xref: /openbmc/linux/arch/riscv/Kconfig (revision 95777591)
1#
2# For a description of the syntax of this configuration file,
3# see Documentation/kbuild/kconfig-language.txt.
4#
5
6config 64BIT
7	bool
8
9config 32BIT
10	bool
11
12config RISCV
13	def_bool y
14	# even on 32-bit, physical (and DMA) addresses are > 32-bits
15	select PHYS_ADDR_T_64BIT
16	select OF
17	select OF_EARLY_FLATTREE
18	select OF_IRQ
19	select ARCH_WANT_FRAME_POINTERS
20	select CLONE_BACKWARDS
21	select COMMON_CLK
22	select GENERIC_CLOCKEVENTS
23	select GENERIC_CPU_DEVICES
24	select GENERIC_IRQ_SHOW
25	select GENERIC_PCI_IOMAP
26	select GENERIC_SCHED_CLOCK
27	select GENERIC_STRNCPY_FROM_USER
28	select GENERIC_STRNLEN_USER
29	select GENERIC_SMP_IDLE_THREAD
30	select GENERIC_ATOMIC64 if !64BIT || !RISCV_ISA_A
31	select HAVE_ARCH_AUDITSYSCALL
32	select HAVE_MEMBLOCK_NODE_MAP
33	select HAVE_DMA_CONTIGUOUS
34	select HAVE_FUTEX_CMPXCHG if FUTEX
35	select HAVE_GENERIC_DMA_COHERENT
36	select HAVE_PERF_EVENTS
37	select HAVE_SYSCALL_TRACEPOINTS
38	select IRQ_DOMAIN
39	select RISCV_ISA_A if SMP
40	select SPARSE_IRQ
41	select SYSCTL_EXCEPTION_TRACE
42	select HAVE_ARCH_TRACEHOOK
43	select HAVE_PCI
44	select MODULES_USE_ELF_RELA if MODULES
45	select MODULE_SECTIONS if MODULES
46	select THREAD_INFO_IN_TASK
47	select PCI_DOMAINS_GENERIC if PCI
48	select PCI_MSI if PCI
49	select RISCV_TIMER
50	select GENERIC_IRQ_MULTI_HANDLER
51	select ARCH_HAS_PTE_SPECIAL
52	select HAVE_EBPF_JIT if 64BIT
53
54config MMU
55	def_bool y
56
57config ZONE_DMA32
58	bool
59	default y if 64BIT
60
61config PAGE_OFFSET
62	hex
63	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
64	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
65	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
66
67config STACKTRACE_SUPPORT
68	def_bool y
69
70config TRACE_IRQFLAGS_SUPPORT
71	def_bool y
72
73config RWSEM_GENERIC_SPINLOCK
74	def_bool y
75
76config GENERIC_BUG
77	def_bool y
78	depends on BUG
79	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
80
81config GENERIC_BUG_RELATIVE_POINTERS
82	bool
83
84config GENERIC_CALIBRATE_DELAY
85	def_bool y
86
87config GENERIC_CSUM
88	def_bool y
89
90config GENERIC_HWEIGHT
91	def_bool y
92
93config PGTABLE_LEVELS
94	int
95	default 3 if 64BIT
96	default 2
97
98config HAVE_KPROBES
99	def_bool n
100
101menu "Platform type"
102
103choice
104	prompt "Base ISA"
105	default ARCH_RV64I
106	help
107	  This selects the base ISA that this kernel will target and must match
108	  the target platform.
109
110config ARCH_RV32I
111	bool "RV32I"
112	select 32BIT
113	select GENERIC_LIB_ASHLDI3
114	select GENERIC_LIB_ASHRDI3
115	select GENERIC_LIB_LSHRDI3
116	select GENERIC_LIB_UCMPDI2
117
118config ARCH_RV64I
119	bool "RV64I"
120	select 64BIT
121	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
122	select HAVE_FUNCTION_TRACER
123	select HAVE_FUNCTION_GRAPH_TRACER
124	select HAVE_FTRACE_MCOUNT_RECORD
125	select HAVE_DYNAMIC_FTRACE
126	select HAVE_DYNAMIC_FTRACE_WITH_REGS
127	select SWIOTLB
128
129endchoice
130
131# We must be able to map all physical memory into the kernel, but the compiler
132# is still a bit more efficient when generating code if it's setup in a manner
133# such that it can only map 2GiB of memory.
