xref: /linux/arch/riscv/Kconfig (revision 9f15e0f9ef514b8e1a80707931f6d07362e8ebc4)
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_CURRENT_STACK_POINTER
28	select ARCH_HAS_DEBUG_VIRTUAL if MMU
29	select ARCH_HAS_DEBUG_VM_PGTABLE
30	select ARCH_HAS_DEBUG_WX
31	select ARCH_HAS_FAST_MULTIPLIER
32	select ARCH_HAS_FORTIFY_SOURCE
33	select ARCH_HAS_GCOV_PROFILE_ALL
34	select ARCH_HAS_GIGANTIC_PAGE
35	select ARCH_HAS_HW_PTE_YOUNG
36	select ARCH_HAS_KCOV
37	select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU
38	select ARCH_HAS_MEMBARRIER_CALLBACKS
39	select ARCH_HAS_MEMBARRIER_SYNC_CORE
40	select ARCH_HAS_MMIOWB
41	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
42	select ARCH_HAS_PMEM_API
43	select ARCH_HAS_PREEMPT_LAZY
44	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
45	select ARCH_HAS_PTDUMP if MMU
46	select ARCH_HAS_PTE_SPECIAL
47	select ARCH_HAS_SET_DIRECT_MAP if MMU
48	select ARCH_HAS_SET_MEMORY if MMU
49	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
50	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
51	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
52	select ARCH_HAS_SYSCALL_WRAPPER
53	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
54	select ARCH_HAS_UBSAN
55	select ARCH_HAS_VDSO_ARCH_DATA if HAVE_GENERIC_VDSO
56	select ARCH_KEEP_MEMBLOCK if ACPI
57	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE	if 64BIT && MMU
58	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
59	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
60	select ARCH_STACKWALK
61	select ARCH_SUPPORTS_ATOMIC_RMW
62	# clang >= 17: https://github.com/llvm/llvm-project/commit/62fa708ceb027713b386c7e0efda994f8bdc27e2
63	select ARCH_SUPPORTS_CFI_CLANG if CLANG_VERSION >= 170000
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_MSEAL_SYSTEM_MAPPINGS if 64BIT && MMU
71	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
72	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
73	select ARCH_SUPPORTS_RT
74	select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
75	select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
76	select ARCH_USE_MEMTEST
77	select ARCH_USE_QUEUED_RWLOCKS
78	select ARCH_USE_SYM_ANNOTATIONS
79	select ARCH_USES_CFI_TRAPS if CFI_CLANG
80	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU
81	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
82	select ARCH_WANT_FRAME_POINTERS
83	select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
84	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
85	select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
86	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
87	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
88	select ARCH_WANTS_NO_INSTR
89	select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
90	select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS
91	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
92	select BUILDTIME_TABLE_SORT if MMU
93	select CLINT_TIMER if RISCV_M_MODE
94	select CLONE_BACKWARDS
95	select COMMON_CLK
96	select CPU_NO_EFFICIENT_FFS if !RISCV_ISA_ZBB
97	select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
98	select DYNAMIC_FTRACE if FUNCTION_TRACER
99	select EDAC_SUPPORT
100	select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
101	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
102	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
103	select GENERIC_ARCH_TOPOLOGY
104	select GENERIC_ATOMIC64 if !64BIT
105	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
106	select GENERIC_CPU_DEVICES
107	select GENERIC_CPU_VULNERABILITIES
108	select GENERIC_EARLY_IOREMAP
109	select GENERIC_ENTRY
110	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO && 64BIT
111	select GENERIC_IDLE_POLL_SETUP
112	select GENERIC_IOREMAP if MMU
113	select GENERIC_IRQ_IPI if SMP
114	select GENERIC_IRQ_IPI_MUX if SMP
115	select GENERIC_IRQ_MULTI_HANDLER
116	select GENERIC_IRQ_SHOW
117	select GENERIC_IRQ_SHOW_LEVEL
118	select GENERIC_LIB_DEVMEM_IS_ALLOWED
119	select GENERIC_PENDING_IRQ if SMP
120	select GENERIC_PCI_IOMAP
121	select GENERIC_SCHED_CLOCK
122	select GENERIC_SMP_IDLE_THREAD
123	select GENERIC_TIME_VSYSCALL if GENERIC_GETTIMEOFDAY
124	select HARDIRQS_SW_RESEND
125	select HAS_IOPORT if MMU
126	select HAVE_ALIGNED_STRUCT_PAGE
127	select HAVE_ARCH_AUDITSYSCALL
128	select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
129	select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT
130	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
131	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
132	select HAVE_ARCH_KASAN if MMU && 64BIT
133	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
134	select HAVE_ARCH_KFENCE if MMU && 64BIT
135	select HAVE_ARCH_KSTACK_ERASE
136	select HAVE_ARCH_KGDB if !XIP_KERNEL
137	select HAVE_ARCH_KGDB_QXFER_PKT
138	select HAVE_ARCH_MMAP_RND_BITS if MMU
139	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
140	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
141	select HAVE_ARCH_SECCOMP_FILTER
142	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
143	select HAVE_ARCH_TRACEHOOK
144	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
145	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if 64BIT && MMU
146	select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
147	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
148	select HAVE_ASM_MODVERSIONS
149	select HAVE_CONTEXT_TRACKING_USER
150	select HAVE_DEBUG_KMEMLEAK
151	select HAVE_DMA_CONTIGUOUS if MMU
152	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
153	select FUNCTION_ALIGNMENT_4B if HAVE_DYNAMIC_FTRACE && RISCV_ISA_C
154	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS if HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS
155	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG)
156	select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
157	select HAVE_FTRACE_GRAPH_FUNC
158	select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS
159	select HAVE_FUNCTION_GRAPH_FREGS
160	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && HAVE_DYNAMIC_FTRACE
161	select HAVE_EBPF_JIT if MMU
162	select HAVE_GUP_FAST if MMU
163	select HAVE_FUNCTION_ARG_ACCESS_API
164	select HAVE_FUNCTION_ERROR_INJECTION
165	select HAVE_GCC_PLUGINS
166	select HAVE_GENERIC_VDSO if MMU
167	select HAVE_IRQ_TIME_ACCOUNTING
