xref: /linux/arch/riscv/Kconfig (revision 223970df2bff4caa308246404383baee2b79dba2)
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_ARCH_DATA if GENERIC_VDSO_DATA_STORE
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_HUGETLBFS if MMU
66	# LLD >= 14: https://github.com/llvm/llvm-project/issues/50505
67	select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000
68	select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000
69	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
70	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
71	select ARCH_SUPPORTS_RT
72	select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
73	select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
74	select ARCH_USE_MEMTEST
75	select ARCH_USE_QUEUED_RWLOCKS
76	select ARCH_USE_SYM_ANNOTATIONS
77	select ARCH_USES_CFI_TRAPS if CFI_CLANG
78	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU
79	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
80	select ARCH_WANT_FRAME_POINTERS
81	select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
82	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
83	select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
84	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
85	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
86	select ARCH_WANTS_NO_INSTR
87	select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
88	select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS
89	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
90	select BUILDTIME_TABLE_SORT if MMU
91	select CLINT_TIMER if RISCV_M_MODE
92	select CLONE_BACKWARDS
93	select COMMON_CLK
94	select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
95	select EDAC_SUPPORT
96	select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
97	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
98	select GENERIC_ARCH_TOPOLOGY
99	select GENERIC_ATOMIC64 if !64BIT
100	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
101	select GENERIC_CPU_DEVICES
102	select GENERIC_CPU_VULNERABILITIES
103	select GENERIC_EARLY_IOREMAP
104	select GENERIC_ENTRY
105	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
106	select GENERIC_IDLE_POLL_SETUP
107	select GENERIC_IOREMAP if MMU
108	select GENERIC_IRQ_IPI if SMP
109	select GENERIC_IRQ_IPI_MUX if SMP
110	select GENERIC_IRQ_MULTI_HANDLER
111	select GENERIC_IRQ_SHOW
112	select GENERIC_IRQ_SHOW_LEVEL
113	select GENERIC_LIB_DEVMEM_IS_ALLOWED
114	select GENERIC_PCI_IOMAP
115	select GENERIC_PTDUMP if MMU
116	select GENERIC_SCHED_CLOCK
117	select GENERIC_SMP_IDLE_THREAD
118	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
119	select GENERIC_VDSO_DATA_STORE if MMU
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.
571
572	  If you don't know what to do here, say Y.
573
574config RISCV_ISA_SUPM
575	bool "Supm extension for userspace pointer masking"
576	depends on 64BIT
577	default y
578	help
579	  Add support for pointer masking in userspace (Supm) when the
580	  underlying hardware extension (Smnpm or Ssnpm) is detected at boot.
581
582	  If this option is disabled, userspace will be unable to use
583	  the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API.
584
585config RISCV_ISA_SVNAPOT
586	bool "Svnapot extension support for supervisor mode NAPOT pages"
587	depends on 64BIT && MMU
588	depends on RISCV_ALTERNATIVE
589	default y
590	help
591	  Allow kernel to detect the Svnapot ISA-extension dynamically at boot
592	  time and enable its usage.
593
594	  The Svnapot extension is used to mark contiguous PTEs as a range
595	  of contiguous virtual-to-physical translations for a naturally
596	  aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
597	  size. When HUGETLBFS is also selected this option unconditionally
598	  allocates some memory for each NAPOT page size supported by the kernel.
599	  When optimizing for low memory consumption and for platforms without
600	  the Svnapot extension, it may be better to say N here.
601
602	  If you don't know what to do here, say Y.
603
604config RISCV_ISA_SVPBMT
605	bool "Svpbmt extension support for supervisor mode page-based memory types"
606	depends on 64BIT && MMU
607	depends on RISCV_ALTERNATIVE
608	default y
609	help
610	   Adds support to dynamically detect the presence of the Svpbmt
611	   ISA-extension (Supervisor-mode: page-based memory types) and
612	   enable its usage.
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	  Say N here if you want to disable all vector related procedure
638	  in the kernel.
