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_CRC64 if 64BIT && RISCV_ISA_ZBC
29	select ARCH_HAS_CRC_T10DIF if RISCV_ISA_ZBC
30	select ARCH_HAS_CURRENT_STACK_POINTER
31	select ARCH_HAS_DEBUG_VIRTUAL if MMU
32	select ARCH_HAS_DEBUG_VM_PGTABLE
33	select ARCH_HAS_DEBUG_WX
34	select ARCH_HAS_FAST_MULTIPLIER
35	select ARCH_HAS_FORTIFY_SOURCE
36	select ARCH_HAS_GCOV_PROFILE_ALL
37	select ARCH_HAS_GIGANTIC_PAGE
38	select ARCH_HAS_HW_PTE_YOUNG
39	select ARCH_HAS_KCOV
40	select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU
41	select ARCH_HAS_MEMBARRIER_CALLBACKS
42	select ARCH_HAS_MEMBARRIER_SYNC_CORE
43	select ARCH_HAS_MMIOWB
44	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
45	select ARCH_HAS_PMEM_API
46	select ARCH_HAS_PREEMPT_LAZY
47	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
48	select ARCH_HAS_PTDUMP if MMU
49	select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU
50	select ARCH_HAS_PTE_SPECIAL
51	select ARCH_HAS_SET_DIRECT_MAP if MMU
52	select ARCH_HAS_SET_MEMORY if MMU
53	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
54	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
55	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
56	select ARCH_HAS_SYSCALL_WRAPPER
57	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
58	select ARCH_HAS_UBSAN
59	select ARCH_HAS_VDSO_ARCH_DATA if GENERIC_VDSO_DATA_STORE
60	select ARCH_KEEP_MEMBLOCK if ACPI
61	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE	if 64BIT && MMU
62	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
63	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
64	select ARCH_STACKWALK
65	select ARCH_SUPPORTS_ATOMIC_RMW
66	select ARCH_SUPPORTS_CFI_CLANG
67	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
68	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
69	select ARCH_SUPPORTS_HUGETLBFS if MMU
70	# LLD >= 14: https://github.com/llvm/llvm-project/issues/50505
71	select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000
72	select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000
73	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
74	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
75	select ARCH_SUPPORTS_RT
76	select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
77	select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
78	select ARCH_USE_MEMTEST
79	select ARCH_USE_QUEUED_RWLOCKS
80	select ARCH_USE_SYM_ANNOTATIONS
81	select ARCH_USES_CFI_TRAPS if CFI_CLANG
82	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU
83	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
84	select ARCH_WANT_FRAME_POINTERS
85	select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
86	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
87	select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
88	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
89	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
90	select ARCH_WANTS_NO_INSTR
91	select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
92	select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS
93	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
94	select BUILDTIME_TABLE_SORT if MMU
95	select CLINT_TIMER if RISCV_M_MODE
96	select CLONE_BACKWARDS
97	select COMMON_CLK
98	select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
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 GENERIC_ARCH_TOPOLOGY
103	select GENERIC_ATOMIC64 if !64BIT
104	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
105	select GENERIC_CPU_DEVICES
106	select GENERIC_CPU_VULNERABILITIES
107	select GENERIC_EARLY_IOREMAP
108	select GENERIC_ENTRY
109	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
110	select GENERIC_IDLE_POLL_SETUP
111	select GENERIC_IOREMAP if MMU
112	select GENERIC_IRQ_IPI if SMP
113	select GENERIC_IRQ_IPI_MUX if SMP
114	select GENERIC_IRQ_MULTI_HANDLER
115	select GENERIC_IRQ_SHOW
116	select GENERIC_IRQ_SHOW_LEVEL
117	select GENERIC_LIB_DEVMEM_IS_ALLOWED
118	select GENERIC_PENDING_IRQ if SMP
119	select GENERIC_PCI_IOMAP
120	select GENERIC_SCHED_CLOCK
121	select GENERIC_SMP_IDLE_THREAD
122	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
123	select GENERIC_VDSO_DATA_STORE if MMU
124	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
125	select HARDIRQS_SW_RESEND
126	select HAS_IOPORT if MMU
127	select HAVE_ALIGNED_STRUCT_PAGE
128	select HAVE_ARCH_AUDITSYSCALL
129	select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
130	select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT
131	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
132	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
133	select HAVE_ARCH_KASAN if MMU && 64BIT
134	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
135	select HAVE_ARCH_KFENCE if MMU && 64BIT
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_STACKLEAK
143	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
144	select HAVE_ARCH_TRACEHOOK
145	select HAVE_ARCH_TRANSPARENT_HUGEPAGE 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 HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
154	select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
155	select HAVE_FTRACE_GRAPH_FUNC
156	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
157	select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS
158	select HAVE_FUNCTION_GRAPH_FREGS
159	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
160	select HAVE_EBPF_JIT if MMU
161	select HAVE_GUP_FAST if MMU
162	select HAVE_FUNCTION_ARG_ACCESS_API
163	select HAVE_FUNCTION_ERROR_INJECTION
164	select HAVE_GCC_PLUGINS
165	select HAVE_GENERIC_VDSO if MMU && 64BIT
166	select HAVE_IRQ_TIME_ACCOUNTING
167	select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT
168	select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT
169	select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT
170	select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT
171	select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT
172	select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT
173	select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT
174	select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT
175	select HAVE_KPROBES if !XIP_KERNEL
176	select HAVE_KRETPROBES if !XIP_KERNEL
177	# https://github.com/ClangBuiltLinux/linux/issues/1881
178	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
179	select HAVE_MOVE_PMD
180	select HAVE_MOVE_PUD
181	select HAVE_PAGE_SIZE_4KB
182	select HAVE_PCI
183	select HAVE_PERF_EVENTS
184	select HAVE_PERF_REGS
185	select HAVE_PERF_USER_STACK_DUMP
186	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
187	select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
188	select HAVE_REGS_AND_STACK_ACCESS_API
189	select HAVE_RETHOOK if !XIP_KERNEL
190	select HAVE_RSEQ
191	select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG
192	select HAVE_SAMPLE_FTRACE_DIRECT
193	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
194	select HAVE_STACKPROTECTOR
195	select HAVE_SYSCALL_TRACEPOINTS
196	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
197	select IRQ_DOMAIN
198	select IRQ_FORCED_THREADING
199	select KASAN_VMALLOC if KASAN
200	select LOCK_MM_AND_FIND_VMA
201	select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU
202	select MODULES_USE_ELF_RELA if MODULES
203	select OF
204	select OF_EARLY_FLATTREE
205	select OF_IRQ
206	select PCI_DOMAINS_GENERIC if PCI
207	select PCI_ECAM if (ACPI && PCI)
208	select PCI_MSI if PCI
209	select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED
210	select RISCV_ALTERNATIVE if !XIP_KERNEL
211	select RISCV_APLIC
212	select RISCV_IMSIC
213	select RISCV_INTC
214	select RISCV_TIMER if RISCV_SBI
215	select SIFIVE_PLIC
216	select SPARSE_IRQ
217	select SYSCTL_EXCEPTION_TRACE
218	select THREAD_INFO_IN_TASK
219	select TRACE_IRQFLAGS_SUPPORT
220	select UACCESS_MEMCPY if !MMU
221	select USER_STACKTRACE_SUPPORT
222	select ZONE_DMA32 if 64BIT
223
224config RUSTC_SUPPORTS_RISCV
225	def_bool y
226	depends on 64BIT
227	# Shadow call stack requires rustc version 1.82+ due to use of the
228	# -Zsanitizer=shadow-call-stack flag.
