xref: /linux/arch/riscv/Kconfig (revision 334fbe734e687404f346eba7d5d96ed2b44d35ab)
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_RIMT if ACPI
20	select ACPI_SPCR_TABLE if ACPI
21	select ARCH_DMA_DEFAULT_COHERENT
22	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
23	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM_VMEMMAP
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_ELF_CORE_EFLAGS if BINFMT_ELF && ELF_CORE
32	select ARCH_HAS_FAST_MULTIPLIER
33	select ARCH_HAS_FORTIFY_SOURCE
34	select ARCH_HAS_GCOV_PROFILE_ALL
35	select ARCH_HAS_GIGANTIC_PAGE
36	select ARCH_HAS_HW_PTE_YOUNG
37	select ARCH_HAS_KCOV
38	select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU
39	select ARCH_HAS_MEMBARRIER_CALLBACKS
40	select ARCH_HAS_MEMBARRIER_SYNC_CORE
41	select ARCH_HAS_MMIOWB
42	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
43	select ARCH_HAS_PMEM_API
44	select ARCH_HAS_PREEMPT_LAZY
45	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
46	select ARCH_HAS_PTDUMP if MMU
47	select ARCH_HAS_PTE_SPECIAL
48	select ARCH_HAS_SET_DIRECT_MAP if MMU
49	select ARCH_HAS_SET_MEMORY if MMU
50	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
51	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
52	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
53	select ARCH_HAS_SYSCALL_WRAPPER
54	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
55	select ARCH_HAS_UBSAN
56	select ARCH_HAS_VDSO_ARCH_DATA if HAVE_GENERIC_VDSO
57	select ARCH_HAVE_NMI_SAFE_CMPXCHG
58	select ARCH_KEEP_MEMBLOCK if ACPI
59	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE	if 64BIT && MMU
60	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
61	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
62	select ARCH_STACKWALK
63	select ARCH_SUPPORTS_ATOMIC_RMW
64	# clang >= 17: https://github.com/llvm/llvm-project/commit/62fa708ceb027713b386c7e0efda994f8bdc27e2
65	select ARCH_SUPPORTS_CFI if (!CC_IS_CLANG || CLANG_VERSION >= 170000)
66	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
67	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
68	select ARCH_SUPPORTS_HUGETLBFS if MMU
69	select ARCH_SUPPORTS_LTO_CLANG if CMODEL_MEDANY
70	select ARCH_SUPPORTS_LTO_CLANG_THIN
71	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS if 64BIT && MMU
72	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
73	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
74	select ARCH_SUPPORTS_RT
75	select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
76	select ARCH_SUPPORTS_SCHED_MC if SMP
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
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_NO_EFFICIENT_FFS if !RISCV_ISA_ZBB
99	select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
100	select DYNAMIC_FTRACE if FUNCTION_TRACER
101	select EDAC_SUPPORT
102	select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE)
103	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
104	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
105	select GENERIC_ARCH_TOPOLOGY
106	select GENERIC_ATOMIC64 if !64BIT
107	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
108	select GENERIC_CPU_DEVICES
109	select GENERIC_CPU_VULNERABILITIES
110	select GENERIC_EARLY_IOREMAP
111	select GENERIC_ENTRY
112	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO && 64BIT
113	select GENERIC_IDLE_POLL_SETUP
114	select GENERIC_IOREMAP if MMU
115	select GENERIC_IRQ_IPI if SMP
116	select GENERIC_IRQ_IPI_MUX if SMP
117	select GENERIC_IRQ_MULTI_HANDLER
118	select GENERIC_IRQ_SHOW
119	select GENERIC_IRQ_SHOW_LEVEL
120	select GENERIC_LIB_DEVMEM_IS_ALLOWED
121	select GENERIC_PENDING_IRQ if SMP
122	select GENERIC_PCI_IOMAP
123	select GENERIC_SCHED_CLOCK
124	select GENERIC_SMP_IDLE_THREAD
125	select GENERIC_TIME_VSYSCALL if GENERIC_GETTIMEOFDAY
126	select HARDIRQS_SW_RESEND
127	select HAS_IOPORT if MMU
128	select HAVE_ALIGNED_STRUCT_PAGE
129	select HAVE_ARCH_AUDITSYSCALL
130	select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
131	select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT
132	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
133	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
134	select HAVE_ARCH_KASAN if MMU && 64BIT
135	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
136	select HAVE_ARCH_KFENCE if MMU && 64BIT
137	select HAVE_ARCH_KSTACK_ERASE
138	select HAVE_ARCH_KGDB if !XIP_KERNEL
139	select HAVE_ARCH_KGDB_QXFER_PKT
140	select HAVE_ARCH_MMAP_RND_BITS if MMU
141	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
142	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
143	select HAVE_ARCH_SECCOMP_FILTER
144	select HAVE_ARCH_SOFT_DIRTY if 64BIT && MMU && RISCV_ISA_SVRSW60T59B
145	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
146	select HAVE_ARCH_TRACEHOOK
147	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
148	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if 64BIT && MMU
149	select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
150	select HAVE_ARCH_USERFAULTFD_WP if 64BIT && MMU && USERFAULTFD && RISCV_ISA_SVRSW60T59B
151	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
152	select HAVE_ASM_MODVERSIONS
153	select HAVE_CONTEXT_TRACKING_USER
154	select HAVE_DEBUG_KMEMLEAK
155	select HAVE_DMA_CONTIGUOUS if MMU
156	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
157	select FUNCTION_ALIGNMENT_4B if HAVE_DYNAMIC_FTRACE && RISCV_ISA_C
158	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS if HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS
159	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS if (DYNAMIC_FTRACE_WITH_ARGS && !CFI)
160	select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
161	select HAVE_FTRACE_GRAPH_FUNC
162	select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS
163	select HAVE_FUNCTION_GRAPH_FREGS
164	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && HAVE_DYNAMIC_FTRACE
165	select HAVE_EBPF_JIT if MMU
166	select HAVE_GENERIC_TIF_BITS
167	select HAVE_GUP_FAST if MMU
168	select HAVE_FUNCTION_ARG_ACCESS_API