639
640	  If you don't know what to do here, say Y.
641
642config RISCV_ISA_V_DEFAULT_ENABLE
643	bool "Enable userspace Vector by default"
644	depends on RISCV_ISA_V
645	default y
646	help
647	  Say Y here if you want to enable Vector in userspace by default.
648	  Otherwise, userspace has to make explicit prctl() call to enable
649	  Vector, or enable it via the sysctl interface.
650
651	  If you don't know what to do here, say Y.
652
653config RISCV_ISA_V_UCOPY_THRESHOLD
654	int "Threshold size for vectorized user copies"
655	depends on RISCV_ISA_V
656	default 768
657	help
658	  Prefer using vectorized copy_to_user()/copy_from_user() when the
659	  workload size exceeds this value.
660
661config RISCV_ISA_V_PREEMPTIVE
662	bool "Run kernel-mode Vector with kernel preemption"
663	depends on PREEMPTION
664	depends on RISCV_ISA_V
665	default y
666	help
667	  Usually, in-kernel SIMD routines are run with preemption disabled.
668	  Functions which envoke long running SIMD thus must yield core's
669	  vector unit to prevent blocking other tasks for too long.
670
671	  This config allows kernel to run SIMD without explicitly disable
672	  preemption. Enabling this config will result in higher memory
673	  consumption due to the allocation of per-task's kernel Vector context.
674
675config RISCV_ISA_ZAWRS
676	bool "Zawrs extension support for more efficient busy waiting"
677	depends on RISCV_ALTERNATIVE
678	default y
679	help
680	  The Zawrs extension defines instructions to be used in polling loops
681	  which allow a hart to enter a low-power state or to trap to the
682	  hypervisor while waiting on a store to a memory location. Enable the
683	  use of these instructions in the kernel when the Zawrs extension is
684	  detected at boot.
685
686config TOOLCHAIN_HAS_ZABHA
687	bool
688	default y
689	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha)
690	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha)
691	depends on AS_HAS_OPTION_ARCH
692
693config RISCV_ISA_ZABHA
694	bool "Zabha extension support for atomic byte/halfword operations"
695	depends on TOOLCHAIN_HAS_ZABHA
696	depends on RISCV_ALTERNATIVE
697	default y
698	help
699	  Enable the use of the Zabha ISA-extension to implement kernel
700	  byte/halfword atomic memory operations when it is detected at boot.
701
702	  If you don't know what to do here, say Y.
703
704config TOOLCHAIN_HAS_ZACAS
705	bool
706	default y
707	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas)
708	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas)
709	depends on AS_HAS_OPTION_ARCH
710
711config RISCV_ISA_ZACAS
712	bool "Zacas extension support for atomic CAS"
713	depends on TOOLCHAIN_HAS_ZACAS
714	depends on RISCV_ALTERNATIVE
715	default y
716	help
717	  Enable the use of the Zacas ISA-extension to implement kernel atomic
718	  cmpxchg operations when it is detected at boot.
719
720	  If you don't know what to do here, say Y.
721
722config TOOLCHAIN_HAS_ZBB
723	bool
724	default y
725	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
726	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
727	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
728	depends on AS_HAS_OPTION_ARCH
729
730# This symbol indicates that the toolchain supports all v1.0 vector crypto
731# extensions, including Zvk*, Zvbb, and Zvbc.  LLVM added all of these at once.
732# binutils added all except Zvkb, then added Zvkb.  So we just check for Zvkb.
733config TOOLCHAIN_HAS_VECTOR_CRYPTO
734	def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
735	depends on AS_HAS_OPTION_ARCH
736
737config RISCV_ISA_ZBA
738	bool "Zba extension support for bit manipulation instructions"
739	default y
740	help
741	   Add support for enabling optimisations in the kernel when the Zba
742	   extension is detected at boot.
743
744	   The Zba extension provides instructions to accelerate the generation
745	   of addresses that index into arrays of basic data types.
746
747	   If you don't know what to do here, say Y.
748
749config RISCV_ISA_ZBB
750	bool "Zbb extension support for bit manipulation instructions"
751	depends on TOOLCHAIN_HAS_ZBB
752	depends on RISCV_ALTERNATIVE
753	default y
754	help
755	   Adds support to dynamically detect the presence of the ZBB
756	   extension (basic bit manipulation) and enable its usage.