229	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200
230
231config CLANG_SUPPORTS_DYNAMIC_FTRACE
232	def_bool CC_IS_CLANG
233	# https://github.com/ClangBuiltLinux/linux/issues/1817
234	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
235
236config GCC_SUPPORTS_DYNAMIC_FTRACE
237	def_bool CC_IS_GCC
238	depends on $(cc-option,-fpatchable-function-entry=8)
239
240config HAVE_SHADOW_CALL_STACK
241	def_bool $(cc-option,-fsanitize=shadow-call-stack)
242	# https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
243	depends on $(ld-option,--no-relax-gp)
244
245config RISCV_USE_LINKER_RELAXATION
246	def_bool y
247	# https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985
248	depends on !LD_IS_LLD || LLD_VERSION >= 150000
249
250# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
251config ARCH_HAS_BROKEN_DWARF5
252	def_bool y
253	depends on RISCV_USE_LINKER_RELAXATION
254	# https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
255	depends on AS_IS_LLVM && AS_VERSION < 180000
256	# https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
257	depends on LD_IS_LLD && LLD_VERSION < 180000
258
259config ARCH_MMAP_RND_BITS_MIN
260	default 18 if 64BIT
261	default 8
262
263config ARCH_MMAP_RND_COMPAT_BITS_MIN
264	default 8
265
266# max bits determined by the following formula:
267#  VA_BITS - PAGE_SHIFT - 3
268config ARCH_MMAP_RND_BITS_MAX
269	default 24 if 64BIT # SV39 based
270	default 17
271
272config ARCH_MMAP_RND_COMPAT_BITS_MAX
273	default 17
274
275# set if we run in machine mode, cleared if we run in supervisor mode
276config RISCV_M_MODE
277	bool "Build a kernel that runs in machine mode"
278	depends on !MMU
279	default y
280	help
281	  Select this option if you want to run the kernel in M-mode,
282	  without the assistance of any other firmware.
283
284# set if we are running in S-mode and can use SBI calls
285config RISCV_SBI
286	bool
287	depends on !RISCV_M_MODE
288	default y
289
290config MMU
291	bool "MMU-based Paged Memory Management Support"
292	default y
293	help
294	  Select if you want MMU-based virtualised addressing space
295	  support by paged memory management. If unsure, say 'Y'.
296
297config KASAN_SHADOW_OFFSET
298	hex
299	depends on KASAN_GENERIC
300	default 0xdfffffff00000000 if 64BIT
301	default 0xffffffff if 32BIT
302
303config ARCH_FLATMEM_ENABLE
304	def_bool !NUMA
305
306config ARCH_SPARSEMEM_ENABLE
307	def_bool y
308	depends on MMU
309	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
310	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
311
312config ARCH_SELECT_MEMORY_MODEL
313	def_bool ARCH_SPARSEMEM_ENABLE
314
315config ARCH_SUPPORTS_UPROBES
316	def_bool y
317
318config STACKTRACE_SUPPORT
319	def_bool y
320
321config GENERIC_BUG
322	def_bool y
323	depends on BUG
324	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
325
326config GENERIC_BUG_RELATIVE_POINTERS
327	bool
328
329config GENERIC_CALIBRATE_DELAY
330	def_bool y
331
332config GENERIC_CSUM
333	def_bool y
334
335config GENERIC_HWEIGHT
336	def_bool y
337
338config FIX_EARLYCON_MEM
339	def_bool MMU
340
341config ILLEGAL_POINTER_VALUE
342	hex
343	default 0 if 32BIT
344	default 0xdead000000000000 if 64BIT
345
346config PGTABLE_LEVELS
347	int
348	default 5 if 64BIT
349	default 2
350
351config LOCKDEP_SUPPORT
352	def_bool y
353
354config RISCV_DMA_NONCOHERENT
355	bool
356	select ARCH_HAS_DMA_PREP_COHERENT
357	select ARCH_HAS_SETUP_DMA_OPS
358	select ARCH_HAS_SYNC_DMA_FOR_CPU
359	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
360	select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
361
362config RISCV_NONSTANDARD_CACHE_OPS
363	bool
364	help
365	  This enables function pointer support for non-standard noncoherent
366	  systems to handle cache management.
