xref: /openbmc/linux/arch/riscv/Kconfig (revision 6c9111bc)
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_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_GCOV_PROFILE_ALL
22	select ARCH_HAS_GIGANTIC_PAGE
23	select ARCH_HAS_KCOV
24	select ARCH_HAS_MMIOWB
25	select ARCH_HAS_PTE_SPECIAL
26	select ARCH_HAS_SET_DIRECT_MAP
27	select ARCH_HAS_SET_MEMORY
28	select ARCH_HAS_STRICT_KERNEL_RWX if MMU
29	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
30	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
31	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
32	select ARCH_WANT_FRAME_POINTERS
33	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
34	select CLONE_BACKWARDS
35	select CLINT_TIMER if !MMU
36	select COMMON_CLK
37	select EDAC_SUPPORT
38	select GENERIC_ARCH_TOPOLOGY if SMP
39	select GENERIC_ATOMIC64 if !64BIT
40	select GENERIC_CLOCKEVENTS
41	select GENERIC_EARLY_IOREMAP
42	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
43	select GENERIC_IOREMAP
44	select GENERIC_IRQ_MULTI_HANDLER
45	select GENERIC_IRQ_SHOW
46	select GENERIC_PCI_IOMAP
47	select GENERIC_PTDUMP if MMU
48	select GENERIC_SCHED_CLOCK
49	select GENERIC_SMP_IDLE_THREAD
50	select GENERIC_STRNCPY_FROM_USER if MMU
51	select GENERIC_STRNLEN_USER if MMU
52	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
53	select HANDLE_DOMAIN_IRQ
54	select HAVE_ARCH_AUDITSYSCALL
55	select HAVE_ARCH_JUMP_LABEL
56	select HAVE_ARCH_JUMP_LABEL_RELATIVE
57	select HAVE_ARCH_KASAN if MMU && 64BIT
58	select HAVE_ARCH_KGDB
59	select HAVE_ARCH_KGDB_QXFER_PKT
60	select HAVE_ARCH_MMAP_RND_BITS if MMU
61	select HAVE_ARCH_SECCOMP_FILTER
62	select HAVE_ARCH_TRACEHOOK
63	select HAVE_ASM_MODVERSIONS
64	select HAVE_CONTEXT_TRACKING
65	select HAVE_DEBUG_KMEMLEAK
66	select HAVE_DMA_CONTIGUOUS if MMU
67	select HAVE_EBPF_JIT if MMU
68	select HAVE_FUTEX_CMPXCHG if FUTEX
69	select HAVE_GCC_PLUGINS
70	select HAVE_GENERIC_VDSO if MMU && 64BIT
71	select HAVE_PCI
72	select HAVE_PERF_EVENTS
73	select HAVE_PERF_REGS
74	select HAVE_PERF_USER_STACK_DUMP
75	select HAVE_STACKPROTECTOR
76	select HAVE_SYSCALL_TRACEPOINTS
77	select IRQ_DOMAIN
78	select MODULES_USE_ELF_RELA if MODULES
79	select MODULE_SECTIONS if MODULES
80	select OF
81	select OF_EARLY_FLATTREE
82	select OF_IRQ
83	select PCI_DOMAINS_GENERIC if PCI
84	select PCI_MSI if PCI
85	select RISCV_INTC
86	select RISCV_TIMER if RISCV_SBI
87	select SPARSEMEM_STATIC if 32BIT
88	select SPARSE_IRQ
89	select SYSCTL_EXCEPTION_TRACE
90	select THREAD_INFO_IN_TASK
91	select UACCESS_MEMCPY if !MMU
92
93config ARCH_MMAP_RND_BITS_MIN
94	default 18 if 64BIT
95	default 8
96
97# max bits determined by the following formula:
98#  VA_BITS - PAGE_SHIFT - 3
99config ARCH_MMAP_RND_BITS_MAX
100	default 24 if 64BIT # SV39 based
101	default 17
102
103# set if we run in machine mode, cleared if we run in supervisor mode
104config RISCV_M_MODE
105	bool
106	default !MMU
107
108# set if we are running in S-mode and can use SBI calls
109config RISCV_SBI
110	bool
111	depends on !RISCV_M_MODE
112	default y
113
114config MMU
115	bool "MMU-based Paged Memory Management Support"
116	default y
117	help
118	  Select if you want MMU-based virtualised addressing space
119	  support by paged memory management. If unsure, say 'Y'.
