xref: /linux/arch/riscv/Kconfig (revision db3f02df1853acf4d678bcddb3f1eab23219b410)
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 ARCH_CLOCKSOURCE_INIT
16	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
17	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
18	select ARCH_HAS_BINFMT_FLAT
19	select ARCH_HAS_DEBUG_VM_PGTABLE
20	select ARCH_HAS_DEBUG_VIRTUAL if MMU
21	select ARCH_HAS_DEBUG_WX
22	select ARCH_HAS_FORTIFY_SOURCE
23	select ARCH_HAS_GCOV_PROFILE_ALL
24	select ARCH_HAS_GIGANTIC_PAGE
25	select ARCH_HAS_KCOV
26	select ARCH_HAS_MMIOWB
27	select ARCH_HAS_PTE_SPECIAL
28	select ARCH_HAS_SET_DIRECT_MAP if MMU
29	select ARCH_HAS_SET_MEMORY if MMU
30	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
31	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
32	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
33	select ARCH_HAS_UBSAN_SANITIZE_ALL
34	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
35	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
36	select ARCH_STACKWALK
37	select ARCH_SUPPORTS_ATOMIC_RMW
38	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
39	select ARCH_SUPPORTS_HUGETLBFS if MMU
40	select ARCH_USE_MEMTEST
41	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
42	select ARCH_WANT_FRAME_POINTERS
43	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
44	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
45	select BUILDTIME_TABLE_SORT if MMU
46	select CLONE_BACKWARDS
47	select CLINT_TIMER if !MMU
48	select COMMON_CLK
49	select EDAC_SUPPORT
50	select GENERIC_ARCH_TOPOLOGY if SMP
51	select GENERIC_ATOMIC64 if !64BIT
52	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
53	select GENERIC_EARLY_IOREMAP
54	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
55	select GENERIC_IDLE_POLL_SETUP
56	select GENERIC_IOREMAP if MMU
57	select GENERIC_IRQ_MULTI_HANDLER
58	select GENERIC_IRQ_SHOW
59	select GENERIC_IRQ_SHOW_LEVEL
60	select GENERIC_LIB_DEVMEM_IS_ALLOWED
61	select GENERIC_PCI_IOMAP
62	select GENERIC_PTDUMP if MMU
63	select GENERIC_SCHED_CLOCK
64	select GENERIC_SMP_IDLE_THREAD
65	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
66	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
67	select HAVE_ARCH_AUDITSYSCALL
68	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
69	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
70	select HAVE_ARCH_KASAN if MMU && 64BIT
71	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
72	select HAVE_ARCH_KFENCE if MMU && 64BIT
73	select HAVE_ARCH_KGDB if !XIP_KERNEL
74	select HAVE_ARCH_KGDB_QXFER_PKT
75	select HAVE_ARCH_MMAP_RND_BITS if MMU
76	select HAVE_ARCH_SECCOMP_FILTER
77	select HAVE_ARCH_TRACEHOOK
78	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
79	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
80	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
81	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
82	select HAVE_ASM_MODVERSIONS
83	select HAVE_CONTEXT_TRACKING
84	select HAVE_DEBUG_KMEMLEAK
85	select HAVE_DMA_CONTIGUOUS if MMU
86	select HAVE_EBPF_JIT if MMU
87	select HAVE_FUNCTION_ERROR_INJECTION
88	select HAVE_GCC_PLUGINS
89	select HAVE_GENERIC_VDSO if MMU && 64BIT
90	select HAVE_IRQ_TIME_ACCOUNTING
91	select HAVE_KPROBES if !XIP_KERNEL
92	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
93	select HAVE_KRETPROBES if !XIP_KERNEL
94	select HAVE_MOVE_PMD
95	select HAVE_MOVE_PUD
96	select HAVE_PCI
97	select HAVE_PERF_EVENTS
98	select HAVE_PERF_REGS
99	select HAVE_PERF_USER_STACK_DUMP
100	select HAVE_REGS_AND_STACK_ACCESS_API
101	select HAVE_FUNCTION_ARG_ACCESS_API
102	select HAVE_STACKPROTECTOR
103	select HAVE_SYSCALL_TRACEPOINTS
104	select IRQ_DOMAIN
105	select IRQ_FORCED_THREADING
106	select MODULES_USE_ELF_RELA if MODULES
107	select MODULE_SECTIONS if MODULES
108	select OF
109	select OF_EARLY_FLATTREE
110	select OF_IRQ
111	select PCI_DOMAINS_GENERIC if PCI
112	select PCI_MSI if PCI
113	select RISCV_INTC
114	select RISCV_TIMER if RISCV_SBI
115	select SPARSE_IRQ
116	select SYSCTL_EXCEPTION_TRACE
117	select THREAD_INFO_IN_TASK
118	select TRACE_IRQFLAGS_SUPPORT
119	select UACCESS_MEMCPY if !MMU
120	select ZONE_DMA32 if 64BIT
121
122config ARCH_MMAP_RND_BITS_MIN
123	default 18 if 64BIT
124	default 8
125
126# max bits determined by the following formula:
127#  VA_BITS - PAGE_SHIFT - 3
128config ARCH_MMAP_RND_BITS_MAX
129	default 24 if 64BIT # SV39 based
130	default 17
131
132# set if we run in machine mode, cleared if we run in supervisor mode
133config RISCV_M_MODE
134	bool
135	default !MMU
136
137# set if we are running in S-mode and can use SBI calls
138config RISCV_SBI
139	bool
140	depends on !RISCV_M_MODE
141	default y
142
143config MMU
144	bool "MMU-based Paged Memory Management Support"
145	default y
146	help
147	  Select if you want MMU-based virtualised addressing space
148	  support by paged memory management. If unsure, say 'Y'.