367
368config AS_HAS_INSN
369	def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
370
371config AS_HAS_OPTION_ARCH
372	# https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4
373	def_bool y
374	depends on $(as-instr, .option arch$(comma) +m)
375
376source "arch/riscv/Kconfig.socs"
377source "arch/riscv/Kconfig.errata"
378
379menu "Platform type"
380
381config NONPORTABLE
382	bool "Allow configurations that result in non-portable kernels"
383	help
384	  RISC-V kernel binaries are compatible between all known systems
385	  whenever possible, but there are some use cases that can only be
386	  satisfied by configurations that result in kernel binaries that are
387	  not portable between systems.
388
389	  Selecting N does not guarantee kernels will be portable to all known
390	  systems.  Selecting any of the options guarded by NONPORTABLE will
391	  result in kernel binaries that are unlikely to be portable between
392	  systems.
393
394	  If unsure, say N.
395
396choice
397	prompt "Base ISA"
398	default ARCH_RV64I
399	help
400	  This selects the base ISA that this kernel will target and must match
401	  the target platform.
402
403config ARCH_RV32I
404	bool "RV32I"
405	depends on NONPORTABLE
406	select 32BIT
407	select GENERIC_LIB_ASHLDI3
408	select GENERIC_LIB_ASHRDI3
409	select GENERIC_LIB_LSHRDI3
410	select GENERIC_LIB_UCMPDI2
411
412config ARCH_RV64I
413	bool "RV64I"
414	select 64BIT
415	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
416	select SWIOTLB if MMU
417
418endchoice
419
420# We must be able to map all physical memory into the kernel, but the compiler
421# is still a bit more efficient when generating code if it's setup in a manner
422# such that it can only map 2GiB of memory.
423choice
424	prompt "Kernel Code Model"
425	default CMODEL_MEDLOW if 32BIT
426	default CMODEL_MEDANY if 64BIT
427
428	config CMODEL_MEDLOW
429		bool "medium low code model"
430	config CMODEL_MEDANY
431		bool "medium any code model"
432endchoice
433
434config MODULE_SECTIONS
435	bool
436	select HAVE_MOD_ARCH_SPECIFIC
437
438config SMP
439	bool "Symmetric Multi-Processing"
440	help
441	  This enables support for systems with more than one CPU.  If
442	  you say N here, the kernel will run on single and
443	  multiprocessor machines, but will use only one CPU of a
444	  multiprocessor machine. If you say Y here, the kernel will run
445	  on many, but not all, single processor machines. On a single
446	  processor machine, the kernel will run faster if you say N
447	  here.
448
449	  If you don't know what to do here, say N.
450
451config SCHED_MC
452	bool "Multi-core scheduler support"
453	depends on SMP
454	help
455	  Multi-core scheduler support improves the CPU scheduler's decision
456	  making when dealing with multi-core CPU chips at a cost of slightly
457	  increased overhead in some places. If unsure say N here.
458
459config NR_CPUS
460	int "Maximum number of CPUs (2-512)"
461	depends on SMP
462	range 2 512 if !RISCV_SBI_V01
463	range 2 32 if RISCV_SBI_V01 && 32BIT
464	range 2 64 if RISCV_SBI_V01 && 64BIT
465	default "32" if 32BIT
466	default "64" if 64BIT
467
468config HOTPLUG_CPU
469	bool "Support for hot-pluggable CPUs"
470	depends on SMP
471	select GENERIC_IRQ_MIGRATION
472	help
473
474	  Say Y here to experiment with turning CPUs off and on.  CPUs
475	  can be controlled through /sys/devices/system/cpu.
476
477	  Say N if you want to disable CPU hotplug.
478
479choice
480	prompt "CPU Tuning"
481	default TUNE_GENERIC
482
483config TUNE_GENERIC
484	bool "generic"
485
486endchoice
487
488# Common NUMA Features
489config NUMA
490	bool "NUMA Memory Allocation and Scheduler Support"
491	depends on SMP && MMU
492	select ARCH_SUPPORTS_NUMA_BALANCING
493	select GENERIC_ARCH_NUMA
494	select HAVE_SETUP_PER_CPU_AREA
495	select NEED_PER_CPU_EMBED_FIRST_CHUNK
496	select NEED_PER_CPU_PAGE_FIRST_CHUNK
497	select OF_NUMA
498	select USE_PERCPU_NUMA_NODE_ID
499	help
500	  Enable NUMA (Non-Uniform Memory Access) support.
501
502	  The kernel will try to allocate memory used by a CPU on the
503	  local memory of the CPU and add some more NUMA awareness to the kernel.
504
505config NODES_SHIFT
506	int "Maximum NUMA Nodes (as a power of 2)"
507	range 1 10
508	default "2"
509	depends on NUMA
510	help
511	  Specify the maximum number of NUMA Nodes available on the target
512	  system.  Increases memory reserved to accommodate various tables.
513
514choice
515	prompt "RISC-V spinlock type"
516	default RISCV_COMBO_SPINLOCKS
517
518config RISCV_TICKET_SPINLOCKS
519	bool "Using ticket spinlock"
520
521config RISCV_QUEUED_SPINLOCKS
522	bool "Using queued spinlock"
523	depends on SMP && MMU && NONPORTABLE
524	select ARCH_USE_QUEUED_SPINLOCKS
525	help
526	  The queued spinlock implementation requires the forward progress
527	  guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or
528	  LR/SC with Ziccrse provide such guarantee.
529
530	  Select this if and only if Zabha or Ziccrse is available on your
531	  platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms
532	  without one of those extensions.
533
534	  If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks
535	  when supported and otherwise ticket spinlocks.
536
537config RISCV_COMBO_SPINLOCKS
538	bool "Using combo spinlock"
539	depends on SMP && MMU
540	select ARCH_USE_QUEUED_SPINLOCKS
541	help
542	  Embed both queued spinlock and ticket lock so that the spinlock
543	  implementation can be chosen at runtime.