134choice
135	prompt "Kernel Code Model"
136	default CMODEL_MEDLOW if 32BIT
137	default CMODEL_MEDANY if 64BIT
138
139	config CMODEL_MEDLOW
140		bool "medium low code model"
141	config CMODEL_MEDANY
142		bool "medium any code model"
143endchoice
144
145config MODULE_SECTIONS
146	bool
147	select HAVE_MOD_ARCH_SPECIFIC
148
149choice
150	prompt "Maximum Physical Memory"
151	default MAXPHYSMEM_2GB if 32BIT
152	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
153	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
154
155	config MAXPHYSMEM_2GB
156		bool "2GiB"
157	config MAXPHYSMEM_128GB
158		depends on 64BIT && CMODEL_MEDANY
159		bool "128GiB"
160endchoice
161
162
163config SMP
164	bool "Symmetric Multi-Processing"
165	help
166	  This enables support for systems with more than one CPU.  If
167	  you say N here, the kernel will run on single and
168	  multiprocessor machines, but will use only one CPU of a
169	  multiprocessor machine. If you say Y here, the kernel will run
170	  on many, but not all, single processor machines. On a single
171	  processor machine, the kernel will run faster if you say N
172	  here.
173
174	  If you don't know what to do here, say N.
175
176config NR_CPUS
177	int "Maximum number of CPUs (2-32)"
178	range 2 32
179	depends on SMP
180	default "8"
181
182choice
183	prompt "CPU Tuning"
184	default TUNE_GENERIC
185
186config TUNE_GENERIC
187	bool "generic"
188
189endchoice
190
191config RISCV_ISA_C
192	bool "Emit compressed instructions when building Linux"
193	default y
194	help
195	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
196	   when building Linux, which results in compressed instructions in the
197	   Linux binary.
198
199	   If you don't know what to do here, say Y.
200
201config RISCV_ISA_A
202	def_bool y
203
204menu "supported PMU type"
205	depends on PERF_EVENTS
206
207config RISCV_BASE_PMU
208	bool "Base Performance Monitoring Unit"
209	def_bool y
210	help
211	  A base PMU that serves as a reference implementation and has limited
212	  feature of perf.  It can run on any RISC-V machines so serves as the
213	  fallback, but this option can also be disable to reduce kernel size.
214
215endmenu
216
217config FPU
218	bool "FPU support"
219	default y
220	help
221	  Say N here if you want to disable all floating-point related procedure
222	  in the kernel.
223
224	  If you don't know what to do here, say Y.
225
226endmenu
227
228menu "Kernel features"
229
230source "kernel/Kconfig.hz"
231
232endmenu
233
234menu "Boot options"
235
236config CMDLINE
237	string "Built-in kernel command line"
238	help
239	  For most platforms, the arguments for the kernel's command line
240	  are provided at run-time, during boot. However, there are cases
241	  where either no arguments are being provided or the provided
242	  arguments are insufficient or even invalid.
243
244	  When that occurs, it is possible to define a built-in command
245	  line here and choose how the kernel should use it later on.
246
247choice
248	prompt "Built-in command line usage" if CMDLINE != ""
249	default CMDLINE_FALLBACK
250	help
251	  Choose how the kernel will handle the provided built-in command
252	  line.
253
254config CMDLINE_FALLBACK
255	bool "Use bootloader kernel arguments if available"
256	help
257	  Use the built-in command line as fallback in case we get nothing
258	  during boot. This is the default behaviour.
259
260config CMDLINE_EXTEND
261	bool "Extend bootloader kernel arguments"
262	help
263	  The command-line arguments provided during boot will be
264	  appended to the built-in command line. This is useful in
265	  cases where the provided arguments are insufficient and
266	  you don't want to or cannot modify them.
267
268
269config CMDLINE_FORCE
270	bool "Always use the default kernel command string"
271	help
272	  Always use the built-in command line, even if we get one during
273	  boot. This is useful in case you need to override the provided
274	  command line on systems where you don't have or want control
275	  over it.
276
277endchoice
278
279endmenu
280
281menu "Power management options"
282
283source "kernel/power/Kconfig"
284
285endmenu
286