149
150config PAGE_OFFSET
151	hex
152	default 0xC0000000 if 32BIT
153	default 0x80000000 if 64BIT && !MMU
154	default 0xffffaf8000000000 if 64BIT
155
156config KASAN_SHADOW_OFFSET
157	hex
158	depends on KASAN_GENERIC
159	default 0xdfffffff00000000 if 64BIT
160	default 0xffffffff if 32BIT
161
162config ARCH_FLATMEM_ENABLE
163	def_bool !NUMA
164
165config ARCH_SPARSEMEM_ENABLE
166	def_bool y
167	depends on MMU
168	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
169	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
170
171config ARCH_SELECT_MEMORY_MODEL
172	def_bool ARCH_SPARSEMEM_ENABLE
173
174config ARCH_WANT_GENERAL_HUGETLB
175	def_bool y
176
177config ARCH_SUPPORTS_UPROBES
178	def_bool y
179
180config STACKTRACE_SUPPORT
181	def_bool y
182
183config GENERIC_BUG
184	def_bool y
185	depends on BUG
186	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
187
188config GENERIC_BUG_RELATIVE_POINTERS
189	bool
190
191config GENERIC_CALIBRATE_DELAY
192	def_bool y
193
194config GENERIC_CSUM
195	def_bool y
196
197config GENERIC_HWEIGHT
198	def_bool y
199
200config FIX_EARLYCON_MEM
201	def_bool MMU
202
203config PGTABLE_LEVELS
204	int
205	default 4 if 64BIT
206	default 2
207
208config LOCKDEP_SUPPORT
209	def_bool y
210
211source "arch/riscv/Kconfig.socs"
212source "arch/riscv/Kconfig.erratas"
213
214menu "Platform type"
215
216choice
217	prompt "Base ISA"
218	default ARCH_RV64I
219	help
220	  This selects the base ISA that this kernel will target and must match
221	  the target platform.
222
223config ARCH_RV32I
224	bool "RV32I"
225	select 32BIT
226	select GENERIC_LIB_ASHLDI3
227	select GENERIC_LIB_ASHRDI3
228	select GENERIC_LIB_LSHRDI3
229	select GENERIC_LIB_UCMPDI2
230	select MMU
231
232config ARCH_RV64I
233	bool "RV64I"
234	select 64BIT
235	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
236	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
237	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
238	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
239	select HAVE_FUNCTION_GRAPH_TRACER
240	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
241	select SWIOTLB if MMU
242
243endchoice
244
245# We must be able to map all physical memory into the kernel, but the compiler
246# is still a bit more efficient when generating code if it's setup in a manner
247# such that it can only map 2GiB of memory.
248choice
249	prompt "Kernel Code Model"
250	default CMODEL_MEDLOW if 32BIT
251	default CMODEL_MEDANY if 64BIT
252
253	config CMODEL_MEDLOW
254		bool "medium low code model"
255	config CMODEL_MEDANY
256		bool "medium any code model"
257endchoice
258
259config MODULE_SECTIONS
260	bool
261	select HAVE_MOD_ARCH_SPECIFIC
262
263config SMP
264	bool "Symmetric Multi-Processing"
265	help
266	  This enables support for systems with more than one CPU.  If
267	  you say N here, the kernel will run on single and
268	  multiprocessor machines, but will use only one CPU of a
269	  multiprocessor machine. If you say Y here, the kernel will run
270	  on many, but not all, single processor machines. On a single
271	  processor machine, the kernel will run faster if you say N
272	  here.