544
545endchoice
546
547config RISCV_ALTERNATIVE
548	bool
549	depends on !XIP_KERNEL
550	help
551	  This Kconfig allows the kernel to automatically patch the
552	  erratum or cpufeature required by the execution platform at run
553	  time. The code patching overhead is minimal, as it's only done
554	  once at boot and once on each module load.
555
556config RISCV_ALTERNATIVE_EARLY
557	bool
558	depends on RISCV_ALTERNATIVE
559	help
560	  Allows early patching of the kernel for special errata
561
562config RISCV_ISA_C
563	bool "Emit compressed instructions when building Linux"
564	default y
565	help
566	  Adds "C" to the ISA subsets that the toolchain is allowed to emit
567	  when building Linux, which results in compressed instructions in the
568	  Linux binary. This option produces a kernel that will not run on
569	  systems that do not support compressed instructions.
570
571	  If you don't know what to do here, say Y.
572
573config RISCV_ISA_SUPM
574	bool "Supm extension for userspace pointer masking"
575	depends on 64BIT
576	default y
577	help
578	  Add support for pointer masking in userspace (Supm) when the
579	  underlying hardware extension (Smnpm or Ssnpm) is detected at boot.
580
581	  If this option is disabled, userspace will be unable to use
582	  the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API.
583
584config RISCV_ISA_SVNAPOT
585	bool "Svnapot extension support for supervisor mode NAPOT pages"
586	depends on 64BIT && MMU
587	depends on RISCV_ALTERNATIVE
588	default y
589	help
590	  Enable support for the Svnapot ISA-extension when it is detected
591	  at boot.
592
593	  The Svnapot extension is used to mark contiguous PTEs as a range
594	  of contiguous virtual-to-physical translations for a naturally
595	  aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
596	  size. When HUGETLBFS is also selected this option unconditionally
597	  allocates some memory for each NAPOT page size supported by the kernel.
598	  When optimizing for low memory consumption and for platforms without
599	  the Svnapot extension, it may be better to say N here.
600
601	  If you don't know what to do here, say Y.
602
603config RISCV_ISA_SVPBMT
604	bool "Svpbmt extension support for supervisor mode page-based memory types"
605	depends on 64BIT && MMU
606	depends on RISCV_ALTERNATIVE
607	default y
608	help
609	   Add support for the Svpbmt ISA-extension (Supervisor-mode:
610	   page-based memory types) in the kernel when it is detected at boot.
611
612	   The memory type for a page contains a combination of attributes
613	   that indicate the cacheability, idempotency, and ordering
614	   properties for access to that page.
615
616	   The Svpbmt extension is only available on 64-bit cpus.
617
618	   If you don't know what to do here, say Y.
619
620config TOOLCHAIN_HAS_V
621	bool
622	default y
623	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv)
624	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv)
625	depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
626	depends on AS_HAS_OPTION_ARCH
627
628config RISCV_ISA_V
629	bool "Vector extension support"
630	depends on TOOLCHAIN_HAS_V
631	depends on FPU
632	select DYNAMIC_SIGFRAME
633	default y
634	help
635	  Add support for the Vector extension when it is detected at boot.
636	  When this option is disabled, neither the kernel nor userspace may
637	  use vector procedures.
638
639	  If you don't know what to do here, say Y.
640
641config RISCV_ISA_V_DEFAULT_ENABLE
642	bool "Enable userspace Vector by default"
643	depends on RISCV_ISA_V
644	default y
645	help
646	  Say Y here if you want to enable Vector in userspace by default.
647	  Otherwise, userspace has to make explicit prctl() call to enable
648	  Vector, or enable it via the sysctl interface.
649
650	  If you don't know what to do here, say Y.
651
652config RISCV_ISA_V_UCOPY_THRESHOLD
653	int "Threshold size for vectorized user copies"
654	depends on RISCV_ISA_V
655	default 768
656	help
657	  Prefer using vectorized copy_to_user()/copy_from_user() when the
658	  workload size exceeds this value.
659
660config RISCV_ISA_V_PREEMPTIVE
661	bool "Run kernel-mode Vector with kernel preemption"
662	depends on PREEMPTION
663	depends on RISCV_ISA_V
664	default y
665	help
666	  Usually, in-kernel SIMD routines are run with preemption disabled.
667	  Functions which envoke long running SIMD thus must yield core's
668	  vector unit to prevent blocking other tasks for too long.
669
670	  This config allows kernel to run SIMD without explicitly disable
671	  preemption. Enabling this config will result in higher memory
672	  consumption due to the allocation of per-task's kernel Vector context.
673
674config RISCV_ISA_ZAWRS
675	bool "Zawrs extension support for more efficient busy waiting"
676	depends on RISCV_ALTERNATIVE
677	default y
678	help
679	  The Zawrs extension defines instructions to be used in polling loops
680	  which allow a hart to enter a low-power state or to trap to the
681	  hypervisor while waiting on a store to a memory location. Enable the
682	  use of these instructions in the kernel when the Zawrs extension is
683	  detected at boot.
684
685config TOOLCHAIN_HAS_ZABHA
686	bool
687	default y
688	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha)
689	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha)
690	depends on AS_HAS_OPTION_ARCH
691
692config RISCV_ISA_ZABHA
693	bool "Zabha extension support for atomic byte/halfword operations"
694	depends on TOOLCHAIN_HAS_ZABHA
695	depends on RISCV_ALTERNATIVE
696	default y
697	help
698	  Enable the use of the Zabha ISA-extension to implement kernel
699	  byte/halfword atomic memory operations when it is detected at boot.