169	select HAVE_FUNCTION_ERROR_INJECTION
170	select HAVE_GCC_PLUGINS
171	select HAVE_GENERIC_VDSO if MMU
172	select HAVE_IRQ_TIME_ACCOUNTING
173	select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT
174	select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT
175	select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT
176	select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT
177	select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT
178	select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT
179	select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT
180	select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT
181	select HAVE_KPROBES if !XIP_KERNEL
182	select HAVE_KRETPROBES if !XIP_KERNEL
183	# https://github.com/ClangBuiltLinux/linux/issues/1881
184	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
185	select HAVE_MOVE_PMD
186	select HAVE_MOVE_PUD
187	select HAVE_PAGE_SIZE_4KB
188	select HAVE_PCI
189	select HAVE_PERF_EVENTS
190	select HAVE_PERF_REGS
191	select HAVE_PERF_USER_STACK_DUMP
192	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
193	select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL
194	select HAVE_REGS_AND_STACK_ACCESS_API
195	select HAVE_RETHOOK if !XIP_KERNEL
196	select HAVE_RSEQ
197	select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG
198	select HAVE_SAMPLE_FTRACE_DIRECT
199	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
200	select HAVE_STACKPROTECTOR
201	select HAVE_SYSCALL_TRACEPOINTS
202	select HOTPLUG_PARALLEL if HOTPLUG_CPU
203	select IRQ_DOMAIN
204	select IRQ_FORCED_THREADING
205	select KASAN_VMALLOC if KASAN
206	select LOCK_MM_AND_FIND_VMA
207	select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU
208	select MODULES_USE_ELF_RELA if MODULES
209	select OF
210	select OF_EARLY_FLATTREE
211	select OF_IRQ
212	select PCI_DOMAINS_GENERIC if PCI
213	select PCI_ECAM if (ACPI && PCI)
214	select PCI_MSI if PCI
215	select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED
216	select RISCV_ALTERNATIVE if !XIP_KERNEL
217	select RISCV_APLIC
218	select RISCV_IMSIC
219	select RISCV_INTC
220	select RISCV_TIMER if RISCV_SBI
221	select SIFIVE_PLIC
222	select SPARSE_IRQ
223	select SYSCTL_EXCEPTION_TRACE
224	select THREAD_INFO_IN_TASK
225	select TRACE_IRQFLAGS_SUPPORT
226	select UACCESS_MEMCPY if !MMU
227	select VDSO_GETRANDOM if HAVE_GENERIC_VDSO && 64BIT
228	select USER_STACKTRACE_SUPPORT
229	select ZONE_DMA32 if 64BIT
230
231config RUSTC_SUPPORTS_RISCV
232	def_bool y
233	depends on 64BIT
234
235config CLANG_SUPPORTS_DYNAMIC_FTRACE
236	def_bool CC_IS_CLANG
237	# https://github.com/ClangBuiltLinux/linux/issues/1817
238	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
239
240config GCC_SUPPORTS_DYNAMIC_FTRACE
241	def_bool CC_IS_GCC
242	depends on $(cc-option,-fpatchable-function-entry=8)
243	depends on CC_HAS_MIN_FUNCTION_ALIGNMENT || !RISCV_ISA_C
244
245config HAVE_SHADOW_CALL_STACK
246	def_bool $(cc-option,-fsanitize=shadow-call-stack)
247	# https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
248	depends on $(ld-option,--no-relax-gp)
249
250# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
251config ARCH_HAS_BROKEN_DWARF5
252	def_bool y
253	# https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
254	depends on AS_IS_LLVM && AS_VERSION < 180000
255	# https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
256	depends on LD_IS_LLD && LLD_VERSION < 180000
257
258config ARCH_MMAP_RND_BITS_MIN
259	default 18 if 64BIT
260	default 8
261
262config ARCH_MMAP_RND_COMPAT_BITS_MIN
263	default 8
264
265# max bits determined by the following formula:
266#  VA_BITS - PAGE_SHIFT - 3
267config ARCH_MMAP_RND_BITS_MAX
268	default 24 if 64BIT # SV39 based
269	default 17
270
271config ARCH_MMAP_RND_COMPAT_BITS_MAX
272	default 17
273
274# set if we run in machine mode, cleared if we run in supervisor mode
275config RISCV_M_MODE
276	bool "Build a kernel that runs in machine mode"
277	depends on !MMU
278	default y
279	help
280	  Select this option if you want to run the kernel in M-mode,
281	  without the assistance of any other firmware.
282
283# set if we are running in S-mode and can use SBI calls
284config RISCV_SBI
285	bool
286	depends on !RISCV_M_MODE
287	default y
288
289config MMU
290	bool "MMU-based Paged Memory Management Support"
291	default y
292	help
293	  Select if you want MMU-based virtualised addressing space
294	  support by paged memory management. If unsure, say 'Y'.
295
296config KASAN_SHADOW_OFFSET
297	hex
298	depends on KASAN_GENERIC
299	default 0xdfffffff00000000 if 64BIT
300	default 0xffffffff if 32BIT
301
302config ARCH_FLATMEM_ENABLE
303	def_bool !NUMA
304
305config ARCH_SPARSEMEM_ENABLE
306	def_bool y
307	depends on MMU
308	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
309	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
310
311config ARCH_SELECT_MEMORY_MODEL
312	def_bool ARCH_SPARSEMEM_ENABLE
313
314config ARCH_SUPPORTS_UPROBES
315	def_bool y
316
317config STACKTRACE_SUPPORT
318	def_bool y
319
320config GENERIC_BUG
321	def_bool y
322	depends on BUG
323	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
324
325config GENERIC_BUG_RELATIVE_POINTERS
326	bool
327
328config GENERIC_CALIBRATE_DELAY
329	def_bool y
330
331config GENERIC_CSUM
332	def_bool y
333
334config GENERIC_HWEIGHT
335	def_bool y
336
337config FIX_EARLYCON_MEM
338	def_bool MMU
339
340config ILLEGAL_POINTER_VALUE
341	hex
342	default 0 if 32BIT
343	default 0xdead000000000000 if 64BIT
344
345config PGTABLE_LEVELS
346	int
347	default 5 if 64BIT
348	default 2
349
350config LOCKDEP_SUPPORT
351	def_bool y
352
353config RISCV_DMA_NONCOHERENT
354	bool
355	select ARCH_HAS_DMA_PREP_COHERENT
356	select ARCH_HAS_SETUP_DMA_OPS
357	select ARCH_HAS_SYNC_DMA_FOR_CPU
358	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
359	select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
360
361config RISCV_NONSTANDARD_CACHE_OPS
362	bool
363	help
364	  This enables function pointer support for non-standard noncoherent
365	  systems to handle cache management.
