xref: /linux/arch/riscv/Kconfig (revision 03a679a1a4ec8fbe44119a6d06eeabdf7944883d)
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_USE_QUEUED_RWLOCKS
43	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
44	select ARCH_WANT_FRAME_POINTERS
45	select ARCH_WANT_GENERAL_HUGETLB
46	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
47	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
48	select BUILDTIME_TABLE_SORT if MMU
49	select CLONE_BACKWARDS
50	select CLINT_TIMER if !MMU
51	select COMMON_CLK
52	select CPU_PM if CPU_IDLE
53	select EDAC_SUPPORT
54	select GENERIC_ARCH_TOPOLOGY if SMP
55	select GENERIC_ATOMIC64 if !64BIT
56	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
57	select GENERIC_EARLY_IOREMAP
58	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
59	select GENERIC_IDLE_POLL_SETUP
60	select GENERIC_IOREMAP if MMU
61	select GENERIC_IRQ_MULTI_HANDLER
62	select GENERIC_IRQ_SHOW
63	select GENERIC_IRQ_SHOW_LEVEL
64	select GENERIC_LIB_DEVMEM_IS_ALLOWED
65	select GENERIC_PCI_IOMAP
66	select GENERIC_PTDUMP if MMU
67	select GENERIC_SCHED_CLOCK
68	select GENERIC_SMP_IDLE_THREAD
69	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
70	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
71	select HAVE_ARCH_AUDITSYSCALL
72	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
73	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
74	select HAVE_ARCH_KASAN if MMU && 64BIT
75	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
76	select HAVE_ARCH_KFENCE if MMU && 64BIT
77	select HAVE_ARCH_KGDB if !XIP_KERNEL
78	select HAVE_ARCH_KGDB_QXFER_PKT
79	select HAVE_ARCH_MMAP_RND_BITS if MMU
80	select HAVE_ARCH_SECCOMP_FILTER
81	select HAVE_ARCH_TRACEHOOK
82	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
83	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
84	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
85	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
86	select HAVE_ASM_MODVERSIONS
87	select HAVE_CONTEXT_TRACKING
88	select HAVE_DEBUG_KMEMLEAK
89	select HAVE_DMA_CONTIGUOUS if MMU
90	select HAVE_EBPF_JIT if MMU
91	select HAVE_FUNCTION_ERROR_INJECTION
92	select HAVE_GCC_PLUGINS
93	select HAVE_GENERIC_VDSO if MMU && 64BIT
94	select HAVE_IRQ_TIME_ACCOUNTING
95	select HAVE_KPROBES if !XIP_KERNEL
96	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
97	select HAVE_KRETPROBES if !XIP_KERNEL
98	select HAVE_MOVE_PMD
99	select HAVE_MOVE_PUD
100	select HAVE_PCI
101	select HAVE_PERF_EVENTS
102	select HAVE_PERF_REGS
103	select HAVE_PERF_USER_STACK_DUMP
104	select HAVE_REGS_AND_STACK_ACCESS_API
105	select HAVE_FUNCTION_ARG_ACCESS_API
106	select HAVE_STACKPROTECTOR
107	select HAVE_SYSCALL_TRACEPOINTS
108	select HAVE_RSEQ
109	select IRQ_DOMAIN
110	select IRQ_FORCED_THREADING
111	select MODULES_USE_ELF_RELA if MODULES
112	select MODULE_SECTIONS if MODULES
113	select OF
114	select OF_EARLY_FLATTREE
115	select OF_IRQ
116	select PCI_DOMAINS_GENERIC if PCI
117	select PCI_MSI if PCI
118	select RISCV_INTC
119	select RISCV_TIMER if RISCV_SBI
120	select SPARSE_IRQ
121	select SYSCTL_EXCEPTION_TRACE
122	select THREAD_INFO_IN_TASK
123	select TRACE_IRQFLAGS_SUPPORT
124	select UACCESS_MEMCPY if !MMU
125	select ZONE_DMA32 if 64BIT
126
127config ARCH_MMAP_RND_BITS_MIN
128	default 18 if 64BIT
129	default 8
130
131# max bits determined by the following formula:
132#  VA_BITS - PAGE_SHIFT - 3
133config ARCH_MMAP_RND_BITS_MAX
134	default 24 if 64BIT # SV39 based
135	default 17
136
137# set if we run in machine mode, cleared if we run in supervisor mode
138config RISCV_M_MODE
139	bool
140	default !MMU
141
142# set if we are running in S-mode and can use SBI calls
143config RISCV_SBI
144	bool
145	depends on !RISCV_M_MODE
146	default y
147
148config MMU
149	bool "MMU-based Paged Memory Management Support"
150	default y
151	help
152	  Select if you want MMU-based virtualised addressing space
153	  support by paged memory management. If unsure, say 'Y'.