700
701	  If you don't know what to do here, say Y.
702
703config TOOLCHAIN_HAS_ZACAS
704	bool
705	default y
706	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas)
707	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas)
708	depends on AS_HAS_OPTION_ARCH
709
710config RISCV_ISA_ZACAS
711	bool "Zacas extension support for atomic CAS"
712	depends on TOOLCHAIN_HAS_ZACAS
713	depends on RISCV_ALTERNATIVE
714	default y
715	help
716	  Enable the use of the Zacas ISA-extension to implement kernel atomic
717	  cmpxchg operations when it is detected at boot.
718
719	  If you don't know what to do here, say Y.
720
721config TOOLCHAIN_HAS_ZBB
722	bool
723	default y
724	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
725	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
726	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
727	depends on AS_HAS_OPTION_ARCH
728
729# This symbol indicates that the toolchain supports all v1.0 vector crypto
730# extensions, including Zvk*, Zvbb, and Zvbc.  LLVM added all of these at once.
731# binutils added all except Zvkb, then added Zvkb.  So we just check for Zvkb.
732config TOOLCHAIN_HAS_VECTOR_CRYPTO
733	def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
734	depends on AS_HAS_OPTION_ARCH
735
736config TOOLCHAIN_HAS_ZBA
737	bool
738	default y
739	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba)
740	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba)
741	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
742	depends on AS_HAS_OPTION_ARCH
743
744config RISCV_ISA_ZBA
745	bool "Zba extension support for bit manipulation instructions"
746	default y
747	help
748	   Add support for enabling optimisations in the kernel when the Zba
749	   extension is detected at boot.
750
751	   The Zba extension provides instructions to accelerate the generation
752	   of addresses that index into arrays of basic data types.
753
754	   If you don't know what to do here, say Y.
755
756config RISCV_ISA_ZBB
757	bool "Zbb extension support for bit manipulation instructions"
758	depends on RISCV_ALTERNATIVE
759	default y
760	help
761	   Add support for enabling optimisations in the kernel when the
762	   Zbb extension is detected at boot. Some optimisations may
763	   additionally depend on toolchain support for Zbb.
764
765	   The Zbb extension provides instructions to accelerate a number
766	   of bit-specific operations (count bit population, sign extending,
767	   bitrotation, etc).
768
769	   If you don't know what to do here, say Y.
770
771config TOOLCHAIN_HAS_ZBC
772	bool
773	default y
774	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
775	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
776	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
777	depends on AS_HAS_OPTION_ARCH
778
779config RISCV_ISA_ZBC
780	bool "Zbc extension support for carry-less multiplication instructions"
781	depends on TOOLCHAIN_HAS_ZBC
782	depends on MMU
783	depends on RISCV_ALTERNATIVE
784	default y
785	help
786	   Adds support to dynamically detect the presence of the Zbc
787	   extension (carry-less multiplication) and enable its usage.
788
789	   The Zbc extension could accelerate CRC (cyclic redundancy check)
790	   calculations.
791
792	   If you don't know what to do here, say Y.
793
794config TOOLCHAIN_HAS_ZBKB
795	bool
796	default y
797	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb)
798	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb)
799	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
800	depends on AS_HAS_OPTION_ARCH
801
802config RISCV_ISA_ZBKB
803	bool "Zbkb extension support for bit manipulation instructions"
804	depends on TOOLCHAIN_HAS_ZBKB
805	depends on RISCV_ALTERNATIVE
806	default y
807	help
808	   Adds support to dynamically detect the presence of the ZBKB
809	   extension (bit manipulation for cryptography) and enable its usage.
810
811	   The Zbkb extension provides instructions to accelerate a number
812	   of common cryptography operations (pack, zip, etc).
813
814	   If you don't know what to do here, say Y.
815
816config RISCV_ISA_ZICBOM
817	bool "Zicbom extension support for non-coherent DMA operation"
818	depends on MMU
819	depends on RISCV_ALTERNATIVE
820	default y
821	select RISCV_DMA_NONCOHERENT
822	select DMA_DIRECT_REMAP
823	help
824	   Add support for the Zicbom extension (Cache Block Management
825	   Operations) and enable its use in the kernel when it is detected
826	   at boot.
827
828	   The Zicbom extension can be used to handle for example
829	   non-coherent DMA support on devices that need it.
830
831	   If you don't know what to do here, say Y.
832
833config RISCV_ISA_ZICBOZ
834	bool "Zicboz extension support for faster zeroing of memory"
835	depends on RISCV_ALTERNATIVE
836	default y
837	help
838	   Enable the use of the Zicboz extension (cbo.zero instruction)
839	   in the kernel when it is detected at boot.
840
841	   The Zicboz extension is used for faster zeroing of memory.
842
843	   If you don't know what to do here, say Y.
844
845config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
846	def_bool y
847	# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
848	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
849	depends on AS_IS_GNU && AS_VERSION >= 23600
850	help
851	  Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
852	  20191213 version, which moves some instructions from the I extension to
853	  the Zicsr and Zifencei extensions. This requires explicitly specifying
854	  Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
855	  and Zifencei are supported in binutils from version 2.36 onwards.
856	  To make life easier, and avoid forcing toolchains that default to a
857	  newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
858	  For clang < 17 or GCC < 11.3.0, for which this is not possible or need
859	  special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
860
861config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
862	def_bool y
863	depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
864	# https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
865	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
866	depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
867	help
868	  Certain versions of clang and GCC do not support zicsr and zifencei via
869	  -march. This option causes an older ISA spec compatible with these older
870	  versions of clang and GCC to be passed to GAS, which has the same result
871	  as passing zicsr and zifencei to -march.
872
873config FPU
874	bool "FPU support"
875	default y
876	help
877	  Add support for floating point operations when an FPU is detected at
878	  boot. When this option is disabled, neither the kernel nor userspace
879	  may use the floating point unit.