168	select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT
169	select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT
170	select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT
171	select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT
172	select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT
173	select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT
174	select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT
175	select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT
176	select HAVE_KPROBES if !XIP_KERNEL
177	select HAVE_KRETPROBES if !XIP_KERNEL
178	# https://github.com/ClangBuiltLinux/linux/issues/1881
179	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
180	select HAVE_MOVE_PMD
181	select HAVE_MOVE_PUD
182	select HAVE_PAGE_SIZE_4KB
183	select HAVE_PCI
184	select HAVE_PERF_EVENTS
185	select HAVE_PERF_REGS
186	select HAVE_PERF_USER_STACK_DUMP
187	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
188	select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
189	select HAVE_REGS_AND_STACK_ACCESS_API
190	select HAVE_RETHOOK if !XIP_KERNEL
191	select HAVE_RSEQ
192	select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG
193	select HAVE_SAMPLE_FTRACE_DIRECT
194	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
195	select HAVE_STACKPROTECTOR
196	select HAVE_SYSCALL_TRACEPOINTS
197	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
198	select IRQ_DOMAIN
199	select IRQ_FORCED_THREADING
200	select KASAN_VMALLOC if KASAN
201	select LOCK_MM_AND_FIND_VMA
202	select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU
203	select MODULES_USE_ELF_RELA if MODULES
204	select OF
205	select OF_EARLY_FLATTREE
206	select OF_IRQ
207	select PCI_DOMAINS_GENERIC if PCI
208	select PCI_ECAM if (ACPI && PCI)
209	select PCI_MSI if PCI
210	select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED
211	select RISCV_ALTERNATIVE if !XIP_KERNEL
212	select RISCV_APLIC
213	select RISCV_IMSIC
214	select RISCV_INTC
215	select RISCV_TIMER if RISCV_SBI
216	select SIFIVE_PLIC
217	select SPARSE_IRQ
218	select SYSCTL_EXCEPTION_TRACE
219	select THREAD_INFO_IN_TASK
220	select TRACE_IRQFLAGS_SUPPORT
221	select UACCESS_MEMCPY if !MMU
222	select VDSO_GETRANDOM if HAVE_GENERIC_VDSO && 64BIT
223	select USER_STACKTRACE_SUPPORT
224	select ZONE_DMA32 if 64BIT
225
226config RUSTC_SUPPORTS_RISCV
227	def_bool y
228	depends on 64BIT
229	# Shadow call stack requires rustc version 1.82+ due to use of the
230	# -Zsanitizer=shadow-call-stack flag.
231	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200
232
233config CLANG_SUPPORTS_DYNAMIC_FTRACE
234	def_bool CC_IS_CLANG
235	# https://github.com/ClangBuiltLinux/linux/issues/1817
236	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
237
238config GCC_SUPPORTS_DYNAMIC_FTRACE
239	def_bool CC_IS_GCC
240	depends on $(cc-option,-fpatchable-function-entry=8)
241	depends on CC_HAS_MIN_FUNCTION_ALIGNMENT || !RISCV_ISA_C
242
243config HAVE_SHADOW_CALL_STACK
244	def_bool $(cc-option,-fsanitize=shadow-call-stack)
245	# https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
246	depends on $(ld-option,--no-relax-gp)
247
248config RISCV_USE_LINKER_RELAXATION
249	def_bool y
250	# https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
251	depends on !LD_IS_LLD || LLD_VERSION >= 150000
252
253# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
254config ARCH_HAS_BROKEN_DWARF5
255	def_bool y
256	depends on RISCV_USE_LINKER_RELAXATION
257	# https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
258	depends on AS_IS_LLVM && AS_VERSION < 180000
259	# https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
260	depends on LD_IS_LLD && LLD_VERSION < 180000
261
262config ARCH_MMAP_RND_BITS_MIN
263	default 18 if 64BIT
264	default 8
265
266config ARCH_MMAP_RND_COMPAT_BITS_MIN
267	default 8
268
269# max bits determined by the following formula:
270#  VA_BITS - PAGE_SHIFT - 3
271config ARCH_MMAP_RND_BITS_MAX
272	default 24 if 64BIT # SV39 based
273	default 17
274
275config ARCH_MMAP_RND_COMPAT_BITS_MAX
276	default 17
277
278# set if we run in machine mode, cleared if we run in supervisor mode
279config RISCV_M_MODE
280	bool "Build a kernel that runs in machine mode"
281	depends on !MMU
282	default y
283	help
284	  Select this option if you want to run the kernel in M-mode,
285	  without the assistance of any other firmware.
286
287# set if we are running in S-mode and can use SBI calls
288config RISCV_SBI
289	bool
290	depends on !RISCV_M_MODE
291	default y
292
293config MMU
294	bool "MMU-based Paged Memory Management Support"
295	default y
296	help
297	  Select if you want MMU-based virtualised addressing space
298	  support by paged memory management. If unsure, say 'Y'.
299
300config KASAN_SHADOW_OFFSET
301	hex
302	depends on KASAN_GENERIC
303	default 0xdfffffff00000000 if 64BIT
304	default 0xffffffff if 32BIT
305
306config ARCH_FLATMEM_ENABLE
307	def_bool !NUMA
308
309config ARCH_SPARSEMEM_ENABLE
310	def_bool y
311	depends on MMU
312	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
313	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
314
315config ARCH_SELECT_MEMORY_MODEL
316	def_bool ARCH_SPARSEMEM_ENABLE
317
318config ARCH_SUPPORTS_UPROBES
319	def_bool y
320
321config STACKTRACE_SUPPORT
322	def_bool y
323
324config GENERIC_BUG
325	def_bool y
326	depends on BUG
327	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
328
329config GENERIC_BUG_RELATIVE_POINTERS
330	bool
331
332config GENERIC_CALIBRATE_DELAY
333	def_bool y
334
335config GENERIC_CSUM
336	def_bool y
337
338config GENERIC_HWEIGHT
339	def_bool y
340
341config FIX_EARLYCON_MEM
342	def_bool MMU
343
344config ILLEGAL_POINTER_VALUE
345	hex
346	default 0 if 32BIT
347	default 0xdead000000000000 if 64BIT
348
349config PGTABLE_LEVELS
350	int
351	default 5 if 64BIT
352	default 2
353
354config LOCKDEP_SUPPORT
355	def_bool y
356
357config RISCV_DMA_NONCOHERENT
358	bool
359	select ARCH_HAS_DMA_PREP_COHERENT
360	select ARCH_HAS_SETUP_DMA_OPS
361	select ARCH_HAS_SYNC_DMA_FOR_CPU
362	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
363	select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
364
365config RISCV_NONSTANDARD_CACHE_OPS
366	bool
367	help
368	  This enables function pointer support for non-standard noncoherent
369	  systems to handle cache management.
