xref: /linux/arch/riscv/Kconfig (revision a50eba1e778ad4da5b6f9ddbbf57dabbea59bc05)
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_CC_CAN_LINK
28	select ARCH_HAS_CURRENT_STACK_POINTER
29	select ARCH_HAS_DEBUG_VIRTUAL if MMU
30	select ARCH_HAS_DEBUG_VM_PGTABLE
31	select ARCH_HAS_DEBUG_WX
32	select ARCH_HAS_ELF_CORE_EFLAGS if BINFMT_ELF && ELF_CORE
33	select ARCH_HAS_FAST_MULTIPLIER
34	select ARCH_HAS_FORTIFY_SOURCE
35	select ARCH_HAS_GCOV_PROFILE_ALL
36	select ARCH_HAS_GIGANTIC_PAGE
37	select ARCH_HAS_HW_PTE_YOUNG
38	select ARCH_HAS_KCOV
39	select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU
40	select ARCH_HAS_MEMBARRIER_CALLBACKS
41	select ARCH_HAS_MEMBARRIER_SYNC_CORE
42	select ARCH_HAS_MMIOWB
43	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
44	select ARCH_HAS_PMEM_API
45	select ARCH_HAS_PREEMPT_LAZY
46	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
47	select ARCH_HAS_PTDUMP if MMU
48	select ARCH_HAS_PTE_SPECIAL
49	select ARCH_HAS_SET_DIRECT_MAP if MMU
50	select ARCH_HAS_SET_MEMORY if MMU
51	select ARCH_HAS_STRICT_KERNEL_RWX if MMU
52	select ARCH_HAS_STRICT_MODULE_RWX if MMU
53	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
54	select ARCH_HAS_SYSCALL_WRAPPER
55	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
56	select ARCH_HAS_UBSAN
57	select ARCH_HAS_VDSO_ARCH_DATA if HAVE_GENERIC_VDSO
58	select ARCH_HAVE_NMI_SAFE_CMPXCHG
59	select ARCH_KEEP_MEMBLOCK if ACPI || KEXEC
60	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE	if 64BIT && MMU
61	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
62	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
63	select ARCH_STACKWALK
64	select ARCH_SUPPORTS_ATOMIC_RMW
65	select ARCH_SUPPORTS_CFI
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
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_BITREVERSE if HAVE_ARCH_BITREVERSE
108	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
109	select GENERIC_CPU_DEVICES
110	select GENERIC_CPU_VULNERABILITIES
111	select GENERIC_EARLY_IOREMAP
112	select GENERIC_ENTRY
113	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO && 64BIT
114	select GENERIC_IDLE_POLL_SETUP
115	select GENERIC_IOREMAP if MMU
116	select HAVE_IOREMAP_PROT if MMU
117	select GENERIC_IRQ_IPI if SMP
118	select GENERIC_IRQ_IPI_MUX if SMP
119	select GENERIC_IRQ_MULTI_HANDLER
120	select GENERIC_IRQ_SHOW
121	select GENERIC_IRQ_SHOW_LEVEL
122	select GENERIC_LIB_DEVMEM_IS_ALLOWED
123	select GENERIC_PENDING_IRQ if SMP
124	select GENERIC_PCI_IOMAP
125	select GENERIC_SCHED_CLOCK
126	select GENERIC_SMP_IDLE_THREAD
127	select HARDIRQS_SW_RESEND
128	select HAS_IOPORT if MMU
129	select HAVE_ALIGNED_STRUCT_PAGE
130	select HAVE_ARCH_AUDITSYSCALL
131	select HAVE_ARCH_BITREVERSE if RISCV_ISA_ZBKB && BITREVERSE
132	select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
133	select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT
134	select HAVE_ARCH_JUMP_LABEL
135	select HAVE_ARCH_JUMP_LABEL_RELATIVE
136	select HAVE_ARCH_KASAN if MMU && 64BIT
137	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
138	select HAVE_ARCH_KFENCE if MMU && 64BIT
139	select HAVE_ARCH_KSTACK_ERASE
140	select HAVE_ARCH_KGDB
141	select HAVE_ARCH_KGDB_QXFER_PKT
142	select HAVE_ARCH_MMAP_RND_BITS if MMU
143	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
144	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
145	select HAVE_ARCH_SECCOMP_FILTER
146	select HAVE_ARCH_SOFT_DIRTY if 64BIT && MMU && RISCV_ISA_SVRSW60T59B
147	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
148	select HAVE_ARCH_TRACEHOOK
149	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
150	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if 64BIT && MMU
151	select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
