xref: /linux/arch/riscv/Kconfig (revision e64f737ad70fee4a3c57d147fc511e5d5014b5dd)
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_CURRENT_STACK_POINTER
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 if MMU
30	select ARCH_HAS_SET_MEMORY if MMU
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_HAS_UBSAN_SANITIZE_ALL
35	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
36	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
37	select ARCH_STACKWALK
38	select ARCH_SUPPORTS_ATOMIC_RMW
39	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
40	select ARCH_SUPPORTS_HUGETLBFS if MMU
41	select ARCH_USE_MEMTEST
42	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
43	select ARCH_WANT_FRAME_POINTERS
44	select ARCH_WANT_GENERAL_HUGETLB
45	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
46	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
47	select BUILDTIME_TABLE_SORT if MMU
48	select CLONE_BACKWARDS
49	select CLINT_TIMER if !MMU
50	select COMMON_CLK
51	select CPU_PM if CPU_IDLE
52	select EDAC_SUPPORT
53	select GENERIC_ARCH_TOPOLOGY if SMP
54	select GENERIC_ATOMIC64 if !64BIT
55	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
56	select GENERIC_EARLY_IOREMAP
57	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
58	select GENERIC_IDLE_POLL_SETUP
59	select GENERIC_IOREMAP if MMU
60	select GENERIC_IRQ_MULTI_HANDLER
61	select GENERIC_IRQ_SHOW
62	select GENERIC_IRQ_SHOW_LEVEL
63	select GENERIC_LIB_DEVMEM_IS_ALLOWED
64	select GENERIC_PCI_IOMAP
65	select GENERIC_PTDUMP if MMU
66	select GENERIC_SCHED_CLOCK
67	select GENERIC_SMP_IDLE_THREAD
68	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
69	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
70	select HAVE_ARCH_AUDITSYSCALL
71	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
72	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
73	select HAVE_ARCH_KASAN if MMU && 64BIT
74	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
75	select HAVE_ARCH_KFENCE if MMU && 64BIT
76	select HAVE_ARCH_KGDB if !XIP_KERNEL
77	select HAVE_ARCH_KGDB_QXFER_PKT
78	select HAVE_ARCH_MMAP_RND_BITS if MMU
79	select HAVE_ARCH_SECCOMP_FILTER
80	select HAVE_ARCH_TRACEHOOK
81	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
82	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
83	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
84	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
85	select HAVE_ASM_MODVERSIONS
86	select HAVE_CONTEXT_TRACKING
87	select HAVE_DEBUG_KMEMLEAK
88	select HAVE_DMA_CONTIGUOUS if MMU
89	select HAVE_EBPF_JIT if MMU
90	select HAVE_FUNCTION_ERROR_INJECTION
91	select HAVE_GCC_PLUGINS
92	select HAVE_GENERIC_VDSO if MMU && 64BIT
93	select HAVE_IRQ_TIME_ACCOUNTING
94	select HAVE_KPROBES if !XIP_KERNEL
95	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
96	select HAVE_KRETPROBES if !XIP_KERNEL
97	select HAVE_MOVE_PMD
98	select HAVE_MOVE_PUD
99	select HAVE_PCI
100	select HAVE_PERF_EVENTS
101	select HAVE_PERF_REGS
102	select HAVE_PERF_USER_STACK_DUMP
103	select HAVE_REGS_AND_STACK_ACCESS_API
104	select HAVE_FUNCTION_ARG_ACCESS_API
105	select HAVE_STACKPROTECTOR
106	select HAVE_SYSCALL_TRACEPOINTS
107	select HAVE_RSEQ
108	select IRQ_DOMAIN
109	select IRQ_FORCED_THREADING
110	select MODULES_USE_ELF_RELA if MODULES
111	select MODULE_SECTIONS if MODULES
112	select OF
113	select OF_EARLY_FLATTREE
114	select OF_IRQ
115	select PCI_DOMAINS_GENERIC if PCI
116	select PCI_MSI if PCI
117	select RISCV_INTC
118	select RISCV_TIMER if RISCV_SBI
119	select SPARSE_IRQ
120	select SYSCTL_EXCEPTION_TRACE
121	select THREAD_INFO_IN_TASK
122	select TRACE_IRQFLAGS_SUPPORT
123	select UACCESS_MEMCPY if !MMU
124	select ZONE_DMA32 if 64BIT
125
126config ARCH_MMAP_RND_BITS_MIN
127	default 18 if 64BIT
128	default 8
129
130# max bits determined by the following formula:
131#  VA_BITS - PAGE_SHIFT - 3
132config ARCH_MMAP_RND_BITS_MAX
133	default 24 if 64BIT # SV39 based
134	default 17
135
136# set if we run in machine mode, cleared if we run in supervisor mode
137config RISCV_M_MODE
138	bool
139	default !MMU
140
141# set if we are running in S-mode and can use SBI calls
142config RISCV_SBI
143	bool
144	depends on !RISCV_M_MODE
145	default y
146
147config MMU
148	bool "MMU-based Paged Memory Management Support"
149	default y
150	help
151	  Select if you want MMU-based virtualised addressing space
152	  support by paged memory management. If unsure, say 'Y'.