366
367config AS_HAS_INSN
368	def_bool $(as-instr,.insn 0x100000f)
369
370config AS_HAS_OPTION_ARCH
371	# https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4
372	def_bool y
373	depends on $(as-instr, .option arch$(comma) +m)
374
375source "arch/riscv/Kconfig.socs"
376source "arch/riscv/Kconfig.errata"
377
378menu "Platform type"
379
380config NONPORTABLE
381	bool "Allow configurations that result in non-portable kernels"
382	help
383	  RISC-V kernel binaries are compatible between all known systems
384	  whenever possible, but there are some use cases that can only be
385	  satisfied by configurations that result in kernel binaries that are
386	  not portable between systems.
387
388	  Selecting N does not guarantee kernels will be portable to all known
389	  systems.  Selecting any of the options guarded by NONPORTABLE will
390	  result in kernel binaries that are unlikely to be portable between
391	  systems.
392
393	  If unsure, say N.
394
395choice
396	prompt "Base ISA"
397	default ARCH_RV64I
398	help
399	  This selects the base ISA that this kernel will target and must match
400	  the target platform.
401
402config ARCH_RV32I
403	bool "RV32I"
404	depends on NONPORTABLE
405	select 32BIT
406	select GENERIC_LIB_ASHLDI3
407	select GENERIC_LIB_ASHRDI3
408	select GENERIC_LIB_LSHRDI3
409	select GENERIC_LIB_UCMPDI2
410
411config ARCH_RV64I
412	bool "RV64I"
413	select 64BIT
414	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
415	select SWIOTLB if MMU
416
417endchoice
418
419# We must be able to map all physical memory into the kernel, but the compiler
420# is still a bit more efficient when generating code if it's setup in a manner
421# such that it can only map 2GiB of memory.
422choice
423	prompt "Kernel Code Model"
424	default CMODEL_MEDLOW if 32BIT
425	default CMODEL_MEDANY if 64BIT
426
427	config CMODEL_MEDLOW
428		bool "medium low code model"
429	config CMODEL_MEDANY
430		bool "medium any code model"
431endchoice
432
433config MODULE_SECTIONS
434	bool
435	select HAVE_MOD_ARCH_SPECIFIC
436
437config SMP
438	bool "Symmetric Multi-Processing"
439	help
440	  This enables support for systems with more than one CPU.  If
441	  you say N here, the kernel will run on single and
442	  multiprocessor machines, but will use only one CPU of a
443	  multiprocessor machine. If you say Y here, the kernel will run
444	  on many, but not all, single processor machines. On a single
445	  processor machine, the kernel will run faster if you say N
446	  here.
447
448	  If you don't know what to do here, say N.
449
450config NR_CPUS
451	int "Maximum number of CPUs (2-512)"
452	depends on SMP
453	range 2 512 if !RISCV_SBI_V01
454	range 2 32 if RISCV_SBI_V01 && 32BIT
455	range 2 64 if RISCV_SBI_V01 && 64BIT
456	default "32" if 32BIT
457	default "64" if 64BIT
458
459config HOTPLUG_CPU
460	bool "Support for hot-pluggable CPUs"
461	depends on SMP
462	select GENERIC_IRQ_MIGRATION
463	help
464
465	  Say Y here to experiment with turning CPUs off and on.  CPUs
466	  can be controlled through /sys/devices/system/cpu.
467
468	  Say N if you want to disable CPU hotplug.
469
470choice
471	prompt "CPU Tuning"
472	default TUNE_GENERIC
473
474config TUNE_GENERIC
475	bool "generic"
476
477endchoice
478
479# Common NUMA Features
480config NUMA
481	bool "NUMA Memory Allocation and Scheduler Support"
482	depends on SMP && MMU
483	select ARCH_SUPPORTS_NUMA_BALANCING
484	select GENERIC_ARCH_NUMA
485	select HAVE_SETUP_PER_CPU_AREA
486	select NEED_PER_CPU_EMBED_FIRST_CHUNK
487	select NEED_PER_CPU_PAGE_FIRST_CHUNK
488	select OF_NUMA
489	select USE_PERCPU_NUMA_NODE_ID
490	help
491	  Enable NUMA (Non-Uniform Memory Access) support.
492
493	  The kernel will try to allocate memory used by a CPU on the
494	  local memory of the CPU and add some more NUMA awareness to the kernel.
495
496config NODES_SHIFT
497	int "Maximum NUMA Nodes (as a power of 2)"
498	range 1 10
499	default "2"
500	depends on NUMA
501	help
502	  Specify the maximum number of NUMA Nodes available on the target
503	  system.  Increases memory reserved to accommodate various tables.
504
505choice
506	prompt "RISC-V spinlock type"
507	default RISCV_COMBO_SPINLOCKS
508
509config RISCV_TICKET_SPINLOCKS
510	bool "Using ticket spinlock"
511
512config RISCV_QUEUED_SPINLOCKS
513	bool "Using queued spinlock"
514	depends on SMP && MMU && NONPORTABLE
515	select ARCH_USE_QUEUED_SPINLOCKS
516	help
517	  The queued spinlock implementation requires the forward progress
518	  guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or
519	  LR/SC with Ziccrse provide such guarantee.
520
521	  Select this if and only if Zabha or Ziccrse is available on your
522	  platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms
523	  without one of those extensions.
524
525	  If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks
526	  when supported and otherwise ticket spinlocks.
527
528config RISCV_COMBO_SPINLOCKS
529	bool "Using combo spinlock"
530	depends on SMP && MMU
531	select ARCH_USE_QUEUED_SPINLOCKS
532	help
533	  Embed both queued spinlock and ticket lock so that the spinlock
534	  implementation can be chosen at runtime.
535
536endchoice
537
538config RISCV_ALTERNATIVE
539	bool
540	depends on !XIP_KERNEL
541	help
542	  This Kconfig allows the kernel to automatically patch the
543	  erratum or cpufeature required by the execution platform at run
544	  time. The code patching overhead is minimal, as it's only done
545	  once at boot and once on each module load.