880
881	  If you don't know what to do here, say Y.
882
883config IRQ_STACKS
884	bool "Independent irq & softirq stacks" if EXPERT
885	default y
886	select HAVE_IRQ_EXIT_ON_IRQ_STACK
887	select HAVE_SOFTIRQ_ON_OWN_STACK
888	help
889	  Add independent irq & softirq stacks for percpu to prevent kernel stack
890	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
891
892config THREAD_SIZE_ORDER
893	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
894	range 0 4
895	default 1 if 32BIT
896	default 2
897	help
898	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
899	  affects irq stack size, which is equal to thread stack size.
900
901config RISCV_MISALIGNED
902	bool
903	help
904	  Embed support for detecting and emulating misaligned
905	  scalar or vector loads and stores.
906
907config RISCV_SCALAR_MISALIGNED
908	bool
909	select RISCV_MISALIGNED
910	select SYSCTL_ARCH_UNALIGN_ALLOW
911	help
912	  Embed support for emulating misaligned loads and stores.
913
914config RISCV_VECTOR_MISALIGNED
915	bool
916	select RISCV_MISALIGNED
917	depends on RISCV_ISA_V
918	help
919	  Enable detecting support for vector misaligned loads and stores.
920
921choice
922	prompt "Unaligned Accesses Support"
923	default RISCV_PROBE_UNALIGNED_ACCESS
924	help
925	  This determines the level of support for unaligned accesses. This
926	  information is used by the kernel to perform optimizations. It is also
927	  exposed to user space via the hwprobe syscall. The hardware will be
928	  probed at boot by default.
929
930config RISCV_PROBE_UNALIGNED_ACCESS
931	bool "Probe for hardware unaligned access support"
932	select RISCV_SCALAR_MISALIGNED
933	help
934	  During boot, the kernel will run a series of tests to determine the
935	  speed of unaligned accesses. This probing will dynamically determine
936	  the speed of unaligned accesses on the underlying system. If unaligned
937	  memory accesses trap into the kernel as they are not supported by the
938	  system, the kernel will emulate the unaligned accesses to preserve the
939	  UABI.
940
941config RISCV_EMULATED_UNALIGNED_ACCESS
942	bool "Emulate unaligned access where system support is missing"
943	select RISCV_SCALAR_MISALIGNED
944	help
945	  If unaligned memory accesses trap into the kernel as they are not
946	  supported by the system, the kernel will emulate the unaligned
947	  accesses to preserve the UABI. When the underlying system does support
948	  unaligned accesses, the unaligned accesses are assumed to be slow.
949
950config RISCV_SLOW_UNALIGNED_ACCESS
951	bool "Assume the system supports slow unaligned memory accesses"
952	depends on NONPORTABLE
953	help
954	  Assume that the system supports slow unaligned memory accesses. The
955	  kernel and userspace programs may not be able to run at all on systems
956	  that do not support unaligned memory accesses.
957
958config RISCV_EFFICIENT_UNALIGNED_ACCESS
959	bool "Assume the system supports fast unaligned memory accesses"
960	depends on NONPORTABLE
961	select DCACHE_WORD_ACCESS if MMU
962	select HAVE_EFFICIENT_UNALIGNED_ACCESS
963	help
964	  Assume that the system supports fast unaligned memory accesses. When
965	  enabled, this option improves the performance of the kernel on such
966	  systems. However, the kernel and userspace programs will run much more
967	  slowly, or will not be able to run at all, on systems that do not
968	  support efficient unaligned memory accesses.
969
970endchoice
971
972choice
973	prompt "Vector unaligned Accesses Support"
974	depends on RISCV_ISA_V
975	default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
976	help
977	  This determines the level of support for vector unaligned accesses. This
978	  information is used by the kernel to perform optimizations. It is also
979	  exposed to user space via the hwprobe syscall. The hardware will be
980	  probed at boot by default.
981
982config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
983	bool "Probe speed of vector unaligned accesses"
984	select RISCV_VECTOR_MISALIGNED
985	depends on RISCV_ISA_V
986	help
987	  During boot, the kernel will run a series of tests to determine the
988	  speed of vector unaligned accesses if they are supported. This probing
989	  will dynamically determine the speed of vector unaligned accesses on
990	  the underlying system if they are supported.
991
992config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
993	bool "Assume the system supports slow vector unaligned memory accesses"
994	depends on NONPORTABLE
995	help
996	  Assume that the system supports slow vector unaligned memory accesses. The
997	  kernel and userspace programs may not be able to run at all on systems
998	  that do not support unaligned memory accesses.
999
1000config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
1001	bool "Assume the system supports fast vector unaligned memory accesses"
1002	depends on NONPORTABLE
1003	help
1004	  Assume that the system supports fast vector unaligned memory accesses. When
1005	  enabled, this option improves the performance of the kernel on such
1006	  systems. However, the kernel and userspace programs will run much more
1007	  slowly, or will not be able to run at all, on systems that do not
1008	  support efficient unaligned memory accesses.
1009
1010endchoice
1011
1012source "arch/riscv/Kconfig.vendor"
1013
1014endmenu # "Platform type"
1015
1016menu "Kernel features"
1017
1018source "kernel/Kconfig.hz"
1019
1020config RISCV_SBI_V01
1021	bool "SBI v0.1 support"
1022	depends on RISCV_SBI
1023	help
1024	  This config allows kernel to use SBI v0.1 APIs. This will be
1025	  deprecated in future once legacy M-mode software are no longer in use.
1026
1027config RISCV_BOOT_SPINWAIT
1028	bool "Spinwait booting method"
1029	depends on SMP
1030	default y if RISCV_SBI_V01 || RISCV_M_MODE
1031	help
1032	  This enables support for booting Linux via spinwait method. In the
1033	  spinwait method, all cores randomly jump to Linux. One of the cores
1034	  gets chosen via lottery and all other keep spinning on a percpu
1035	  variable. This method cannot support CPU hotplug and sparse hartid
1036	  scheme. It should be only enabled for M-mode Linux or platforms relying
1037	  on older firmware without SBI HSM extension. All other platforms should
1038	  rely on ordered booting via SBI HSM extension which gets chosen
1039	  dynamically at runtime if the firmware supports it.