120
121config ZONE_DMA32
122	bool
123	default y if 64BIT
124
125config VA_BITS
126	int
127	default 32 if 32BIT
128	default 39 if 64BIT
129
130config PA_BITS
131	int
132	default 34 if 32BIT
133	default 56 if 64BIT
134
135config PAGE_OFFSET
136	hex
137	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
138	default 0x80000000 if 64BIT && !MMU
139	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
140	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
141
142config ARCH_FLATMEM_ENABLE
143	def_bool y
144
145config ARCH_SPARSEMEM_ENABLE
146	def_bool y
147	depends on MMU
148	select SPARSEMEM_VMEMMAP_ENABLE
149
150config ARCH_SELECT_MEMORY_MODEL
151	def_bool ARCH_SPARSEMEM_ENABLE
152
153config ARCH_WANT_GENERAL_HUGETLB
154	def_bool y
155
156config ARCH_SUPPORTS_DEBUG_PAGEALLOC
157	def_bool y
158
159config SYS_SUPPORTS_HUGETLBFS
160	depends on MMU
161	def_bool y
162
163config STACKTRACE_SUPPORT
164	def_bool y
165
166config TRACE_IRQFLAGS_SUPPORT
167	def_bool y
168
169config GENERIC_BUG
170	def_bool y
171	depends on BUG
172	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
173
174config GENERIC_BUG_RELATIVE_POINTERS
175	bool
176
177config GENERIC_CALIBRATE_DELAY
178	def_bool y
179
180config GENERIC_CSUM
181	def_bool y
182
183config GENERIC_HWEIGHT
184	def_bool y
185
186config FIX_EARLYCON_MEM
187	def_bool MMU
188
189config PGTABLE_LEVELS
190	int
191	default 3 if 64BIT
192	default 2
193
194config LOCKDEP_SUPPORT
195	def_bool y
196
197source "arch/riscv/Kconfig.socs"
198
199menu "Platform type"
200
201choice
202	prompt "Base ISA"
203	default ARCH_RV64I
204	help
205	  This selects the base ISA that this kernel will target and must match
206	  the target platform.
207
208config ARCH_RV32I
209	bool "RV32I"
210	select 32BIT
211	select GENERIC_LIB_ASHLDI3
212	select GENERIC_LIB_ASHRDI3
213	select GENERIC_LIB_LSHRDI3
214	select GENERIC_LIB_UCMPDI2
215	select MMU
216
217config ARCH_RV64I
218	bool "RV64I"
219	select 64BIT
220	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
221	select HAVE_DYNAMIC_FTRACE if MMU
222	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
223	select HAVE_FTRACE_MCOUNT_RECORD
224	select HAVE_FUNCTION_GRAPH_TRACER
225	select HAVE_FUNCTION_TRACER
226	select SWIOTLB if MMU
227
228endchoice
229
230# We must be able to map all physical memory into the kernel, but the compiler
231# is still a bit more efficient when generating code if it's setup in a manner
232# such that it can only map 2GiB of memory.
233choice
234	prompt "Kernel Code Model"
235	default CMODEL_MEDLOW if 32BIT
236	default CMODEL_MEDANY if 64BIT
237
238	config CMODEL_MEDLOW
239		bool "medium low code model"
240	config CMODEL_MEDANY
241		bool "medium any code model"
242endchoice
243
244config MODULE_SECTIONS
245	bool
246	select HAVE_MOD_ARCH_SPECIFIC
247
248choice
249	prompt "Maximum Physical Memory"
250	default MAXPHYSMEM_2GB if 32BIT
251	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
252	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
253
254	config MAXPHYSMEM_2GB
255		bool "2GiB"
256	config MAXPHYSMEM_128GB
257		depends on 64BIT && CMODEL_MEDANY
258		bool "128GiB"
259endchoice
260
261
262config SMP
263	bool "Symmetric Multi-Processing"
264	help
265	  This enables support for systems with more than one CPU.  If
266	  you say N here, the kernel will run on single and
267	  multiprocessor machines, but will use only one CPU of a
268	  multiprocessor machine. If you say Y here, the kernel will run
269	  on many, but not all, single processor machines. On a single
270	  processor machine, the kernel will run faster if you say N
271	  here.