757
758	   The Zbb extension provides instructions to accelerate a number
759	   of bit-specific operations (count bit population, sign extending,
760	   bitrotation, etc).
761
762	   If you don't know what to do here, say Y.
763
764config TOOLCHAIN_HAS_ZBC
765	bool
766	default y
767	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
768	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
769	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
770	depends on AS_HAS_OPTION_ARCH
771
772config RISCV_ISA_ZBC
773	bool "Zbc extension support for carry-less multiplication instructions"
774	depends on TOOLCHAIN_HAS_ZBC
775	depends on MMU
776	depends on RISCV_ALTERNATIVE
777	default y
778	help
779	   Adds support to dynamically detect the presence of the Zbc
780	   extension (carry-less multiplication) and enable its usage.
781
782	   The Zbc extension could accelerate CRC (cyclic redundancy check)
783	   calculations.
784
785	   If you don't know what to do here, say Y.
786
787config RISCV_ISA_ZICBOM
788	bool "Zicbom extension support for non-coherent DMA operation"
789	depends on MMU
790	depends on RISCV_ALTERNATIVE
791	default y
792	select RISCV_DMA_NONCOHERENT
793	select DMA_DIRECT_REMAP
794	help
795	   Adds support to dynamically detect the presence of the ZICBOM
796	   extension (Cache Block Management Operations) and enable its
797	   usage.
798
799	   The Zicbom extension can be used to handle for example
800	   non-coherent DMA support on devices that need it.
801
802	   If you don't know what to do here, say Y.
803
804config RISCV_ISA_ZICBOZ
805	bool "Zicboz extension support for faster zeroing of memory"
806	depends on RISCV_ALTERNATIVE
807	default y
808	help
809	   Enable the use of the Zicboz extension (cbo.zero instruction)
810	   when available.
811
812	   The Zicboz extension is used for faster zeroing of memory.
813
814	   If you don't know what to do here, say Y.
815
816config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
817	def_bool y
818	# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
819	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
820	depends on AS_IS_GNU && AS_VERSION >= 23600
821	help
822	  Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
823	  20191213 version, which moves some instructions from the I extension to
824	  the Zicsr and Zifencei extensions. This requires explicitly specifying
825	  Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
826	  and Zifencei are supported in binutils from version 2.36 onwards.
827	  To make life easier, and avoid forcing toolchains that default to a
828	  newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
829	  For clang < 17 or GCC < 11.3.0, for which this is not possible or need
830	  special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
831
832config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
833	def_bool y
834	depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
835	# https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
836	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
837	depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
838	help
839	  Certain versions of clang and GCC do not support zicsr and zifencei via
840	  -march. This option causes an older ISA spec compatible with these older
841	  versions of clang and GCC to be passed to GAS, which has the same result
842	  as passing zicsr and zifencei to -march.
843
844config FPU
845	bool "FPU support"
846	default y
847	help
848	  Say N here if you want to disable all floating-point related procedure
849	  in the kernel.
850
851	  If you don't know what to do here, say Y.
852
853config IRQ_STACKS
854	bool "Independent irq & softirq stacks" if EXPERT
855	default y
856	select HAVE_IRQ_EXIT_ON_IRQ_STACK
857	select HAVE_SOFTIRQ_ON_OWN_STACK
858	help
859	  Add independent irq & softirq stacks for percpu to prevent kernel stack
860	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
861
862config THREAD_SIZE_ORDER
863	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
864	range 0 4
865	default 1 if 32BIT
866	default 2
867	help
868	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
869	  affects irq stack size, which is equal to thread stack size.
870
871config RISCV_MISALIGNED
872	bool
873	help
874	  Embed support for detecting and emulating misaligned
875	  scalar or vector loads and stores.
876
877config RISCV_SCALAR_MISALIGNED
878	bool
879	select RISCV_MISALIGNED
880	select SYSCTL_ARCH_UNALIGN_ALLOW
881	help
882	  Embed support for emulating misaligned loads and stores.
883
884config RISCV_VECTOR_MISALIGNED
885	bool
886	select RISCV_MISALIGNED
887	depends on RISCV_ISA_V
888	help
889	  Enable detecting support for vector misaligned loads and stores.
890
891choice
892	prompt "Unaligned Accesses Support"
893	default RISCV_PROBE_UNALIGNED_ACCESS
894	help
895	  This determines the level of support for unaligned accesses. This
896	  information is used by the kernel to perform optimizations. It is also
897	  exposed to user space via the hwprobe syscall. The hardware will be
898	  probed at boot by default.