273
274	  If you don't know what to do here, say N.
275
276config NR_CPUS
277	int "Maximum number of CPUs (2-32)"
278	range 2 32
279	depends on SMP
280	default "8"
281
282config HOTPLUG_CPU
283	bool "Support for hot-pluggable CPUs"
284	depends on SMP
285	select GENERIC_IRQ_MIGRATION
286	help
287
288	  Say Y here to experiment with turning CPUs off and on.  CPUs
289	  can be controlled through /sys/devices/system/cpu.
290
291	  Say N if you want to disable CPU hotplug.
292
293choice
294	prompt "CPU Tuning"
295	default TUNE_GENERIC
296
297config TUNE_GENERIC
298	bool "generic"
299
300endchoice
301
302# Common NUMA Features
303config NUMA
304	bool "NUMA Memory Allocation and Scheduler Support"
305	depends on SMP && MMU
306	select GENERIC_ARCH_NUMA
307	select OF_NUMA
308	select ARCH_SUPPORTS_NUMA_BALANCING
309	help
310	  Enable NUMA (Non-Uniform Memory Access) support.
311
312	  The kernel will try to allocate memory used by a CPU on the
313	  local memory of the CPU and add some more NUMA awareness to the kernel.
314
315config NODES_SHIFT
316	int "Maximum NUMA Nodes (as a power of 2)"
317	range 1 10
318	default "2"
319	depends on NUMA
320	help
321	  Specify the maximum number of NUMA Nodes available on the target
322	  system.  Increases memory reserved to accommodate various tables.
323
324config USE_PERCPU_NUMA_NODE_ID
325	def_bool y
326	depends on NUMA
327
328config NEED_PER_CPU_EMBED_FIRST_CHUNK
329	def_bool y
330	depends on NUMA
331
332config RISCV_ISA_C
333	bool "Emit compressed instructions when building Linux"
334	default y
335	help
336	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
337	   when building Linux, which results in compressed instructions in the
338	   Linux binary.
339
340	   If you don't know what to do here, say Y.
341
342menu "supported PMU type"
343	depends on PERF_EVENTS
344
345config RISCV_BASE_PMU
346	bool "Base Performance Monitoring Unit"
347	def_bool y
348	help
349	  A base PMU that serves as a reference implementation and has limited
350	  feature of perf.  It can run on any RISC-V machines so serves as the
351	  fallback, but this option can also be disable to reduce kernel size.
352
353endmenu
354
355config FPU
356	bool "FPU support"
357	default y
358	help
359	  Say N here if you want to disable all floating-point related procedure
360	  in the kernel.
361
362	  If you don't know what to do here, say Y.
363
364endmenu
365
366menu "Kernel features"
367
368source "kernel/Kconfig.hz"
369
370config RISCV_SBI_V01
371	bool "SBI v0.1 support"
372	depends on RISCV_SBI
373	help
374	  This config allows kernel to use SBI v0.1 APIs. This will be
375	  deprecated in future once legacy M-mode software are no longer in use.
376
377config RISCV_BOOT_SPINWAIT
378	bool "Spinwait booting method"
379	depends on SMP
380	default y
381	help
382	  This enables support for booting Linux via spinwait method. In the
383	  spinwait method, all cores randomly jump to Linux. One of the cores
384	  gets chosen via lottery and all other keep spinning on a percpu
385	  variable. This method cannot support CPU hotplug and sparse hartid
386	  scheme. It should be only enabled for M-mode Linux or platforms relying
387	  on older firmware without SBI HSM extension. All other platforms should
388	  rely on ordered booting via SBI HSM extension which gets chosen
389	  dynamically at runtime if the firmware supports it.
390
391config KEXEC
392	bool "Kexec system call"
393	select KEXEC_CORE
394	select HOTPLUG_CPU if SMP
395	depends on MMU
396	help
397	  kexec is a system call that implements the ability to shutdown your
398	  current kernel, and to start another kernel. It is like a reboot
399	  but it is independent of the system firmware. And like a reboot
400	  you can start any kernel with it, not just Linux.
401
402	  The name comes from the similarity to the exec system call.
403
404config CRASH_DUMP
405	bool "Build kdump crash kernel"
406	help
407	  Generate crash dump after being started by kexec. This should
408	  be normally only set in special crash dump kernels which are
409	  loaded in the main kernel with kexec-tools into a specially
410	  reserved region and then later executed after a crash by
411	  kdump/kexec.
412
413	  For more details see Documentation/admin-guide/kdump/kdump.rst
414
415endmenu
416
417menu "Boot options"
418
419config CMDLINE
420	string "Built-in kernel command line"
421	help
422	  For most platforms, the arguments for the kernel's command line
423	  are provided at run-time, during boot. However, there are cases
424	  where either no arguments are being provided or the provided
425	  arguments are insufficient or even invalid.
