combination of attributes
615	   that indicate the cacheability, idempotency, and ordering
616	   properties for access to that page.
617
618	   The Svpbmt extension is only available on 64-bit cpus.
619
620	   If you don't know what to do here, say Y.
621
622config TOOLCHAIN_HAS_V
623	bool
624	default y
625	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv)
626	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv)
627	depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
628	depends on AS_HAS_OPTION_ARCH
629
630config RISCV_ISA_V
631	bool "Vector extension support"
632	depends on TOOLCHAIN_HAS_V
633	depends on FPU
634	select DYNAMIC_SIGFRAME
635	default y
636	help
637	  Add support for the Vector extension when it is detected at boot.
638	  When this option is disabled, neither the kernel nor userspace may
639	  use vector procedures.
640
641	  If you don't know what to do here, say Y.
642
643config RISCV_ISA_V_DEFAULT_ENABLE
644	bool "Enable userspace Vector by default"
645	depends on RISCV_ISA_V
646	default y
647	help
648	  Say Y here if you want to enable Vector in userspace by default.
649	  Otherwise, userspace has to make explicit prctl() call to enable
650	  Vector, or enable it via the sysctl interface.
651
652	  If you don't know what to do here, say Y.
653
654config RISCV_ISA_V_UCOPY_THRESHOLD
655	int "Threshold size for vectorized user copies"
656	depends on RISCV_ISA_V
657	default 768
658	help
659	  Prefer using vectorized copy_to_user()/copy_from_user() when the
660	  workload size exceeds this value.
661
662config RISCV_ISA_V_PREEMPTIVE
663	bool "Run kernel-mode Vector with kernel preemption"
664	depends on PREEMPTION
665	depends on RISCV_ISA_V
666	default y
667	help
668	  Usually, in-kernel SIMD routines are run with preemption disabled.
669	  Functions which envoke long running SIMD thus must yield core's
670	  vector unit to prevent blocking other tasks for too long.
671
672	  This config allows kernel to run SIMD without explicitly disable
673	  preemption. Enabling this config will result in higher memory
674	  consumption due to the allocation of per-task's kernel Vector context.
675
676config RISCV_ISA_ZAWRS
677	bool "Zawrs extension support for more efficient busy waiting"
678	depends on RISCV_ALTERNATIVE
679	default y
680	help
681	  The Zawrs extension defines instructions to be used in polling loops
682	  which allow a hart to enter a low-power state or to trap to the
683	  hypervisor while waiting on a store to a memory location. Enable the
684	  use of these instructions in the kernel when the Zawrs extension is
685	  detected at boot.
686
687config TOOLCHAIN_HAS_ZABHA
688	bool
689	default y
690	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha)
691	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha)
692	depends on AS_HAS_OPTION_ARCH
693
694config RISCV_ISA_ZABHA
695	bool "Zabha extension support for atomic byte/halfword operations"
696	depends on TOOLCHAIN_HAS_ZABHA
697	depends on RISCV_ALTERNATIVE
698	default y
699	help
700	  Enable the use of the Zabha ISA-extension to implement kernel
701	  byte/halfword atomic memory operations when it is detected at boot.
702
703	  If you don't know what to do here, say Y.
704
705config TOOLCHAIN_HAS_ZACAS
706	bool
707	default y
708	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas)
709	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas)
710	depends on AS_HAS_OPTION_ARCH
711
712config RISCV_ISA_ZACAS
713	bool "Zacas extension support for atomic CAS"
714	depends on TOOLCHAIN_HAS_ZACAS
715	depends on RISCV_ALTERNATIVE
716	default y
717	help
718	  Enable the use of the Zacas ISA-extension to implement kernel atomic
719	  cmpxchg operations when it is detected at boot.
720
721	  If you don't know what to do here, say Y.
722
723config TOOLCHAIN_HAS_ZBB
724	bool
725	default y
726	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
727	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
728	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
729	depends on AS_HAS_OPTION_ARCH
730
731# This symbol indicates that the toolchain supports all v1.0 vector crypto
732# extensions, including Zvk*, Zvbb, and Zvbc.  LLVM added all of these at once.
733# binutils added all except Zvkb, then added Zvkb.  So we just check for Zvkb.