370
371config AS_HAS_INSN
372	def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
373
374config AS_HAS_OPTION_ARCH
375	# https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4
376	def_bool y
377	depends on $(as-instr, .option arch$(comma) +m)
378
379source "arch/riscv/Kconfig.socs"
380source "arch/riscv/Kconfig.errata"
381
382menu "Platform type"
383
384config NONPORTABLE
385	bool "Allow configurations that result in non-portable kernels"
386	help
387	  RISC-V kernel binaries are compatible between all known systems
388	  whenever possible, but there are some use cases that can only be
389	  satisfied by configurations that result in kernel binaries that are
390	  not portable between systems.
391
392	  Selecting N does not guarantee kernels will be portable to all known
393	  systems.  Selecting any of the options guarded by NONPORTABLE will
394	  result in kernel binaries that are unlikely to be portable between
395	  systems.
396
397	  If unsure, say N.
398
399choice
400	prompt "Base ISA"
401	default ARCH_RV64I
402	help
403	  This selects the base ISA that this kernel will target and must match
404	  the target platform.
405
406config ARCH_RV32I
407	bool "RV32I"
408	depends on NONPORTABLE
409	select 32BIT
410	select GENERIC_LIB_ASHLDI3
411	select GENERIC_LIB_ASHRDI3
412	select GENERIC_LIB_LSHRDI3
413	select GENERIC_LIB_UCMPDI2
414
415config ARCH_RV64I
416	bool "RV64I"
417	select 64BIT
418	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
419	select SWIOTLB if MMU
420
421endchoice
422
423# We must be able to map all physical memory into the kernel, but the compiler
424# is still a bit more efficient when generating code if it's setup in a manner
425# such that it can only map 2GiB of memory.
426choice
427	prompt "Kernel Code Model"
428	default CMODEL_MEDLOW if 32BIT
429	default CMODEL_MEDANY if 64BIT
430
431	config CMODEL_MEDLOW
432		bool "medium low code model"
433	config CMODEL_MEDANY
434		bool "medium any code model"
435endchoice
436
437config MODULE_SECTIONS
438	bool
439	select HAVE_MOD_ARCH_SPECIFIC
440
441config SMP
442	bool "Symmetric Multi-Processing"
443	help
444	  This enables support for systems with more than one CPU.  If
445	  you say N here, the kernel will run on single and
446	  multiprocessor machines, but will use only one CPU of a
447	  multiprocessor machine. If you say Y here, the kernel will run
448	  on many, but not all, single processor machines. On a single
449	  processor machine, the kernel will run faster if you say N
450	  here.
451
452	  If you don't know what to do here, say N.
453
454config SCHED_MC
455	bool "Multi-core scheduler support"
456	depends on SMP
457	help
458	  Multi-core scheduler support improves the CPU scheduler's decision
459	  making when dealing with multi-core CPU chips at a cost of slightly
460	  increased overhead in some places. If unsure say N here.
461
462config NR_CPUS
463	int "Maximum number of CPUs (2-512)"
464	depends on SMP
465	range 2 512 if !RISCV_SBI_V01
466	range 2 32 if RISCV_SBI_V01 && 32BIT
467	range 2 64 if RISCV_SBI_V01 && 64BIT
468	default "32" if 32BIT
469	default "64" if 64BIT
470
471config HOTPLUG_CPU
472	bool "Support for hot-pluggable CPUs"
473	depends on SMP
474	select GENERIC_IRQ_MIGRATION
475	help
476
477	  Say Y here to experiment with turning CPUs off and on.  CPUs
478	  can be controlled through /sys/devices/system/cpu.
479
480	  Say N if you want to disable CPU hotplug.
481
482choice
483	prompt "CPU Tuning"
484	default TUNE_GENERIC
485
486config TUNE_GENERIC
487	bool "generic"
488
489endchoice
490
491# Common NUMA Features
492config NUMA
493	bool "NUMA Memory Allocation and Scheduler Support"
494	depends on SMP && MMU
495	select ARCH_SUPPORTS_NUMA_BALANCING
496	select GENERIC_ARCH_NUMA
497	select HAVE_SETUP_PER_CPU_AREA
498	select NEED_PER_CPU_EMBED_FIRST_CHUNK
499	select NEED_PER_CPU_PAGE_FIRST_CHUNK
500	select OF_NUMA
501	select USE_PERCPU_NUMA_NODE_ID
502	help
503	  Enable NUMA (Non-Uniform Memory Access) support.
504
505	  The kernel will try to allocate memory used by a CPU on the
506	  local memory of the CPU and add some more NUMA awareness to the kernel.
507
508config NODES_SHIFT
509	int "Maximum NUMA Nodes (as a power of 2)"
510	range 1 10
511	default "2"
512	depends on NUMA
513	help
514	  Specify the maximum number of NUMA Nodes available on the target
515	  system.  Increases memory reserved to accommodate various tables.
516
517choice
518	prompt "RISC-V spinlock type"
519	default RISCV_COMBO_SPINLOCKS
520
521config RISCV_TICKET_SPINLOCKS
522	bool "Using ticket spinlock"
523
524config RISCV_QUEUED_SPINLOCKS
525	bool "Using queued spinlock"
526	depends on SMP && MMU && NONPORTABLE
527	select ARCH_USE_QUEUED_SPINLOCKS
528	help
529	  The queued spinlock implementation requires the forward progress
530	  guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or
531	  LR/SC with Ziccrse provide such guarantee.
532
533	  Select this if and only if Zabha or Ziccrse is available on your
534	  platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms
535	  without one of those extensions.