899
900config RISCV_PROBE_UNALIGNED_ACCESS
901	bool "Probe for hardware unaligned access support"
902	select RISCV_SCALAR_MISALIGNED
903	help
904	  During boot, the kernel will run a series of tests to determine the
905	  speed of unaligned accesses. This probing will dynamically determine
906	  the speed of unaligned accesses on the underlying system. If unaligned
907	  memory accesses trap into the kernel as they are not supported by the
908	  system, the kernel will emulate the unaligned accesses to preserve the
909	  UABI.
910
911config RISCV_EMULATED_UNALIGNED_ACCESS
912	bool "Emulate unaligned access where system support is missing"
913	select RISCV_SCALAR_MISALIGNED
914	help
915	  If unaligned memory accesses trap into the kernel as they are not
916	  supported by the system, the kernel will emulate the unaligned
917	  accesses to preserve the UABI. When the underlying system does support
918	  unaligned accesses, the unaligned accesses are assumed to be slow.
919
920config RISCV_SLOW_UNALIGNED_ACCESS
921	bool "Assume the system supports slow unaligned memory accesses"
922	depends on NONPORTABLE
923	help
924	  Assume that the system supports slow unaligned memory accesses. The
925	  kernel and userspace programs may not be able to run at all on systems
926	  that do not support unaligned memory accesses.
927
928config RISCV_EFFICIENT_UNALIGNED_ACCESS
929	bool "Assume the system supports fast unaligned memory accesses"
930	depends on NONPORTABLE
931	select DCACHE_WORD_ACCESS if MMU
932	select HAVE_EFFICIENT_UNALIGNED_ACCESS
933	help
934	  Assume that the system supports fast unaligned memory accesses. When
935	  enabled, this option improves the performance of the kernel on such
936	  systems. However, the kernel and userspace programs will run much more
937	  slowly, or will not be able to run at all, on systems that do not
938	  support efficient unaligned memory accesses.
939
940endchoice
941
942choice
943	prompt "Vector unaligned Accesses Support"
944	depends on RISCV_ISA_V
945	default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
946	help
947	  This determines the level of support for vector unaligned accesses. This
948	  information is used by the kernel to perform optimizations. It is also
949	  exposed to user space via the hwprobe syscall. The hardware will be
950	  probed at boot by default.
951
952config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
953	bool "Probe speed of vector unaligned accesses"
954	select RISCV_VECTOR_MISALIGNED
955	depends on RISCV_ISA_V
956	help
957	  During boot, the kernel will run a series of tests to determine the
958	  speed of vector unaligned accesses if they are supported. This probing
959	  will dynamically determine the speed of vector unaligned accesses on
960	  the underlying system if they are supported.
961
962config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
963	bool "Assume the system supports slow vector unaligned memory accesses"
964	depends on NONPORTABLE
965	help
966	  Assume that the system supports slow vector unaligned memory accesses. The
967	  kernel and userspace programs may not be able to run at all on systems
968	  that do not support unaligned memory accesses.
969
970config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
971	bool "Assume the system supports fast vector unaligned memory accesses"
972	depends on NONPORTABLE
973	help
974	  Assume that the system supports fast vector unaligned memory accesses. When
975	  enabled, this option improves the performance of the kernel on such
976	  systems. However, the kernel and userspace programs will run much more
977	  slowly, or will not be able to run at all, on systems that do not
978	  support efficient unaligned memory accesses.
979
980endchoice
981
982source "arch/riscv/Kconfig.vendor"
983
984endmenu # "Platform type"
985
986menu "Kernel features"
987
988source "kernel/Kconfig.hz"
989
990config RISCV_SBI_V01
991	bool "SBI v0.1 support"
992	depends on RISCV_SBI
993	help
994	  This config allows kernel to use SBI v0.1 APIs. This will be
995	  deprecated in future once legacy M-mode software are no longer in use.
