xref: /linux/arch/riscv/Kconfig (revision f1b744f65e2f9682347c5faf6377e61e2ab19a67)
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 VA_BITS
151	int
152	default 32 if 32BIT
153	default 39 if 64BIT
154
155config PA_BITS
156	int
157	default 34 if 32BIT
158	default 56 if 64BIT
159
160config PAGE_OFFSET
161	hex
162	default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB
163	default 0x80000000 if 64BIT && !MMU
164	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
165	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
166
167config KASAN_SHADOW_OFFSET
168	hex
169	depends on KASAN_GENERIC
170	default 0xdfffffc800000000 if 64BIT
171	default 0xffffffff if 32BIT
172
173config ARCH_FLATMEM_ENABLE
174	def_bool !NUMA
175
176config ARCH_SPARSEMEM_ENABLE
177	def_bool y
178	depends on MMU
179	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
180	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
181
182config ARCH_SELECT_MEMORY_MODEL
183	def_bool ARCH_SPARSEMEM_ENABLE
184
185config ARCH_WANT_GENERAL_HUGETLB
186	def_bool y
187
188config ARCH_SUPPORTS_UPROBES
189	def_bool y
190
191config STACKTRACE_SUPPORT
192	def_bool y
193
194config GENERIC_BUG
195	def_bool y
196	depends on BUG
197	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
198
199config GENERIC_BUG_RELATIVE_POINTERS
200	bool
201
202config GENERIC_CALIBRATE_DELAY
203	def_bool y
204
205config GENERIC_CSUM
206	def_bool y
207
208config GENERIC_HWEIGHT
209	def_bool y
210
211config FIX_EARLYCON_MEM
212	def_bool MMU
213
214config PGTABLE_LEVELS
215	int
216	default 3 if 64BIT
217	default 2
218
219config LOCKDEP_SUPPORT
220	def_bool y
221
222source "arch/riscv/Kconfig.socs"
223source "arch/riscv/Kconfig.erratas"
224
225menu "Platform type"
226
227choice
228	prompt "Base ISA"
229	default ARCH_RV64I
230	help
231	  This selects the base ISA that this kernel will target and must match
232	  the target platform.
233
234config ARCH_RV32I
235	bool "RV32I"
236	select 32BIT
237	select GENERIC_LIB_ASHLDI3
238	select GENERIC_LIB_ASHRDI3
239	select GENERIC_LIB_LSHRDI3
240	select GENERIC_LIB_UCMPDI2
241	select MMU
242
243config ARCH_RV64I
244	bool "RV64I"
245	select 64BIT
246	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
247	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
248	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
249	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
250	select HAVE_FUNCTION_GRAPH_TRACER
251	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
252	select SWIOTLB if MMU
253
254endchoice
255
256# We must be able to map all physical memory into the kernel, but the compiler
257# is still a bit more efficient when generating code if it's setup in a manner
258# such that it can only map 2GiB of memory.
259choice
260	prompt "Kernel Code Model"
261	default CMODEL_MEDLOW if 32BIT
262	default CMODEL_MEDANY if 64BIT
263
264	config CMODEL_MEDLOW
265		bool "medium low code model"
266	config CMODEL_MEDANY
267		bool "medium any code model"
268endchoice
269
270config MODULE_SECTIONS
271	bool
272	select HAVE_MOD_ARCH_SPECIFIC
273
274choice
275	prompt "Maximum Physical Memory"
276	default MAXPHYSMEM_1GB if 32BIT
277	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
278	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
279
280	config MAXPHYSMEM_1GB
281		depends on 32BIT
282		bool "1GiB"
283	config MAXPHYSMEM_2GB
284		depends on 64BIT
285		bool "2GiB"
286	config MAXPHYSMEM_128GB
287		depends on 64BIT && CMODEL_MEDANY
288		bool "128GiB"
289endchoice
290
291
292config SMP
293	bool "Symmetric Multi-Processing"
294	help
295	  This enables support for systems with more than one CPU.  If
296	  you say N here, the kernel will run on single and
297	  multiprocessor machines, but will use only one CPU of a
298	  multiprocessor machine. If you say Y here, the kernel will run
299	  on many, but not all, single processor machines. On a single
300	  processor machine, the kernel will run faster if you say N
301	  here.