734config TOOLCHAIN_HAS_VECTOR_CRYPTO
735	def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
736	depends on AS_HAS_OPTION_ARCH
737
738config RISCV_ISA_ZBA
739	bool "Zba extension support for bit manipulation instructions"
740	default y
741	help
742	   Add support for enabling optimisations in the kernel when the Zba
743	   extension is detected at boot.
744
745	   The Zba extension provides instructions to accelerate the generation
746	   of addresses that index into arrays of basic data types.
747
748	   If you don't know what to do here, say Y.
749
750config RISCV_ISA_ZBB
751	bool "Zbb extension support for bit manipulation instructions"
752	depends on RISCV_ALTERNATIVE
753	default y
754	help
755	   Add support for enabling optimisations in the kernel when the
756	   Zbb extension is detected at boot. Some optimisations may
757	   additionally depend on toolchain support for Zbb.
758
759	   The Zbb extension provides instructions to accelerate a number
760	   of bit-specific operations (count bit population, sign extending,
761	   bitrotation, etc).
762
763	   If you don't know what to do here, say Y.
764
765config TOOLCHAIN_HAS_ZBC
766	bool
767	default y
768	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
769	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
770	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
771	depends on AS_HAS_OPTION_ARCH
772
773config RISCV_ISA_ZBC
774	bool "Zbc extension support for carry-less multiplication instructions"
775	depends on TOOLCHAIN_HAS_ZBC
776	depends on MMU
777	depends on RISCV_ALTERNATIVE
778	default y
779	help
780	   Adds support to dynamically detect the presence of the Zbc
781	   extension (carry-less multiplication) and enable its usage.
782
783	   The Zbc extension could accelerate CRC (cyclic redundancy check)
784	   calculations.
785
786	   If you don't know what to do here, say Y.
787
788config RISCV_ISA_ZICBOM
789	bool "Zicbom extension support for non-coherent DMA operation"
790	depends on MMU
791	depends on RISCV_ALTERNATIVE
792	default y
793	select RISCV_DMA_NONCOHERENT
794	select DMA_DIRECT_REMAP
795	help
796	   Add support for the Zicbom extension (Cache Block Management
797	   Operations) and enable its use in the kernel when it is detected
798	   at boot.
799
800	   The Zicbom extension can be used to handle for example
801	   non-coherent DMA support on devices that need it.
802
803	   If you don't know what to do here, say Y.
804
805config RISCV_ISA_ZICBOZ
806	bool "Zicboz extension support for faster zeroing of memory"
807	depends on RISCV_ALTERNATIVE
808	default y
809	help
810	   Enable the use of the Zicboz extension (cbo.zero instruction)
811	   in the kernel when it is detected at boot.
812
813	   The Zicboz extension is used for faster zeroing of memory.
814
815	   If you don't know what to do here, say Y.
816
817config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
818	def_bool y
819	# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
820	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
821	depends on AS_IS_GNU && AS_VERSION >= 23600
822	help
823	  Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
824	  20191213 version, which moves some instructions from the I extension to
825	  the Zicsr and Zifencei extensions. This requires explicitly specifying
826	  Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
827	  and Zifencei are supported in binutils from version 2.36 onwards.
828	  To make life easier, and avoid forcing toolchains that default to a
829	  newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
830	  For clang < 17 or GCC < 11.3.0, for which this is not possible or need
831	  special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
832
833config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
834	def_bool y
835	depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
836	# https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
837	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
838	depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
839	help
840	  Certain versions of clang and GCC do not support zicsr and zifencei via
841	  -march. This option causes an older ISA spec compatible with these older
842	  versions of clang and GCC to be passed to GAS, which has the same result
843	  as passing zicsr and zifencei to -march.
844
845config FPU
846	bool "FPU support"
847	default y
848	help
849	  Add support for floating point operations when an FPU is detected at
850	  boot. When this option is disabled, neither the kernel nor userspace
851	  may use the floating point unit.
852
853	  If you don't know what to do here, say Y.
854
855config IRQ_STACKS
856	bool "Independent irq & softirq stacks" if EXPERT
857	default y
858	select HAVE_IRQ_EXIT_ON_IRQ_STACK
859	select HAVE_SOFTIRQ_ON_OWN_STACK
860	help
861	  Add independent irq & softirq stacks for percpu to prevent kernel stack
862	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
863
864config THREAD_SIZE_ORDER
865	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
866	range 0 4
867	default 1 if 32BIT
868	default 2
869	help
870	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
871	  affects irq stack size, which is equal to thread stack size.