536
537	  If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks
538	  when supported and otherwise ticket spinlocks.
539
540config RISCV_COMBO_SPINLOCKS
541	bool "Using combo spinlock"
542	depends on SMP && MMU
543	select ARCH_USE_QUEUED_SPINLOCKS
544	help
545	  Embed both queued spinlock and ticket lock so that the spinlock
546	  implementation can be chosen at runtime.
547
548endchoice
549
550config RISCV_ALTERNATIVE
551	bool
552	depends on !XIP_KERNEL
553	help
554	  This Kconfig allows the kernel to automatically patch the
555	  erratum or cpufeature required by the execution platform at run
556	  time. The code patching overhead is minimal, as it's only done
557	  once at boot and once on each module load.
558
559config RISCV_ALTERNATIVE_EARLY
560	bool
561	depends on RISCV_ALTERNATIVE
562	help
563	  Allows early patching of the kernel for special errata
564
565config RISCV_ISA_C
566	bool "Emit compressed instructions when building Linux"
567	default y
568	help
569	  Adds "C" to the ISA subsets that the toolchain is allowed to emit
570	  when building Linux, which results in compressed instructions in the
571	  Linux binary. This option produces a kernel that will not run on
572	  systems that do not support compressed instructions.
573
574	  If you don't know what to do here, say Y.
575
576config RISCV_ISA_SUPM
577	bool "Supm extension for userspace pointer masking"
578	depends on 64BIT
579	default y
580	help
581	  Add support for pointer masking in userspace (Supm) when the
582	  underlying hardware extension (Smnpm or Ssnpm) is detected at boot.
583
584	  If this option is disabled, userspace will be unable to use
585	  the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API.
586
587config RISCV_ISA_SVNAPOT
588	bool "Svnapot extension support for supervisor mode NAPOT pages"
589	depends on 64BIT && MMU
590	depends on RISCV_ALTERNATIVE
591	default y
592	help
593	  Enable support for the Svnapot ISA-extension when it is detected
594	  at boot.
595
596	  The Svnapot extension is used to mark contiguous PTEs as a range
597	  of contiguous virtual-to-physical translations for a naturally
598	  aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
599	  size. When HUGETLBFS is also selected this option unconditionally
600	  allocates some memory for each NAPOT page size supported by the kernel.
601	  When optimizing for low memory consumption and for platforms without
602	  the Svnapot extension, it may be better to say N here.
603
604	  If you don't know what to do here, say Y.
605
606config RISCV_ISA_SVPBMT
607	bool "Svpbmt extension support for supervisor mode page-based memory types"
608	depends on 64BIT && MMU
609	depends on RISCV_ALTERNATIVE
610	default y
611	help
612	   Add support for the Svpbmt ISA-extension (Supervisor-mode:
613	   page-based memory types) in the kernel when it is detected at boot.
614
615	   The memory type for a page contains a combination of attributes
616	   that indicate the cacheability, idempotency, and ordering
617	   properties for access to that page.
618
619	   The Svpbmt extension is only available on 64-bit cpus.
620
621	   If you don't know what to do here, say Y.
622
623config TOOLCHAIN_HAS_V
624	bool
625	default y
626	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv)
627	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv)
628	depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
629	depends on AS_HAS_OPTION_ARCH
630
631config RISCV_ISA_V
632	bool "Vector extension support"
633	depends on TOOLCHAIN_HAS_V
634	depends on FPU
635	select DYNAMIC_SIGFRAME
636	default y
637	help
638	  Add support for the Vector extension when it is detected at boot.
639	  When this option is disabled, neither the kernel nor userspace may
640	  use vector procedures.
641
642	  If you don't know what to do here, say Y.
643
644config RISCV_ISA_V_DEFAULT_ENABLE
645	bool "Enable userspace Vector by default"
646	depends on RISCV_ISA_V
647	default y
648	help
649	  Say Y here if you want to enable Vector in userspace by default.
650	  Otherwise, userspace has to make explicit prctl() call to enable
651	  Vector, or enable it via the sysctl interface.
652
653	  If you don't know what to do here, say Y.
654
655config RISCV_ISA_V_UCOPY_THRESHOLD
656	int "Threshold size for vectorized user copies"
657	depends on RISCV_ISA_V
658	default 768
659	help
660	  Prefer using vectorized copy_to_user()/copy_from_user() when the
661	  workload size exceeds this value.
662
663config RISCV_ISA_V_PREEMPTIVE
664	bool "Run kernel-mode Vector with kernel preemption"
665	depends on PREEMPTION
666	depends on RISCV_ISA_V
667	default y
668	help
669	  Usually, in-kernel SIMD routines are run with preemption disabled.
670	  Functions which invoke long running SIMD thus must yield the core's
671	  vector unit to prevent blocking other tasks for too long.
672
673	  This config allows the kernel to run SIMD without explicitly disabling
674	  preemption. Enabling this config will result in higher memory consumption
675	  due to the allocation of per-task's kernel Vector context.
676
677config RISCV_ISA_ZAWRS
678	bool "Zawrs extension support for more efficient busy waiting"
679	depends on RISCV_ALTERNATIVE
680	default y
681	help
682	  The Zawrs extension defines instructions to be used in polling loops
683	  which allow a hart to enter a low-power state or to trap to the
684	  hypervisor while waiting on a store to a memory location. Enable the
685	  use of these instructions in the kernel when the Zawrs extension is
686	  detected at boot.
687
688config TOOLCHAIN_HAS_ZABHA
689	bool
690	default y
691	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha)
692	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha)
693	depends on AS_HAS_OPTION_ARCH
694
695config RISCV_ISA_ZABHA
696	bool "Zabha extension support for atomic byte/halfword operations"
697	depends on TOOLCHAIN_HAS_ZABHA
698	depends on RISCV_ALTERNATIVE
699	default y
700	help
701	  Enable the use of the Zabha ISA-extension to implement kernel
702	  byte/halfword atomic memory operations when it is detected at boot.
