xref: /openbmc/linux/arch/riscv/Kconfig (revision 51bc620b)
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_MEMBLOCK_NODE_MAP
35	select HAVE_DMA_CONTIGUOUS
36	select HAVE_FUTEX_CMPXCHG if FUTEX
37	select HAVE_PERF_EVENTS
38	select HAVE_PERF_REGS
39	select HAVE_PERF_USER_STACK_DUMP
40	select HAVE_SYSCALL_TRACEPOINTS
41	select IRQ_DOMAIN
42	select SPARSE_IRQ
43	select SYSCTL_EXCEPTION_TRACE
44	select HAVE_ARCH_TRACEHOOK
45	select HAVE_PCI
46	select MODULES_USE_ELF_RELA if MODULES
47	select MODULE_SECTIONS if MODULES
48	select THREAD_INFO_IN_TASK
49	select PCI_DOMAINS_GENERIC if PCI
50	select PCI_MSI if PCI
51	select RISCV_TIMER
52	select GENERIC_IRQ_MULTI_HANDLER
53	select GENERIC_ARCH_TOPOLOGY if SMP
54	select ARCH_HAS_PTE_SPECIAL
55	select ARCH_HAS_MMIOWB
56	select HAVE_EBPF_JIT if 64BIT
57	select EDAC_SUPPORT
58	select ARCH_HAS_GIGANTIC_PAGE
59	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
60	select SPARSEMEM_STATIC if 32BIT
61
62config MMU
63	def_bool y
64
65config ZONE_DMA32
66	bool
67	default y if 64BIT
68
69config VA_BITS
70	int
71	default 32 if 32BIT
72	default 39 if 64BIT
73
74config PA_BITS
75	int
76	default 34 if 32BIT
77	default 56 if 64BIT
78
79config PAGE_OFFSET
80	hex
81	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
82	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
83	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
84
85config ARCH_FLATMEM_ENABLE
86	def_bool y
87
88config ARCH_SPARSEMEM_ENABLE
89	def_bool y
90	select SPARSEMEM_VMEMMAP_ENABLE
91
92config ARCH_SELECT_MEMORY_MODEL
93	def_bool ARCH_SPARSEMEM_ENABLE
94
95config ARCH_WANT_GENERAL_HUGETLB
96	def_bool y
97
98config SYS_SUPPORTS_HUGETLBFS
99	def_bool y
100
101config STACKTRACE_SUPPORT
102	def_bool y
103
104config TRACE_IRQFLAGS_SUPPORT
105	def_bool y
106
107config GENERIC_BUG
108	def_bool y
109	depends on BUG
110	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
111
112config GENERIC_BUG_RELATIVE_POINTERS
113	bool
114
115config GENERIC_CALIBRATE_DELAY
116	def_bool y
117
118config GENERIC_CSUM
119	def_bool y
120
121config GENERIC_HWEIGHT
122	def_bool y
123
124config FIX_EARLYCON_MEM
125	def_bool y
126
127config PGTABLE_LEVELS
128	int
129	default 3 if 64BIT
130	default 2
131
132source "arch/riscv/Kconfig.socs"
133
134menu "Platform type"
135
136choice
137	prompt "Base ISA"
138	default ARCH_RV64I
139	help
140	  This selects the base ISA that this kernel will target and must match
141	  the target platform.
142
143config ARCH_RV32I
144	bool "RV32I"
145	select 32BIT
146	select GENERIC_LIB_ASHLDI3
147	select GENERIC_LIB_ASHRDI3
148	select GENERIC_LIB_LSHRDI3
149	select GENERIC_LIB_UCMPDI2
150
151config ARCH_RV64I
152	bool "RV64I"
153	select 64BIT
154	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
155	select HAVE_FUNCTION_TRACER
156	select HAVE_FUNCTION_GRAPH_TRACER
157	select HAVE_FTRACE_MCOUNT_RECORD
158	select HAVE_DYNAMIC_FTRACE
159	select HAVE_DYNAMIC_FTRACE_WITH_REGS
160	select SWIOTLB
161
162endchoice
163
164# We must be able to map all physical memory into the kernel, but the compiler
165# is still a bit more efficient when generating code if it's setup in a manner
166# such that it can only map 2GiB of memory.
