xref: /linux/arch/riscv/Kconfig (revision 6bd33e1ece528f67646db33bf97406b747dafda0)
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	# even on 32-bit, physical (and DMA) addresses are > 32-bits
16	select PHYS_ADDR_T_64BIT
17	select OF
18	select OF_EARLY_FLATTREE
19	select OF_IRQ
20	select ARCH_HAS_BINFMT_FLAT
21	select ARCH_WANT_FRAME_POINTERS
22	select CLONE_BACKWARDS
23	select COMMON_CLK
24	select GENERIC_CLOCKEVENTS
25	select GENERIC_CPU_DEVICES
26	select GENERIC_IRQ_SHOW
27	select GENERIC_PCI_IOMAP
28	select GENERIC_SCHED_CLOCK
29	select GENERIC_STRNCPY_FROM_USER if MMU
30	select GENERIC_STRNLEN_USER if MMU
31	select GENERIC_SMP_IDLE_THREAD
32	select GENERIC_ATOMIC64 if !64BIT
33	select HAVE_ARCH_AUDITSYSCALL
34	select HAVE_ASM_MODVERSIONS
35	select HAVE_MEMBLOCK_NODE_MAP
36	select HAVE_DMA_CONTIGUOUS if MMU
37	select HAVE_FUTEX_CMPXCHG if FUTEX
38	select HAVE_PERF_EVENTS
39	select HAVE_PERF_REGS
40	select HAVE_PERF_USER_STACK_DUMP
41	select HAVE_SYSCALL_TRACEPOINTS
42	select IRQ_DOMAIN
43	select SPARSE_IRQ
44	select SYSCTL_EXCEPTION_TRACE
45	select HAVE_ARCH_TRACEHOOK
46	select HAVE_PCI
47	select MODULES_USE_ELF_RELA if MODULES
48	select MODULE_SECTIONS if MODULES
49	select THREAD_INFO_IN_TASK
50	select PCI_DOMAINS_GENERIC if PCI
51	select PCI_MSI if PCI
52	select RISCV_TIMER
53	select UACCESS_MEMCPY if !MMU
54	select GENERIC_IRQ_MULTI_HANDLER
55	select GENERIC_ARCH_TOPOLOGY if SMP
56	select ARCH_HAS_PTE_SPECIAL
57	select ARCH_HAS_MMIOWB
58	select HAVE_EBPF_JIT if 64BIT
59	select EDAC_SUPPORT
60	select ARCH_HAS_GIGANTIC_PAGE
61	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
62	select SPARSEMEM_STATIC if 32BIT
63	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
64	select HAVE_ARCH_MMAP_RND_BITS if MMU
65
66config ARCH_MMAP_RND_BITS_MIN
67	default 18 if 64BIT
68	default 8
69
70# max bits determined by the following formula:
71#  VA_BITS - PAGE_SHIFT - 3
72config ARCH_MMAP_RND_BITS_MAX
73	default 24 if 64BIT # SV39 based
74	default 17
75
76# set if we run in machine mode, cleared if we run in supervisor mode
77config RISCV_M_MODE
78	bool
79	default !MMU
80
81# set if we are running in S-mode and can use SBI calls
82config RISCV_SBI
83	bool
84	depends on !RISCV_M_MODE
85	default y
86
87config MMU
88	bool "MMU-based Paged Memory Management Support"
89	default y
90	help
91	  Select if you want MMU-based virtualised addressing space
92	  support by paged memory management. If unsure, say 'Y'.
93
94config ZONE_DMA32
95	bool
96	default y if 64BIT
97
98config VA_BITS
99	int
100	default 32 if 32BIT
101	default 39 if 64BIT
102
103config PA_BITS
104	int
105	default 34 if 32BIT
106	default 56 if 64BIT
107
108config PAGE_OFFSET
109	hex
110	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
111	default 0x80000000 if 64BIT && !MMU
112	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
113	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
114
115config ARCH_FLATMEM_ENABLE
116	def_bool y
117
118config ARCH_SPARSEMEM_ENABLE
119	def_bool y
120	select SPARSEMEM_VMEMMAP_ENABLE
121
122config ARCH_SELECT_MEMORY_MODEL
123	def_bool ARCH_SPARSEMEM_ENABLE
124
125config ARCH_WANT_GENERAL_HUGETLB
126	def_bool y
127
128config SYS_SUPPORTS_HUGETLBFS
129	def_bool y
130
131config STACKTRACE_SUPPORT
132	def_bool y
133
134config TRACE_IRQFLAGS_SUPPORT
135	def_bool y
136
137config GENERIC_BUG
138	def_bool y
139	depends on BUG
140	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
141
142config GENERIC_BUG_RELATIVE_POINTERS
143	bool
144
145config GENERIC_CALIBRATE_DELAY
146	def_bool y
147
148config GENERIC_CSUM
149	def_bool y
150
151config GENERIC_HWEIGHT
152	def_bool y
153
154config FIX_EARLYCON_MEM
155	def_bool CONFIG_MMU
156
157config PGTABLE_LEVELS
158	int
159	default 3 if 64BIT
160	default 2
161
162source "arch/riscv/Kconfig.socs"
163
164menu "Platform type"
165
166choice
167	prompt "Base ISA"
168	default ARCH_RV64I
169	help
170	  This selects the base ISA that this kernel will target and must match
171	  the target platform.