152	select HAVE_ARCH_USERFAULTFD_WP if 64BIT && MMU && USERFAULTFD && RISCV_ISA_SVRSW60T59B
153	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
154	select HAVE_ASM_MODVERSIONS
155	select HAVE_BUILDTIME_MCOUNT_SORT
156	select HAVE_CONTEXT_TRACKING_USER
157	select HAVE_DEBUG_KMEMLEAK
158	select HAVE_DMA_CONTIGUOUS if MMU
159	select HAVE_DYNAMIC_FTRACE if MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
160	select FUNCTION_ALIGNMENT_4B if DYNAMIC_FTRACE && RISCV_ISA_C
161	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS if HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS
162	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS if (DYNAMIC_FTRACE_WITH_ARGS && !CFI)
163	select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
164	select HAVE_FTRACE_GRAPH_FUNC
165	select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS
166	select HAVE_FUNCTION_GRAPH_FREGS
167	select HAVE_FUNCTION_TRACER if HAVE_DYNAMIC_FTRACE
168	select HAVE_EBPF_JIT if MMU
169	select HAVE_GENERIC_TIF_BITS
170	select HAVE_GUP_FAST if MMU
171	select HAVE_FUNCTION_ARG_ACCESS_API
172	select HAVE_FUNCTION_ERROR_INJECTION
173	select HAVE_GCC_PLUGINS
174	select HAVE_GENERIC_VDSO if MMU
175	select HAVE_IRQ_TIME_ACCOUNTING
176	select HAVE_KERNEL_BZIP2 if !EFI_ZBOOT
177	select HAVE_KERNEL_GZIP if !EFI_ZBOOT
178	select HAVE_KERNEL_LZ4 if !EFI_ZBOOT
179	select HAVE_KERNEL_LZMA if !EFI_ZBOOT
180	select HAVE_KERNEL_LZO if !EFI_ZBOOT
181	select HAVE_KERNEL_UNCOMPRESSED if !EFI_ZBOOT
182	select HAVE_KERNEL_ZSTD if !EFI_ZBOOT
183	select HAVE_KERNEL_XZ if !EFI_ZBOOT
184	select HAVE_KPROBES
185	select HAVE_KRETPROBES
186	# https://github.com/ClangBuiltLinux/linux/issues/1881
187	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
188	select HAVE_MOVE_PMD
189	select HAVE_MOVE_PUD
190	select HAVE_PAGE_SIZE_4KB
191	select HAVE_PCI
192	select HAVE_PERF_EVENTS
193	select HAVE_PERF_REGS
194	select HAVE_PERF_USER_STACK_DUMP
195	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
196	select HAVE_PREEMPT_DYNAMIC_KEY
197	select HAVE_REGS_AND_STACK_ACCESS_API
198	select HAVE_RETHOOK
199	select HAVE_RSEQ
200	select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG
201	select HAVE_SAMPLE_FTRACE_DIRECT
202	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
203	select HAVE_STACKPROTECTOR
204	select HAVE_SYSCALL_TRACEPOINTS
205	select HOTPLUG_PARALLEL if HOTPLUG_CPU
206	select IRQ_DOMAIN
207	select IRQ_FORCED_THREADING
208	select KASAN_VMALLOC if KASAN
209	select LOCK_MM_AND_FIND_VMA
210	select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU
211	select MODULES_USE_ELF_RELA if MODULES
212	select OF
213	select OF_EARLY_FLATTREE
214	select OF_IRQ
215	select PCI_DOMAINS_GENERIC if PCI
216	select PCI_ECAM if (ACPI && PCI)
217	select PCI_MSI if PCI
218	select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED
219	select RISCV_ALTERNATIVE
220	select RISCV_APLIC
221	select RISCV_IMSIC
222	select RISCV_INTC
223	select RISCV_TIMER if RISCV_SBI
224	select SIFIVE_PLIC
225	select SPARSE_IRQ
226	select SYSCTL_EXCEPTION_TRACE
227	select THREAD_INFO_IN_TASK
228	select TRACE_IRQFLAGS_SUPPORT
229	select UACCESS_MEMCPY if !MMU
230	select VDSO_GETRANDOM if HAVE_GENERIC_VDSO && 64BIT
231	select USER_STACKTRACE_SUPPORT
232	select ZONE_DMA32 if 64BIT
233
234config RUSTC_SUPPORTS_RISCV
235	def_bool y
236	depends on 64BIT
237
238config CLANG_SUPPORTS_DYNAMIC_FTRACE
239	def_bool CC_IS_CLANG
240	# https://github.com/ClangBuiltLinux/linux/issues/1817
241	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
242
243config GCC_SUPPORTS_DYNAMIC_FTRACE
244	def_bool CC_IS_GCC
245	depends on $(cc-option,-fpatchable-function-entry=8)
246	depends on CC_HAS_MIN_FUNCTION_ALIGNMENT || !RISCV_ISA_C
247
248config HAVE_SHADOW_CALL_STACK
249	def_bool $(cc-option,-fsanitize=shadow-call-stack)