153
154config PAGE_OFFSET
155	hex
156	default 0xC0000000 if 32BIT
157	default 0x80000000 if 64BIT && !MMU
158	default 0xff60000000000000 if 64BIT
159
160config KASAN_SHADOW_OFFSET
161	hex
162	depends on KASAN_GENERIC
163	default 0xdfffffff00000000 if 64BIT
164	default 0xffffffff if 32BIT
165
166config ARCH_FLATMEM_ENABLE
167	def_bool !NUMA
168
169config ARCH_SPARSEMEM_ENABLE
170	def_bool y
171	depends on MMU
172	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
173	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
174
175config ARCH_SELECT_MEMORY_MODEL
176	def_bool ARCH_SPARSEMEM_ENABLE
177
178config ARCH_SUPPORTS_UPROBES
179	def_bool y
180
181config STACKTRACE_SUPPORT
182	def_bool y
183
184config GENERIC_BUG
185	def_bool y
186	depends on BUG
187	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
188
189config GENERIC_BUG_RELATIVE_POINTERS
190	bool
191
192config GENERIC_CALIBRATE_DELAY
193	def_bool y
194
195config GENERIC_CSUM
196	def_bool y
197
198config GENERIC_HWEIGHT
199	def_bool y
200
201config FIX_EARLYCON_MEM
202	def_bool MMU
203
204config PGTABLE_LEVELS
205	int
206	default 5 if 64BIT
207	default 2
208
209config LOCKDEP_SUPPORT
210	def_bool y
211
212source "arch/riscv/Kconfig.socs"
213source "arch/riscv/Kconfig.erratas"
214
215menu "Platform type"
216
217choice
218	prompt "Base ISA"
219	default ARCH_RV64I
220	help
221	  This selects the base ISA that this kernel will target and must match
222	  the target platform.
223
224config ARCH_RV32I
225	bool "RV32I"
226	select 32BIT
227	select GENERIC_LIB_ASHLDI3
228	select GENERIC_LIB_ASHRDI3
229	select GENERIC_LIB_LSHRDI3
230	select GENERIC_LIB_UCMPDI2
231	select MMU
232
233config ARCH_RV64I
234	bool "RV64I"
235	select 64BIT
236	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
237	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
238	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
239	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
240	select HAVE_FUNCTION_GRAPH_TRACER
241	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
242	select SWIOTLB if MMU
243
244endchoice
245
246# We must be able to map all physical memory into the kernel, but the compiler
247# is still a bit more efficient when generating code if it's setup in a manner
248# such that it can only map 2GiB of memory.
249choice
250	prompt "Kernel Code Model"
251	default CMODEL_MEDLOW if 32BIT
252	default CMODEL_MEDANY if 64BIT
253
254	config CMODEL_MEDLOW
255		bool "medium low code model"
256	config CMODEL_MEDANY
257		bool "medium any code model"
258endchoice
259
260config MODULE_SECTIONS
261	bool
262	select HAVE_MOD_ARCH_SPECIFIC
263
264config SMP
265	bool "Symmetric Multi-Processing"
266	help
267	  This enables support for systems with more than one CPU.  If
268	  you say N here, the kernel will run on single and
269	  multiprocessor machines, but will use only one CPU of a
270	  multiprocessor machine. If you say Y here, the kernel will run
271	  on many, but not all, single processor machines. On a single
272	  processor machine, the kernel will run faster if you say N
273	  here.
274
275	  If you don't know what to do here, say N.
276
277config NR_CPUS
278	int "Maximum number of CPUs (2-32)"
279	range 2 32
280	depends on SMP
281	default "8"
282
283config HOTPLUG_CPU
284	bool "Support for hot-pluggable CPUs"
285	depends on SMP
286	select GENERIC_IRQ_MIGRATION
287	help
288
289	  Say Y here to experiment with turning CPUs off and on.  CPUs
290	  can be controlled through /sys/devices/system/cpu.