272
273	  If you don't know what to do here, say N.
274
275config NR_CPUS
276	int "Maximum number of CPUs (2-32)"
277	range 2 32
278	depends on SMP
279	default "8"
280
281config HOTPLUG_CPU
282	bool "Support for hot-pluggable CPUs"
283	depends on SMP
284	select GENERIC_IRQ_MIGRATION
285	help
286
287	  Say Y here to experiment with turning CPUs off and on.  CPUs
288	  can be controlled through /sys/devices/system/cpu.
289
290	  Say N if you want to disable CPU hotplug.
291
292choice
293	prompt "CPU Tuning"
294	default TUNE_GENERIC
295
296config TUNE_GENERIC
297	bool "generic"
298
299endchoice
300
301config RISCV_ISA_C
302	bool "Emit compressed instructions when building Linux"
303	default y
304	help
305	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
306	   when building Linux, which results in compressed instructions in the
307	   Linux binary.
308
309	   If you don't know what to do here, say Y.
310
311menu "supported PMU type"
312	depends on PERF_EVENTS
313
314config RISCV_BASE_PMU
315	bool "Base Performance Monitoring Unit"
316	def_bool y
317	help
318	  A base PMU that serves as a reference implementation and has limited
319	  feature of perf.  It can run on any RISC-V machines so serves as the
320	  fallback, but this option can also be disable to reduce kernel size.
321
322endmenu
323
324config FPU
325	bool "FPU support"
326	default y
327	help
328	  Say N here if you want to disable all floating-point related procedure
329	  in the kernel.
330
331	  If you don't know what to do here, say Y.
332
333endmenu
334
335menu "Kernel features"
336
337source "kernel/Kconfig.hz"
338
339config RISCV_SBI_V01
340	bool "SBI v0.1 support"
341	default y
342	depends on RISCV_SBI
343	help
344	  This config allows kernel to use SBI v0.1 APIs. This will be
345	  deprecated in future once legacy M-mode software are no longer in use.
346endmenu
347
348menu "Boot options"
349
350config CMDLINE
351	string "Built-in kernel command line"
352	help
353	  For most platforms, the arguments for the kernel's command line
354	  are provided at run-time, during boot. However, there are cases
355	  where either no arguments are being provided or the provided
356	  arguments are insufficient or even invalid.
357
358	  When that occurs, it is possible to define a built-in command
359	  line here and choose how the kernel should use it later on.
360
361choice
362	prompt "Built-in command line usage" if CMDLINE != ""
363	default CMDLINE_FALLBACK
364	help
365	  Choose how the kernel will handle the provided built-in command
366	  line.
367
368config CMDLINE_FALLBACK
369	bool "Use bootloader kernel arguments if available"
370	help
371	  Use the built-in command line as fallback in case we get nothing
372	  during boot. This is the default behaviour.
373
374config CMDLINE_EXTEND
375	bool "Extend bootloader kernel arguments"
376	help
377	  The command-line arguments provided during boot will be
378	  appended to the built-in command line. This is useful in
379	  cases where the provided arguments are insufficient and
380	  you don't want to or cannot modify them.
381
382
383config CMDLINE_FORCE
384	bool "Always use the default kernel command string"
385	help
386	  Always use the built-in command line, even if we get one during
387	  boot. This is useful in case you need to override the provided
388	  command line on systems where you don't have or want control
389	  over it.
390
391endchoice
392
393config EFI_STUB
394	bool
395
396config EFI
397	bool "UEFI runtime support"
398	depends on OF
399	select LIBFDT
400	select UCS2_STRING
401	select EFI_PARAMS_FROM_FDT
402	select EFI_STUB
403	select EFI_GENERIC_STUB
404	select EFI_RUNTIME_WRAPPERS
405	select RISCV_ISA_C
406	depends on MMU
407	default y
408	help
409	  This option provides support for runtime services provided
410	  by UEFI firmware (such as non-volatile variables, realtime
411	  clock, and platform reset). A UEFI stub is also provided to
412	  allow the kernel to be booted as an EFI application. This
413	  is only useful on systems that have UEFI firmware.
414
415endmenu
416
417config BUILTIN_DTB
418	def_bool n
419	depends on RISCV_M_MODE
420	depends on OF
421
422menu "Power management options"
423
424source "kernel/power/Kconfig"
425
426endmenu
427
428source "drivers/firmware/Kconfig"
429