872
873config RISCV_MISALIGNED
874	bool
875	help
876	  Embed support for detecting and emulating misaligned
877	  scalar or vector loads and stores.
878
879config RISCV_SCALAR_MISALIGNED
880	bool
881	select RISCV_MISALIGNED
882	select SYSCTL_ARCH_UNALIGN_ALLOW
883	help
884	  Embed support for emulating misaligned loads and stores.
885
886config RISCV_VECTOR_MISALIGNED
887	bool
888	select RISCV_MISALIGNED
889	depends on RISCV_ISA_V
890	help
891	  Enable detecting support for vector misaligned loads and stores.
892
893choice
894	prompt "Unaligned Accesses Support"
895	default RISCV_PROBE_UNALIGNED_ACCESS
896	help
897	  This determines the level of support for unaligned accesses. This
898	  information is used by the kernel to perform optimizations. It is also
899	  exposed to user space via the hwprobe syscall. The hardware will be
900	  probed at boot by default.
901
902config RISCV_PROBE_UNALIGNED_ACCESS
903	bool "Probe for hardware unaligned access support"
904	select RISCV_SCALAR_MISALIGNED
905	help
906	  During boot, the kernel will run a series of tests to determine the
907	  speed of unaligned accesses. This probing will dynamically determine
908	  the speed of unaligned accesses on the underlying system. If unaligned
909	  memory accesses trap into the kernel as they are not supported by the
910	  system, the kernel will emulate the unaligned accesses to preserve the
911	  UABI.
912
913config RISCV_EMULATED_UNALIGNED_ACCESS
914	bool "Emulate unaligned access where system support is missing"
915	select RISCV_SCALAR_MISALIGNED
916	help
917	  If unaligned memory accesses trap into the kernel as they are not
918	  supported by the system, the kernel will emulate the unaligned
919	  accesses to preserve the UABI. When the underlying system does support
920	  unaligned accesses, the unaligned accesses are assumed to be slow.
921
922config RISCV_SLOW_UNALIGNED_ACCESS
923	bool "Assume the system supports slow unaligned memory accesses"
924	depends on NONPORTABLE
925	help
926	  Assume that the system supports slow unaligned memory accesses. The
927	  kernel and userspace programs may not be able to run at all on systems
928	  that do not support unaligned memory accesses.
929
930config RISCV_EFFICIENT_UNALIGNED_ACCESS
931	bool "Assume the system supports fast unaligned memory accesses"
932	depends on NONPORTABLE
933	select DCACHE_WORD_ACCESS if MMU
934	select HAVE_EFFICIENT_UNALIGNED_ACCESS
935	help
936	  Assume that the system supports fast unaligned memory accesses. When
937	  enabled, this option improves the performance of the kernel on such
938	  systems. However, the kernel and userspace programs will run much more
939	  slowly, or will not be able to run at all, on systems that do not
940	  support efficient unaligned memory accesses.
941
942endchoice
943
944choice
945	prompt "Vector unaligned Accesses Support"
946	depends on RISCV_ISA_V
947	default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
948	help
949	  This determines the level of support for vector unaligned accesses. This
950	  information is used by the kernel to perform optimizations. It is also
951	  exposed to user space via the hwprobe syscall. The hardware will be
952	  probed at boot by default.
953
954config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
955	bool "Probe speed of vector unaligned accesses"
956	select RISCV_VECTOR_MISALIGNED
957	depends on RISCV_ISA_V
958	help
959	  During boot, the kernel will run a series of tests to determine the
960	  speed of vector unaligned accesses if they are supported. This probing
961	  will dynamically determine the speed of vector unaligned accesses on
962	  the underlying system if they are supported.
963
964config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
965	bool "Assume the system supports slow vector unaligned memory accesses"
966	depends on NONPORTABLE
967	help
968	  Assume that the system supports slow vector unaligned memory accesses. The
969	  kernel and userspace programs may not be able to run at all on systems
970	  that do not support unaligned memory accesses.
971
972config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
973	bool "Assume the system supports fast vector unaligned memory accesses"
974	depends on NONPORTABLE
975	help
976	  Assume that the system supports fast vector unaligned memory accesses. When
977	  enabled, this option improves the performance of the kernel on such
978	  systems. However, the kernel and userspace programs will run much more
979	  slowly, or will not be able to run at all, on systems that do not
980	  support efficient unaligned memory accesses.