154
155config PAGE_OFFSET
156	hex
157	default 0xC0000000 if 32BIT
158	default 0x80000000 if 64BIT && !MMU
159	default 0xff60000000000000 if 64BIT
160
161config KASAN_SHADOW_OFFSET
162	hex
163	depends on KASAN_GENERIC
164	default 0xdfffffff00000000 if 64BIT
165	default 0xffffffff if 32BIT
166
167config ARCH_FLATMEM_ENABLE
168	def_bool !NUMA
169
170config ARCH_SPARSEMEM_ENABLE
171	def_bool y
172	depends on MMU
173	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
174	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
175
176config ARCH_SELECT_MEMORY_MODEL
177	def_bool ARCH_SPARSEMEM_ENABLE
178
179config ARCH_SUPPORTS_UPROBES
180	def_bool y
181
182config STACKTRACE_SUPPORT
183	def_bool y
184
185config GENERIC_BUG
186	def_bool y
187	depends on BUG
188	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
189
190config GENERIC_BUG_RELATIVE_POINTERS
191	bool
192
193config GENERIC_CALIBRATE_DELAY
194	def_bool y
195
196config GENERIC_CSUM
197	def_bool y
198
199config GENERIC_HWEIGHT
200	def_bool y
201
202config FIX_EARLYCON_MEM
203	def_bool MMU
204
205config PGTABLE_LEVELS
206	int
207	default 5 if 64BIT
208	default 2
209
210config LOCKDEP_SUPPORT
211	def_bool y
212
213source "arch/riscv/Kconfig.socs"
214source "arch/riscv/Kconfig.erratas"
215
216menu "Platform type"
217
218choice
219	prompt "Base ISA"
220	default ARCH_RV64I
221	help
222	  This selects the base ISA that this kernel will target and must match
223	  the target platform.
224
225config ARCH_RV32I
226	bool "RV32I"
227	select 32BIT
228	select GENERIC_LIB_ASHLDI3
229	select GENERIC_LIB_ASHRDI3
230	select GENERIC_LIB_LSHRDI3
231	select GENERIC_LIB_UCMPDI2
232	select MMU
233
234config ARCH_RV64I
235	bool "RV64I"
236	select 64BIT
237	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
238	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
239	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
240	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
241	select HAVE_FUNCTION_GRAPH_TRACER
242	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
243	select SWIOTLB if MMU
244
245endchoice
246
247# We must be able to map all physical memory into the kernel, but the compiler
248# is still a bit more efficient when generating code if it's setup in a manner
249# such that it can only map 2GiB of memory.
250choice
251	prompt "Kernel Code Model"
252	default CMODEL_MEDLOW if 32BIT
253	default CMODEL_MEDANY if 64BIT
254
255	config CMODEL_MEDLOW
256		bool "medium low code model"
257	config CMODEL_MEDANY
258		bool "medium any code model"
259endchoice
260
261config MODULE_SECTIONS
262	bool
263	select HAVE_MOD_ARCH_SPECIFIC
264
265config SMP
266	bool "Symmetric Multi-Processing"
267	help
268	  This enables support for systems with more than one CPU.  If
269	  you say N here, the kernel will run on single and
270	  multiprocessor machines, but will use only one CPU of a
271	  multiprocessor machine. If you say Y here, the kernel will run
272	  on many, but not all, single processor machines. On a single
273	  processor machine, the kernel will run faster if you say N
274	  here.
275
276	  If you don't know what to do here, say N.
277
278config NR_CPUS
279	int "Maximum number of CPUs (2-32)"
280	range 2 32
281	depends on SMP
282	default "8"
283
284config HOTPLUG_CPU
285	bool "Support for hot-pluggable CPUs"
286	depends on SMP
287	select GENERIC_IRQ_MIGRATION
288	help
289
290	  Say Y here to experiment with turning CPUs off and on.  CPUs
291	  can be controlled through /sys/devices/system/cpu.
