xref: /linux/arch/riscv/Kconfig (revision 9dbbc3b9d09d6deba9f3b9e1d5b355032ed46a75)
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_SUPPORTS_ATOMIC_RMW
17	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
18	select ARCH_STACKWALK
19	select ARCH_HAS_BINFMT_FLAT
20	select ARCH_HAS_DEBUG_VM_PGTABLE
21	select ARCH_HAS_DEBUG_VIRTUAL if MMU
22	select ARCH_HAS_DEBUG_WX
23	select ARCH_HAS_FORTIFY_SOURCE
24	select ARCH_HAS_GCOV_PROFILE_ALL
25	select ARCH_HAS_GIGANTIC_PAGE
26	select ARCH_HAS_KCOV
27	select ARCH_HAS_MMIOWB
28	select ARCH_HAS_PTE_SPECIAL
29	select ARCH_HAS_SET_DIRECT_MAP
30	select ARCH_HAS_SET_MEMORY
31	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
32	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
33	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
34	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
35	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
36	select ARCH_SUPPORTS_HUGETLBFS if MMU
37	select ARCH_USE_MEMTEST
38	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
39	select ARCH_WANT_FRAME_POINTERS
40	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
41	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
42	select CLONE_BACKWARDS
43	select CLINT_TIMER if !MMU
44	select COMMON_CLK
45	select EDAC_SUPPORT
46	select GENERIC_ARCH_TOPOLOGY if SMP
47	select GENERIC_ATOMIC64 if !64BIT
48	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
49	select GENERIC_EARLY_IOREMAP
50	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
51	select GENERIC_IOREMAP
52	select GENERIC_IRQ_MULTI_HANDLER
53	select GENERIC_IRQ_SHOW
54	select GENERIC_LIB_DEVMEM_IS_ALLOWED
55	select GENERIC_PCI_IOMAP
56	select GENERIC_PTDUMP if MMU
57	select GENERIC_SCHED_CLOCK
58	select GENERIC_SMP_IDLE_THREAD
59	select GENERIC_STRNCPY_FROM_USER if MMU
60	select GENERIC_STRNLEN_USER if MMU
61	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
62	select HANDLE_DOMAIN_IRQ
63	select HAVE_ARCH_AUDITSYSCALL
64	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
65	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
66	select HAVE_ARCH_KASAN if MMU && 64BIT
67	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
68	select HAVE_ARCH_KGDB if !XIP_KERNEL
69	select HAVE_ARCH_KGDB_QXFER_PKT
70	select HAVE_ARCH_MMAP_RND_BITS if MMU
71	select HAVE_ARCH_SECCOMP_FILTER
72	select HAVE_ARCH_TRACEHOOK
73	select HAVE_ASM_MODVERSIONS
74	select HAVE_CONTEXT_TRACKING
75	select HAVE_DEBUG_KMEMLEAK
76	select HAVE_DMA_CONTIGUOUS if MMU
77	select HAVE_EBPF_JIT if MMU
78	select HAVE_FUNCTION_ERROR_INJECTION
79	select HAVE_FUTEX_CMPXCHG if FUTEX
80	select HAVE_GCC_PLUGINS
81	select HAVE_GENERIC_VDSO if MMU && 64BIT
82	select HAVE_IRQ_TIME_ACCOUNTING
83	select HAVE_KPROBES if !XIP_KERNEL
84	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
85	select HAVE_KRETPROBES if !XIP_KERNEL
86	select HAVE_PCI
87	select HAVE_PERF_EVENTS
88	select HAVE_PERF_REGS
89	select HAVE_PERF_USER_STACK_DUMP
90	select HAVE_REGS_AND_STACK_ACCESS_API
91	select HAVE_STACKPROTECTOR
92	select HAVE_SYSCALL_TRACEPOINTS
93	select IRQ_DOMAIN
94	select MODULES_USE_ELF_RELA if MODULES
95	select MODULE_SECTIONS if MODULES
96	select OF
97	select OF_EARLY_FLATTREE
98	select OF_IRQ
99	select PCI_DOMAINS_GENERIC if PCI
100	select PCI_MSI if PCI
101	select RISCV_INTC
102	select RISCV_TIMER if RISCV_SBI
103	select SPARSE_IRQ
104	select SYSCTL_EXCEPTION_TRACE
105	select THREAD_INFO_IN_TASK
106	select UACCESS_MEMCPY if !MMU
107	select ZONE_DMA32 if 64BIT
108
109config ARCH_MMAP_RND_BITS_MIN
110	default 18 if 64BIT
111	default 8
112
113# max bits determined by the following formula:
114#  VA_BITS - PAGE_SHIFT - 3
115config ARCH_MMAP_RND_BITS_MAX
116	default 24 if 64BIT # SV39 based
117	default 17
118
119# set if we run in machine mode, cleared if we run in supervisor mode
120config RISCV_M_MODE
121	bool
122	default !MMU
123
124# set if we are running in S-mode and can use SBI calls
125config RISCV_SBI
126	bool
127	depends on !RISCV_M_MODE
128	default y
129
130config MMU
131	bool "MMU-based Paged Memory Management Support"
132	default y
133	help
134	  Select if you want MMU-based virtualised addressing space
135	  support by paged memory management. If unsure, say 'Y'.
