xref: /linux/arch/riscv/Kconfig (revision e0c1b49f5b674cca7b10549c53b3791d0bbc90a8)
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_HAS_BINFMT_FLAT
18	select ARCH_HAS_DEBUG_VM_PGTABLE
19	select ARCH_HAS_DEBUG_VIRTUAL if MMU
20	select ARCH_HAS_DEBUG_WX
21	select ARCH_HAS_FORTIFY_SOURCE
22	select ARCH_HAS_GCOV_PROFILE_ALL
23	select ARCH_HAS_GIGANTIC_PAGE
24	select ARCH_HAS_KCOV
25	select ARCH_HAS_MMIOWB
26	select ARCH_HAS_PTE_SPECIAL
27	select ARCH_HAS_SET_DIRECT_MAP if MMU
28	select ARCH_HAS_SET_MEMORY if MMU
29	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
30	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
31	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
32	select ARCH_HAS_UBSAN_SANITIZE_ALL
33	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
34	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
35	select ARCH_STACKWALK
36	select ARCH_SUPPORTS_ATOMIC_RMW
37	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
38	select ARCH_SUPPORTS_HUGETLBFS if MMU
39	select ARCH_USE_MEMTEST
40	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
41	select ARCH_WANT_FRAME_POINTERS
42	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
43	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
44	select BUILDTIME_TABLE_SORT if MMU
45	select CLONE_BACKWARDS
46	select CLINT_TIMER if !MMU
47	select COMMON_CLK
48	select EDAC_SUPPORT
49	select GENERIC_ARCH_TOPOLOGY if SMP
50	select GENERIC_ATOMIC64 if !64BIT
51	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
52	select GENERIC_EARLY_IOREMAP
53	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
54	select GENERIC_IDLE_POLL_SETUP
55	select GENERIC_IOREMAP if MMU
56	select GENERIC_IRQ_MULTI_HANDLER
57	select GENERIC_IRQ_SHOW
58	select GENERIC_IRQ_SHOW_LEVEL
59	select GENERIC_LIB_DEVMEM_IS_ALLOWED
60	select GENERIC_PCI_IOMAP
61	select GENERIC_PTDUMP if MMU
62	select GENERIC_SCHED_CLOCK
63	select GENERIC_SMP_IDLE_THREAD
64	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
65	select HAVE_ARCH_AUDITSYSCALL
66	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
67	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
68	select HAVE_ARCH_KASAN if MMU && 64BIT
69	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
70	select HAVE_ARCH_KFENCE if MMU && 64BIT
71	select HAVE_ARCH_KGDB if !XIP_KERNEL
72	select HAVE_ARCH_KGDB_QXFER_PKT
73	select HAVE_ARCH_MMAP_RND_BITS if MMU
74	select HAVE_ARCH_SECCOMP_FILTER
75	select HAVE_ARCH_TRACEHOOK
76	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
77	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
78	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
79	select HAVE_ASM_MODVERSIONS
80	select HAVE_CONTEXT_TRACKING
81	select HAVE_DEBUG_KMEMLEAK
82	select HAVE_DMA_CONTIGUOUS if MMU
83	select HAVE_EBPF_JIT if MMU
84	select HAVE_FUNCTION_ERROR_INJECTION
85	select HAVE_FUTEX_CMPXCHG if FUTEX
86	select HAVE_GCC_PLUGINS
87	select HAVE_GENERIC_VDSO if MMU && 64BIT
88	select HAVE_IRQ_TIME_ACCOUNTING
89	select HAVE_KPROBES if !XIP_KERNEL
90	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
91	select HAVE_KRETPROBES if !XIP_KERNEL
92	select HAVE_MOVE_PMD
93	select HAVE_MOVE_PUD
94	select HAVE_PCI
95	select HAVE_PERF_EVENTS
96	select HAVE_PERF_REGS
97	select HAVE_PERF_USER_STACK_DUMP
98	select HAVE_REGS_AND_STACK_ACCESS_API
99	select HAVE_FUNCTION_ARG_ACCESS_API
100	select HAVE_STACKPROTECTOR
101	select HAVE_SYSCALL_TRACEPOINTS
102	select IRQ_DOMAIN
103	select IRQ_FORCED_THREADING
104	select MODULES_USE_ELF_RELA if MODULES
105	select MODULE_SECTIONS if MODULES
106	select OF
107	select OF_EARLY_FLATTREE
108	select OF_IRQ
109	select PCI_DOMAINS_GENERIC if PCI
110	select PCI_MSI if PCI
111	select RISCV_INTC
112	select RISCV_TIMER if RISCV_SBI
113	select SPARSE_IRQ
114	select SYSCTL_EXCEPTION_TRACE
115	select THREAD_INFO_IN_TASK
116	select TRACE_IRQFLAGS_SUPPORT
117	select UACCESS_MEMCPY if !MMU
118	select ZONE_DMA32 if 64BIT
119
120config ARCH_MMAP_RND_BITS_MIN
121	default 18 if 64BIT
122	default 8
123
124# max bits determined by the following formula:
125#  VA_BITS - PAGE_SHIFT - 3
126config ARCH_MMAP_RND_BITS_MAX
127	default 24 if 64BIT # SV39 based
128	default 17
129
130# set if we run in machine mode, cleared if we run in supervisor mode
131config RISCV_M_MODE
132	bool
133	default !MMU
134
135# set if we are running in S-mode and can use SBI calls
136config RISCV_SBI
137	bool
138	depends on !RISCV_M_MODE
139	default y
140
141config MMU
142	bool "MMU-based Paged Memory Management Support"
143	default y
144	help
145	  Select if you want MMU-based virtualised addressing space
146	  support by paged memory management. If unsure, say 'Y'.