291
292	  Say N if you want to disable CPU hotplug.
293
294choice
295	prompt "CPU Tuning"
296	default TUNE_GENERIC
297
298config TUNE_GENERIC
299	bool "generic"
300
301endchoice
302
303# Common NUMA Features
304config NUMA
305	bool "NUMA Memory Allocation and Scheduler Support"
306	depends on SMP && MMU
307	select GENERIC_ARCH_NUMA
308	select OF_NUMA
309	select ARCH_SUPPORTS_NUMA_BALANCING
310	select USE_PERCPU_NUMA_NODE_ID
311	select NEED_PER_CPU_EMBED_FIRST_CHUNK
312	help
313	  Enable NUMA (Non-Uniform Memory Access) support.
314
315	  The kernel will try to allocate memory used by a CPU on the
316	  local memory of the CPU and add some more NUMA awareness to the kernel.
317
318config NODES_SHIFT
319	int "Maximum NUMA Nodes (as a power of 2)"
320	range 1 10
321	default "2"
322	depends on NUMA
323	help
324	  Specify the maximum number of NUMA Nodes available on the target
325	  system.  Increases memory reserved to accommodate various tables.
326
327config RISCV_ALTERNATIVE
328	bool
329	depends on !XIP_KERNEL
330	help
331	  This Kconfig allows the kernel to automatically patch the
332	  errata required by the execution platform at run time. The
333	  code patching is performed once in the boot stages. It means
334	  that the overhead from this mechanism is just taken once.
335
336config RISCV_ISA_C
337	bool "Emit compressed instructions when building Linux"
338	default y
339	help
340	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
341	   when building Linux, which results in compressed instructions in the
342	   Linux binary.
343
344	   If you don't know what to do here, say Y.
345
346config FPU
347	bool "FPU support"
348	default y
349	help
350	  Say N here if you want to disable all floating-point related procedure
351	  in the kernel.
352
353	  If you don't know what to do here, say Y.
354
355endmenu
356
357menu "Kernel features"
358
359source "kernel/Kconfig.hz"
360
361config RISCV_SBI_V01
362	bool "SBI v0.1 support"
363	depends on RISCV_SBI
364	help
365	  This config allows kernel to use SBI v0.1 APIs. This will be
366	  deprecated in future once legacy M-mode software are no longer in use.
367
368config RISCV_BOOT_SPINWAIT
369	bool "Spinwait booting method"
370	depends on SMP
371	default y
372	help
373	  This enables support for booting Linux via spinwait method. In the
374	  spinwait method, all cores randomly jump to Linux. One of the cores
375	  gets chosen via lottery and all other keep spinning on a percpu
376	  variable. This method cannot support CPU hotplug and sparse hartid
377	  scheme. It should be only enabled for M-mode Linux or platforms relying
378	  on older firmware without SBI HSM extension. All other platforms should
379	  rely on ordered booting via SBI HSM extension which gets chosen
380	  dynamically at runtime if the firmware supports it.
381
382config KEXEC
383	bool "Kexec system call"
384	select KEXEC_CORE
385	select HOTPLUG_CPU if SMP
386	depends on MMU
387	help
388	  kexec is a system call that implements the ability to shutdown your
389	  current kernel, and to start another kernel. It is like a reboot
390	  but it is independent of the system firmware. And like a reboot
391	  you can start any kernel with it, not just Linux.
392
393	  The name comes from the similarity to the exec system call.
394
395config CRASH_DUMP
396	bool "Build kdump crash kernel"
397	help
398	  Generate crash dump after being started by kexec. This should
399	  be normally only set in special crash dump kernels which are
400	  loaded in the main kernel with kexec-tools into a specially
401	  reserved region and then later executed after a crash by
402	  kdump/kexec.
403
404	  For more details see Documentation/admin-guide/kdump/kdump.rst
405
406endmenu
407
408menu "Boot options"
409
410config CMDLINE
411	string "Built-in kernel command line"
412	help
413	  For most platforms, the arguments for the kernel's command line
414	  are provided at run-time, during boot. However, there are cases
415	  where either no arguments are being provided or the provided
416	  arguments are insufficient or even invalid.
417
418	  When that occurs, it is possible to define a built-in command
419	  line here and choose how the kernel should use it later on.