250	# https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769
251	depends on $(ld-option,--no-relax-gp)
252
253# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
254config ARCH_HAS_BROKEN_DWARF5
255	def_bool y
256	# https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a
257	depends on AS_IS_LLVM && AS_VERSION < 180000
258	# https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77
259	depends on LD_IS_LLD && LLD_VERSION < 180000
260
261config ARCH_MMAP_RND_BITS_MIN
262	default 18 if 64BIT
263	default 8
264
265config ARCH_MMAP_RND_COMPAT_BITS_MIN
266	default 8
267
268# max bits determined by the following formula:
269#  VA_BITS - PAGE_SHIFT - 3
270config ARCH_MMAP_RND_BITS_MAX
271	default 24 if 64BIT # SV39 based
272	default 17
273
274config ARCH_MMAP_RND_COMPAT_BITS_MAX
275	default 17
276
277# set if we run in machine mode, cleared if we run in supervisor mode
278config RISCV_M_MODE
279	bool "Build a kernel that runs in machine mode"
280	depends on !MMU
281	default y
282	help
283	  Select this option if you want to run the kernel in M-mode,
284	  without the assistance of any other firmware.
285
286# set if we are running in S-mode and can use SBI calls
287config RISCV_SBI
288	bool
289	depends on !RISCV_M_MODE
290	default y
291
292config MMU
293	bool "MMU-based Paged Memory Management Support"
294	default y
295	help
296	  Select if you want MMU-based virtualised addressing space
297	  support by paged memory management. If unsure, say 'Y'.
298
299config KASAN_SHADOW_OFFSET
300	hex
301	depends on KASAN_GENERIC
302	default 0xdfffffff00000000 if 64BIT
303	default 0xffffffff if 32BIT
304
305config ARCH_FLATMEM_ENABLE
306	def_bool !NUMA
307
308config ARCH_SPARSEMEM_ENABLE
309	def_bool y
310	depends on MMU
311	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
312	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
313
314config ARCH_SELECT_MEMORY_MODEL
315	def_bool ARCH_SPARSEMEM_ENABLE
316
317config ARCH_SUPPORTS_UPROBES
318	def_bool y
319
320config STACKTRACE_SUPPORT
321	def_bool y
322
323config GENERIC_BUG
324	def_bool y
325	depends on BUG
326	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
327
328config GENERIC_BUG_RELATIVE_POINTERS
329	bool
330
331config GENERIC_CALIBRATE_DELAY
332	def_bool y
333
334config GENERIC_CSUM
335	def_bool y
336
337config GENERIC_HWEIGHT
338	def_bool y
339
340config FIX_EARLYCON_MEM
341	def_bool MMU
342
343config ILLEGAL_POINTER_VALUE
344	hex
345	default 0 if 32BIT
346	default 0xdead000000000000 if 64BIT
347
348config PGTABLE_LEVELS
349	int
350	default 5 if 64BIT
351	default 2
352
353config LOCKDEP_SUPPORT
354	def_bool y
355
356config RISCV_DMA_NONCOHERENT
357	bool
358	select ARCH_HAS_DMA_PREP_COHERENT
359	select ARCH_HAS_SETUP_DMA_OPS
360	select ARCH_HAS_SYNC_DMA_FOR_CPU
361	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
362	select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
363
364config RISCV_NONSTANDARD_CACHE_OPS
365	bool
366	help
367	  This enables function pointer support for non-standard noncoherent
368	  systems to handle cache management.
369
370config AS_HAS_INSN
371	def_bool $(as-instr,.insn 0x100000f)
372
373config AS_HAS_OPTION_ARCH
374	# https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4
375	def_bool y
376	depends on $(as-instr, .option arch$(comma) +m)
377
378source "arch/riscv/Kconfig.socs"
379source "arch/riscv/Kconfig.errata"
380
381menu "Platform type"
382
383config NONPORTABLE
384	bool "Allow configurations that result in non-portable kernels"
385	help
386	  RISC-V kernel binaries are compatible between all known systems
387	  whenever possible, but there are some use cases that can only be
388	  satisfied by configurations that result in kernel binaries that are
389	  not portable between systems.