546
547config RISCV_ALTERNATIVE_EARLY
548	bool
549	depends on RISCV_ALTERNATIVE
550	help
551	  Allows early patching of the kernel for special errata
552
553config RISCV_ISA_C
554	bool "Emit compressed instructions when building Linux"
555	default y
556	help
557	  Adds "C" to the ISA subsets that the toolchain is allowed to emit
558	  when building Linux, which results in compressed instructions in the
559	  Linux binary. This option produces a kernel that will not run on
560	  systems that do not support compressed instructions.
561
562	  If you don't know what to do here, say Y.
563
564config RISCV_ISA_SUPM
565	bool "Supm extension for userspace pointer masking"
566	depends on 64BIT
567	default y
568	help
569	  Add support for pointer masking in userspace (Supm) when the
570	  underlying hardware extension (Smnpm or Ssnpm) is detected at boot.
571
572	  If this option is disabled, userspace will be unable to use
573	  the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API.
574
575config RISCV_ISA_SVNAPOT
576	bool "Svnapot extension support for supervisor mode NAPOT pages"
577	depends on 64BIT && MMU
578	depends on RISCV_ALTERNATIVE
579	default y
580	help
581	  Enable support for the Svnapot ISA-extension when it is detected
582	  at boot.
583
584	  The Svnapot extension is used to mark contiguous PTEs as a range
585	  of contiguous virtual-to-physical translations for a naturally
586	  aligned power-of-2 (NAPOT) granularity larger than the base 4KB page
587	  size. When HUGETLBFS is also selected this option unconditionally
588	  allocates some memory for each NAPOT page size supported by the kernel.
589	  When optimizing for low memory consumption and for platforms without
590	  the Svnapot extension, it may be better to say N here.
591
592	  If you don't know what to do here, say Y.
593
594config RISCV_ISA_SVPBMT
595	bool "Svpbmt extension support for supervisor mode page-based memory types"
596	depends on 64BIT && MMU
597	depends on RISCV_ALTERNATIVE
598	default y
599	help
600	   Add support for the Svpbmt ISA-extension (Supervisor-mode:
601	   page-based memory types) in the kernel when it is detected at boot.
602
603	   The memory type for a page contains a combination of attributes
604	   that indicate the cacheability, idempotency, and ordering
605	   properties for access to that page.
606
607	   The Svpbmt extension is only available on 64-bit cpus.
608
609	   If you don't know what to do here, say Y.
610
611config TOOLCHAIN_HAS_V
612	bool
613	default y
614	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv)
615	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv)
616	depends on LD_IS_LLD || LD_VERSION >= 23800
617	depends on AS_HAS_OPTION_ARCH
618
619config RISCV_ISA_V
620	bool "Vector extension support"
621	depends on TOOLCHAIN_HAS_V
622	depends on FPU
623	select DYNAMIC_SIGFRAME
624	default y
625	help
626	  Add support for the Vector extension when it is detected at boot.
627	  When this option is disabled, neither the kernel nor userspace may
628	  use vector procedures.
629
630	  If you don't know what to do here, say Y.
631
632config RISCV_ISA_V_DEFAULT_ENABLE
633	bool "Enable userspace Vector by default"
634	depends on RISCV_ISA_V
635	default y
636	help
637	  Say Y here if you want to enable Vector in userspace by default.
638	  Otherwise, userspace has to make explicit prctl() call to enable
639	  Vector, or enable it via the sysctl interface.
640
641	  If you don't know what to do here, say Y.
642
643config RISCV_ISA_V_UCOPY_THRESHOLD
644	int "Threshold size for vectorized user copies"
645	depends on RISCV_ISA_V
646	default 768
647	help
648	  Prefer using vectorized copy_to_user()/copy_from_user() when the
649	  workload size exceeds this value.
650
651config RISCV_ISA_V_PREEMPTIVE
652	bool "Run kernel-mode Vector with kernel preemption"
653	depends on PREEMPTION
654	depends on RISCV_ISA_V
655	default y
656	help
657	  Usually, in-kernel SIMD routines are run with preemption disabled.
658	  Functions which invoke long running SIMD thus must yield the core's
659	  vector unit to prevent blocking other tasks for too long.
660
661	  This config allows the kernel to run SIMD without explicitly disabling
662	  preemption. Enabling this config will result in higher memory consumption
663	  due to the allocation of per-task's kernel Vector context.
664
665config RISCV_ISA_ZAWRS
666	bool "Zawrs extension support for more efficient busy waiting"
667	depends on RISCV_ALTERNATIVE
668	default y
669	help
670	  The Zawrs extension defines instructions to be used in polling loops
671	  which allow a hart to enter a low-power state or to trap to the
672	  hypervisor while waiting on a store to a memory location. Enable the
673	  use of these instructions in the kernel when the Zawrs extension is
674	  detected at boot.
675
676config TOOLCHAIN_HAS_ZABHA
677	bool
678	default y
679	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha)
680	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha)
681	depends on AS_HAS_OPTION_ARCH
682
683config RISCV_ISA_ZABHA
684	bool "Zabha extension support for atomic byte/halfword operations"
685	depends on TOOLCHAIN_HAS_ZABHA
686	depends on RISCV_ALTERNATIVE
687	default y
688	help
689	  Enable the use of the Zabha ISA-extension to implement kernel
690	  byte/halfword atomic memory operations when it is detected at boot.
691
692	  If you don't know what to do here, say Y.
693
694config TOOLCHAIN_HAS_ZACAS
695	bool
696	default y
697	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas)
698	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas)
699	depends on AS_HAS_OPTION_ARCH
700
701config RISCV_ISA_ZACAS
702	bool "Zacas extension support for atomic CAS"
703	depends on RISCV_ALTERNATIVE
704	default y
705	help
706	  Enable the use of the Zacas ISA-extension to implement kernel atomic
707	  cmpxchg operations when it is detected at boot.
708
709	  If you don't know what to do here, say Y.
710
711config TOOLCHAIN_HAS_ZBB
712	bool
713	default y
714	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
715	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
716	depends on LD_IS_LLD || LD_VERSION >= 23900
717	depends on AS_HAS_OPTION_ARCH
718
719# This symbol indicates that the toolchain supports all v1.0 vector crypto
720# extensions, including Zvk*, Zvbb, and Zvbc.  LLVM added all of these at once.