147
148config VA_BITS
149	int
150	default 32 if 32BIT
151	default 39 if 64BIT
152
153config PA_BITS
154	int
155	default 34 if 32BIT
156	default 56 if 64BIT
157
158config PAGE_OFFSET
159	hex
160	default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB
161	default 0x80000000 if 64BIT && !MMU
162	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
163	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
164
165config KASAN_SHADOW_OFFSET
166	hex
167	depends on KASAN_GENERIC
168	default 0xdfffffc800000000 if 64BIT
169	default 0xffffffff if 32BIT
170
171config ARCH_FLATMEM_ENABLE
172	def_bool !NUMA
173
174config ARCH_SPARSEMEM_ENABLE
175	def_bool y
176	depends on MMU
177	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
178	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
179
180config ARCH_SELECT_MEMORY_MODEL
181	def_bool ARCH_SPARSEMEM_ENABLE
182
183config ARCH_WANT_GENERAL_HUGETLB
184	def_bool y
185
186config ARCH_SUPPORTS_UPROBES
187	def_bool y
188
189config STACKTRACE_SUPPORT
190	def_bool y
191
192config GENERIC_BUG
193	def_bool y
194	depends on BUG
195	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
196
197config GENERIC_BUG_RELATIVE_POINTERS
198	bool
199
200config GENERIC_CALIBRATE_DELAY
201	def_bool y
202
203config GENERIC_CSUM
204	def_bool y
205
206config GENERIC_HWEIGHT
207	def_bool y
208
209config FIX_EARLYCON_MEM
210	def_bool MMU
211
212config PGTABLE_LEVELS
213	int
214	default 3 if 64BIT
215	default 2
216
217config LOCKDEP_SUPPORT
218	def_bool y
219
220source "arch/riscv/Kconfig.socs"
221source "arch/riscv/Kconfig.erratas"
222
223menu "Platform type"
224
225choice
226	prompt "Base ISA"
227	default ARCH_RV64I
228	help
229	  This selects the base ISA that this kernel will target and must match
230	  the target platform.
231
232config ARCH_RV32I
233	bool "RV32I"
234	select 32BIT
235	select GENERIC_LIB_ASHLDI3
236	select GENERIC_LIB_ASHRDI3
237	select GENERIC_LIB_LSHRDI3
238	select GENERIC_LIB_UCMPDI2
239	select MMU
240
241config ARCH_RV64I
242	bool "RV64I"
243	select 64BIT
244	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
245	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
246	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
247	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
248	select HAVE_FUNCTION_GRAPH_TRACER
249	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
250	select SWIOTLB if MMU
251
252endchoice
253
254# We must be able to map all physical memory into the kernel, but the compiler
255# is still a bit more efficient when generating code if it's setup in a manner
256# such that it can only map 2GiB of memory.
257choice
258	prompt "Kernel Code Model"
259	default CMODEL_MEDLOW if 32BIT
260	default CMODEL_MEDANY if 64BIT
261
262	config CMODEL_MEDLOW
263		bool "medium low code model"
264	config CMODEL_MEDANY
265		bool "medium any code model"
266endchoice
267
268config MODULE_SECTIONS
269	bool
270	select HAVE_MOD_ARCH_SPECIFIC
271
272choice
273	prompt "Maximum Physical Memory"
274	default MAXPHYSMEM_1GB if 32BIT
275	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
276	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
277
278	config MAXPHYSMEM_1GB
279		depends on 32BIT
280		bool "1GiB"
281	config MAXPHYSMEM_2GB
282		depends on 64BIT && CMODEL_MEDLOW
283		bool "2GiB"
284	config MAXPHYSMEM_128GB
285		depends on 64BIT && CMODEL_MEDANY
286		bool "128GiB"
287endchoice
288
289
290config SMP
291	bool "Symmetric Multi-Processing"
292	help
293	  This enables support for systems with more than one CPU.  If
294	  you say N here, the kernel will run on single and
295	  multiprocessor machines, but will use only one CPU of a
296	  multiprocessor machine. If you say Y here, the kernel will run
297	  on many, but not all, single processor machines. On a single
298	  processor machine, the kernel will run faster if you say N
299	  here.
