xref: /linux/arch/riscv/Kconfig (revision baaa68a9796ef2cadfe5caaf4c730412eda0f31c)
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_GENERAL_HUGETLB
44	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
45	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
46	select BUILDTIME_TABLE_SORT if MMU
47	select CLONE_BACKWARDS
48	select CLINT_TIMER if !MMU
49	select COMMON_CLK
50	select EDAC_SUPPORT
51	select GENERIC_ARCH_TOPOLOGY if SMP
52	select GENERIC_ATOMIC64 if !64BIT
53	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
54	select GENERIC_EARLY_IOREMAP
55	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
56	select GENERIC_IDLE_POLL_SETUP
57	select GENERIC_IOREMAP if MMU
58	select GENERIC_IRQ_MULTI_HANDLER
59	select GENERIC_IRQ_SHOW
60	select GENERIC_IRQ_SHOW_LEVEL
61	select GENERIC_LIB_DEVMEM_IS_ALLOWED
62	select GENERIC_PCI_IOMAP
63	select GENERIC_PTDUMP if MMU
64	select GENERIC_SCHED_CLOCK
65	select GENERIC_SMP_IDLE_THREAD
66	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
67	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
68	select HAVE_ARCH_AUDITSYSCALL
69	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
70	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
71	select HAVE_ARCH_KASAN if MMU && 64BIT
72	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
73	select HAVE_ARCH_KFENCE if MMU && 64BIT
74	select HAVE_ARCH_KGDB if !XIP_KERNEL
75	select HAVE_ARCH_KGDB_QXFER_PKT
76	select HAVE_ARCH_MMAP_RND_BITS if MMU
77	select HAVE_ARCH_SECCOMP_FILTER
78	select HAVE_ARCH_TRACEHOOK
79	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
80	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
81	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
82	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
83	select HAVE_ASM_MODVERSIONS
84	select HAVE_CONTEXT_TRACKING
85	select HAVE_DEBUG_KMEMLEAK
86	select HAVE_DMA_CONTIGUOUS if MMU
87	select HAVE_EBPF_JIT if MMU
88	select HAVE_FUNCTION_ERROR_INJECTION
89	select HAVE_GCC_PLUGINS
90	select HAVE_GENERIC_VDSO if MMU && 64BIT
91	select HAVE_IRQ_TIME_ACCOUNTING
92	select HAVE_KPROBES if !XIP_KERNEL
93	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
94	select HAVE_KRETPROBES if !XIP_KERNEL
95	select HAVE_MOVE_PMD
96	select HAVE_MOVE_PUD
97	select HAVE_PCI
98	select HAVE_PERF_EVENTS
99	select HAVE_PERF_REGS
100	select HAVE_PERF_USER_STACK_DUMP
101	select HAVE_REGS_AND_STACK_ACCESS_API
102	select HAVE_FUNCTION_ARG_ACCESS_API
103	select HAVE_STACKPROTECTOR
104	select HAVE_SYSCALL_TRACEPOINTS
105	select IRQ_DOMAIN
106	select IRQ_FORCED_THREADING
107	select MODULES_USE_ELF_RELA if MODULES
108	select MODULE_SECTIONS if MODULES
109	select OF
110	select OF_EARLY_FLATTREE
111	select OF_IRQ
112	select PCI_DOMAINS_GENERIC if PCI
113	select PCI_MSI if PCI
114	select RISCV_INTC
115	select RISCV_TIMER if RISCV_SBI
116	select SPARSE_IRQ
117	select SYSCTL_EXCEPTION_TRACE
118	select THREAD_INFO_IN_TASK
119	select TRACE_IRQFLAGS_SUPPORT
120	select UACCESS_MEMCPY if !MMU
121	select ZONE_DMA32 if 64BIT
122
123config ARCH_MMAP_RND_BITS_MIN
124	default 18 if 64BIT
125	default 8
126
127# max bits determined by the following formula:
128#  VA_BITS - PAGE_SHIFT - 3
129config ARCH_MMAP_RND_BITS_MAX
130	default 24 if 64BIT # SV39 based
131	default 17
132
133# set if we run in machine mode, cleared if we run in supervisor mode
134config RISCV_M_MODE
135	bool
136	default !MMU
137
138# set if we are running in S-mode and can use SBI calls
139config RISCV_SBI
140	bool
141	depends on !RISCV_M_MODE
142	default y
143
144config MMU
145	bool "MMU-based Paged Memory Management Support"
146	default y
147	help
148	  Select if you want MMU-based virtualised addressing space
149	  support by paged memory management. If unsure, say 'Y'.