426
427	  When that occurs, it is possible to define a built-in command
428	  line here and choose how the kernel should use it later on.
429
430choice
431	prompt "Built-in command line usage" if CMDLINE != ""
432	default CMDLINE_FALLBACK
433	help
434	  Choose how the kernel will handle the provided built-in command
435	  line.
436
437config CMDLINE_FALLBACK
438	bool "Use bootloader kernel arguments if available"
439	help
440	  Use the built-in command line as fallback in case we get nothing
441	  during boot. This is the default behaviour.
442
443config CMDLINE_EXTEND
444	bool "Extend bootloader kernel arguments"
445	help
446	  The command-line arguments provided during boot will be
447	  appended to the built-in command line. This is useful in
448	  cases where the provided arguments are insufficient and
449	  you don't want to or cannot modify them.
450
451
452config CMDLINE_FORCE
453	bool "Always use the default kernel command string"
454	help
455	  Always use the built-in command line, even if we get one during
456	  boot. This is useful in case you need to override the provided
457	  command line on systems where you don't have or want control
458	  over it.
459
460endchoice
461
462config EFI_STUB
463	bool
464
465config EFI
466	bool "UEFI runtime support"
467	depends on OF && !XIP_KERNEL
468	select LIBFDT
469	select UCS2_STRING
470	select EFI_PARAMS_FROM_FDT
471	select EFI_STUB
472	select EFI_GENERIC_STUB
473	select EFI_RUNTIME_WRAPPERS
474	select RISCV_ISA_C
475	depends on MMU
476	default y
477	help
478	  This option provides support for runtime services provided
479	  by UEFI firmware (such as non-volatile variables, realtime
480	  clock, and platform reset). A UEFI stub is also provided to
481	  allow the kernel to be booted as an EFI application. This
482	  is only useful on systems that have UEFI firmware.
483
484config CC_HAVE_STACKPROTECTOR_TLS
485	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
486
487config STACKPROTECTOR_PER_TASK
488	def_bool y
489	depends on !GCC_PLUGIN_RANDSTRUCT
490	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
491
492config PHYS_RAM_BASE_FIXED
493	bool "Explicitly specified physical RAM address"
494	default n
495
496config PHYS_RAM_BASE
497	hex "Platform Physical RAM address"
498	depends on PHYS_RAM_BASE_FIXED
499	default "0x80000000"
500	help
501	  This is the physical address of RAM in the system. It has to be
502	  explicitly specified to run early relocations of read-write data
503	  from flash to RAM.
504
505config XIP_KERNEL
506	bool "Kernel Execute-In-Place from ROM"
507	depends on MMU && SPARSEMEM
508	# This prevents XIP from being enabled by all{yes,mod}config, which
509	# fail to build since XIP doesn't support large kernels.
510	depends on !COMPILE_TEST
511	select PHYS_RAM_BASE_FIXED
512	help
513	  Execute-In-Place allows the kernel to run from non-volatile storage
514	  directly addressable by the CPU, such as NOR flash. This saves RAM
515	  space since the text section of the kernel is not loaded from flash
516	  to RAM.  Read-write sections, such as the data section and stack,
517	  are still copied to RAM.  The XIP kernel is not compressed since
518	  it has to run directly from flash, so it will take more space to
519	  store it.  The flash address used to link the kernel object files,
520	  and for storing it, is configuration dependent. Therefore, if you
521	  say Y here, you must know the proper physical address where to
522	  store the kernel image depending on your own flash memory usage.
523
524	  Also note that the make target becomes "make xipImage" rather than
525	  "make zImage" or "make Image".  The final kernel binary to put in
526	  ROM memory will be arch/riscv/boot/xipImage.
527
528	  SPARSEMEM is required because the kernel text and rodata that are
529	  flash resident are not backed by memmap, then any attempt to get
530	  a struct page on those regions will trigger a fault.
531
532	  If unsure, say N.
533
534config XIP_PHYS_ADDR
535	hex "XIP Kernel Physical Location"
536	depends on XIP_KERNEL
537	default "0x21000000"
538	help
539	  This is the physical address in your flash memory the kernel will
540	  be linked for and stored to.  This address is dependent on your
541	  own flash usage.
542
543endmenu
544
545config BUILTIN_DTB
546	bool
547	depends on OF
548	default y if XIP_KERNEL
549
550menu "Power management options"
551
552source "kernel/power/Kconfig"
553
554endmenu
555
556source "arch/riscv/kvm/Kconfig"
557