390
391	  Selecting N does not guarantee kernels will be portable to all known
392	  systems.  Selecting any of the options guarded by NONPORTABLE will
393	  result in kernel binaries that are unlikely to be portable between
394	  systems.
395
396	  If unsure, say N.
397
398choice
399	prompt "Base ISA"
400	default ARCH_RV64I
401	help
402	  This selects the base ISA that this kernel will target and must match
403	  the target platform.
404
405config ARCH_RV32I
406	bool "RV32I"
407	depends on NONPORTABLE
408	select 32BIT
409	select GENERIC_LIB_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 RISCV_SBI_V01 && 64BIT
458	default "256" if !RISCV_SBI_V01 && 64BIT
459
460config HOTPLUG_CPU
461	bool "Support for hot-pluggable CPUs"
462	depends on SMP
463	select GENERIC_IRQ_MIGRATION
464	help
465
466	  Say Y here to experiment with turning CPUs off and on.  CPUs
467	  can be controlled through /sys/devices/system/cpu.
468
469	  Say N if you want to disable CPU hotplug.
470
471choice
472	prompt "CPU Tuning"
473	default TUNE_GENERIC
474
475config TUNE_GENERIC
476	bool "generic"
477
478endchoice
479
480# Common NUMA Features
481config NUMA
482	bool "NUMA Memory Allocation and Scheduler Support"
483	depends on SMP && MMU
484	select ARCH_SUPPORTS_NUMA_BALANCING
485	select GENERIC_ARCH_NUMA
486	select HAVE_SETUP_PER_CPU_AREA
487	select NEED_PER_CPU_EMBED_FIRST_CHUNK
488	select NEED_PER_CPU_PAGE_FIRST_CHUNK
489	select OF_NUMA
490	select USE_PERCPU_NUMA_NODE_ID
491	help
492	  Enable NUMA (Non-Uniform Memory Access) support.
493
494	  The kernel will try to allocate memory used by a CPU on the
495	  local memory of the CPU and add some more NUMA awareness to the kernel.
496
497config NODES_SHIFT
498	int "Maximum NUMA Nodes (as a power of 2)"
499	range 1 10
500	default "2"
501	depends on NUMA
502	help
503	  Specify the maximum number of NUMA Nodes available on the target
504	  system.  Increases memory reserved to accommodate various tables.
505
506choice
507	prompt "RISC-V spinlock type"
508	default RISCV_COMBO_SPINLOCKS
509
510config RISCV_TICKET_SPINLOCKS
511	bool "Using ticket spinlock"
512
513config RISCV_QUEUED_SPINLOCKS
514	bool "Using queued spinlock"
515	depends on SMP && MMU && NONPORTABLE
516	select ARCH_USE_QUEUED_SPINLOCKS
517	help
518	  The queued spinlock implementation requires the forward progress
519	  guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or
520	  LR/SC with Ziccrse provide such guarantee.
521
522	  Select this if and only if Zabha or Ziccrse is available on your
523	  platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms
524	  without one of those extensions.
525
526	  If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks
527	  when supported and otherwise ticket spinlocks.
528
529config RISCV_COMBO_SPINLOCKS
530	bool "Using combo spinlock"
531	depends on SMP && MMU
532	select ARCH_USE_QUEUED_SPINLOCKS
533	help
534	  Embed both queued spinlock and ticket lock so that the spinlock
535	  implementation can be chosen at runtime.
536
537endchoice
538
539config RISCV_ALTERNATIVE
540	bool
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 GCC < 11.3.0, for which this is not possible or need special
878	  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://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671
884	depends on CC_IS_GCC && GCC_VERSION < 110300
885	help
886	  Certain versions of GCC do not support zicsr and zifencei via -march.
887	  This option causes an older ISA spec compatible with these older
888	  versions of GCC to be passed to GAS, which has the same result
889	  as passing zicsr and zifencei to -march.
890
891config FPU
892	bool "FPU support"
893	default y
894	help
895	  Add support for floating point operations when an FPU is detected at
896	  boot. When this option is disabled, neither the kernel nor userspace
897	  may use the floating point unit.
898
899	  If you don't know what to do here, say Y.
900
901config IRQ_STACKS
902	bool "Independent irq & softirq stacks" if EXPERT
903	default y
904	select HAVE_IRQ_EXIT_ON_IRQ_STACK
905	select HAVE_SOFTIRQ_ON_OWN_STACK
906	help
907	  Add independent irq & softirq stacks for percpu to prevent kernel stack
908	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
909
910config THREAD_SIZE_ORDER
911	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
912	range 0 4
913	default 1 if 32BIT
914	default 2
915	help
916	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
917	  affects irq stack size, which is equal to thread stack size.