996
997config RISCV_BOOT_SPINWAIT
998	bool "Spinwait booting method"
999	depends on SMP
1000	default y if RISCV_SBI_V01 || RISCV_M_MODE
1001	help
1002	  This enables support for booting Linux via spinwait method. In the
1003	  spinwait method, all cores randomly jump to Linux. One of the cores
1004	  gets chosen via lottery and all other keep spinning on a percpu
1005	  variable. This method cannot support CPU hotplug and sparse hartid
1006	  scheme. It should be only enabled for M-mode Linux or platforms relying
1007	  on older firmware without SBI HSM extension. All other platforms should
1008	  rely on ordered booting via SBI HSM extension which gets chosen
1009	  dynamically at runtime if the firmware supports it.
1010
1011	  Since spinwait is incompatible with sparse hart IDs, it requires
1012	  NR_CPUS be large enough to contain the physical hart ID of the first
1013	  hart to enter Linux.
1014
1015	  If unsure what to do here, say N.
1016
1017config ARCH_SUPPORTS_KEXEC
1018	def_bool y
1019
1020config ARCH_SELECTS_KEXEC
1021	def_bool y
1022	depends on KEXEC
1023	select HOTPLUG_CPU if SMP
1024
1025config ARCH_SUPPORTS_KEXEC_FILE
1026	def_bool 64BIT
1027
1028config ARCH_SELECTS_KEXEC_FILE
1029	def_bool y
1030	depends on KEXEC_FILE
1031	select HAVE_IMA_KEXEC if IMA
1032	select KEXEC_ELF
1033
1034config ARCH_SUPPORTS_KEXEC_PURGATORY
1035	def_bool ARCH_SUPPORTS_KEXEC_FILE
1036
1037config ARCH_SUPPORTS_CRASH_DUMP
1038	def_bool y
1039
1040config ARCH_DEFAULT_CRASH_DUMP
1041	def_bool y
1042
1043config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1044	def_bool CRASH_RESERVE
1045
1046config COMPAT
1047	bool "Kernel support for 32-bit U-mode"
1048	default 64BIT
1049	depends on 64BIT && MMU
1050	help
1051	  This option enables support for a 32-bit U-mode running under a 64-bit
1052	  kernel at S-mode. riscv32-specific components such as system calls,
1053	  the user helper functions (vdso), signal rt_frame functions and the
1054	  ptrace interface are handled appropriately by the kernel.
1055
1056	  If you want to execute 32-bit userspace applications, say Y.
1057
1058config PARAVIRT
1059	bool "Enable paravirtualization code"
1060	depends on RISCV_SBI
1061	help
1062	  This changes the kernel so it can modify itself when it is run
1063	  under a hypervisor, potentially improving performance significantly
1064	  over full virtualization.
1065
1066config PARAVIRT_TIME_ACCOUNTING
1067	bool "Paravirtual steal time accounting"
1068	depends on PARAVIRT
1069	help
1070	  Select this option to enable fine granularity task steal time
1071	  accounting. Time spent executing other tasks in parallel with
1072	  the current vCPU is discounted from the vCPU power. To account for
1073	  that, there can be a small performance impact.
1074
1075	  If in doubt, say N here.
1076
1077config RELOCATABLE
1078	bool "Build a relocatable kernel"
1079	depends on MMU && 64BIT && !XIP_KERNEL
1080	select MODULE_SECTIONS if MODULES
1081	help
1082          This builds a kernel as a Position Independent Executable (PIE),
1083          which retains all relocation metadata required to relocate the
1084          kernel binary at runtime to a different virtual address than the
1085          address it was linked at.
1086          Since RISCV uses the RELA relocation format, this requires a
1087          relocation pass at runtime even if the kernel is loaded at the
1088          same address it was linked at.
1089
1090          If unsure, say N.
1091
1092config RANDOMIZE_BASE
1093        bool "Randomize the address of the kernel image"
1094        select RELOCATABLE
1095        depends on MMU && 64BIT && !XIP_KERNEL
1096        help
1097          Randomizes the virtual address at which the kernel image is
1098          loaded, as a security feature that deters exploit attempts
1099          relying on knowledge of the location of kernel internals.