721# binutils added all except Zvkb, then added Zvkb.  So we just check for Zvkb.
722config TOOLCHAIN_HAS_VECTOR_CRYPTO
723	def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
724	depends on AS_HAS_OPTION_ARCH
725
726config TOOLCHAIN_HAS_ZBA
727	bool
728	default y
729	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba)
730	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba)
731	depends on LD_IS_LLD || LD_VERSION >= 23900
732	depends on AS_HAS_OPTION_ARCH
733
734config RISCV_ISA_ZBA
735	bool "Zba extension support for bit manipulation instructions"
736	default y
737	help
738	   Add support for enabling optimisations in the kernel when the Zba
739	   extension is detected at boot.
740
741	   The Zba extension provides instructions to accelerate the generation
742	   of addresses that index into arrays of basic data types.
743
744	   If you don't know what to do here, say Y.
745
746config RISCV_ISA_ZBB
747	bool "Zbb extension support for bit manipulation instructions"
748	depends on RISCV_ALTERNATIVE
749	default y
750	help
751	   Add support for enabling optimisations in the kernel when the
752	   Zbb extension is detected at boot. Some optimisations may
753	   additionally depend on toolchain support for Zbb.
754
755	   The Zbb extension provides instructions to accelerate a number
756	   of bit-specific operations (count bit population, sign extending,
757	   bitrotation, etc).
758
759	   If you don't know what to do here, say Y.
760
761config TOOLCHAIN_HAS_ZBC
762	bool
763	default y
764	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc)
765	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc)
766	depends on LD_IS_LLD || LD_VERSION >= 23900
767	depends on AS_HAS_OPTION_ARCH
768
769config RISCV_ISA_ZBC
770	bool "Zbc extension support for carry-less multiplication instructions"
771	depends on TOOLCHAIN_HAS_ZBC
772	depends on MMU
773	depends on RISCV_ALTERNATIVE
774	default y
775	help
776	   Adds support to dynamically detect the presence of the Zbc
777	   extension (carry-less multiplication) and enable its usage.
778
779	   The Zbc extension could accelerate CRC (cyclic redundancy check)
780	   calculations.
781
782	   If you don't know what to do here, say Y.
783
784config TOOLCHAIN_HAS_ZBKB
785	bool
786	default y
787	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb)
788	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb)
789	depends on LD_IS_LLD || LD_VERSION >= 23900
790	depends on AS_HAS_OPTION_ARCH
791
792config RISCV_ISA_ZBKB
793	bool "Zbkb extension support for bit manipulation instructions"
794	depends on TOOLCHAIN_HAS_ZBKB
795	depends on RISCV_ALTERNATIVE
796	default y
797	help
798	   Adds support to dynamically detect the presence of the ZBKB
799	   extension (bit manipulation for cryptography) and enable its usage.
800
801	   The Zbkb extension provides instructions to accelerate a number
802	   of common cryptography operations (pack, zip, etc).
803
804	   If you don't know what to do here, say Y.
805
806config RISCV_ISA_ZICBOM
807	bool "Zicbom extension support for non-coherent DMA operation"
808	depends on MMU
809	depends on RISCV_ALTERNATIVE
810	default y
811	select RISCV_DMA_NONCOHERENT
812	select DMA_DIRECT_REMAP
813	help
814	   Add support for the Zicbom extension (Cache Block Management
815	   Operations) and enable its use in the kernel when it is detected
816	   at boot.
817
818	   The Zicbom extension can be used to handle for example
819	   non-coherent DMA support on devices that need it.
820
821	   If you don't know what to do here, say Y.
822
823config RISCV_ISA_ZICBOZ
824	bool "Zicboz extension support for faster zeroing of memory"
825	depends on RISCV_ALTERNATIVE
826	default y
827	help
828	   Enable the use of the Zicboz extension (cbo.zero instruction)
829	   in the kernel when it is detected at boot.
830
831	   The Zicboz extension is used for faster zeroing of memory.
832
833	   If you don't know what to do here, say Y.
834
835config RISCV_ISA_ZICBOP
836	bool "Zicbop extension support for cache block prefetch"
837	depends on MMU
838	depends on RISCV_ALTERNATIVE
839	default y
840	help
841	  Adds support to dynamically detect the presence of the ZICBOP
842	  extension (Cache Block Prefetch Operations) and enable its
843	  usage.
844
845	  The Zicbop extension can be used to prefetch cache blocks for
846	  read/write fetch.
847
848	  If you don't know what to do here, say Y.
849
850config RISCV_ISA_SVRSW60T59B
851	bool "Svrsw60t59b extension support for using PTE bits 60 and 59"
852	depends on MMU && 64BIT
853	depends on RISCV_ALTERNATIVE
854	default y
855	help
856	  Adds support to dynamically detect the presence of the Svrsw60t59b
857	  extension and enable its usage.
858
859	  The Svrsw60t59b extension allows to free the PTE reserved bits 60
860	  and 59 for software to use.
861
862	  If you don't know what to do here, say Y.
863
864config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
865	def_bool y
866	# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc
867	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd
868	depends on AS_IS_GNU && AS_VERSION >= 23600
869	help
870	  Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer
871	  20191213 version, which moves some instructions from the I extension to
872	  the Zicsr and Zifencei extensions. This requires explicitly specifying
873	  Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr
874	  and Zifencei are supported in binutils from version 2.36 onwards.
875	  To make life easier, and avoid forcing toolchains that default to a
876	  newer ISA spec to version 2.2, relax the check to binutils >= 2.36.
877	  For clang < 17 or GCC < 11.3.0, for which this is not possible or need
878	  special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC.
879
880config TOOLCHAIN_NEEDS_OLD_ISA_SPEC
881	def_bool y
882	depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
883	# https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16
884	# https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
885	depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300)
886	help
887	  Certain versions of clang and GCC do not support zicsr and zifencei via
888	  -march. This option causes an older ISA spec compatible with these older
889	  versions of clang and GCC to be passed to GAS, which has the same result
890	  as passing zicsr and zifencei to -march.
891
892config FPU
893	bool "FPU support"
894	default y
895	help
896	  Add support for floating point operations when an FPU is detected at
897	  boot. When this option is disabled, neither the kernel nor userspace
898	  may use the floating point unit.