918
919config RISCV_MISALIGNED
920	bool
921	help
922	  Embed support for detecting and emulating misaligned
923	  scalar or vector loads and stores.
924
925config RISCV_SCALAR_MISALIGNED
926	bool
927	select RISCV_MISALIGNED
928	select SYSCTL_ARCH_UNALIGN_ALLOW
929	help
930	  Embed support for emulating misaligned loads and stores.
931
932config RISCV_VECTOR_MISALIGNED
933	bool
934	select RISCV_MISALIGNED
935	depends on RISCV_ISA_V
936	help
937	  Enable detecting support for vector misaligned loads and stores.
938
939config RISCV_SBI_FWFT_DELEGATE_MISALIGNED
940	bool "Request firmware delegation of unaligned access exceptions"
941	depends on RISCV_SBI
942	depends on NONPORTABLE
943	help
944	  Use SBI FWFT to request delegation of load address misaligned and
945	  store address misaligned exceptions, if possible, and prefer Linux
946	  kernel emulation of these accesses to firmware emulation.
947
948	  Unfortunately, Linux's emulation is still incomplete. Namely, it
949	  currently does not handle vector instructions and KVM guest accesses.
950	  On platforms where these accesses would have been handled by firmware,
951	  enabling this causes unexpected kernel oopses, userspaces crashes and
952	  KVM guest crashes. If you are sure that these are not a problem for
953	  your platform, you can say Y here, which may improve performance.
954
955	  Saying N here will not worsen emulation support for unaligned accesses
956	  even in the case where the firmware also has incomplete support. It
957	  simply keeps the firmware's emulation enabled.
958
959	  If you don't know what to do here, say N.
960
961choice
962	prompt "Unaligned Accesses Support"
963	default RISCV_PROBE_UNALIGNED_ACCESS
964	help
965	  This determines the level of support for unaligned accesses. This
966	  information is used by the kernel to perform optimizations. It is also
967	  exposed to user space via the hwprobe syscall. The hardware will be
968	  probed at boot by default.
969
970config RISCV_PROBE_UNALIGNED_ACCESS
971	bool "Probe for hardware unaligned access support"
972	select RISCV_SCALAR_MISALIGNED
973	help
974	  During boot, the kernel will run a series of tests to determine the
975	  speed of unaligned accesses. This probing will dynamically determine
976	  the speed of unaligned accesses on the underlying system. If unaligned
977	  memory accesses trap into the kernel as they are not supported by the
978	  system, the kernel will emulate the unaligned accesses to preserve the
979	  UABI.
980
981config RISCV_EMULATED_UNALIGNED_ACCESS
982	bool "Emulate unaligned access where system support is missing"
983	select RISCV_SCALAR_MISALIGNED
984	help
985	  If unaligned memory accesses trap into the kernel as they are not
986	  supported by the system, the kernel will emulate the unaligned
987	  accesses to preserve the UABI. When the underlying system does support
988	  unaligned accesses, the unaligned accesses are assumed to be slow.
989
990config RISCV_SLOW_UNALIGNED_ACCESS
991	bool "Assume the system supports slow unaligned memory accesses"
992	depends on NONPORTABLE
993	help
994	  Assume that the system supports slow unaligned memory accesses. The
995	  kernel and userspace programs may not be able to run at all on systems
996	  that do not support unaligned memory accesses.
997
998config RISCV_EFFICIENT_UNALIGNED_ACCESS
999	bool "Assume the system supports fast unaligned memory accesses"
1000	depends on NONPORTABLE
1001	select DCACHE_WORD_ACCESS if MMU
1002	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1003	help
1004	  Assume that the system supports fast 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
1012choice
1013	prompt "Vector unaligned Accesses Support"
1014	depends on RISCV_ISA_V
1015	default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
1016	help
1017	  This determines the level of support for vector unaligned accesses. This
1018	  information is used by the kernel to perform optimizations. It is also
1019	  exposed to user space via the hwprobe syscall. The hardware will be
1020	  probed at boot by default.
1021
1022config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
1023	bool "Probe speed of vector unaligned accesses"
1024	select RISCV_VECTOR_MISALIGNED
1025	help
1026	  During boot, the kernel will run a series of tests to determine the
1027	  speed of vector unaligned accesses if they are supported. This probing
1028	  will dynamically determine the speed of vector unaligned accesses on
1029	  the underlying system if they are supported.