1100
1101          It is the bootloader's job to provide entropy, by passing a
1102          random u64 value in /chosen/kaslr-seed at kernel entry.
1103
1104          When booting via the UEFI stub, it will invoke the firmware's
1105          EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1106          to the kernel proper. In addition, it will randomise the physical
1107          location of the kernel Image as well.
1108
1109          If unsure, say N.
1110
1111endmenu # "Kernel features"
1112
1113menu "Boot options"
1114
1115config CMDLINE
1116	string "Built-in kernel command line"
1117	help
1118	  For most platforms, the arguments for the kernel's command line
1119	  are provided at run-time, during boot. However, there are cases
1120	  where either no arguments are being provided or the provided
1121	  arguments are insufficient or even invalid.
1122
1123	  When that occurs, it is possible to define a built-in command
1124	  line here and choose how the kernel should use it later on.
1125
1126choice
1127	prompt "Built-in command line usage"
1128	depends on CMDLINE != ""
1129	default CMDLINE_FALLBACK
1130	help
1131	  Choose how the kernel will handle the provided built-in command
1132	  line.
1133
1134config CMDLINE_FALLBACK
1135	bool "Use bootloader kernel arguments if available"
1136	help
1137	  Use the built-in command line as fallback in case we get nothing
1138	  during boot. This is the default behaviour.
1139
1140config CMDLINE_EXTEND
1141	bool "Extend bootloader kernel arguments"
1142	help
1143	  The command-line arguments provided during boot will be
1144	  appended to the built-in command line. This is useful in
1145	  cases where the provided arguments are insufficient and
1146	  you don't want to or cannot modify them.
1147
1148config CMDLINE_FORCE
1149	bool "Always use the default kernel command string"
1150	help
1151	  Always use the built-in command line, even if we get one during
1152	  boot. This is useful in case you need to override the provided
1153	  command line on systems where you don't have or want control
1154	  over it.
1155
1156endchoice
1157
1158config EFI_STUB
1159	bool
1160
1161config EFI
1162	bool "UEFI runtime support"
1163	depends on OF && !XIP_KERNEL
1164	depends on MMU
1165	default y
1166	select ARCH_SUPPORTS_ACPI if 64BIT
1167	select EFI_GENERIC_STUB
1168	select EFI_PARAMS_FROM_FDT
1169	select EFI_RUNTIME_WRAPPERS
1170	select EFI_STUB
1171	select LIBFDT
1172	select RISCV_ISA_C
1173	select UCS2_STRING
1174	help
1175	  This option provides support for runtime services provided
1176	  by UEFI firmware (such as non-volatile variables, realtime
1177	  clock, and platform reset). A UEFI stub is also provided to
1178	  allow the kernel to be booted as an EFI application. This
1179	  is only useful on systems that have UEFI firmware.
1180
1181config DMI
1182	bool "Enable support for SMBIOS (DMI) tables"
1183	depends on EFI
1184	default y
1185	help
1186	  This enables SMBIOS/DMI feature for systems.
1187
1188	  This option is only useful on systems that have UEFI firmware.
1189	  However, even with this option, the resultant kernel should
1190	  continue to boot on existing non-UEFI platforms.
1191
1192config CC_HAVE_STACKPROTECTOR_TLS
1193	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
1194
1195config STACKPROTECTOR_PER_TASK
1196	def_bool y
1197	depends on !RANDSTRUCT
1198	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
1199
1200config PHYS_RAM_BASE_FIXED
1201	bool "Explicitly specified physical RAM address"
1202	depends on NONPORTABLE
1203	default n
1204
1205config PHYS_RAM_BASE
1206	hex "Platform Physical RAM address"
1207	depends on PHYS_RAM_BASE_FIXED
1208	default "0x80000000"
1209	help
1210	  This is the physical address of RAM in the system. It has to be
1211	  explicitly specified to run early relocations of read-write data
1212	  from flash to RAM.