172
173config ARCH_RV32I
174	bool "RV32I"
175	select 32BIT
176	select GENERIC_LIB_ASHLDI3
177	select GENERIC_LIB_ASHRDI3
178	select GENERIC_LIB_LSHRDI3
179	select GENERIC_LIB_UCMPDI2
180	select MMU
181
182config ARCH_RV64I
183	bool "RV64I"
184	select 64BIT
185	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
186	select HAVE_FUNCTION_TRACER
187	select HAVE_FUNCTION_GRAPH_TRACER
188	select HAVE_FTRACE_MCOUNT_RECORD
189	select HAVE_DYNAMIC_FTRACE if MMU
190	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
191	select SWIOTLB if MMU
192
193endchoice
194
195# We must be able to map all physical memory into the kernel, but the compiler
196# is still a bit more efficient when generating code if it's setup in a manner
197# such that it can only map 2GiB of memory.
198choice
199	prompt "Kernel Code Model"
200	default CMODEL_MEDLOW if 32BIT
201	default CMODEL_MEDANY if 64BIT
202
203	config CMODEL_MEDLOW
204		bool "medium low code model"
205	config CMODEL_MEDANY
206		bool "medium any code model"
207endchoice
208
209config MODULE_SECTIONS
210	bool
211	select HAVE_MOD_ARCH_SPECIFIC
212
213choice
214	prompt "Maximum Physical Memory"
215	default MAXPHYSMEM_2GB if 32BIT
216	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
217	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
218
219	config MAXPHYSMEM_2GB
220		bool "2GiB"
221	config MAXPHYSMEM_128GB
222		depends on 64BIT && CMODEL_MEDANY
223		bool "128GiB"
224endchoice
225
226
227config SMP
228	bool "Symmetric Multi-Processing"
229	help
230	  This enables support for systems with more than one CPU.  If
231	  you say N here, the kernel will run on single and
232	  multiprocessor machines, but will use only one CPU of a
233	  multiprocessor machine. If you say Y here, the kernel will run
234	  on many, but not all, single processor machines. On a single
235	  processor machine, the kernel will run faster if you say N
236	  here.
237
238	  If you don't know what to do here, say N.
239
240config NR_CPUS
241	int "Maximum number of CPUs (2-32)"
242	range 2 32
243	depends on SMP
244	default "8"
245
246choice
247	prompt "CPU Tuning"
248	default TUNE_GENERIC
249
250config TUNE_GENERIC
251	bool "generic"
252
253endchoice
254
255config RISCV_ISA_C
256	bool "Emit compressed instructions when building Linux"
257	default y
258	help
259	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
260	   when building Linux, which results in compressed instructions in the
261	   Linux binary.
262
263	   If you don't know what to do here, say Y.
264
265menu "supported PMU type"
266	depends on PERF_EVENTS
267
268config RISCV_BASE_PMU
269	bool "Base Performance Monitoring Unit"
270	def_bool y
271	help
272	  A base PMU that serves as a reference implementation and has limited
273	  feature of perf.  It can run on any RISC-V machines so serves as the
274	  fallback, but this option can also be disable to reduce kernel size.
275
276endmenu
277
278config FPU
279	bool "FPU support"
280	default y
281	help
282	  Say N here if you want to disable all floating-point related procedure
283	  in the kernel.
284
285	  If you don't know what to do here, say Y.
286
287endmenu
288
289menu "Kernel features"
290
291source "kernel/Kconfig.hz"
292
293endmenu
294
295menu "Boot options"
296
297config CMDLINE
298	string "Built-in kernel command line"
299	help
300	  For most platforms, the arguments for the kernel's command line
301	  are provided at run-time, during boot. However, there are cases
302	  where either no arguments are being provided or the provided
303	  arguments are insufficient or even invalid.
304
305	  When that occurs, it is possible to define a built-in command
306	  line here and choose how the kernel should use it later on.
307
308choice
309	prompt "Built-in command line usage" if CMDLINE != ""
310	default CMDLINE_FALLBACK
311	help
312	  Choose how the kernel will handle the provided built-in command
313	  line.
314
315config CMDLINE_FALLBACK
316	bool "Use bootloader kernel arguments if available"
317	help
318	  Use the built-in command line as fallback in case we get nothing
319	  during boot. This is the default behaviour.
320
321config CMDLINE_EXTEND
322	bool "Extend bootloader kernel arguments"
323	help
324	  The command-line arguments provided during boot will be
325	  appended to the built-in command line. This is useful in
326	  cases where the provided arguments are insufficient and
327	  you don't want to or cannot modify them.
328
329
330config CMDLINE_FORCE
331	bool "Always use the default kernel command string"
332	help
333	  Always use the built-in command line, even if we get one during
334	  boot. This is useful in case you need to override the provided
335	  command line on systems where you don't have or want control
336	  over it.
337
338endchoice
339
340endmenu
341
342menu "Power management options"
343
344source "kernel/power/Kconfig"
345
346endmenu
347