1030
1031config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
1032	bool "Assume the system supports slow vector unaligned memory accesses"
1033	depends on NONPORTABLE
1034	help
1035	  Assume that the system supports slow vector unaligned memory accesses. The
1036	  kernel and userspace programs may not be able to run at all on systems
1037	  that do not support unaligned memory accesses.
1038
1039config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
1040	bool "Assume the system supports fast vector unaligned memory accesses"
1041	depends on NONPORTABLE
1042	help
1043	  Assume that the system supports fast vector unaligned memory accesses. When
1044	  enabled, this option improves the performance of the kernel on such
1045	  systems. However, the kernel and userspace programs will run much more
1046	  slowly, or will not be able to run at all, on systems that do not
1047	  support efficient unaligned memory accesses.
1048
1049endchoice
1050
1051source "arch/riscv/Kconfig.vendor"
1052
1053endmenu # "Platform type"
1054
1055menu "Kernel features"
1056
1057source "kernel/Kconfig.hz"
1058
1059config RISCV_SBI_V01
1060	bool "SBI v0.1 support"
1061	depends on RISCV_SBI
1062	help
1063	  This config allows kernel to use SBI v0.1 APIs. This will be
1064	  deprecated in future once legacy M-mode software are no longer in use.
1065
1066config RISCV_BOOT_SPINWAIT
1067	bool "Spinwait booting method"
1068	depends on SMP
1069	default y if RISCV_SBI_V01 || RISCV_M_MODE
1070	help
1071	  This enables support for booting Linux via spinwait method. In the
1072	  spinwait method, all cores randomly jump to Linux. One of the cores
1073	  gets chosen via lottery and all other keep spinning on a percpu
1074	  variable. This method cannot support CPU hotplug and sparse hartid
1075	  scheme. It should be only enabled for M-mode Linux or platforms relying
1076	  on older firmware without SBI HSM extension. All other platforms should
1077	  rely on ordered booting via SBI HSM extension which gets chosen
1078	  dynamically at runtime if the firmware supports it.
1079
1080	  Since spinwait is incompatible with sparse hart IDs, it requires
1081	  NR_CPUS be large enough to contain the physical hart ID of the first
1082	  hart to enter Linux.
1083
1084	  If unsure what to do here, say N.
1085
1086config ARCH_SUPPORTS_KEXEC
1087	def_bool y
1088
1089config ARCH_SELECTS_KEXEC
1090	def_bool y
1091	depends on KEXEC
1092	select HOTPLUG_CPU if SMP
1093
1094config ARCH_SUPPORTS_KEXEC_FILE
1095	def_bool 64BIT
1096
1097config ARCH_SELECTS_KEXEC_FILE
1098	def_bool y
1099	depends on KEXEC_FILE
1100	select HAVE_IMA_KEXEC if IMA
1101	select KEXEC_ELF
1102
1103config ARCH_SUPPORTS_KEXEC_PURGATORY
1104	def_bool ARCH_SUPPORTS_KEXEC_FILE
1105
1106config ARCH_SUPPORTS_CRASH_DUMP
1107	def_bool y
1108
1109config ARCH_DEFAULT_CRASH_DUMP
1110	def_bool y
1111
1112config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1113	def_bool CRASH_RESERVE
1114
1115config COMPAT
1116	bool "Kernel support for 32-bit U-mode"
1117	default 64BIT
1118	depends on 64BIT && MMU
1119	help
1120	  This option enables support for a 32-bit U-mode running under a 64-bit
1121	  kernel at S-mode. riscv32-specific components such as system calls,
1122	  the user helper functions (vdso), signal rt_frame functions and the
1123	  ptrace interface are handled appropriately by the kernel.
1124
1125	  If you want to execute 32-bit userspace applications, say Y.
1126
1127config PARAVIRT
1128	bool "Enable paravirtualization code"
1129	depends on RISCV_SBI
1130	select HAVE_PV_STEAL_CLOCK_GEN
1131	help
1132	  This changes the kernel so it can modify itself when it is run
1133	  under a hypervisor, potentially improving performance significantly
1134	  over full virtualization.
1135
1136config PARAVIRT_TIME_ACCOUNTING
1137	bool "Paravirtual steal time accounting"
1138	depends on PARAVIRT
1139	help
1140	  Select this option to enable fine granularity task steal time
1141	  accounting. Time spent executing other tasks in parallel with
1142	  the current vCPU is discounted from the vCPU power. To account for
1143	  that, there can be a small performance impact.