899
900	  If you don't know what to do here, say Y.
901
902config IRQ_STACKS
903	bool "Independent irq & softirq stacks" if EXPERT
904	default y
905	select HAVE_IRQ_EXIT_ON_IRQ_STACK
906	select HAVE_SOFTIRQ_ON_OWN_STACK
907	help
908	  Add independent irq & softirq stacks for percpu to prevent kernel stack
909	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
910
911config THREAD_SIZE_ORDER
912	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
913	range 0 4
914	default 1 if 32BIT
915	default 2
916	help
917	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
918	  affects irq stack size, which is equal to thread stack size.
919
920config RISCV_MISALIGNED
921	bool
922	help
923	  Embed support for detecting and emulating misaligned
924	  scalar or vector loads and stores.
925
926config RISCV_SCALAR_MISALIGNED
927	bool
928	select RISCV_MISALIGNED
929	select SYSCTL_ARCH_UNALIGN_ALLOW
930	help
931	  Embed support for emulating misaligned loads and stores.
932
933config RISCV_VECTOR_MISALIGNED
934	bool
935	select RISCV_MISALIGNED
936	depends on RISCV_ISA_V
937	help
938	  Enable detecting support for vector misaligned loads and stores.
939
940choice
941	prompt "Unaligned Accesses Support"
942	default RISCV_PROBE_UNALIGNED_ACCESS
943	help
944	  This determines the level of support for unaligned accesses. This
945	  information is used by the kernel to perform optimizations. It is also
946	  exposed to user space via the hwprobe syscall. The hardware will be
947	  probed at boot by default.
948
949config RISCV_PROBE_UNALIGNED_ACCESS
950	bool "Probe for hardware unaligned access support"
951	select RISCV_SCALAR_MISALIGNED
952	help
953	  During boot, the kernel will run a series of tests to determine the
954	  speed of unaligned accesses. This probing will dynamically determine
955	  the speed of unaligned accesses on the underlying system. If unaligned
956	  memory accesses trap into the kernel as they are not supported by the
957	  system, the kernel will emulate the unaligned accesses to preserve the
958	  UABI.
959
960config RISCV_EMULATED_UNALIGNED_ACCESS
961	bool "Emulate unaligned access where system support is missing"
962	select RISCV_SCALAR_MISALIGNED
963	help
964	  If unaligned memory accesses trap into the kernel as they are not
965	  supported by the system, the kernel will emulate the unaligned
966	  accesses to preserve the UABI. When the underlying system does support
967	  unaligned accesses, the unaligned accesses are assumed to be slow.
968
969config RISCV_SLOW_UNALIGNED_ACCESS
970	bool "Assume the system supports slow unaligned memory accesses"
971	depends on NONPORTABLE
972	help
973	  Assume that the system supports slow unaligned memory accesses. The
974	  kernel and userspace programs may not be able to run at all on systems
975	  that do not support unaligned memory accesses.
976
977config RISCV_EFFICIENT_UNALIGNED_ACCESS
978	bool "Assume the system supports fast unaligned memory accesses"
979	depends on NONPORTABLE
980	select DCACHE_WORD_ACCESS if MMU
981	select HAVE_EFFICIENT_UNALIGNED_ACCESS
982	help
983	  Assume that the system supports fast unaligned memory accesses. When
984	  enabled, this option improves the performance of the kernel on such
985	  systems. However, the kernel and userspace programs will run much more
986	  slowly, or will not be able to run at all, on systems that do not
987	  support efficient unaligned memory accesses.
988
989endchoice
990
991choice
992	prompt "Vector unaligned Accesses Support"
993	depends on RISCV_ISA_V
994	default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
995	help
996	  This determines the level of support for vector unaligned accesses. This
997	  information is used by the kernel to perform optimizations. It is also
998	  exposed to user space via the hwprobe syscall. The hardware will be
999	  probed at boot by default.
1000
1001config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
1002	bool "Probe speed of vector unaligned accesses"
1003	select RISCV_VECTOR_MISALIGNED
1004	depends on RISCV_ISA_V
1005	help
1006	  During boot, the kernel will run a series of tests to determine the
1007	  speed of vector unaligned accesses if they are supported. This probing
1008	  will dynamically determine the speed of vector unaligned accesses on
1009	  the underlying system if they are supported.
1010
1011config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
1012	bool "Assume the system supports slow vector unaligned memory accesses"
1013	depends on NONPORTABLE
1014	help
1015	  Assume that the system supports slow vector unaligned memory accesses. The
1016	  kernel and userspace programs may not be able to run at all on systems
1017	  that do not support unaligned memory accesses.
1018
1019config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
1020	bool "Assume the system supports fast vector unaligned memory accesses"
1021	depends on NONPORTABLE
1022	help
1023	  Assume that the system supports fast vector unaligned memory accesses. When
1024	  enabled, this option improves the performance of the kernel on such
1025	  systems. However, the kernel and userspace programs will run much more
1026	  slowly, or will not be able to run at all, on systems that do not
1027	  support efficient unaligned memory accesses.
1028
1029endchoice
1030
1031source "arch/riscv/Kconfig.vendor"
1032
1033endmenu # "Platform type"
1034
1035menu "Kernel features"
1036
1037source "kernel/Kconfig.hz"
1038
1039config RISCV_SBI_V01
1040	bool "SBI v0.1 support"
1041	depends on RISCV_SBI
1042	help
1043	  This config allows kernel to use SBI v0.1 APIs. This will be
1044	  deprecated in future once legacy M-mode software are no longer in use.
1045
1046config RISCV_BOOT_SPINWAIT
1047	bool "Spinwait booting method"
1048	depends on SMP
1049	default y if RISCV_SBI_V01 || RISCV_M_MODE
1050	help
1051	  This enables support for booting Linux via spinwait method. In the
1052	  spinwait method, all cores randomly jump to Linux. One of the cores
1053	  gets chosen via lottery and all other keep spinning on a percpu
1054	  variable. This method cannot support CPU hotplug and sparse hartid
1055	  scheme. It should be only enabled for M-mode Linux or platforms relying
1056	  on older firmware without SBI HSM extension. All other platforms should
1057	  rely on ordered booting via SBI HSM extension which gets chosen
1058	  dynamically at runtime if the firmware supports it.
1059
1060	  Since spinwait is incompatible with sparse hart IDs, it requires
1061	  NR_CPUS be large enough to contain the physical hart ID of the first
1062	  hart to enter Linux.