136
137config VA_BITS
138	int
139	default 32 if 32BIT
140	default 39 if 64BIT
141
142config PA_BITS
143	int
144	default 34 if 32BIT
145	default 56 if 64BIT
146
147config PAGE_OFFSET
148	hex
149	default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB
150	default 0x80000000 if 64BIT && !MMU
151	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
152	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
153
154config ARCH_FLATMEM_ENABLE
155	def_bool !NUMA
156
157config ARCH_SPARSEMEM_ENABLE
158	def_bool y
159	depends on MMU
160	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
161	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
162
163config ARCH_SELECT_MEMORY_MODEL
164	def_bool ARCH_SPARSEMEM_ENABLE
165
166config ARCH_WANT_GENERAL_HUGETLB
167	def_bool y
168
169config ARCH_SUPPORTS_UPROBES
170	def_bool y
171
172config STACKTRACE_SUPPORT
173	def_bool y
174
175config TRACE_IRQFLAGS_SUPPORT
176	def_bool y
177
178config GENERIC_BUG
179	def_bool y
180	depends on BUG
181	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
182
183config GENERIC_BUG_RELATIVE_POINTERS
184	bool
185
186config GENERIC_CALIBRATE_DELAY
187	def_bool y
188
189config GENERIC_CSUM
190	def_bool y
191
192config GENERIC_HWEIGHT
193	def_bool y
194
195config FIX_EARLYCON_MEM
196	def_bool MMU
197
198config PGTABLE_LEVELS
199	int
200	default 3 if 64BIT
201	default 2
202
203config LOCKDEP_SUPPORT
204	def_bool y
205
206source "arch/riscv/Kconfig.socs"
207source "arch/riscv/Kconfig.erratas"
208
209menu "Platform type"
210
211choice
212	prompt "Base ISA"
213	default ARCH_RV64I
214	help
215	  This selects the base ISA that this kernel will target and must match
216	  the target platform.
217
218config ARCH_RV32I
219	bool "RV32I"
220	select 32BIT
221	select GENERIC_LIB_ASHLDI3
222	select GENERIC_LIB_ASHRDI3
223	select GENERIC_LIB_LSHRDI3
224	select GENERIC_LIB_UCMPDI2
225	select MMU
226
227config ARCH_RV64I
228	bool "RV64I"
229	select 64BIT
230	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
231	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
232	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
233	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
234	select HAVE_FUNCTION_GRAPH_TRACER
235	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
236	select SWIOTLB if MMU
237
238endchoice
239
240# We must be able to map all physical memory into the kernel, but the compiler
241# is still a bit more efficient when generating code if it's setup in a manner
242# such that it can only map 2GiB of memory.
243choice
244	prompt "Kernel Code Model"
245	default CMODEL_MEDLOW if 32BIT
246	default CMODEL_MEDANY if 64BIT
247
248	config CMODEL_MEDLOW
249		bool "medium low code model"
250	config CMODEL_MEDANY
251		bool "medium any code model"
252endchoice
253
254config MODULE_SECTIONS
255	bool
256	select HAVE_MOD_ARCH_SPECIFIC
257
258choice
259	prompt "Maximum Physical Memory"
260	default MAXPHYSMEM_1GB if 32BIT
261	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
262	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
263
264	config MAXPHYSMEM_1GB
265		depends on 32BIT
266		bool "1GiB"
267	config MAXPHYSMEM_2GB
268		depends on 64BIT && CMODEL_MEDLOW
269		bool "2GiB"
270	config MAXPHYSMEM_128GB
271		depends on 64BIT && CMODEL_MEDANY
272		bool "128GiB"
273endchoice
274
275
276config SMP
277	bool "Symmetric Multi-Processing"
278	help
279	  This enables support for systems with more than one CPU.  If
280	  you say N here, the kernel will run on single and
281	  multiprocessor machines, but will use only one CPU of a
282	  multiprocessor machine. If you say Y here, the kernel will run
283	  on many, but not all, single processor machines. On a single
284	  processor machine, the kernel will run faster if you say N
285	  here.
286
287	  If you don't know what to do here, say N.
288
289config NR_CPUS
290	int "Maximum number of CPUs (2-32)"
291	range 2 32
292	depends on SMP
293	default "8"
294
295config HOTPLUG_CPU
296	bool "Support for hot-pluggable CPUs"
297	depends on SMP
298	select GENERIC_IRQ_MIGRATION
299	help
300
301	  Say Y here to experiment with turning CPUs off and on.  CPUs
302	  can be controlled through /sys/devices/system/cpu.