703
704	  If you don't know what to do here, say Y.
705
706config TOOLCHAIN_HAS_ZACAS
707	bool
708	default y
709	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas)
710	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas)
711	depends on AS_HAS_OPTION_ARCH
712
713config RISCV_ISA_ZACAS
714	bool "Zacas extension support for atomic CAS"
715	depends on TOOLCHAIN_HAS_ZACAS
716	depends on RISCV_ALTERNATIVE
717	default y
718	help
719	  Enable the use of the Zacas ISA-extension to implement kernel atomic
720	  cmpxchg operations when it is detected at boot.
721
722	  If you don't know what to do here, say Y.
723
724config TOOLCHAIN_HAS_ZBB
725	bool
726	default y
727	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
728	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
729	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
730	depends on AS_HAS_OPTION_ARCH
731
732# This symbol indicates that the toolchain supports all v1.0 vector crypto
733# extensions, including Zvk*, Zvbb, and Zvbc.  LLVM added all of these at once.
734# binutils added all except Zvkb, then added Zvkb.  So we just check for Zvkb.
735config TOOLCHAIN_HAS_VECTOR_CRYPTO
736	def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
737	depends on AS_HAS_OPTION_ARCH
738
739config TOOLCHAIN_HAS_ZBA
740	bool
741	default y
742	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba)
743	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba)
744	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
745	depends on AS_HAS_OPTION_ARCH
746
747config RISCV_ISA_ZBA
748	bool "Zba extension support for bit manipulation instructions"
749	default y
750	help
751	   Add support for enabling optimisations in the kernel when the Zba
752	   extension is detected at boot.
753
754	   The Zba extension provides instructions to accelerate the generation
755	   of addresses that index into arrays of basic data types.
756
757	   If you don't know what to do here, say Y.
758
759config RISCV_ISA_ZBB
760	bool "Zbb extension support for bit manipulation instructions"
761	depends on RISCV_ALTERNATIVE
762	default y
763	help
764	   Add support for enabling optimisations in the kernel when the
765	   Zbb extension is detected at boot. Some optimisations may
766	   additionally depend on toolchain support for Zbb.
767
768	   The Zbb extension provides instructions to accelerate a number
769	   of bit-specific operations (count bit population, sign extending,
770	   bitrotation, etc).
771
772	   If you don't know what to do here, say Y.
773
774config TOOLCHAIN_HAS_ZBC
775	bool
776	default y
777	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
778	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
779	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
780	depends on AS_HAS_OPTION_ARCH
781
782config RISCV_ISA_ZBC
783	bool "Zbc extension support for carry-less multiplication instructions"
784	depends on TOOLCHAIN_HAS_ZBC
785	depends on MMU
786	depends on RISCV_ALTERNATIVE
787	default y
788	help
789	   Adds support to dynamically detect the presence of the Zbc
790	   extension (carry-less multiplication) and enable its usage.
791
792	   The Zbc extension could accelerate CRC (cyclic redundancy check)
793	   calculations.
794
795	   If you don't know what to do here, say Y.
796
797config TOOLCHAIN_HAS_ZBKB
798	bool
799	default y
800	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb)
801	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb)
802	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
803	depends on AS_HAS_OPTION_ARCH
804
805config RISCV_ISA_ZBKB
806	bool "Zbkb extension support for bit manipulation instructions"
807	depends on TOOLCHAIN_HAS_ZBKB
808	depends on RISCV_ALTERNATIVE
809	default y
810	help
811	   Adds support to dynamically detect the presence of the ZBKB
812	   extension (bit manipulation for cryptography) and enable its usage.
813
814	   The Zbkb extension provides instructions to accelerate a number
815	   of common cryptography operations (pack, zip, etc).
816
817	   If you don't know what to do here, say Y.
818
819config RISCV_ISA_ZICBOM
820	bool "Zicbom extension support for non-coherent DMA operation"
821	depends on MMU
822	depends on RISCV_ALTERNATIVE
823	default y
824	select RISCV_DMA_NONCOHERENT
825	select DMA_DIRECT_REMAP
826	help
827	   Add support for the Zicbom extension (Cache Block Management
828	   Operations) and enable its use in the kernel when it is detected
829	   at boot.
830
831	   The Zicbom extension can be used to handle for example
832	   non-coherent DMA support on devices that need it.
833
834	   If you don't know what to do here, say Y.
835
836config RISCV_ISA_ZICBOZ
837	bool "Zicboz extension support for faster zeroing of memory"
838	depends on RISCV_ALTERNATIVE
839	default y
840	help
841	   Enable the use of the Zicboz extension (cbo.zero instruction)
842	   in the kernel when it is detected at boot.
843
844	   The Zicboz extension is used for faster zeroing of memory.
845
846	   If you don't know what to do here, say Y.
847
848config RISCV_ISA_ZICBOP
849	bool "Zicbop extension support for cache block prefetch"
850	depends on MMU
851	depends on RISCV_ALTERNATIVE
852	default y
853	help
854	  Adds support to dynamically detect the presence of the ZICBOP
855	  extension (Cache Block Prefetch Operations) and enable its
856	  usage.
857
858	  The Zicbop extension can be used to prefetch cache blocks for
859	  read/write fetch.
860
861	  If you don't know what to do here, say Y.
862
863config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
864	def_bool y
865	# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
866	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
867	depends on AS_IS_GNU && AS_VERSION >= 23600
868	help
869	  Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
870	  20191213 version, which moves some instructions from the I extension to
871	  the Zicsr and Zifencei extensions. This requires explicitly specifying
872	  Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
873	  and Zifencei are supported in binutils from version 2.36 onwards.
874	  To make life easier, and avoid forcing toolchains that default to a
875	  newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
876	  For clang < 17 or GCC < 11.3.0, for which this is not possible or need
877	  special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
878
879config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
880	def_bool y
881	depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
882	# https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
883	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
884	depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
885	help
886	  Certain versions of clang and GCC do not support zicsr and zifencei via
887	  -march. This option causes an older ISA spec compatible with these older
888	  versions of clang and GCC to be passed to GAS, which has the same result
889	  as passing zicsr and zifencei to -march.