300
301	  If you don't know what to do here, say N.
302
303config NR_CPUS
304	int "Maximum number of CPUs (2-32)"
305	range 2 32
306	depends on SMP
307	default "8"
308
309config HOTPLUG_CPU
310	bool "Support for hot-pluggable CPUs"
311	depends on SMP
312	select GENERIC_IRQ_MIGRATION
313	help
314
315	  Say Y here to experiment with turning CPUs off and on.  CPUs
316	  can be controlled through /sys/devices/system/cpu.
317
318	  Say N if you want to disable CPU hotplug.
319
320choice
321	prompt "CPU Tuning"
322	default TUNE_GENERIC
323
324config TUNE_GENERIC
325	bool "generic"
326
327endchoice
328
329# Common NUMA Features
330config NUMA
331	bool "NUMA Memory Allocation and Scheduler Support"
332	depends on SMP && MMU
333	select GENERIC_ARCH_NUMA
334	select OF_NUMA
335	select ARCH_SUPPORTS_NUMA_BALANCING
336	help
337	  Enable NUMA (Non-Uniform Memory Access) support.
338
339	  The kernel will try to allocate memory used by a CPU on the
340	  local memory of the CPU and add some more NUMA awareness to the kernel.
341
342config NODES_SHIFT
343	int "Maximum NUMA Nodes (as a power of 2)"
344	range 1 10
345	default "2"
346	depends on NUMA
347	help
348	  Specify the maximum number of NUMA Nodes available on the target
349	  system.  Increases memory reserved to accommodate various tables.
350
351config USE_PERCPU_NUMA_NODE_ID
352	def_bool y
353	depends on NUMA
354
355config NEED_PER_CPU_EMBED_FIRST_CHUNK
356	def_bool y
357	depends on NUMA
358
359config RISCV_ISA_C
360	bool "Emit compressed instructions when building Linux"
361	default y
362	help
363	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
364	   when building Linux, which results in compressed instructions in the
365	   Linux binary.
366
367	   If you don't know what to do here, say Y.
368
369menu "supported PMU type"
370	depends on PERF_EVENTS
371
372config RISCV_BASE_PMU
373	bool "Base Performance Monitoring Unit"
374	def_bool y
375	help
376	  A base PMU that serves as a reference implementation and has limited
377	  feature of perf.  It can run on any RISC-V machines so serves as the
378	  fallback, but this option can also be disable to reduce kernel size.
379
380endmenu
381
382config FPU
383	bool "FPU support"
384	default y
385	help
386	  Say N here if you want to disable all floating-point related procedure
387	  in the kernel.
388
389	  If you don't know what to do here, say Y.
390
391endmenu
392
393menu "Kernel features"
394
395source "kernel/Kconfig.hz"
396
397config RISCV_SBI_V01
398	bool "SBI v0.1 support"
399	default y
400	depends on RISCV_SBI
401	help
402	  This config allows kernel to use SBI v0.1 APIs. This will be
403	  deprecated in future once legacy M-mode software are no longer in use.
404
405config KEXEC
406	bool "Kexec system call"
407	select KEXEC_CORE
408	select HOTPLUG_CPU if SMP
409	depends on MMU
410	help
411	  kexec is a system call that implements the ability to shutdown your
412	  current kernel, and to start another kernel. It is like a reboot
413	  but it is independent of the system firmware. And like a reboot
414	  you can start any kernel with it, not just Linux.
415
416	  The name comes from the similarity to the exec system call.
417
418config CRASH_DUMP
419	bool "Build kdump crash kernel"
420	help
421	  Generate crash dump after being started by kexec. This should
422	  be normally only set in special crash dump kernels which are
423	  loaded in the main kernel with kexec-tools into a specially
424	  reserved region and then later executed after a crash by
425	  kdump/kexec.
426
427	  For more details see Documentation/admin-guide/kdump/kdump.rst
428
429endmenu
430
431menu "Boot options"
432
433config CMDLINE
434	string "Built-in kernel command line"
435	help
436	  For most platforms, the arguments for the kernel's command line
437	  are provided at run-time, during boot. However, there are cases
438	  where either no arguments are being provided or the provided
439	  arguments are insufficient or even invalid.