292
293	  Say N if you want to disable CPU hotplug.
294
295choice
296	prompt "CPU Tuning"
297	default TUNE_GENERIC
298
299config TUNE_GENERIC
300	bool "generic"
301
302endchoice
303
304# Common NUMA Features
305config NUMA
306	bool "NUMA Memory Allocation and Scheduler Support"
307	depends on SMP && MMU
308	select GENERIC_ARCH_NUMA
309	select OF_NUMA
310	select ARCH_SUPPORTS_NUMA_BALANCING
311	select USE_PERCPU_NUMA_NODE_ID
312	select NEED_PER_CPU_EMBED_FIRST_CHUNK
313	help
314	  Enable NUMA (Non-Uniform Memory Access) support.
315
316	  The kernel will try to allocate memory used by a CPU on the
317	  local memory of the CPU and add some more NUMA awareness to the kernel.
318
319config NODES_SHIFT
320	int "Maximum NUMA Nodes (as a power of 2)"
321	range 1 10
322	default "2"
323	depends on NUMA
324	help
325	  Specify the maximum number of NUMA Nodes available on the target
326	  system.  Increases memory reserved to accommodate various tables.
327
328config RISCV_ISA_C
329	bool "Emit compressed instructions when building Linux"
330	default y
331	help
332	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
333	   when building Linux, which results in compressed instructions in the
334	   Linux binary.
335
336	   If you don't know what to do here, say Y.
337
338config FPU
339	bool "FPU support"
340	default y
341	help
342	  Say N here if you want to disable all floating-point related procedure
343	  in the kernel.
344
345	  If you don't know what to do here, say Y.
346
347endmenu
348
349menu "Kernel features"
350
351source "kernel/Kconfig.hz"
352
353config RISCV_SBI_V01
354	bool "SBI v0.1 support"
355	depends on RISCV_SBI
356	help
357	  This config allows kernel to use SBI v0.1 APIs. This will be
358	  deprecated in future once legacy M-mode software are no longer in use.
359
360config RISCV_BOOT_SPINWAIT
361	bool "Spinwait booting method"
362	depends on SMP
363	default y
364	help
365	  This enables support for booting Linux via spinwait method. In the
366	  spinwait method, all cores randomly jump to Linux. One of the cores
367	  gets chosen via lottery and all other keep spinning on a percpu
368	  variable. This method cannot support CPU hotplug and sparse hartid
369	  scheme. It should be only enabled for M-mode Linux or platforms relying
370	  on older firmware without SBI HSM extension. All other platforms should
371	  rely on ordered booting via SBI HSM extension which gets chosen
372	  dynamically at runtime if the firmware supports it.
373
374config KEXEC
375	bool "Kexec system call"
376	select KEXEC_CORE
377	select HOTPLUG_CPU if SMP
378	depends on MMU
379	help
380	  kexec is a system call that implements the ability to shutdown your
381	  current kernel, and to start another kernel. It is like a reboot
382	  but it is independent of the system firmware. And like a reboot
383	  you can start any kernel with it, not just Linux.
384
385	  The name comes from the similarity to the exec system call.
386
387config CRASH_DUMP
388	bool "Build kdump crash kernel"
389	help
390	  Generate crash dump after being started by kexec. This should
391	  be normally only set in special crash dump kernels which are
392	  loaded in the main kernel with kexec-tools into a specially
393	  reserved region and then later executed after a crash by
394	  kdump/kexec.
395
396	  For more details see Documentation/admin-guide/kdump/kdump.rst
397
398endmenu
399
400menu "Boot options"
401
402config CMDLINE
403	string "Built-in kernel command line"
404	help
405	  For most platforms, the arguments for the kernel's command line
406	  are provided at run-time, during boot. However, there are cases
407	  where either no arguments are being provided or the provided
408	  arguments are insufficient or even invalid.
409
410	  When that occurs, it is possible to define a built-in command
411	  line here and choose how the kernel should use it later on.
412
413choice
414	prompt "Built-in command line usage" if CMDLINE != ""
415	default CMDLINE_FALLBACK
416	help
417	  Choose how the kernel will handle the provided built-in command
418	  line.