303
304	  Say N if you want to disable CPU hotplug.
305
306choice
307	prompt "CPU Tuning"
308	default TUNE_GENERIC
309
310config TUNE_GENERIC
311	bool "generic"
312
313endchoice
314
315# Common NUMA Features
316config NUMA
317	bool "NUMA Memory Allocation and Scheduler Support"
318	depends on SMP && MMU
319	select GENERIC_ARCH_NUMA
320	select OF_NUMA
321	select ARCH_SUPPORTS_NUMA_BALANCING
322	help
323	  Enable NUMA (Non-Uniform Memory Access) support.
324
325	  The kernel will try to allocate memory used by a CPU on the
326	  local memory of the CPU and add some more NUMA awareness to the kernel.
327
328config NODES_SHIFT
329	int "Maximum NUMA Nodes (as a power of 2)"
330	range 1 10
331	default "2"
332	depends on NUMA
333	help
334	  Specify the maximum number of NUMA Nodes available on the target
335	  system.  Increases memory reserved to accommodate various tables.
336
337config USE_PERCPU_NUMA_NODE_ID
338	def_bool y
339	depends on NUMA
340
341config NEED_PER_CPU_EMBED_FIRST_CHUNK
342	def_bool y
343	depends on NUMA
344
345config RISCV_ISA_C
346	bool "Emit compressed instructions when building Linux"
347	default y
348	help
349	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
350	   when building Linux, which results in compressed instructions in the
351	   Linux binary.
352
353	   If you don't know what to do here, say Y.
354
355menu "supported PMU type"
356	depends on PERF_EVENTS
357
358config RISCV_BASE_PMU
359	bool "Base Performance Monitoring Unit"
360	def_bool y
361	help
362	  A base PMU that serves as a reference implementation and has limited
363	  feature of perf.  It can run on any RISC-V machines so serves as the
364	  fallback, but this option can also be disable to reduce kernel size.
365
366endmenu
367
368config FPU
369	bool "FPU support"
370	default y
371	help
372	  Say N here if you want to disable all floating-point related procedure
373	  in the kernel.
374
375	  If you don't know what to do here, say Y.
376
377endmenu
378
379menu "Kernel features"
380
381source "kernel/Kconfig.hz"
382
383config RISCV_SBI_V01
384	bool "SBI v0.1 support"
385	default y
386	depends on RISCV_SBI
387	help
388	  This config allows kernel to use SBI v0.1 APIs. This will be
389	  deprecated in future once legacy M-mode software are no longer in use.
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 STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
490
491config PHYS_RAM_BASE_FIXED
492	bool "Explicitly specified physical RAM address"
493	default n
494
495config PHYS_RAM_BASE
496	hex "Platform Physical RAM address"
497	depends on PHYS_RAM_BASE_FIXED
498	default "0x80000000"
499	help
500	  This is the physical address of RAM in the system. It has to be
501	  explicitly specified to run early relocations of read-write data
502	  from flash to RAM.
503
504config XIP_KERNEL
505	bool "Kernel Execute-In-Place from ROM"
506	depends on MMU && SPARSEMEM
507	# This prevents XIP from being enabled by all{yes,mod}config, which
508	# fail to build since XIP doesn't support large kernels.
509	depends on !COMPILE_TEST
510	select PHYS_RAM_BASE_FIXED
511	help
512	  Execute-In-Place allows the kernel to run from non-volatile storage
513	  directly addressable by the CPU, such as NOR flash. This saves RAM
514	  space since the text section of the kernel is not loaded from flash
515	  to RAM.  Read-write sections, such as the data section and stack,
516	  are still copied to RAM.  The XIP kernel is not compressed since
517	  it has to run directly from flash, so it will take more space to
518	  store it.  The flash address used to link the kernel object files,
519	  and for storing it, is configuration dependent. Therefore, if you
520	  say Y here, you must know the proper physical address where to
521	  store the kernel image depending on your own flash memory usage.
522
523	  Also note that the make target becomes "make xipImage" rather than
524	  "make zImage" or "make Image".  The final kernel binary to put in
525	  ROM memory will be arch/riscv/boot/xipImage.
526
527	  SPARSEMEM is required because the kernel text and rodata that are
528	  flash resident are not backed by memmap, then any attempt to get
529	  a struct page on those regions will trigger a fault.
530
531	  If unsure, say N.
532
533config XIP_PHYS_ADDR
534	hex "XIP Kernel Physical Location"
535	depends on XIP_KERNEL
536	default "0x21000000"
537	help
538	  This is the physical address in your flash memory the kernel will
539	  be linked for and stored to.  This address is dependent on your
540	  own flash usage.
541
542endmenu
543
544config BUILTIN_DTB
545	bool
546	depends on OF
547	default y if XIP_KERNEL
548
549menu "Power management options"
550
551source "kernel/power/Kconfig"
552
553endmenu
554
555source "drivers/firmware/Kconfig"
556