302
303	  If you don't know what to do here, say N.
304
305config NR_CPUS
306	int "Maximum number of CPUs (2-32)"
307	range 2 32
308	depends on SMP
309	default "8"
310
311config HOTPLUG_CPU
312	bool "Support for hot-pluggable CPUs"
313	depends on SMP
314	select GENERIC_IRQ_MIGRATION
315	help
316
317	  Say Y here to experiment with turning CPUs off and on.  CPUs
318	  can be controlled through /sys/devices/system/cpu.
319
320	  Say N if you want to disable CPU hotplug.
321
322choice
323	prompt "CPU Tuning"
324	default TUNE_GENERIC
325
326config TUNE_GENERIC
327	bool "generic"
328
329endchoice
330
331# Common NUMA Features
332config NUMA
333	bool "NUMA Memory Allocation and Scheduler Support"
334	depends on SMP && MMU
335	select GENERIC_ARCH_NUMA
336	select OF_NUMA
337	select ARCH_SUPPORTS_NUMA_BALANCING
338	help
339	  Enable NUMA (Non-Uniform Memory Access) support.
340
341	  The kernel will try to allocate memory used by a CPU on the
342	  local memory of the CPU and add some more NUMA awareness to the kernel.
343
344config NODES_SHIFT
345	int "Maximum NUMA Nodes (as a power of 2)"
346	range 1 10
347	default "2"
348	depends on NUMA
349	help
350	  Specify the maximum number of NUMA Nodes available on the target
351	  system.  Increases memory reserved to accommodate various tables.
352
353config USE_PERCPU_NUMA_NODE_ID
354	def_bool y
355	depends on NUMA
356
357config NEED_PER_CPU_EMBED_FIRST_CHUNK
358	def_bool y
359	depends on NUMA
360
361config RISCV_ISA_C
362	bool "Emit compressed instructions when building Linux"
363	default y
364	help
365	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
366	   when building Linux, which results in compressed instructions in the
367	   Linux binary.
368
369	   If you don't know what to do here, say Y.
370
371menu "supported PMU type"
372	depends on PERF_EVENTS
373
374config RISCV_BASE_PMU
375	bool "Base Performance Monitoring Unit"
376	def_bool y
377	help
378	  A base PMU that serves as a reference implementation and has limited
379	  feature of perf.  It can run on any RISC-V machines so serves as the
380	  fallback, but this option can also be disable to reduce kernel size.
381
382endmenu
383
384config FPU
385	bool "FPU support"
386	default y
387	help
388	  Say N here if you want to disable all floating-point related procedure
389	  in the kernel.
390
391	  If you don't know what to do here, say Y.
392
393endmenu
394
395menu "Kernel features"
396
397source "kernel/Kconfig.hz"
398
399config RISCV_SBI_V01
400	bool "SBI v0.1 support"
401	default y
402	depends on RISCV_SBI
403	help
404	  This config allows kernel to use SBI v0.1 APIs. This will be
405	  deprecated in future once legacy M-mode software are no longer in use.
406
407config KEXEC
408	bool "Kexec system call"
409	select KEXEC_CORE
410	select HOTPLUG_CPU if SMP
411	depends on MMU
412	help
413	  kexec is a system call that implements the ability to shutdown your
414	  current kernel, and to start another kernel. It is like a reboot
415	  but it is independent of the system firmware. And like a reboot
416	  you can start any kernel with it, not just Linux.
417
418	  The name comes from the similarity to the exec system call.
419
420config CRASH_DUMP
421	bool "Build kdump crash kernel"
422	help
423	  Generate crash dump after being started by kexec. This should
424	  be normally only set in special crash dump kernels which are
425	  loaded in the main kernel with kexec-tools into a specially
426	  reserved region and then later executed after a crash by
427	  kdump/kexec.
428
429	  For more details see Documentation/admin-guide/kdump/kdump.rst
430
431endmenu
432
433menu "Boot options"
434
435config CMDLINE
436	string "Built-in kernel command line"
437	help
438	  For most platforms, the arguments for the kernel's command line
439	  are provided at run-time, during boot. However, there are cases
440	  where either no arguments are being provided or the provided
441	  arguments are insufficient or even invalid.
442
443	  When that occurs, it is possible to define a built-in command
444	  line here and choose how the kernel should use it later on.