890
891config FPU
892	bool "FPU support"
893	default y
894	help
895	  Add support for floating point operations when an FPU is detected at
896	  boot. When this option is disabled, neither the kernel nor userspace
897	  may use the floating point unit.
898
899	  If you don't know what to do here, say Y.
900
901config IRQ_STACKS
902	bool "Independent irq & softirq stacks" if EXPERT
903	default y
904	select HAVE_IRQ_EXIT_ON_IRQ_STACK
905	select HAVE_SOFTIRQ_ON_OWN_STACK
906	help
907	  Add independent irq & softirq stacks for percpu to prevent kernel stack
908	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
909
910config THREAD_SIZE_ORDER
911	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
912	range 0 4
913	default 1 if 32BIT
914	default 2
915	help
916	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
917	  affects irq stack size, which is equal to thread stack size.
918
919config RISCV_MISALIGNED
920	bool
921	help
922	  Embed support for detecting and emulating misaligned
923	  scalar or vector loads and stores.
924
925config RISCV_SCALAR_MISALIGNED
926	bool
927	select RISCV_MISALIGNED
928	select SYSCTL_ARCH_UNALIGN_ALLOW
929	help
930	  Embed support for emulating misaligned loads and stores.
931
932config RISCV_VECTOR_MISALIGNED
933	bool
934	select RISCV_MISALIGNED
935	depends on RISCV_ISA_V
936	help
937	  Enable detecting support for vector misaligned loads and stores.
938
939choice
940	prompt "Unaligned Accesses Support"
941	default RISCV_PROBE_UNALIGNED_ACCESS
942	help
943	  This determines the level of support for unaligned accesses. This
944	  information is used by the kernel to perform optimizations. It is also
945	  exposed to user space via the hwprobe syscall. The hardware will be
946	  probed at boot by default.
947
948config RISCV_PROBE_UNALIGNED_ACCESS
949	bool "Probe for hardware unaligned access support"
950	select RISCV_SCALAR_MISALIGNED
951	help
952	  During boot, the kernel will run a series of tests to determine the
953	  speed of unaligned accesses. This probing will dynamically determine
954	  the speed of unaligned accesses on the underlying system. If unaligned
955	  memory accesses trap into the kernel as they are not supported by the
956	  system, the kernel will emulate the unaligned accesses to preserve the
957	  UABI.
958
959config RISCV_EMULATED_UNALIGNED_ACCESS
960	bool "Emulate unaligned access where system support is missing"
961	select RISCV_SCALAR_MISALIGNED
962	help
963	  If unaligned memory accesses trap into the kernel as they are not
964	  supported by the system, the kernel will emulate the unaligned
965	  accesses to preserve the UABI. When the underlying system does support
966	  unaligned accesses, the unaligned accesses are assumed to be slow.
967
968config RISCV_SLOW_UNALIGNED_ACCESS
969	bool "Assume the system supports slow unaligned memory accesses"
970	depends on NONPORTABLE
971	help
972	  Assume that the system supports slow unaligned memory accesses. The
973	  kernel and userspace programs may not be able to run at all on systems
974	  that do not support unaligned memory accesses.
975
976config RISCV_EFFICIENT_UNALIGNED_ACCESS
977	bool "Assume the system supports fast unaligned memory accesses"
978	depends on NONPORTABLE
979	select DCACHE_WORD_ACCESS if MMU
980	select HAVE_EFFICIENT_UNALIGNED_ACCESS
981	help
982	  Assume that the system supports fast unaligned memory accesses. When
983	  enabled, this option improves the performance of the kernel on such
984	  systems. However, the kernel and userspace programs will run much more
985	  slowly, or will not be able to run at all, on systems that do not
986	  support efficient unaligned memory accesses.
987
988endchoice
989
990choice
991	prompt "Vector unaligned Accesses Support"
992	depends on RISCV_ISA_V
993	default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
994	help
995	  This determines the level of support for vector unaligned accesses. This
996	  information is used by the kernel to perform optimizations. It is also
997	  exposed to user space via the hwprobe syscall. The hardware will be
998	  probed at boot by default.
999
1000config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
1001	bool "Probe speed of vector unaligned accesses"
1002	select RISCV_VECTOR_MISALIGNED
1003	depends on RISCV_ISA_V
1004	help
1005	  During boot, the kernel will run a series of tests to determine the
1006	  speed of vector unaligned accesses if they are supported. This probing
1007	  will dynamically determine the speed of vector unaligned accesses on
1008	  the underlying system if they are supported.
1009
1010config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
1011	bool "Assume the system supports slow vector unaligned memory accesses"
1012	depends on NONPORTABLE
1013	help
1014	  Assume that the system supports slow vector unaligned memory accesses. The
1015	  kernel and userspace programs may not be able to run at all on systems
1016	  that do not support unaligned memory accesses.
1017
1018config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
1019	bool "Assume the system supports fast vector unaligned memory accesses"
1020	depends on NONPORTABLE
1021	help
1022	  Assume that the system supports fast vector unaligned memory accesses. When
1023	  enabled, this option improves the performance of the kernel on such
1024	  systems. However, the kernel and userspace programs will run much more
1025	  slowly, or will not be able to run at all, on systems that do not
1026	  support efficient unaligned memory accesses.
1027
1028endchoice
1029
1030source "arch/riscv/Kconfig.vendor"
1031
1032endmenu # "Platform type"
1033
1034menu "Kernel features"
1035
1036source "kernel/Kconfig.hz"
1037
1038config RISCV_SBI_V01
1039	bool "SBI v0.1 support"
1040	depends on RISCV_SBI
1041	help
1042	  This config allows kernel to use SBI v0.1 APIs. This will be
1043	  deprecated in future once legacy M-mode software are no longer in use.