150
151config PAGE_OFFSET
152	hex
153	default 0xC0000000 if 32BIT
154	default 0x80000000 if 64BIT && !MMU
155	default 0xffffaf8000000000 if 64BIT
156
157config KASAN_SHADOW_OFFSET
158	hex
159	depends on KASAN_GENERIC
160	default 0xdfffffff00000000 if 64BIT
161	default 0xffffffff if 32BIT
162
163config ARCH_FLATMEM_ENABLE
164	def_bool !NUMA
165
166config ARCH_SPARSEMEM_ENABLE
167	def_bool y
168	depends on MMU
169	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
170	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
171
172config ARCH_SELECT_MEMORY_MODEL
173	def_bool ARCH_SPARSEMEM_ENABLE
174
175config ARCH_SUPPORTS_UPROBES
176	def_bool y
177
178config STACKTRACE_SUPPORT
179	def_bool y
180
181config GENERIC_BUG
182	def_bool y
183	depends on BUG
184	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
185
186config GENERIC_BUG_RELATIVE_POINTERS
187	bool
188
189config GENERIC_CALIBRATE_DELAY
190	def_bool y
191
192config GENERIC_CSUM
193	def_bool y
194
195config GENERIC_HWEIGHT
196	def_bool y
197
198config FIX_EARLYCON_MEM
199	def_bool MMU
200
201config PGTABLE_LEVELS
202	int
203	default 4 if 64BIT
204	default 2
205
206config LOCKDEP_SUPPORT
207	def_bool y
208
209source "arch/riscv/Kconfig.socs"
210source "arch/riscv/Kconfig.erratas"
211
212menu "Platform type"
213
214choice
215	prompt "Base ISA"
216	default ARCH_RV64I
217	help
218	  This selects the base ISA that this kernel will target and must match
219	  the target platform.
220
221config ARCH_RV32I
222	bool "RV32I"
223	select 32BIT
224	select GENERIC_LIB_ASHLDI3
225	select GENERIC_LIB_ASHRDI3
226	select GENERIC_LIB_LSHRDI3
227	select GENERIC_LIB_UCMPDI2
228	select MMU
229
230config ARCH_RV64I
231	bool "RV64I"
232	select 64BIT
233	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
234	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
235	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
236	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
237	select HAVE_FUNCTION_GRAPH_TRACER
238	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
239	select SWIOTLB if MMU
240
241endchoice
242
243# We must be able to map all physical memory into the kernel, but the compiler
244# is still a bit more efficient when generating code if it's setup in a manner
245# such that it can only map 2GiB of memory.
246choice
247	prompt "Kernel Code Model"
248	default CMODEL_MEDLOW if 32BIT
249	default CMODEL_MEDANY if 64BIT
250
251	config CMODEL_MEDLOW
252		bool "medium low code model"
253	config CMODEL_MEDANY
254		bool "medium any code model"
255endchoice
256
257config MODULE_SECTIONS
258	bool
259	select HAVE_MOD_ARCH_SPECIFIC
260
261config SMP
262	bool "Symmetric Multi-Processing"
263	help
264	  This enables support for systems with more than one CPU.  If
265	  you say N here, the kernel will run on single and
266	  multiprocessor machines, but will use only one CPU of a
267	  multiprocessor machine. If you say Y here, the kernel will run
268	  on many, but not all, single processor machines. On a single
269	  processor machine, the kernel will run faster if you say N
270	  here.
271
272	  If you don't know what to do here, say N.
273
274config NR_CPUS
275	int "Maximum number of CPUs (2-32)"
276	range 2 32
277	depends on SMP
278	default "8"
279
280config HOTPLUG_CPU
281	bool "Support for hot-pluggable CPUs"
282	depends on SMP
283	select GENERIC_IRQ_MIGRATION
284	help
285
286	  Say Y here to experiment with turning CPUs off and on.  CPUs
287	  can be controlled through /sys/devices/system/cpu.