1040
1041	  Since spinwait is incompatible with sparse hart IDs, it requires
1042	  NR_CPUS be large enough to contain the physical hart ID of the first
1043	  hart to enter Linux.
1044
1045	  If unsure what to do here, say N.
1046
1047config ARCH_SUPPORTS_KEXEC
1048	def_bool y
1049
1050config ARCH_SELECTS_KEXEC
1051	def_bool y
1052	depends on KEXEC
1053	select HOTPLUG_CPU if SMP
1054
1055config ARCH_SUPPORTS_KEXEC_FILE
1056	def_bool 64BIT
1057
1058config ARCH_SELECTS_KEXEC_FILE
1059	def_bool y
1060	depends on KEXEC_FILE
1061	select HAVE_IMA_KEXEC if IMA
1062	select KEXEC_ELF
1063
1064config ARCH_SUPPORTS_KEXEC_PURGATORY
1065	def_bool ARCH_SUPPORTS_KEXEC_FILE
1066
1067config ARCH_SUPPORTS_CRASH_DUMP
1068	def_bool y
1069
1070config ARCH_DEFAULT_CRASH_DUMP
1071	def_bool y
1072
1073config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1074	def_bool CRASH_RESERVE
1075
1076config COMPAT
1077	bool "Kernel support for 32-bit U-mode"
1078	default 64BIT
1079	depends on 64BIT && MMU
1080	help
1081	  This option enables support for a 32-bit U-mode running under a 64-bit
1082	  kernel at S-mode. riscv32-specific components such as system calls,
1083	  the user helper functions (vdso), signal rt_frame functions and the
1084	  ptrace interface are handled appropriately by the kernel.
1085
1086	  If you want to execute 32-bit userspace applications, say Y.
1087
1088config PARAVIRT
1089	bool "Enable paravirtualization code"
1090	depends on RISCV_SBI
1091	help
1092	  This changes the kernel so it can modify itself when it is run
1093	  under a hypervisor, potentially improving performance significantly
1094	  over full virtualization.
1095
1096config PARAVIRT_TIME_ACCOUNTING
1097	bool "Paravirtual steal time accounting"
1098	depends on PARAVIRT
1099	help
1100	  Select this option to enable fine granularity task steal time
1101	  accounting. Time spent executing other tasks in parallel with
1102	  the current vCPU is discounted from the vCPU power. To account for
1103	  that, there can be a small performance impact.
1104
1105	  If in doubt, say N here.
1106
1107config RELOCATABLE
1108	bool "Build a relocatable kernel"
1109	depends on !XIP_KERNEL
1110	select MODULE_SECTIONS if MODULES
1111	select ARCH_VMLINUX_NEEDS_RELOCS
1112	help
1113          This builds a kernel as a Position Independent Executable (PIE),
1114          which retains all relocation metadata required to relocate the
1115          kernel binary at runtime to a different virtual address than the
1116          address it was linked at.
1117          Since RISCV uses the RELA relocation format, this requires a
1118          relocation pass at runtime even if the kernel is loaded at the
1119          same address it was linked at.
1120
1121          If unsure, say N.
1122
1123config RANDOMIZE_BASE
1124        bool "Randomize the address of the kernel image"
1125        select RELOCATABLE
1126        depends on MMU && 64BIT && !XIP_KERNEL
1127        help
1128          Randomizes the virtual address at which the kernel image is
1129          loaded, as a security feature that deters exploit attempts
1130          relying on knowledge of the location of kernel internals.
1131
1132          It is the bootloader's job to provide entropy, by passing a
1133          random u64 value in /chosen/kaslr-seed at kernel entry.
1134
1135          When booting via the UEFI stub, it will invoke the firmware's
1136          EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1137          to the kernel proper. In addition, it will randomise the physical
1138          location of the kernel Image as well.
1139
1140          If unsure, say N.
1141
1142endmenu # "Kernel features"
1143
1144menu "Boot options"
1145
1146config CMDLINE
1147	string "Built-in kernel command line"
1148	help
1149	  For most platforms, the arguments for the kernel's command line
1150	  are provided at run-time, during boot. However, there are cases
1151	  where either no arguments are being provided or the provided
1152	  arguments are insufficient or even invalid.
1153
1154	  When that occurs, it is possible to define a built-in command
1155	  line here and choose how the kernel should use it later on.
1156
1157choice
1158	prompt "Built-in command line usage"
1159	depends on CMDLINE != ""
1160	default CMDLINE_FALLBACK
1161	help
1162	  Choose how the kernel will handle the provided built-in command
1163	  line.
1164
1165config CMDLINE_FALLBACK
1166	bool "Use bootloader kernel arguments if available"
1167	help
1168	  Use the built-in command line as fallback in case we get nothing
1169	  during boot. This is the default behaviour.
1170
1171config CMDLINE_EXTEND
1172	bool "Extend bootloader kernel arguments"
1173	help
1174	  The command-line arguments provided during boot will be
1175	  appended to the built-in command line. This is useful in
1176	  cases where the provided arguments are insufficient and
1177	  you don't want to or cannot modify them.
1178
1179config CMDLINE_FORCE
1180	bool "Always use the default kernel command string"
1181	help
1182	  Always use the built-in command line, even if we get one during
1183	  boot. This is useful in case you need to override the provided
1184	  command line on systems where you don't have or want control
1185	  over it.