1044
1045config RISCV_BOOT_SPINWAIT
1046	bool "Spinwait booting method"
1047	depends on SMP
1048	default y if RISCV_SBI_V01 || RISCV_M_MODE
1049	help
1050	  This enables support for booting Linux via spinwait method. In the
1051	  spinwait method, all cores randomly jump to Linux. One of the cores
1052	  gets chosen via lottery and all other keep spinning on a percpu
1053	  variable. This method cannot support CPU hotplug and sparse hartid
1054	  scheme. It should be only enabled for M-mode Linux or platforms relying
1055	  on older firmware without SBI HSM extension. All other platforms should
1056	  rely on ordered booting via SBI HSM extension which gets chosen
1057	  dynamically at runtime if the firmware supports it.
1058
1059	  Since spinwait is incompatible with sparse hart IDs, it requires
1060	  NR_CPUS be large enough to contain the physical hart ID of the first
1061	  hart to enter Linux.
1062
1063	  If unsure what to do here, say N.
1064
1065config ARCH_SUPPORTS_KEXEC
1066	def_bool y
1067
1068config ARCH_SELECTS_KEXEC
1069	def_bool y
1070	depends on KEXEC
1071	select HOTPLUG_CPU if SMP
1072
1073config ARCH_SUPPORTS_KEXEC_FILE
1074	def_bool 64BIT
1075
1076config ARCH_SELECTS_KEXEC_FILE
1077	def_bool y
1078	depends on KEXEC_FILE
1079	select HAVE_IMA_KEXEC if IMA
1080	select KEXEC_ELF
1081
1082config ARCH_SUPPORTS_KEXEC_PURGATORY
1083	def_bool ARCH_SUPPORTS_KEXEC_FILE
1084
1085config ARCH_SUPPORTS_CRASH_DUMP
1086	def_bool y
1087
1088config ARCH_DEFAULT_CRASH_DUMP
1089	def_bool y
1090
1091config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1092	def_bool CRASH_RESERVE
1093
1094config COMPAT
1095	bool "Kernel support for 32-bit U-mode"
1096	default 64BIT
1097	depends on 64BIT && MMU
1098	help
1099	  This option enables support for a 32-bit U-mode running under a 64-bit
1100	  kernel at S-mode. riscv32-specific components such as system calls,
1101	  the user helper functions (vdso), signal rt_frame functions and the
1102	  ptrace interface are handled appropriately by the kernel.
1103
1104	  If you want to execute 32-bit userspace applications, say Y.
1105
1106config PARAVIRT
1107	bool "Enable paravirtualization code"
1108	depends on RISCV_SBI
1109	help
1110	  This changes the kernel so it can modify itself when it is run
1111	  under a hypervisor, potentially improving performance significantly
1112	  over full virtualization.
1113
1114config PARAVIRT_TIME_ACCOUNTING
1115	bool "Paravirtual steal time accounting"
1116	depends on PARAVIRT
1117	help
1118	  Select this option to enable fine granularity task steal time
1119	  accounting. Time spent executing other tasks in parallel with
1120	  the current vCPU is discounted from the vCPU power. To account for
1121	  that, there can be a small performance impact.
1122
1123	  If in doubt, say N here.
1124
1125config RELOCATABLE
1126	bool "Build a relocatable kernel"
1127	depends on !XIP_KERNEL
1128	select MODULE_SECTIONS if MODULES
1129	select ARCH_VMLINUX_NEEDS_RELOCS
1130	help
1131          This builds a kernel as a Position Independent Executable (PIE),
1132          which retains all relocation metadata required to relocate the
1133          kernel binary at runtime to a different virtual address than the
1134          address it was linked at.
1135          Since RISCV uses the RELA relocation format, this requires a
1136          relocation pass at runtime even if the kernel is loaded at the
1137          same address it was linked at.
1138
1139          If unsure, say N.
1140
1141config RANDOMIZE_BASE
1142        bool "Randomize the address of the kernel image"
1143        select RELOCATABLE
1144        depends on MMU && 64BIT && !XIP_KERNEL
1145        help
1146          Randomizes the virtual address at which the kernel image is
1147          loaded, as a security feature that deters exploit attempts
1148          relying on knowledge of the location of kernel internals.
1149
1150          It is the bootloader's job to provide entropy, by passing a
1151          random u64 value in /chosen/kaslr-seed at kernel entry.
1152
1153          When booting via the UEFI stub, it will invoke the firmware's
1154          EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1155          to the kernel proper. In addition, it will randomise the physical
1156          location of the kernel Image as well.
1157
1158          If unsure, say N.
1159
1160endmenu # "Kernel features"
1161
1162menu "Boot options"
1163
1164config CMDLINE
1165	string "Built-in kernel command line"
1166	help
1167	  For most platforms, the arguments for the kernel's command line
1168	  are provided at run-time, during boot. However, there are cases
1169	  where either no arguments are being provided or the provided
1170	  arguments are insufficient or even invalid.
1171
1172	  When that occurs, it is possible to define a built-in command
1173	  line here and choose how the kernel should use it later on.
1174
1175choice
1176	prompt "Built-in command line usage"
1177	depends on CMDLINE != ""
1178	default CMDLINE_FALLBACK
1179	help
1180	  Choose how the kernel will handle the provided built-in command
1181	  line.
1182
1183config CMDLINE_FALLBACK
1184	bool "Use bootloader kernel arguments if available"
1185	help
1186	  Use the built-in command line as fallback in case we get nothing
1187	  during boot. This is the default behaviour.
1188
1189config CMDLINE_EXTEND
1190	bool "Extend bootloader kernel arguments"
1191	help
1192	  The built-in command line will be appended to the command-
1193	  line arguments provided during boot. This is useful in
1194	  cases where the provided arguments are insufficient and
1195	  you don't want to or cannot modify them.
1196
1197config CMDLINE_FORCE
1198	bool "Always use the default kernel command string"
1199	help
1200	  Always use the built-in command line, even if we get one during
1201	  boot. This is useful in case you need to override the provided
1202	  command line on systems where you don't have or want control
1203	  over it.