1144
1145	  If in doubt, say N here.
1146
1147config RELOCATABLE
1148	bool "Build a relocatable kernel"
1149	select MODULE_SECTIONS if MODULES
1150	select ARCH_VMLINUX_NEEDS_RELOCS
1151	help
1152          This builds a kernel as a Position Independent Executable (PIE),
1153          which retains all relocation metadata required to relocate the
1154          kernel binary at runtime to a different virtual address than the
1155          address it was linked at.
1156          Since RISCV uses the RELA relocation format, this requires a
1157          relocation pass at runtime even if the kernel is loaded at the
1158          same address it was linked at.
1159
1160          If unsure, say N.
1161
1162config RANDOMIZE_BASE
1163        bool "Randomize the address of the kernel image"
1164        depends on RELOCATABLE
1165        depends on MMU && 64BIT
1166        help
1167          Randomizes the virtual address at which the kernel image is
1168          loaded, as a security feature that deters exploit attempts
1169          relying on knowledge of the location of kernel internals.
1170
1171          It is the bootloader's job to provide entropy, by passing a
1172          random u64 value in /chosen/kaslr-seed at kernel entry.
1173
1174          When booting via the UEFI stub, it will invoke the firmware's
1175          EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1176          to the kernel proper. In addition, it will randomise the physical
1177          location of the kernel Image as well.
1178
1179          If unsure, say N.
1180
1181config RISCV_USER_CFI
1182	def_bool y
1183	bool "riscv userspace control flow integrity"
1184	depends on 64BIT && MMU && \
1185		$(cc-option,-mabi=lp64 -march=rv64ima_zicfiss_zicfilp -fcf-protection=full)
1186	depends on RISCV_ALTERNATIVE
1187	select RISCV_SBI
1188	select ARCH_HAS_USER_SHADOW_STACK
1189	select ARCH_USES_HIGH_VMA_FLAGS
1190	select DYNAMIC_SIGFRAME
1191	help
1192	  Provides CPU-assisted control flow integrity to userspace tasks.
1193	  Control flow integrity is provided by implementing shadow stack for
1194	  backward edge and indirect branch tracking for forward edge.
1195	  Shadow stack protection is a hardware feature that detects function
1196	  return address corruption. This helps mitigate ROP attacks.
1197	  Indirect branch tracking enforces that all indirect branches must land
1198	  on a landing pad instruction else CPU will fault. This mitigates against
1199	  JOP / COP attacks. Applications must be enabled to use it, and old userspace
1200	  does not get protection "for free".
1201	  default y.
1202
1203endmenu # "Kernel features"
1204
1205menu "Boot options"
1206
1207config CMDLINE
1208	string "Built-in kernel command line"
1209	help
1210	  For most platforms, the arguments for the kernel's command line
1211	  are provided at run-time, during boot. However, there are cases
1212	  where either no arguments are being provided or the provided
1213	  arguments are insufficient or even invalid.
1214
1215	  When that occurs, it is possible to define a built-in command
1216	  line here and choose how the kernel should use it later on.
1217
1218choice
1219	prompt "Built-in command line usage"
1220	depends on CMDLINE != ""
1221	default CMDLINE_FALLBACK
1222	help
1223	  Choose how the kernel will handle the provided built-in command
1224	  line.
1225
1226config CMDLINE_FALLBACK
1227	bool "Use bootloader kernel arguments if available"
1228	help
1229	  Use the built-in command line as fallback in case we get nothing
1230	  during boot. This is the default behaviour.
1231
1232config CMDLINE_EXTEND
1233	bool "Extend bootloader kernel arguments"
1234	help
1235	  The built-in command line will be appended to the command-
1236	  line arguments provided during boot. This is useful in
1237	  cases where the provided arguments are insufficient and
1238	  you don't want to or cannot modify them.
1239
1240config CMDLINE_FORCE
1241	bool "Always use the default kernel command string"
1242	help
1243	  Always use the built-in command line, even if we get one during
1244	  boot. This is useful in case you need to override the provided
1245	  command line on systems where you don't have or want control
1246	  over it.
1247
1248endchoice
1249
1250config EFI_STUB
1251	bool
1252
1253config EFI
1254	bool "UEFI runtime support"
1255	depends on OF
1256	depends on MMU
1257	default y
1258	select ARCH_SUPPORTS_ACPI if 64BIT
1259	select EFI_GENERIC_STUB
1260	select EFI_PARAMS_FROM_FDT
1261	select EFI_RUNTIME_WRAPPERS
1262	select EFI_STUB
1263	select LIBFDT
1264	select RISCV_ISA_C
1265	select UCS2_STRING
1266	help
1267	  This option provides support for runtime services provided
1268	  by UEFI firmware (such as non-volatile variables, realtime
1269	  clock, and platform reset). A UEFI stub is also provided to
1270	  allow the kernel to be booted as an EFI application. This
1271	  is only useful on systems that have UEFI firmware.