419
420config CMDLINE_FALLBACK
421	bool "Use bootloader kernel arguments if available"
422	help
423	  Use the built-in command line as fallback in case we get nothing
424	  during boot. This is the default behaviour.
425
426config CMDLINE_EXTEND
427	bool "Extend bootloader kernel arguments"
428	help
429	  The command-line arguments provided during boot will be
430	  appended to the built-in command line. This is useful in
431	  cases where the provided arguments are insufficient and
432	  you don't want to or cannot modify them.
433
434
435config CMDLINE_FORCE
436	bool "Always use the default kernel command string"
437	help
438	  Always use the built-in command line, even if we get one during
439	  boot. This is useful in case you need to override the provided
440	  command line on systems where you don't have or want control
441	  over it.
442
443endchoice
444
445config EFI_STUB
446	bool
447
448config EFI
449	bool "UEFI runtime support"
450	depends on OF && !XIP_KERNEL
451	select LIBFDT
452	select UCS2_STRING
453	select EFI_PARAMS_FROM_FDT
454	select EFI_STUB
455	select EFI_GENERIC_STUB
456	select EFI_RUNTIME_WRAPPERS
457	select RISCV_ISA_C
458	depends on MMU
459	default y
460	help
461	  This option provides support for runtime services provided
462	  by UEFI firmware (such as non-volatile variables, realtime
463	  clock, and platform reset). A UEFI stub is also provided to
464	  allow the kernel to be booted as an EFI application. This
465	  is only useful on systems that have UEFI firmware.
466
467config CC_HAVE_STACKPROTECTOR_TLS
468	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
469
470config STACKPROTECTOR_PER_TASK
471	def_bool y
472	depends on !GCC_PLUGIN_RANDSTRUCT
473	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
474
475config PHYS_RAM_BASE_FIXED
476	bool "Explicitly specified physical RAM address"
477	default n
478
479config PHYS_RAM_BASE
480	hex "Platform Physical RAM address"
481	depends on PHYS_RAM_BASE_FIXED
482	default "0x80000000"
483	help
484	  This is the physical address of RAM in the system. It has to be
485	  explicitly specified to run early relocations of read-write data
486	  from flash to RAM.
487
488config XIP_KERNEL
489	bool "Kernel Execute-In-Place from ROM"
490	depends on MMU && SPARSEMEM
491	# This prevents XIP from being enabled by all{yes,mod}config, which
492	# fail to build since XIP doesn't support large kernels.
493	depends on !COMPILE_TEST
494	select PHYS_RAM_BASE_FIXED
495	help
496	  Execute-In-Place allows the kernel to run from non-volatile storage
497	  directly addressable by the CPU, such as NOR flash. This saves RAM
498	  space since the text section of the kernel is not loaded from flash
499	  to RAM.  Read-write sections, such as the data section and stack,
500	  are still copied to RAM.  The XIP kernel is not compressed since
501	  it has to run directly from flash, so it will take more space to
502	  store it.  The flash address used to link the kernel object files,
503	  and for storing it, is configuration dependent. Therefore, if you
504	  say Y here, you must know the proper physical address where to
505	  store the kernel image depending on your own flash memory usage.
506
507	  Also note that the make target becomes "make xipImage" rather than
508	  "make zImage" or "make Image".  The final kernel binary to put in
509	  ROM memory will be arch/riscv/boot/xipImage.
510
511	  SPARSEMEM is required because the kernel text and rodata that are
512	  flash resident are not backed by memmap, then any attempt to get
513	  a struct page on those regions will trigger a fault.
514
515	  If unsure, say N.
516
517config XIP_PHYS_ADDR
518	hex "XIP Kernel Physical Location"
519	depends on XIP_KERNEL
520	default "0x21000000"
521	help
522	  This is the physical address in your flash memory the kernel will
523	  be linked for and stored to.  This address is dependent on your
524	  own flash usage.
525
526endmenu
527
528config BUILTIN_DTB
529	bool
530	depends on OF
531	default y if XIP_KERNEL
532
533menu "Power management options"
534
535source "kernel/power/Kconfig"
536
537endmenu
538
539menu "CPU Power Management"
540
541source "drivers/cpuidle/Kconfig"
542
543endmenu
544
545source "arch/riscv/kvm/Kconfig"
546