1186
1187endchoice
1188
1189config EFI_STUB
1190	bool
1191
1192config EFI
1193	bool "UEFI runtime support"
1194	depends on OF && !XIP_KERNEL
1195	depends on MMU
1196	default y
1197	select ARCH_SUPPORTS_ACPI if 64BIT
1198	select EFI_GENERIC_STUB
1199	select EFI_PARAMS_FROM_FDT
1200	select EFI_RUNTIME_WRAPPERS
1201	select EFI_STUB
1202	select LIBFDT
1203	select RISCV_ISA_C
1204	select UCS2_STRING
1205	help
1206	  This option provides support for runtime services provided
1207	  by UEFI firmware (such as non-volatile variables, realtime
1208	  clock, and platform reset). A UEFI stub is also provided to
1209	  allow the kernel to be booted as an EFI application. This
1210	  is only useful on systems that have UEFI firmware.
1211
1212config DMI
1213	bool "Enable support for SMBIOS (DMI) tables"
1214	depends on EFI
1215	default y
1216	help
1217	  This enables SMBIOS/DMI feature for systems.
1218
1219	  This option is only useful on systems that have UEFI firmware.
1220	  However, even with this option, the resultant kernel should
1221	  continue to boot on existing non-UEFI platforms.
1222
1223config CC_HAVE_STACKPROTECTOR_TLS
1224	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
1225
1226config STACKPROTECTOR_PER_TASK
1227	def_bool y
1228	depends on !RANDSTRUCT
1229	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
1230
1231config PHYS_RAM_BASE_FIXED
1232	bool "Explicitly specified physical RAM address"
1233	depends on NONPORTABLE
1234	default n
1235
1236config PHYS_RAM_BASE
1237	hex "Platform Physical RAM address"
1238	depends on PHYS_RAM_BASE_FIXED
1239	default "0x80000000"
1240	help
1241	  This is the physical address of RAM in the system. It has to be
1242	  explicitly specified to run early relocations of read-write data
1243	  from flash to RAM.
1244
1245config XIP_KERNEL
1246	bool "Kernel Execute-In-Place from ROM"
1247	depends on MMU && SPARSEMEM && NONPORTABLE
1248	# This prevents XIP from being enabled by all{yes,mod}config, which
1249	# fail to build since XIP doesn't support large kernels.
1250	depends on !COMPILE_TEST
1251	select PHYS_RAM_BASE_FIXED
1252	help
1253	  Execute-In-Place allows the kernel to run from non-volatile storage
1254	  directly addressable by the CPU, such as NOR flash. This saves RAM
1255	  space since the text section of the kernel is not loaded from flash
1256	  to RAM.  Read-write sections, such as the data section and stack,
1257	  are still copied to RAM.  The XIP kernel is not compressed since
1258	  it has to run directly from flash, so it will take more space to
1259	  store it.  The flash address used to link the kernel object files,
1260	  and for storing it, is configuration dependent. Therefore, if you
1261	  say Y here, you must know the proper physical address where to
1262	  store the kernel image depending on your own flash memory usage.
1263
1264	  Also note that the make target becomes "make xipImage" rather than
1265	  "make zImage" or "make Image".  The final kernel binary to put in
1266	  ROM memory will be arch/riscv/boot/xipImage.
1267
1268	  SPARSEMEM is required because the kernel text and rodata that are
1269	  flash resident are not backed by memmap, then any attempt to get
1270	  a struct page on those regions will trigger a fault.
1271
1272	  If unsure, say N.
1273
1274config XIP_PHYS_ADDR
1275	hex "XIP Kernel Physical Location"
1276	depends on XIP_KERNEL
1277	default "0x21000000"
1278	help
1279	  This is the physical address in your flash memory the kernel will
1280	  be linked for and stored to.  This address is dependent on your
1281	  own flash usage.
1282
1283config RISCV_ISA_FALLBACK
1284	bool "Permit falling back to parsing riscv,isa for extension support by default"
1285	default y
1286	help
1287	  Parsing the "riscv,isa" devicetree property has been deprecated and
1288	  replaced by a list of explicitly defined strings. For compatibility
1289	  with existing platforms, the kernel will fall back to parsing the
1290	  "riscv,isa" property if the replacements are not found.
1291
1292	  Selecting N here will result in a kernel that does not use the
1293	  fallback, unless the commandline "riscv_isa_fallback" parameter is
1294	  present.
1295
1296	  Please see the dt-binding, located at
1297	  Documentation/devicetree/bindings/riscv/extensions.yaml for details
1298	  on the replacement properties, "riscv,isa-base" and
1299	  "riscv,isa-extensions".
1300
1301config BUILTIN_DTB
1302	bool "Built-in device tree"
1303	depends on OF && NONPORTABLE
1304	select GENERIC_BUILTIN_DTB
1305	help
1306	  Build a device tree into the Linux image.
1307	  This option should be selected if no bootloader is being used.
1308	  If unsure, say N.
1309
1310
1311config BUILTIN_DTB_NAME
1312	string "Built-in device tree source"
1313	depends on BUILTIN_DTB
1314	help
1315	  DTS file path (without suffix, relative to arch/riscv/boot/dts)
1316	  for the DTS file that will be used to produce the DTB linked into the
1317	  kernel.
1318
1319endmenu # "Boot options"
1320
1321config PORTABLE
1322	bool
1323	default !NONPORTABLE
1324	select EFI
1325	select MMU
1326	select OF
1327
1328config ARCH_PROC_KCORE_TEXT
1329	def_bool y
1330
1331menu "Power management options"
1332
1333source "kernel/power/Kconfig"
1334
1335config ARCH_HIBERNATION_POSSIBLE
1336	def_bool y
1337
1338config ARCH_HIBERNATION_HEADER
1339	def_bool HIBERNATION
1340
1341config ARCH_SUSPEND_POSSIBLE
1342	def_bool y
1343
1344endmenu # "Power management options"
1345
1346menu "CPU Power Management"
1347
1348source "drivers/cpuidle/Kconfig"
1349
1350source "drivers/cpufreq/Kconfig"
1351
1352endmenu # "CPU Power Management"
1353
1354source "arch/riscv/kvm/Kconfig"
1355
1356source "drivers/acpi/Kconfig"
1357