288
289	  Say N if you want to disable CPU hotplug.
290
291choice
292	prompt "CPU Tuning"
293	default TUNE_GENERIC
294
295config TUNE_GENERIC
296	bool "generic"
297
298endchoice
299
300# Common NUMA Features
301config NUMA
302	bool "NUMA Memory Allocation and Scheduler Support"
303	depends on SMP && MMU
304	select GENERIC_ARCH_NUMA
305	select OF_NUMA
306	select ARCH_SUPPORTS_NUMA_BALANCING
307	select USE_PERCPU_NUMA_NODE_ID
308	select NEED_PER_CPU_EMBED_FIRST_CHUNK
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 RISCV_ISA_C
325	bool "Emit compressed instructions when building Linux"
326	default y
327	help
328	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
329	   when building Linux, which results in compressed instructions in the
330	   Linux binary.
331
332	   If you don't know what to do here, say Y.
333
334menu "supported PMU type"
335	depends on PERF_EVENTS
336
337config RISCV_BASE_PMU
338	bool "Base Performance Monitoring Unit"
339	def_bool y
340	help
341	  A base PMU that serves as a reference implementation and has limited
342	  feature of perf.  It can run on any RISC-V machines so serves as the
343	  fallback, but this option can also be disable to reduce kernel size.
344
345endmenu
346
347config FPU
348	bool "FPU support"
349	default y
350	help
351	  Say N here if you want to disable all floating-point related procedure
352	  in the kernel.
353
354	  If you don't know what to do here, say Y.
355
356endmenu
357
358menu "Kernel features"
359
360source "kernel/Kconfig.hz"
361
362config RISCV_SBI_V01
363	bool "SBI v0.1 support"
364	depends on RISCV_SBI
365	help
366	  This config allows kernel to use SBI v0.1 APIs. This will be
367	  deprecated in future once legacy M-mode software are no longer in use.
368
369config RISCV_BOOT_SPINWAIT
370	bool "Spinwait booting method"
371	depends on SMP
372	default y
373	help
374	  This enables support for booting Linux via spinwait method. In the
375	  spinwait method, all cores randomly jump to Linux. One of the cores
376	  gets chosen via lottery and all other keep spinning on a percpu
377	  variable. This method cannot support CPU hotplug and sparse hartid
378	  scheme. It should be only enabled for M-mode Linux or platforms relying
379	  on older firmware without SBI HSM extension. All other platforms should
380	  rely on ordered booting via SBI HSM extension which gets chosen
381	  dynamically at runtime if the firmware supports it.
382
383config KEXEC
384	bool "Kexec system call"
385	select KEXEC_CORE
386	select HOTPLUG_CPU if SMP
387	depends on MMU
388	help
389	  kexec is a system call that implements the ability to shutdown your
390	  current kernel, and to start another kernel. It is like a reboot
391	  but it is independent of the system firmware. And like a reboot
392	  you can start any kernel with it, not just Linux.
393
394	  The name comes from the similarity to the exec system call.
395
396config CRASH_DUMP
397	bool "Build kdump crash kernel"
398	help
399	  Generate crash dump after being started by kexec. This should
400	  be normally only set in special crash dump kernels which are
401	  loaded in the main kernel with kexec-tools into a specially
402	  reserved region and then later executed after a crash by
403	  kdump/kexec.
404
405	  For more details see Documentation/admin-guide/kdump/kdump.rst
406
407endmenu
408
409menu "Boot options"
410
411config CMDLINE
412	string "Built-in kernel command line"
413	help
414	  For most platforms, the arguments for the kernel's command line
415	  are provided at run-time, during boot. However, there are cases
416	  where either no arguments are being provided or the provided
417	  arguments are insufficient or even invalid.
418
419	  When that occurs, it is possible to define a built-in command
420	  line here and choose how the kernel should use it later on.
421
422choice
423	prompt "Built-in command line usage" if CMDLINE != ""
424	default CMDLINE_FALLBACK
425	help
426	  Choose how the kernel will handle the provided built-in command
427	  line.