981
982endchoice
983
984source "arch/riscv/Kconfig.vendor"
985
986endmenu # "Platform type"
987
988menu "Kernel features"
989
990source "kernel/Kconfig.hz"
991
992config RISCV_SBI_V01
993	bool "SBI v0.1 support"
994	depends on RISCV_SBI
995	help
996	  This config allows kernel to use SBI v0.1 APIs. This will be
997	  deprecated in future once legacy M-mode software are no longer in use.
998
999config RISCV_BOOT_SPINWAIT
1000	bool "Spinwait booting method"
1001	depends on SMP
1002	default y if RISCV_SBI_V01 || RISCV_M_MODE
1003	help
1004	  This enables support for booting Linux via spinwait method. In the
1005	  spinwait method, all cores randomly jump to Linux. One of the cores
1006	  gets chosen via lottery and all other keep spinning on a percpu
1007	  variable. This method cannot support CPU hotplug and sparse hartid
1008	  scheme. It should be only enabled for M-mode Linux or platforms relying
1009	  on older firmware without SBI HSM extension. All other platforms should
1010	  rely on ordered booting via SBI HSM extension which gets chosen
1011	  dynamically at runtime if the firmware supports it.
1012
1013	  Since spinwait is incompatible with sparse hart IDs, it requires
1014	  NR_CPUS be large enough to contain the physical hart ID of the first
1015	  hart to enter Linux.
1016
1017	  If unsure what to do here, say N.
1018
1019config ARCH_SUPPORTS_KEXEC
1020	def_bool y
1021
1022config ARCH_SELECTS_KEXEC
1023	def_bool y
1024	depends on KEXEC
1025	select HOTPLUG_CPU if SMP
1026
1027config ARCH_SUPPORTS_KEXEC_FILE
1028	def_bool 64BIT
1029
1030config ARCH_SELECTS_KEXEC_FILE
1031	def_bool y
1032	depends on KEXEC_FILE
1033	select HAVE_IMA_KEXEC if IMA
1034	select KEXEC_ELF
1035
1036config ARCH_SUPPORTS_KEXEC_PURGATORY
1037	def_bool ARCH_SUPPORTS_KEXEC_FILE
1038
1039config ARCH_SUPPORTS_CRASH_DUMP
1040	def_bool y
1041
1042config ARCH_DEFAULT_CRASH_DUMP
1043	def_bool y
1044
1045config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1046	def_bool CRASH_RESERVE
1047
1048config COMPAT
1049	bool "Kernel support for 32-bit U-mode"
1050	default 64BIT
1051	depends on 64BIT && MMU
1052	help
1053	  This option enables support for a 32-bit U-mode running under a 64-bit
1054	  kernel at S-mode. riscv32-specific components such as system calls,
1055	  the user helper functions (vdso), signal rt_frame functions and the
1056	  ptrace interface are handled appropriately by the kernel.
1057
1058	  If you want to execute 32-bit userspace applications, say Y.
1059
1060config PARAVIRT
1061	bool "Enable paravirtualization code"
1062	depends on RISCV_SBI
1063	help
1064	  This changes the kernel so it can modify itself when it is run
1065	  under a hypervisor, potentially improving performance significantly
1066	  over full virtualization.
1067
1068config PARAVIRT_TIME_ACCOUNTING
1069	bool "Paravirtual steal time accounting"
1070	depends on PARAVIRT
1071	help
1072	  Select this option to enable fine granularity task steal time
1073	  accounting. Time spent executing other tasks in parallel with
1074	  the current vCPU is discounted from the vCPU power. To account for
1075	  that, there can be a small performance impact.
1076
1077	  If in doubt, say N here.
1078
1079config RELOCATABLE
1080	bool "Build a relocatable kernel"
1081	depends on MMU && 64BIT && !XIP_KERNEL
1082	select MODULE_SECTIONS if MODULES
1083	help
1084          This builds a kernel as a Position Independent Executable (PIE),
1085          which retains all relocation metadata required to relocate the
1086          kernel binary at runtime to a different virtual address than the
1087          address it was linked at.