440
441	  When that occurs, it is possible to define a built-in command
442	  line here and choose how the kernel should use it later on.
443
444choice
445	prompt "Built-in command line usage" if CMDLINE != ""
446	default CMDLINE_FALLBACK
447	help
448	  Choose how the kernel will handle the provided built-in command
449	  line.
450
451config CMDLINE_FALLBACK
452	bool "Use bootloader kernel arguments if available"
453	help
454	  Use the built-in command line as fallback in case we get nothing
455	  during boot. This is the default behaviour.
456
457config CMDLINE_EXTEND
458	bool "Extend bootloader kernel arguments"
459	help
460	  The command-line arguments provided during boot will be
461	  appended to the built-in command line. This is useful in
462	  cases where the provided arguments are insufficient and
463	  you don't want to or cannot modify them.
464
465
466config CMDLINE_FORCE
467	bool "Always use the default kernel command string"
468	help
469	  Always use the built-in command line, even if we get one during
470	  boot. This is useful in case you need to override the provided
471	  command line on systems where you don't have or want control
472	  over it.
473
474endchoice
475
476config EFI_STUB
477	bool
478
479config EFI
480	bool "UEFI runtime support"
481	depends on OF && !XIP_KERNEL
482	select LIBFDT
483	select UCS2_STRING
484	select EFI_PARAMS_FROM_FDT
485	select EFI_STUB
486	select EFI_GENERIC_STUB
487	select EFI_RUNTIME_WRAPPERS
488	select RISCV_ISA_C
489	depends on MMU
490	default y
491	help
492	  This option provides support for runtime services provided
493	  by UEFI firmware (such as non-volatile variables, realtime
494	  clock, and platform reset). A UEFI stub is also provided to
495	  allow the kernel to be booted as an EFI application. This
496	  is only useful on systems that have UEFI firmware.
497
498config CC_HAVE_STACKPROTECTOR_TLS
499	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
500
501config STACKPROTECTOR_PER_TASK
502	def_bool y
503	depends on !GCC_PLUGIN_RANDSTRUCT
504	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
505
506config PHYS_RAM_BASE_FIXED
507	bool "Explicitly specified physical RAM address"
508	default n
509
510config PHYS_RAM_BASE
511	hex "Platform Physical RAM address"
512	depends on PHYS_RAM_BASE_FIXED
513	default "0x80000000"
514	help
515	  This is the physical address of RAM in the system. It has to be
516	  explicitly specified to run early relocations of read-write data
517	  from flash to RAM.
518
519config XIP_KERNEL
520	bool "Kernel Execute-In-Place from ROM"
521	depends on MMU && SPARSEMEM
522	# This prevents XIP from being enabled by all{yes,mod}config, which
523	# fail to build since XIP doesn't support large kernels.
524	depends on !COMPILE_TEST
525	select PHYS_RAM_BASE_FIXED
526	help
527	  Execute-In-Place allows the kernel to run from non-volatile storage
528	  directly addressable by the CPU, such as NOR flash. This saves RAM
529	  space since the text section of the kernel is not loaded from flash
530	  to RAM.  Read-write sections, such as the data section and stack,
531	  are still copied to RAM.  The XIP kernel is not compressed since
532	  it has to run directly from flash, so it will take more space to
533	  store it.  The flash address used to link the kernel object files,
534	  and for storing it, is configuration dependent. Therefore, if you
535	  say Y here, you must know the proper physical address where to
536	  store the kernel image depending on your own flash memory usage.
537
538	  Also note that the make target becomes "make xipImage" rather than
539	  "make zImage" or "make Image".  The final kernel binary to put in
540	  ROM memory will be arch/riscv/boot/xipImage.
541
542	  SPARSEMEM is required because the kernel text and rodata that are
543	  flash resident are not backed by memmap, then any attempt to get
544	  a struct page on those regions will trigger a fault.
545
546	  If unsure, say N.
547
548config XIP_PHYS_ADDR
549	hex "XIP Kernel Physical Location"
550	depends on XIP_KERNEL
551	default "0x21000000"
552	help
553	  This is the physical address in your flash memory the kernel will
554	  be linked for and stored to.  This address is dependent on your
555	  own flash usage.
556
557endmenu
558
559config BUILTIN_DTB
560	bool
561	depends on OF
562	default y if XIP_KERNEL
563
564menu "Power management options"
565
566source "kernel/power/Kconfig"
567
568endmenu
569
570source "arch/riscv/kvm/Kconfig"
571