1063
1064	  If unsure what to do here, say N.
1065
1066config ARCH_SUPPORTS_KEXEC
1067	def_bool y
1068
1069config ARCH_SELECTS_KEXEC
1070	def_bool y
1071	depends on KEXEC
1072	select HOTPLUG_CPU if SMP
1073
1074config ARCH_SUPPORTS_KEXEC_FILE
1075	def_bool 64BIT
1076
1077config ARCH_SELECTS_KEXEC_FILE
1078	def_bool y
1079	depends on KEXEC_FILE
1080	select HAVE_IMA_KEXEC if IMA
1081	select KEXEC_ELF
1082
1083config ARCH_SUPPORTS_KEXEC_PURGATORY
1084	def_bool ARCH_SUPPORTS_KEXEC_FILE
1085
1086config ARCH_SUPPORTS_CRASH_DUMP
1087	def_bool y
1088
1089config ARCH_DEFAULT_CRASH_DUMP
1090	def_bool y
1091
1092config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1093	def_bool CRASH_RESERVE
1094
1095config COMPAT
1096	bool "Kernel support for 32-bit U-mode"
1097	default 64BIT
1098	depends on 64BIT && MMU
1099	help
1100	  This option enables support for a 32-bit U-mode running under a 64-bit
1101	  kernel at S-mode. riscv32-specific components such as system calls,
1102	  the user helper functions (vdso), signal rt_frame functions and the
1103	  ptrace interface are handled appropriately by the kernel.
1104
1105	  If you want to execute 32-bit userspace applications, say Y.
1106
1107config PARAVIRT
1108	bool "Enable paravirtualization code"
1109	depends on RISCV_SBI
1110	select HAVE_PV_STEAL_CLOCK_GEN
1111	help
1112	  This changes the kernel so it can modify itself when it is run
1113	  under a hypervisor, potentially improving performance significantly
1114	  over full virtualization.
1115
1116config PARAVIRT_TIME_ACCOUNTING
1117	bool "Paravirtual steal time accounting"
1118	depends on PARAVIRT
1119	help
1120	  Select this option to enable fine granularity task steal time
1121	  accounting. Time spent executing other tasks in parallel with
1122	  the current vCPU is discounted from the vCPU power. To account for
1123	  that, there can be a small performance impact.
1124
1125	  If in doubt, say N here.
1126
1127config RELOCATABLE
1128	bool "Build a relocatable kernel"
1129	depends on !XIP_KERNEL
1130	select MODULE_SECTIONS if MODULES
1131	select ARCH_VMLINUX_NEEDS_RELOCS
1132	help
1133          This builds a kernel as a Position Independent Executable (PIE),
1134          which retains all relocation metadata required to relocate the
1135          kernel binary at runtime to a different virtual address than the
1136          address it was linked at.
1137          Since RISCV uses the RELA relocation format, this requires a
1138          relocation pass at runtime even if the kernel is loaded at the
1139          same address it was linked at.
1140
1141          If unsure, say N.
1142
1143config RANDOMIZE_BASE
1144        bool "Randomize the address of the kernel image"
1145        select RELOCATABLE
1146        depends on MMU && 64BIT && !XIP_KERNEL
1147        help
1148          Randomizes the virtual address at which the kernel image is
1149          loaded, as a security feature that deters exploit attempts
1150          relying on knowledge of the location of kernel internals.
1151
1152          It is the bootloader's job to provide entropy, by passing a
1153          random u64 value in /chosen/kaslr-seed at kernel entry.
1154
1155          When booting via the UEFI stub, it will invoke the firmware's
1156          EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1157          to the kernel proper. In addition, it will randomise the physical
1158          location of the kernel Image as well.
1159
1160          If unsure, say N.
1161
1162config RISCV_USER_CFI
1163	def_bool y
1164	bool "riscv userspace control flow integrity"
1165	depends on 64BIT && MMU && \
1166		$(cc-option,-mabi=lp64 -march=rv64ima_zicfiss_zicfilp -fcf-protection=full)
1167	depends on RISCV_ALTERNATIVE
1168	select RISCV_SBI
1169	select ARCH_HAS_USER_SHADOW_STACK
1170	select ARCH_USES_HIGH_VMA_FLAGS
1171	select DYNAMIC_SIGFRAME
1172	help
1173	  Provides CPU-assisted control flow integrity to userspace tasks.
1174	  Control flow integrity is provided by implementing shadow stack for
1175	  backward edge and indirect branch tracking for forward edge.
1176	  Shadow stack protection is a hardware feature that detects function
1177	  return address corruption. This helps mitigate ROP attacks.
1178	  Indirect branch tracking enforces that all indirect branches must land
1179	  on a landing pad instruction else CPU will fault. This mitigates against
1180	  JOP / COP attacks. Applications must be enabled to use it, and old userspace
1181	  does not get protection "for free".
1182	  default y.
1183
1184endmenu # "Kernel features"
1185
1186menu "Boot options"
1187
1188config CMDLINE
1189	string "Built-in kernel command line"
1190	help
1191	  For most platforms, the arguments for the kernel's command line
1192	  are provided at run-time, during boot. However, there are cases
1193	  where either no arguments are being provided or the provided
1194	  arguments are insufficient or even invalid.
1195
1196	  When that occurs, it is possible to define a built-in command
1197	  line here and choose how the kernel should use it later on.
1198
1199choice
1200	prompt "Built-in command line usage"
1201	depends on CMDLINE != ""
1202	default CMDLINE_FALLBACK
1203	help
1204	  Choose how the kernel will handle the provided built-in command
1205	  line.
1206
1207config CMDLINE_FALLBACK
1208	bool "Use bootloader kernel arguments if available"
1209	help
1210	  Use the built-in command line as fallback in case we get nothing
1211	  during boot. This is the default behaviour.
1212
1213config CMDLINE_EXTEND
1214	bool "Extend bootloader kernel arguments"
1215	help
1216	  The built-in command line will be appended to the command-
1217	  line arguments provided during boot. This is useful in
1218	  cases where the provided arguments are insufficient and
1219	  you don't want to or cannot modify them.
1220
1221config CMDLINE_FORCE
1222	bool "Always use the default kernel command string"
1223	help
1224	  Always use the built-in command line, even if we get one during
1225	  boot. This is useful in case you need to override the provided
1226	  command line on systems where you don't have or want control
1227	  over it.