1088          Since RISCV uses the RELA relocation format, this requires a
1089          relocation pass at runtime even if the kernel is loaded at the
1090          same address it was linked at.
1091
1092          If unsure, say N.
1093
1094config RANDOMIZE_BASE
1095        bool "Randomize the address of the kernel image"
1096        select RELOCATABLE
1097        depends on MMU && 64BIT && !XIP_KERNEL
1098        help
1099          Randomizes the virtual address at which the kernel image is
1100          loaded, as a security feature that deters exploit attempts
1101          relying on knowledge of the location of kernel internals.
1102
1103          It is the bootloader's job to provide entropy, by passing a
1104          random u64 value in /chosen/kaslr-seed at kernel entry.
1105
1106          When booting via the UEFI stub, it will invoke the firmware's
1107          EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1108          to the kernel proper. In addition, it will randomise the physical
1109          location of the kernel Image as well.
1110
1111          If unsure, say N.
1112
1113endmenu # "Kernel features"
1114
1115menu "Boot options"
1116
1117config CMDLINE
1118	string "Built-in kernel command line"
1119	help
1120	  For most platforms, the arguments for the kernel's command line
1121	  are provided at run-time, during boot. However, there are cases
1122	  where either no arguments are being provided or the provided
1123	  arguments are insufficient or even invalid.
1124
1125	  When that occurs, it is possible to define a built-in command
1126	  line here and choose how the kernel should use it later on.
1127
1128choice
1129	prompt "Built-in command line usage"
1130	depends on CMDLINE != ""
1131	default CMDLINE_FALLBACK
1132	help
1133	  Choose how the kernel will handle the provided built-in command
1134	  line.
1135
1136config CMDLINE_FALLBACK
1137	bool "Use bootloader kernel arguments if available"
1138	help
1139	  Use the built-in command line as fallback in case we get nothing
1140	  during boot. This is the default behaviour.
1141
1142config CMDLINE_EXTEND
1143	bool "Extend bootloader kernel arguments"
1144	help
1145	  The command-line arguments provided during boot will be
1146	  appended to the built-in command line. This is useful in
1147	  cases where the provided arguments are insufficient and
1148	  you don't want to or cannot modify them.
1149
1150config CMDLINE_FORCE
1151	bool "Always use the default kernel command string"
1152	help
1153	  Always use the built-in command line, even if we get one during
1154	  boot. This is useful in case you need to override the provided
1155	  command line on systems where you don't have or want control
1156	  over it.
1157
1158endchoice
1159
1160config EFI_STUB
1161	bool
1162
1163config EFI
1164	bool "UEFI runtime support"
1165	depends on OF && !XIP_KERNEL
1166	depends on MMU
1167	default y
1168	select ARCH_SUPPORTS_ACPI if 64BIT
1169	select EFI_GENERIC_STUB
1170	select EFI_PARAMS_FROM_FDT
1171	select EFI_RUNTIME_WRAPPERS
1172	select EFI_STUB
1173	select LIBFDT
1174	select RISCV_ISA_C
1175	select UCS2_STRING
1176	help
1177	  This option provides support for runtime services provided
1178	  by UEFI firmware (such as non-volatile variables, realtime
1179	  clock, and platform reset). A UEFI stub is also provided to
1180	  allow the kernel to be booted as an EFI application. This
1181	  is only useful on systems that have UEFI firmware.
1182
1183config DMI
1184	bool "Enable support for SMBIOS (DMI) tables"
1185	depends on EFI
1186	default y
1187	help
1188	  This enables SMBIOS/DMI feature for systems.
1189
1190	  This option is only useful on systems that have UEFI firmware.
1191	  However, even with this option, the resultant kernel should
1192	  continue to boot on existing non-UEFI platforms.
1193
1194config CC_HAVE_STACKPROTECTOR_TLS
1195	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
1196
1197config STACKPROTECTOR_PER_TASK
1198	def_bool y
1199	depends on !RANDSTRUCT
1200	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
1201
1202config PHYS_RAM_BASE_FIXED
1203	bool "Explicitly specified physical RAM address"
1204	depends on NONPORTABLE
1205	default n
1206
1207config PHYS_RAM_BASE
1208	hex "Platform Physical RAM address"
1209	depends on PHYS_RAM_BASE_FIXED
1210	default "0x80000000"
1211	help
1212	  This is the physical address of RAM in the system. It has to be
1213	  explicitly specified to run early relocations of read-write data
1214	  from flash to RAM.