1204
1205endchoice
1206
1207config EFI_STUB
1208	bool
1209
1210config EFI
1211	bool "UEFI runtime support"
1212	depends on OF && !XIP_KERNEL
1213	depends on MMU
1214	default y
1215	select ARCH_SUPPORTS_ACPI if 64BIT
1216	select EFI_GENERIC_STUB
1217	select EFI_PARAMS_FROM_FDT
1218	select EFI_RUNTIME_WRAPPERS
1219	select EFI_STUB
1220	select LIBFDT
1221	select RISCV_ISA_C
1222	select UCS2_STRING
1223	help
1224	  This option provides support for runtime services provided
1225	  by UEFI firmware (such as non-volatile variables, realtime
1226	  clock, and platform reset). A UEFI stub is also provided to
1227	  allow the kernel to be booted as an EFI application. This
1228	  is only useful on systems that have UEFI firmware.
1229
1230config DMI
1231	bool "Enable support for SMBIOS (DMI) tables"
1232	depends on EFI
1233	default y
1234	help
1235	  This enables SMBIOS/DMI feature for systems.
1236
1237	  This option is only useful on systems that have UEFI firmware.
1238	  However, even with this option, the resultant kernel should
1239	  continue to boot on existing non-UEFI platforms.
1240
1241config CC_HAVE_STACKPROTECTOR_TLS
1242	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
1243
1244config STACKPROTECTOR_PER_TASK
1245	def_bool y
1246	depends on !RANDSTRUCT
1247	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
1248
1249config PHYS_RAM_BASE_FIXED
1250	bool "Explicitly specified physical RAM address"
1251	depends on NONPORTABLE
1252	default n
1253
1254config PHYS_RAM_BASE
1255	hex "Platform Physical RAM address"
1256	depends on PHYS_RAM_BASE_FIXED
1257	default "0x80000000"
1258	help
1259	  This is the physical address of RAM in the system. It has to be
1260	  explicitly specified to run early relocations of read-write data
1261	  from flash to RAM.
1262
1263config XIP_KERNEL
1264	bool "Kernel Execute-In-Place from ROM"
1265	depends on MMU && SPARSEMEM && NONPORTABLE
1266	# This prevents XIP from being enabled by all{yes,mod}config, which
1267	# fail to build since XIP doesn't support large kernels.
1268	depends on !COMPILE_TEST
1269	select PHYS_RAM_BASE_FIXED
1270	help
1271	  Execute-In-Place allows the kernel to run from non-volatile storage
1272	  directly addressable by the CPU, such as NOR flash. This saves RAM
1273	  space since the text section of the kernel is not loaded from flash
1274	  to RAM.  Read-write sections, such as the data section and stack,
1275	  are still copied to RAM.  The XIP kernel is not compressed since
1276	  it has to run directly from flash, so it will take more space to
1277	  store it.  The flash address used to link the kernel object files,
1278	  and for storing it, is configuration dependent. Therefore, if you
1279	  say Y here, you must know the proper physical address where to
1280	  store the kernel image depending on your own flash memory usage.
1281
1282	  Also note that the make target becomes "make xipImage" rather than
1283	  "make zImage" or "make Image".  The final kernel binary to put in
1284	  ROM memory will be arch/riscv/boot/xipImage.
1285
1286	  SPARSEMEM is required because the kernel text and rodata that are
1287	  flash resident are not backed by memmap, then any attempt to get
1288	  a struct page on those regions will trigger a fault.
1289
1290	  If unsure, say N.
1291
1292config XIP_PHYS_ADDR
1293	hex "XIP Kernel Physical Location"
1294	depends on XIP_KERNEL
1295	default "0x21000000"
1296	help
1297	  This is the physical address in your flash memory the kernel will
1298	  be linked for and stored to.  This address is dependent on your
1299	  own flash usage.
1300
1301config RISCV_ISA_FALLBACK
1302	bool "Permit falling back to parsing riscv,isa for extension support by default"
1303	default y
1304	help
1305	  Parsing the "riscv,isa" devicetree property has been deprecated and
1306	  replaced by a list of explicitly defined strings. For compatibility
1307	  with existing platforms, the kernel will fall back to parsing the
1308	  "riscv,isa" property if the replacements are not found.
1309
1310	  Selecting N here will result in a kernel that does not use the
1311	  fallback, unless the commandline "riscv_isa_fallback" parameter is
1312	  present.
1313
1314	  Please see the dt-binding, located at
1315	  Documentation/devicetree/bindings/riscv/extensions.yaml for details
1316	  on the replacement properties, "riscv,isa-base" and
1317	  "riscv,isa-extensions".
1318
1319config BUILTIN_DTB
1320	bool "Built-in device tree"
1321	depends on OF && NONPORTABLE
1322	select GENERIC_BUILTIN_DTB
1323	help
1324	  Build a device tree into the Linux image.
1325	  This option should be selected if no bootloader is being used.
1326	  If unsure, say N.
1327
1328
1329config BUILTIN_DTB_NAME
1330	string "Built-in device tree source"
1331	depends on BUILTIN_DTB
1332	help
1333	  DTS file path (without suffix, relative to arch/riscv/boot/dts)
1334	  for the DTS file that will be used to produce the DTB linked into the
1335	  kernel.
1336
1337endmenu # "Boot options"
1338
1339config PORTABLE
1340	bool
1341	default !NONPORTABLE
1342	select EFI
1343	select MMU
1344	select OF
1345
1346config ARCH_PROC_KCORE_TEXT
1347	def_bool y
1348
1349menu "Power management options"
1350
1351source "kernel/power/Kconfig"
1352
1353config ARCH_HIBERNATION_POSSIBLE
1354	def_bool y
1355
1356config ARCH_HIBERNATION_HEADER
1357	def_bool HIBERNATION
1358
1359config ARCH_SUSPEND_POSSIBLE
1360	def_bool y
1361
1362endmenu # "Power management options"
1363
1364menu "CPU Power Management"
1365
1366source "drivers/cpuidle/Kconfig"
1367
1368source "drivers/cpufreq/Kconfig"
1369
1370endmenu # "CPU Power Management"
1371
1372source "arch/riscv/kvm/Kconfig"
1373
1374source "drivers/acpi/Kconfig"
1375