xref: /openbmc/linux/arch/riscv/Kconfig (revision e553d2a5)
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
30	select GENERIC_STRNLEN_USER
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
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 GENERIC_IRQ_MULTI_HANDLER
54	select GENERIC_ARCH_TOPOLOGY if SMP
55	select ARCH_HAS_PTE_SPECIAL
56	select ARCH_HAS_MMIOWB
57	select HAVE_EBPF_JIT if 64BIT
58	select EDAC_SUPPORT
59	select ARCH_HAS_GIGANTIC_PAGE
60	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
61	select SPARSEMEM_STATIC if 32BIT
62
63config MMU
64	def_bool y
65
66config ZONE_DMA32
67	bool
68	default y if 64BIT
69
70config VA_BITS
71	int
72	default 32 if 32BIT
73	default 39 if 64BIT
74
75config PA_BITS
76	int
77	default 34 if 32BIT
78	default 56 if 64BIT
79
80config PAGE_OFFSET
81	hex
82	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
83	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
84	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
85
86config ARCH_FLATMEM_ENABLE
87	def_bool y
88
89config ARCH_SPARSEMEM_ENABLE
90	def_bool y
91	select SPARSEMEM_VMEMMAP_ENABLE
92
93config ARCH_SELECT_MEMORY_MODEL
94	def_bool ARCH_SPARSEMEM_ENABLE
95
96config ARCH_WANT_GENERAL_HUGETLB
97	def_bool y
98
99config SYS_SUPPORTS_HUGETLBFS
100	def_bool y
101
102config STACKTRACE_SUPPORT
103	def_bool y
104
105config TRACE_IRQFLAGS_SUPPORT
106	def_bool y
107
108config GENERIC_BUG
109	def_bool y
110	depends on BUG
111	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
112
113config GENERIC_BUG_RELATIVE_POINTERS
114	bool
115
116config GENERIC_CALIBRATE_DELAY
117	def_bool y
118
119config GENERIC_CSUM
120	def_bool y
121
122config GENERIC_HWEIGHT
123	def_bool y
124
125config FIX_EARLYCON_MEM
126	def_bool y
127
128config PGTABLE_LEVELS
129	int
130	default 3 if 64BIT
131	default 2
132
133source "arch/riscv/Kconfig.socs"
134
135menu "Platform type"
136
137choice
138	prompt "Base ISA"
139	default ARCH_RV64I
140	help
141	  This selects the base ISA that this kernel will target and must match
142	  the target platform.
143
144config ARCH_RV32I
145	bool "RV32I"
146	select 32BIT
147	select GENERIC_LIB_ASHLDI3
148	select GENERIC_LIB_ASHRDI3
149	select GENERIC_LIB_LSHRDI3
150	select GENERIC_LIB_UCMPDI2
151
152config ARCH_RV64I
153	bool "RV64I"
154	select 64BIT
155	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
156	select HAVE_FUNCTION_TRACER
157	select HAVE_FUNCTION_GRAPH_TRACER
158	select HAVE_FTRACE_MCOUNT_RECORD
159	select HAVE_DYNAMIC_FTRACE
160	select HAVE_DYNAMIC_FTRACE_WITH_REGS
161	select SWIOTLB
162
163endchoice
164
165# We must be able to map all physical memory into the kernel, but the compiler
166# is still a bit more efficient when generating code if it's setup in a manner
167# such that it can only map 2GiB of memory.
168choice
169	prompt "Kernel Code Model"
170	default CMODEL_MEDLOW if 32BIT
171	default CMODEL_MEDANY if 64BIT
172
173	config CMODEL_MEDLOW
174		bool "medium low code model"
175	config CMODEL_MEDANY
176		bool "medium any code model"
177endchoice
178
179config MODULE_SECTIONS
180	bool
181	select HAVE_MOD_ARCH_SPECIFIC
182
183choice
184	prompt "Maximum Physical Memory"
185	default MAXPHYSMEM_2GB if 32BIT
186	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
187	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
188
189	config MAXPHYSMEM_2GB
190		bool "2GiB"
191	config MAXPHYSMEM_128GB
192		depends on 64BIT && CMODEL_MEDANY
193		bool "128GiB"
194endchoice
195
196
197config SMP
198	bool "Symmetric Multi-Processing"
199	help
200	  This enables support for systems with more than one CPU.  If
201	  you say N here, the kernel will run on single and
202	  multiprocessor machines, but will use only one CPU of a
203	  multiprocessor machine. If you say Y here, the kernel will run
204	  on many, but not all, single processor machines. On a single
205	  processor machine, the kernel will run faster if you say N
206	  here.
207
208	  If you don't know what to do here, say N.
209
210config NR_CPUS
211	int "Maximum number of CPUs (2-32)"
212	range 2 32
213	depends on SMP
214	default "8"
215
216choice
217	prompt "CPU Tuning"
218	default TUNE_GENERIC
219
220config TUNE_GENERIC
221	bool "generic"
222
223endchoice
224
225config RISCV_ISA_C
226	bool "Emit compressed instructions when building Linux"
227	default y
228	help
229	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
230	   when building Linux, which results in compressed instructions in the
231	   Linux binary.
232
233	   If you don't know what to do here, say Y.
234
235menu "supported PMU type"
236	depends on PERF_EVENTS
237
238config RISCV_BASE_PMU
239	bool "Base Performance Monitoring Unit"
240	def_bool y
241	help
242	  A base PMU that serves as a reference implementation and has limited
243	  feature of perf.  It can run on any RISC-V machines so serves as the
244	  fallback, but this option can also be disable to reduce kernel size.
245
246endmenu
247
248config FPU
249	bool "FPU support"
250	default y
251	help
252	  Say N here if you want to disable all floating-point related procedure
253	  in the kernel.
254
255	  If you don't know what to do here, say Y.
256
257endmenu
258
259menu "Kernel features"
260
261source "kernel/Kconfig.hz"
262
263endmenu
264
265menu "Boot options"
266
267config CMDLINE
268	string "Built-in kernel command line"
269	help
270	  For most platforms, the arguments for the kernel's command line
271	  are provided at run-time, during boot. However, there are cases
272	  where either no arguments are being provided or the provided
273	  arguments are insufficient or even invalid.
274
275	  When that occurs, it is possible to define a built-in command
276	  line here and choose how the kernel should use it later on.
277
278choice
279	prompt "Built-in command line usage" if CMDLINE != ""
280	default CMDLINE_FALLBACK
281	help
282	  Choose how the kernel will handle the provided built-in command
283	  line.
284
285config CMDLINE_FALLBACK
286	bool "Use bootloader kernel arguments if available"
287	help
288	  Use the built-in command line as fallback in case we get nothing
289	  during boot. This is the default behaviour.
290
291config CMDLINE_EXTEND
292	bool "Extend bootloader kernel arguments"
293	help
294	  The command-line arguments provided during boot will be
295	  appended to the built-in command line. This is useful in
296	  cases where the provided arguments are insufficient and
297	  you don't want to or cannot modify them.
298
299
300config CMDLINE_FORCE
301	bool "Always use the default kernel command string"
302	help
303	  Always use the built-in command line, even if we get one during
304	  boot. This is useful in case you need to override the provided
305	  command line on systems where you don't have or want control
306	  over it.
307
308endchoice
309
310endmenu
311
312menu "Power management options"
313
314source "kernel/power/Kconfig"
315
316endmenu
317