1228
1229endchoice
1230
1231config EFI_STUB
1232	bool
1233
1234config EFI
1235	bool "UEFI runtime support"
1236	depends on OF && !XIP_KERNEL
1237	depends on MMU
1238	default y
1239	select ARCH_SUPPORTS_ACPI if 64BIT
1240	select EFI_GENERIC_STUB
1241	select EFI_PARAMS_FROM_FDT
1242	select EFI_RUNTIME_WRAPPERS
1243	select EFI_STUB
1244	select LIBFDT
1245	select RISCV_ISA_C
1246	select UCS2_STRING
1247	help
1248	  This option provides support for runtime services provided
1249	  by UEFI firmware (such as non-volatile variables, realtime
1250	  clock, and platform reset). A UEFI stub is also provided to
1251	  allow the kernel to be booted as an EFI application. This
1252	  is only useful on systems that have UEFI firmware.
1253
1254config DMI
1255	bool "Enable support for SMBIOS (DMI) tables"
1256	depends on EFI
1257	default y
1258	help
1259	  This enables SMBIOS/DMI feature for systems.
1260
1261	  This option is only useful on systems that have UEFI firmware.
1262	  However, even with this option, the resultant kernel should
1263	  continue to boot on existing non-UEFI platforms.
1264
1265config CC_HAVE_STACKPROTECTOR_TLS
1266	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
1267
1268config STACKPROTECTOR_PER_TASK
1269	def_bool y
1270	depends on !RANDSTRUCT
1271	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
1272
1273config PHYS_RAM_BASE_FIXED
1274	bool "Explicitly specified physical RAM address"
1275	depends on NONPORTABLE
1276	default n
1277
1278config PHYS_RAM_BASE
1279	hex "Platform Physical RAM address"
1280	depends on PHYS_RAM_BASE_FIXED
1281	default "0x80000000"
1282	help
1283	  This is the physical address of RAM in the system. It has to be
1284	  explicitly specified to run early relocations of read-write data
1285	  from flash to RAM.
1286
1287config XIP_KERNEL
1288	bool "Kernel Execute-In-Place from ROM"
1289	depends on MMU && SPARSEMEM && NONPORTABLE
1290	# This prevents XIP from being enabled by all{yes,mod}config, which
1291	# fail to build since XIP doesn't support large kernels.
1292	depends on !COMPILE_TEST
1293	select PHYS_RAM_BASE_FIXED
1294	help
1295	  Execute-In-Place allows the kernel to run from non-volatile storage
1296	  directly addressable by the CPU, such as NOR flash. This saves RAM
1297	  space since the text section of the kernel is not loaded from flash
1298	  to RAM.  Read-write sections, such as the data section and stack,
1299	  are still copied to RAM.  The XIP kernel is not compressed since
1300	  it has to run directly from flash, so it will take more space to
1301	  store it.  The flash address used to link the kernel object files,
1302	  and for storing it, is configuration dependent. Therefore, if you
1303	  say Y here, you must know the proper physical address where to
1304	  store the kernel image depending on your own flash memory usage.
1305
1306	  Also note that the make target becomes "make xipImage" rather than
1307	  "make zImage" or "make Image".  The final kernel binary to put in
1308	  ROM memory will be arch/riscv/boot/xipImage.
1309
1310	  SPARSEMEM is required because the kernel text and rodata that are
1311	  flash resident are not backed by memmap, then any attempt to get
1312	  a struct page on those regions will trigger a fault.
1313
1314	  If unsure, say N.
1315
1316config XIP_PHYS_ADDR
1317	hex "XIP Kernel Physical Location"
1318	depends on XIP_KERNEL
1319	default "0x21000000"
1320	help
1321	  This is the physical address in your flash memory the kernel will
1322	  be linked for and stored to.  This address is dependent on your
1323	  own flash usage.
1324
1325config RISCV_ISA_FALLBACK
1326	bool "Permit falling back to parsing riscv,isa for extension support by default"
1327	default y
1328	help
1329	  Parsing the "riscv,isa" devicetree property has been deprecated and
1330	  replaced by a list of explicitly defined strings. For compatibility
1331	  with existing platforms, the kernel will fall back to parsing the
1332	  "riscv,isa" property if the replacements are not found.
1333
1334	  Selecting N here will result in a kernel that does not use the
1335	  fallback, unless the commandline "riscv_isa_fallback" parameter is
1336	  present.
1337
1338	  Please see the dt-binding, located at
1339	  Documentation/devicetree/bindings/riscv/extensions.yaml for details
1340	  on the replacement properties, "riscv,isa-base" and
1341	  "riscv,isa-extensions".
1342
1343config BUILTIN_DTB
1344	bool "Built-in device tree"
1345	depends on OF && NONPORTABLE
1346	select GENERIC_BUILTIN_DTB
1347	help
1348	  Build a device tree into the Linux image.
1349	  This option should be selected if no bootloader is being used.
1350	  If unsure, say N.
1351
1352
1353config BUILTIN_DTB_NAME
1354	string "Built-in device tree source"
1355	depends on BUILTIN_DTB
1356	help
1357	  DTS file path (without suffix, relative to arch/riscv/boot/dts)
1358	  for the DTS file that will be used to produce the DTB linked into the
1359	  kernel.
1360
1361endmenu # "Boot options"
1362
1363config PORTABLE
1364	bool
1365	default !NONPORTABLE
1366	select EFI
1367	select MMU
1368	select OF
1369
1370config ARCH_PROC_KCORE_TEXT
1371	def_bool y
1372
1373menu "Power management options"
1374
1375source "kernel/power/Kconfig"
1376
1377config ARCH_HIBERNATION_POSSIBLE
1378	def_bool y
1379
1380config ARCH_HIBERNATION_HEADER
1381	def_bool HIBERNATION
1382
1383config ARCH_SUSPEND_POSSIBLE
1384	def_bool y
1385
1386endmenu # "Power management options"
1387
1388menu "CPU Power Management"
1389
1390source "drivers/cpuidle/Kconfig"
1391
1392source "drivers/cpufreq/Kconfig"
1393
1394endmenu # "CPU Power Management"
1395
1396source "arch/riscv/kvm/Kconfig"
1397
1398source "drivers/acpi/Kconfig"
1399