1213
1214config XIP_KERNEL
1215	bool "Kernel Execute-In-Place from ROM"
1216	depends on MMU && SPARSEMEM && NONPORTABLE
1217	# This prevents XIP from being enabled by all{yes,mod}config, which
1218	# fail to build since XIP doesn't support large kernels.
1219	depends on !COMPILE_TEST
1220	select PHYS_RAM_BASE_FIXED
1221	help
1222	  Execute-In-Place allows the kernel to run from non-volatile storage
1223	  directly addressable by the CPU, such as NOR flash. This saves RAM
1224	  space since the text section of the kernel is not loaded from flash
1225	  to RAM.  Read-write sections, such as the data section and stack,
1226	  are still copied to RAM.  The XIP kernel is not compressed since
1227	  it has to run directly from flash, so it will take more space to
1228	  store it.  The flash address used to link the kernel object files,
1229	  and for storing it, is configuration dependent. Therefore, if you
1230	  say Y here, you must know the proper physical address where to
1231	  store the kernel image depending on your own flash memory usage.
1232
1233	  Also note that the make target becomes "make xipImage" rather than
1234	  "make zImage" or "make Image".  The final kernel binary to put in
1235	  ROM memory will be arch/riscv/boot/xipImage.
1236
1237	  SPARSEMEM is required because the kernel text and rodata that are
1238	  flash resident are not backed by memmap, then any attempt to get
1239	  a struct page on those regions will trigger a fault.
1240
1241	  If unsure, say N.
1242
1243config XIP_PHYS_ADDR
1244	hex "XIP Kernel Physical Location"
1245	depends on XIP_KERNEL
1246	default "0x21000000"
1247	help
1248	  This is the physical address in your flash memory the kernel will
1249	  be linked for and stored to.  This address is dependent on your
1250	  own flash usage.
1251
1252config RISCV_ISA_FALLBACK
1253	bool "Permit falling back to parsing riscv,isa for extension support by default"
1254	default y
1255	help
1256	  Parsing the "riscv,isa" devicetree property has been deprecated and
1257	  replaced by a list of explicitly defined strings. For compatibility
1258	  with existing platforms, the kernel will fall back to parsing the
1259	  "riscv,isa" property if the replacements are not found.
1260
1261	  Selecting N here will result in a kernel that does not use the
1262	  fallback, unless the commandline "riscv_isa_fallback" parameter is
1263	  present.
1264
1265	  Please see the dt-binding, located at
1266	  Documentation/devicetree/bindings/riscv/extensions.yaml for details
1267	  on the replacement properties, "riscv,isa-base" and
1268	  "riscv,isa-extensions".
1269
1270config BUILTIN_DTB
1271	bool "Built-in device tree"
1272	depends on OF && NONPORTABLE
1273	help
1274	  Build a device tree into the Linux image.
1275	  This option should be selected if no bootloader is being used.
1276	  If unsure, say N.
1277
1278
1279config BUILTIN_DTB_SOURCE
1280	string "Built-in device tree source"
1281	depends on BUILTIN_DTB
1282	help
1283	  DTS file path (without suffix, relative to arch/riscv/boot/dts)
1284	  for the DTS file that will be used to produce the DTB linked into the
1285	  kernel.
1286
1287endmenu # "Boot options"
1288
1289config PORTABLE
1290	bool
1291	default !NONPORTABLE
1292	select EFI
1293	select MMU
1294	select OF
1295
1296config ARCH_PROC_KCORE_TEXT
1297	def_bool y
1298
1299menu "Power management options"
1300
1301source "kernel/power/Kconfig"
1302
1303config ARCH_HIBERNATION_POSSIBLE
1304	def_bool y
1305
1306config ARCH_HIBERNATION_HEADER
1307	def_bool HIBERNATION
1308
1309config ARCH_SUSPEND_POSSIBLE
1310	def_bool y
1311
1312endmenu # "Power management options"
1313
1314menu "CPU Power Management"
1315
1316source "drivers/cpuidle/Kconfig"
1317
1318source "drivers/cpufreq/Kconfig"
1319
1320endmenu # "CPU Power Management"
1321
1322source "arch/riscv/kvm/Kconfig"
1323
1324source "drivers/acpi/Kconfig"
1325