445
446choice
447	prompt "Built-in command line usage" if CMDLINE != ""
448	default CMDLINE_FALLBACK
449	help
450	  Choose how the kernel will handle the provided built-in command
451	  line.
452
453config CMDLINE_FALLBACK
454	bool "Use bootloader kernel arguments if available"
455	help
456	  Use the built-in command line as fallback in case we get nothing
457	  during boot. This is the default behaviour.
458
459config CMDLINE_EXTEND
460	bool "Extend bootloader kernel arguments"
461	help
462	  The command-line arguments provided during boot will be
463	  appended to the built-in command line. This is useful in
464	  cases where the provided arguments are insufficient and
465	  you don't want to or cannot modify them.
466
467
468config CMDLINE_FORCE
469	bool "Always use the default kernel command string"
470	help
471	  Always use the built-in command line, even if we get one during
472	  boot. This is useful in case you need to override the provided
473	  command line on systems where you don't have or want control
474	  over it.
475
476endchoice
477
478config EFI_STUB
479	bool
480
481config EFI
482	bool "UEFI runtime support"
483	depends on OF && !XIP_KERNEL
484	select LIBFDT
485	select UCS2_STRING
486	select EFI_PARAMS_FROM_FDT
487	select EFI_STUB
488	select EFI_GENERIC_STUB
489	select EFI_RUNTIME_WRAPPERS
490	select RISCV_ISA_C
491	depends on MMU
492	default y
493	help
494	  This option provides support for runtime services provided
495	  by UEFI firmware (such as non-volatile variables, realtime
496	  clock, and platform reset). A UEFI stub is also provided to
497	  allow the kernel to be booted as an EFI application. This
498	  is only useful on systems that have UEFI firmware.
499
500config CC_HAVE_STACKPROTECTOR_TLS
501	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
502
503config STACKPROTECTOR_PER_TASK
504	def_bool y
505	depends on !GCC_PLUGIN_RANDSTRUCT
506	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
507
508config PHYS_RAM_BASE_FIXED
509	bool "Explicitly specified physical RAM address"
510	default n
511
512config PHYS_RAM_BASE
513	hex "Platform Physical RAM address"
514	depends on PHYS_RAM_BASE_FIXED
515	default "0x80000000"
516	help
517	  This is the physical address of RAM in the system. It has to be
518	  explicitly specified to run early relocations of read-write data
519	  from flash to RAM.
520
521config XIP_KERNEL
522	bool "Kernel Execute-In-Place from ROM"
523	depends on MMU && SPARSEMEM
524	# This prevents XIP from being enabled by all{yes,mod}config, which
525	# fail to build since XIP doesn't support large kernels.
526	depends on !COMPILE_TEST
527	select PHYS_RAM_BASE_FIXED
528	help
529	  Execute-In-Place allows the kernel to run from non-volatile storage
530	  directly addressable by the CPU, such as NOR flash. This saves RAM
531	  space since the text section of the kernel is not loaded from flash
532	  to RAM.  Read-write sections, such as the data section and stack,
533	  are still copied to RAM.  The XIP kernel is not compressed since
534	  it has to run directly from flash, so it will take more space to
535	  store it.  The flash address used to link the kernel object files,
536	  and for storing it, is configuration dependent. Therefore, if you
537	  say Y here, you must know the proper physical address where to
538	  store the kernel image depending on your own flash memory usage.
539
540	  Also note that the make target becomes "make xipImage" rather than
541	  "make zImage" or "make Image".  The final kernel binary to put in
542	  ROM memory will be arch/riscv/boot/xipImage.
543
544	  SPARSEMEM is required because the kernel text and rodata that are
545	  flash resident are not backed by memmap, then any attempt to get
546	  a struct page on those regions will trigger a fault.
547
548	  If unsure, say N.
549
550config XIP_PHYS_ADDR
551	hex "XIP Kernel Physical Location"
552	depends on XIP_KERNEL
553	default "0x21000000"
554	help
555	  This is the physical address in your flash memory the kernel will
556	  be linked for and stored to.  This address is dependent on your
557	  own flash usage.
558
559endmenu
560
561config BUILTIN_DTB
562	bool
563	depends on OF
564	default y if XIP_KERNEL
565
566menu "Power management options"
567
568source "kernel/power/Kconfig"
569
570endmenu
571
572source "arch/riscv/kvm/Kconfig"
573