1272
1273config DMI
1274	bool "Enable support for SMBIOS (DMI) tables"
1275	depends on EFI
1276	default y
1277	help
1278	  This enables SMBIOS/DMI feature for systems.
1279
1280	  This option is only useful on systems that have UEFI firmware.
1281	  However, even with this option, the resultant kernel should
1282	  continue to boot on existing non-UEFI platforms.
1283
1284config CC_HAVE_STACKPROTECTOR_TLS
1285	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
1286
1287config STACKPROTECTOR_PER_TASK
1288	def_bool y
1289	depends on !RANDSTRUCT
1290	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
1291
1292config PHYS_RAM_BASE_FIXED
1293	bool "Explicitly specified physical RAM address"
1294	depends on NONPORTABLE
1295	default n
1296
1297config PHYS_RAM_BASE
1298	hex "Platform Physical RAM address"
1299	depends on PHYS_RAM_BASE_FIXED
1300	default "0x80000000"
1301	help
1302	  This is the physical address of RAM in the system. It has to be
1303	  explicitly specified to run early relocations of read-write data
1304	  from flash to RAM.
1305
1306config RISCV_ISA_FALLBACK
1307	bool "Permit falling back to parsing riscv,isa for extension support by default"
1308	default y
1309	help
1310	  Parsing the "riscv,isa" devicetree property has been deprecated and
1311	  replaced by a list of explicitly defined strings. For compatibility
1312	  with existing platforms, the kernel will fall back to parsing the
1313	  "riscv,isa" property if the replacements are not found.
1314
1315	  Selecting N here will result in a kernel that does not use the
1316	  fallback, unless the commandline "riscv_isa_fallback" parameter is
1317	  present.
1318
1319	  Please see the dt-binding, located at
1320	  Documentation/devicetree/bindings/riscv/extensions.yaml for details
1321	  on the replacement properties, "riscv,isa-base" and
1322	  "riscv,isa-extensions".
1323
1324config BUILTIN_DTB
1325	bool "Built-in device tree"
1326	depends on OF && NONPORTABLE
1327	select GENERIC_BUILTIN_DTB
1328	help
1329	  Build a device tree into the Linux image.
1330	  This option should be selected if no bootloader is being used.
1331	  If unsure, say N.
1332
1333
1334config BUILTIN_DTB_NAME
1335	string "Built-in device tree source"
1336	depends on BUILTIN_DTB
1337	help
1338	  DTS file path (without suffix, relative to arch/riscv/boot/dts)
1339	  for the DTS file that will be used to produce the DTB linked into the
1340	  kernel.
1341
1342endmenu # "Boot options"
1343
1344config PORTABLE
1345	bool
1346	default !NONPORTABLE
1347	select EFI
1348	select MMU
1349	select OF
1350
1351config ARCH_PROC_KCORE_TEXT
1352	def_bool y
1353
1354config ARCH_CC_CAN_LINK
1355	bool
1356	default $(cc_can_link_user,-march=rv64g -mabi=lp64d) if 64BIT && FPU
1357	default $(cc_can_link_user,-march=rv64g -mabi=lp64) if 64BIT
1358	default $(cc_can_link_user,-march=rv32g -mabi=ilp32d) if FPU
1359	default $(cc_can_link_user,-march=rv32g -mabi=ilp32)
1360
1361config ARCH_USERFLAGS
1362	string
1363	default "-march=rv64g -mabi=lp64d" if 64BIT && FPU
1364	default "-march=rv64g -mabi=lp64" if 64BIT
1365	default "-march=rv32g -mabi=ilp32d" if FPU
1366	default "-march=rv32g -mabi=ilp32"
1367
1368menu "Power management options"
1369
1370source "kernel/power/Kconfig"
1371
1372config ARCH_HIBERNATION_POSSIBLE
1373	def_bool y
1374
1375config ARCH_HIBERNATION_HEADER
1376	def_bool HIBERNATION
1377
1378config ARCH_SUSPEND_POSSIBLE
1379	def_bool y
1380
1381endmenu # "Power management options"
1382
1383menu "CPU Power Management"
1384
1385source "drivers/cpuidle/Kconfig"
1386
1387source "drivers/cpufreq/Kconfig"
1388
1389endmenu # "CPU Power Management"
1390
1391source "arch/riscv/kvm/Kconfig"
1392
1393source "drivers/acpi/Kconfig"
1394