428
429config CMDLINE_FALLBACK
430	bool "Use bootloader kernel arguments if available"
431	help
432	  Use the built-in command line as fallback in case we get nothing
433	  during boot. This is the default behaviour.
434
435config CMDLINE_EXTEND
436	bool "Extend bootloader kernel arguments"
437	help
438	  The command-line arguments provided during boot will be
439	  appended to the built-in command line. This is useful in
440	  cases where the provided arguments are insufficient and
441	  you don't want to or cannot modify them.
442
443
444config CMDLINE_FORCE
445	bool "Always use the default kernel command string"
446	help
447	  Always use the built-in command line, even if we get one during
448	  boot. This is useful in case you need to override the provided
449	  command line on systems where you don't have or want control
450	  over it.
451
452endchoice
453
454config EFI_STUB
455	bool
456
457config EFI
458	bool "UEFI runtime support"
459	depends on OF && !XIP_KERNEL
460	select LIBFDT
461	select UCS2_STRING
462	select EFI_PARAMS_FROM_FDT
463	select EFI_STUB
464	select EFI_GENERIC_STUB
465	select EFI_RUNTIME_WRAPPERS
466	select RISCV_ISA_C
467	depends on MMU
468	default y
469	help
470	  This option provides support for runtime services provided
471	  by UEFI firmware (such as non-volatile variables, realtime
472	  clock, and platform reset). A UEFI stub is also provided to
473	  allow the kernel to be booted as an EFI application. This
474	  is only useful on systems that have UEFI firmware.
475
476config CC_HAVE_STACKPROTECTOR_TLS
477	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
478
479config STACKPROTECTOR_PER_TASK
480	def_bool y
481	depends on !GCC_PLUGIN_RANDSTRUCT
482	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
483
484config PHYS_RAM_BASE_FIXED
485	bool "Explicitly specified physical RAM address"
486	default n
487
488config PHYS_RAM_BASE
489	hex "Platform Physical RAM address"
490	depends on PHYS_RAM_BASE_FIXED
491	default "0x80000000"
492	help
493	  This is the physical address of RAM in the system. It has to be
494	  explicitly specified to run early relocations of read-write data
495	  from flash to RAM.
496
497config XIP_KERNEL
498	bool "Kernel Execute-In-Place from ROM"
499	depends on MMU && SPARSEMEM
500	# This prevents XIP from being enabled by all{yes,mod}config, which
501	# fail to build since XIP doesn't support large kernels.
502	depends on !COMPILE_TEST
503	select PHYS_RAM_BASE_FIXED
504	help
505	  Execute-In-Place allows the kernel to run from non-volatile storage
506	  directly addressable by the CPU, such as NOR flash. This saves RAM
507	  space since the text section of the kernel is not loaded from flash
508	  to RAM.  Read-write sections, such as the data section and stack,
509	  are still copied to RAM.  The XIP kernel is not compressed since
510	  it has to run directly from flash, so it will take more space to
511	  store it.  The flash address used to link the kernel object files,
512	  and for storing it, is configuration dependent. Therefore, if you
513	  say Y here, you must know the proper physical address where to
514	  store the kernel image depending on your own flash memory usage.
515
516	  Also note that the make target becomes "make xipImage" rather than
517	  "make zImage" or "make Image".  The final kernel binary to put in
518	  ROM memory will be arch/riscv/boot/xipImage.
519
520	  SPARSEMEM is required because the kernel text and rodata that are
521	  flash resident are not backed by memmap, then any attempt to get
522	  a struct page on those regions will trigger a fault.
523
524	  If unsure, say N.
525
526config XIP_PHYS_ADDR
527	hex "XIP Kernel Physical Location"
528	depends on XIP_KERNEL
529	default "0x21000000"
530	help
531	  This is the physical address in your flash memory the kernel will
532	  be linked for and stored to.  This address is dependent on your
533	  own flash usage.
534
535endmenu
536
537config BUILTIN_DTB
538	bool
539	depends on OF
540	default y if XIP_KERNEL
541
542menu "Power management options"
543
544source "kernel/power/Kconfig"
545
546endmenu
547
548source "arch/riscv/kvm/Kconfig"
549