420
421choice
422	prompt "Built-in command line usage" if CMDLINE != ""
423	default CMDLINE_FALLBACK
424	help
425	  Choose how the kernel will handle the provided built-in command
426	  line.
427
428config CMDLINE_FALLBACK
429	bool "Use bootloader kernel arguments if available"
430	help
431	  Use the built-in command line as fallback in case we get nothing
432	  during boot. This is the default behaviour.
433
434config CMDLINE_EXTEND
435	bool "Extend bootloader kernel arguments"
436	help
437	  The command-line arguments provided during boot will be
438	  appended to the built-in command line. This is useful in
439	  cases where the provided arguments are insufficient and
440	  you don't want to or cannot modify them.
441
442
443config CMDLINE_FORCE
444	bool "Always use the default kernel command string"
445	help
446	  Always use the built-in command line, even if we get one during
447	  boot. This is useful in case you need to override the provided
448	  command line on systems where you don't have or want control
449	  over it.
450
451endchoice
452
453config EFI_STUB
454	bool
455
456config EFI
457	bool "UEFI runtime support"
458	depends on OF && !XIP_KERNEL
459	select LIBFDT
460	select UCS2_STRING
461	select EFI_PARAMS_FROM_FDT
462	select EFI_STUB
463	select EFI_GENERIC_STUB
464	select EFI_RUNTIME_WRAPPERS
465	select RISCV_ISA_C
466	depends on MMU
467	default y
468	help
469	  This option provides support for runtime services provided
470	  by UEFI firmware (such as non-volatile variables, realtime
471	  clock, and platform reset). A UEFI stub is also provided to
472	  allow the kernel to be booted as an EFI application. This
473	  is only useful on systems that have UEFI firmware.
474
475config CC_HAVE_STACKPROTECTOR_TLS
476	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
477
478config STACKPROTECTOR_PER_TASK
479	def_bool y
480	depends on !GCC_PLUGIN_RANDSTRUCT
481	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
482
483config PHYS_RAM_BASE_FIXED
484	bool "Explicitly specified physical RAM address"
485	default n
486
487config PHYS_RAM_BASE
488	hex "Platform Physical RAM address"
489	depends on PHYS_RAM_BASE_FIXED
490	default "0x80000000"
491	help
492	  This is the physical address of RAM in the system. It has to be
493	  explicitly specified to run early relocations of read-write data
494	  from flash to RAM.
495
496config XIP_KERNEL
497	bool "Kernel Execute-In-Place from ROM"
498	depends on MMU && SPARSEMEM
499	# This prevents XIP from being enabled by all{yes,mod}config, which
500	# fail to build since XIP doesn't support large kernels.
501	depends on !COMPILE_TEST
502	select PHYS_RAM_BASE_FIXED
503	help
504	  Execute-In-Place allows the kernel to run from non-volatile storage
505	  directly addressable by the CPU, such as NOR flash. This saves RAM
506	  space since the text section of the kernel is not loaded from flash
507	  to RAM.  Read-write sections, such as the data section and stack,
508	  are still copied to RAM.  The XIP kernel is not compressed since
509	  it has to run directly from flash, so it will take more space to
510	  store it.  The flash address used to link the kernel object files,
511	  and for storing it, is configuration dependent. Therefore, if you
512	  say Y here, you must know the proper physical address where to
513	  store the kernel image depending on your own flash memory usage.
514
515	  Also note that the make target becomes "make xipImage" rather than
516	  "make zImage" or "make Image".  The final kernel binary to put in
517	  ROM memory will be arch/riscv/boot/xipImage.
518
519	  SPARSEMEM is required because the kernel text and rodata that are
520	  flash resident are not backed by memmap, then any attempt to get
521	  a struct page on those regions will trigger a fault.
522
523	  If unsure, say N.
524
525config XIP_PHYS_ADDR
526	hex "XIP Kernel Physical Location"
527	depends on XIP_KERNEL
528	default "0x21000000"
529	help
530	  This is the physical address in your flash memory the kernel will
531	  be linked for and stored to.  This address is dependent on your
532	  own flash usage.
533
534endmenu
535
536config BUILTIN_DTB
537	bool
538	depends on OF
539	default y if XIP_KERNEL
540
541menu "Power management options"
542
543source "kernel/power/Kconfig"
544
545endmenu
546
547menu "CPU Power Management"
548
549source "drivers/cpuidle/Kconfig"
550
551endmenu
552
553source "arch/riscv/kvm/Kconfig"
554