1215
1216config XIP_KERNEL
1217	bool "Kernel Execute-In-Place from ROM"
1218	depends on MMU && SPARSEMEM && NONPORTABLE
1219	# This prevents XIP from being enabled by all{yes,mod}config, which
1220	# fail to build since XIP doesn't support large kernels.
1221	depends on !COMPILE_TEST
1222	select PHYS_RAM_BASE_FIXED
1223	help
1224	  Execute-In-Place allows the kernel to run from non-volatile storage
1225	  directly addressable by the CPU, such as NOR flash. This saves RAM
1226	  space since the text section of the kernel is not loaded from flash
1227	  to RAM.  Read-write sections, such as the data section and stack,
1228	  are still copied to RAM.  The XIP kernel is not compressed since
1229	  it has to run directly from flash, so it will take more space to
1230	  store it.  The flash address used to link the kernel object files,
1231	  and for storing it, is configuration dependent. Therefore, if you
1232	  say Y here, you must know the proper physical address where to
1233	  store the kernel image depending on your own flash memory usage.
1234
1235	  Also note that the make target becomes "make xipImage" rather than
1236	  "make zImage" or "make Image".  The final kernel binary to put in
1237	  ROM memory will be arch/riscv/boot/xipImage.
1238
1239	  SPARSEMEM is required because the kernel text and rodata that are
1240	  flash resident are not backed by memmap, then any attempt to get
1241	  a struct page on those regions will trigger a fault.
1242
1243	  If unsure, say N.
1244
1245config XIP_PHYS_ADDR
1246	hex "XIP Kernel Physical Location"
1247	depends on XIP_KERNEL
1248	default "0x21000000"
1249	help
1250	  This is the physical address in your flash memory the kernel will
1251	  be linked for and stored to.  This address is dependent on your
1252	  own flash usage.
1253
1254config RISCV_ISA_FALLBACK
1255	bool "Permit falling back to parsing riscv,isa for extension support by default"
1256	default y
1257	help
1258	  Parsing the "riscv,isa" devicetree property has been deprecated and
1259	  replaced by a list of explicitly defined strings. For compatibility
1260	  with existing platforms, the kernel will fall back to parsing the
1261	  "riscv,isa" property if the replacements are not found.
1262
1263	  Selecting N here will result in a kernel that does not use the
1264	  fallback, unless the commandline "riscv_isa_fallback" parameter is
1265	  present.
1266
1267	  Please see the dt-binding, located at
1268	  Documentation/devicetree/bindings/riscv/extensions.yaml for details
1269	  on the replacement properties, "riscv,isa-base" and
1270	  "riscv,isa-extensions".
1271
1272config BUILTIN_DTB
1273	bool "Built-in device tree"
1274	depends on OF && NONPORTABLE
1275	help
1276	  Build a device tree into the Linux image.
1277	  This option should be selected if no bootloader is being used.
1278	  If unsure, say N.
1279
1280
1281config BUILTIN_DTB_SOURCE
1282	string "Built-in device tree source"
1283	depends on BUILTIN_DTB
1284	help
1285	  DTS file path (without suffix, relative to arch/riscv/boot/dts)
1286	  for the DTS file that will be used to produce the DTB linked into the
1287	  kernel.
1288
1289endmenu # "Boot options"
1290
1291config PORTABLE
1292	bool
1293	default !NONPORTABLE
1294	select EFI
1295	select MMU
1296	select OF
1297
1298config ARCH_PROC_KCORE_TEXT
1299	def_bool y
1300
1301menu "Power management options"
1302
1303source "kernel/power/Kconfig"
1304
1305config ARCH_HIBERNATION_POSSIBLE
1306	def_bool y
1307
1308config ARCH_HIBERNATION_HEADER
1309	def_bool HIBERNATION
1310
1311config ARCH_SUSPEND_POSSIBLE
1312	def_bool y
1313
1314endmenu # "Power management options"
1315
1316menu "CPU Power Management"
1317
1318source "drivers/cpuidle/Kconfig"
1319
1320source "drivers/cpufreq/Kconfig"
1321
1322endmenu # "CPU Power Management"
1323
1324source "arch/riscv/kvm/Kconfig"
1325
1326source "drivers/acpi/Kconfig"
1327