167choice
168	prompt "Kernel Code Model"
169	default CMODEL_MEDLOW if 32BIT
170	default CMODEL_MEDANY if 64BIT
171
172	config CMODEL_MEDLOW
173		bool "medium low code model"
174	config CMODEL_MEDANY
175		bool "medium any code model"
176endchoice
177
178config MODULE_SECTIONS
179	bool
180	select HAVE_MOD_ARCH_SPECIFIC
181
182choice
183	prompt "Maximum Physical Memory"
184	default MAXPHYSMEM_2GB if 32BIT
185	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
186	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
187
188	config MAXPHYSMEM_2GB
189		bool "2GiB"
190	config MAXPHYSMEM_128GB
191		depends on 64BIT && CMODEL_MEDANY
192		bool "128GiB"
193endchoice
194
195
196config SMP
197	bool "Symmetric Multi-Processing"
198	help
199	  This enables support for systems with more than one CPU.  If
200	  you say N here, the kernel will run on single and
201	  multiprocessor machines, but will use only one CPU of a
202	  multiprocessor machine. If you say Y here, the kernel will run
203	  on many, but not all, single processor machines. On a single
204	  processor machine, the kernel will run faster if you say N
205	  here.
206
207	  If you don't know what to do here, say N.
208
209config NR_CPUS
210	int "Maximum number of CPUs (2-32)"
211	range 2 32
212	depends on SMP
213	default "8"
214
215choice
216	prompt "CPU Tuning"
217	default TUNE_GENERIC
218
219config TUNE_GENERIC
220	bool "generic"
221
222endchoice
223
224config RISCV_ISA_C
225	bool "Emit compressed instructions when building Linux"
226	default y
227	help
228	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
229	   when building Linux, which results in compressed instructions in the
230	   Linux binary.
231
232	   If you don't know what to do here, say Y.
233
234menu "supported PMU type"
235	depends on PERF_EVENTS
236
237config RISCV_BASE_PMU
238	bool "Base Performance Monitoring Unit"
239	def_bool y
240	help
241	  A base PMU that serves as a reference implementation and has limited
242	  feature of perf.  It can run on any RISC-V machines so serves as the
243	  fallback, but this option can also be disable to reduce kernel size.
244
245endmenu
246
247config FPU
248	bool "FPU support"
249	default y
250	help
251	  Say N here if you want to disable all floating-point related procedure
252	  in the kernel.
253
254	  If you don't know what to do here, say Y.
255
256endmenu
257
258menu "Kernel features"
259
260source "kernel/Kconfig.hz"
261
262endmenu
263
264menu "Boot options"
265
266config CMDLINE
267	string "Built-in kernel command line"
268	help
269	  For most platforms, the arguments for the kernel's command line
270	  are provided at run-time, during boot. However, there are cases
271	  where either no arguments are being provided or the provided
272	  arguments are insufficient or even invalid.
273
274	  When that occurs, it is possible to define a built-in command
275	  line here and choose how the kernel should use it later on.
276
277choice
278	prompt "Built-in command line usage" if CMDLINE != ""
279	default CMDLINE_FALLBACK
280	help
281	  Choose how the kernel will handle the provided built-in command
282	  line.
283
284config CMDLINE_FALLBACK
285	bool "Use bootloader kernel arguments if available"
286	help
287	  Use the built-in command line as fallback in case we get nothing
288	  during boot. This is the default behaviour.
289
290config CMDLINE_EXTEND
291	bool "Extend bootloader kernel arguments"
292	help
293	  The command-line arguments provided during boot will be
294	  appended to the built-in command line. This is useful in
295	  cases where the provided arguments are insufficient and
296	  you don't want to or cannot modify them.
297
298
299config CMDLINE_FORCE
300	bool "Always use the default kernel command string"
301	help
302	  Always use the built-in command line, even if we get one during
303	  boot. This is useful in case you need to override the provided
304	  command line on systems where you don't have or want control
305	  over it.
306
307endchoice
308
309endmenu
310
311menu "Power management options"
312
313source "kernel/power/Kconfig"
314
315endmenu
316