xref: /openbmc/linux/arch/riscv/Kconfig (revision 8a5aaf97)
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_MEMBLOCK_NODE_MAP
32	select HAVE_DMA_CONTIGUOUS
33	select HAVE_FUTEX_CMPXCHG if FUTEX
34	select HAVE_GENERIC_DMA_COHERENT
35	select HAVE_PERF_EVENTS
36	select IRQ_DOMAIN
37	select RISCV_ISA_A if SMP
38	select SPARSE_IRQ
39	select SYSCTL_EXCEPTION_TRACE
40	select HAVE_ARCH_TRACEHOOK
41	select HAVE_PCI
42	select MODULES_USE_ELF_RELA if MODULES
43	select THREAD_INFO_IN_TASK
44	select PCI_DOMAINS_GENERIC if PCI
45	select PCI_MSI if PCI
46	select RISCV_TIMER
47	select GENERIC_IRQ_MULTI_HANDLER
48	select ARCH_HAS_PTE_SPECIAL
49
50config MMU
51	def_bool y
52
53config ZONE_DMA32
54	bool
55	default y if 64BIT
56
57config PAGE_OFFSET
58	hex
59	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
60	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
61	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
62
63config STACKTRACE_SUPPORT
64	def_bool y
65
66config TRACE_IRQFLAGS_SUPPORT
67	def_bool y
68
69config RWSEM_GENERIC_SPINLOCK
70	def_bool y
71
72config GENERIC_BUG
73	def_bool y
74	depends on BUG
75	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
76
77config GENERIC_BUG_RELATIVE_POINTERS
78	bool
79
80config GENERIC_CALIBRATE_DELAY
81	def_bool y
82
83config GENERIC_CSUM
84	def_bool y
85
86config GENERIC_HWEIGHT
87	def_bool y
88
89config PGTABLE_LEVELS
90	int
91	default 3 if 64BIT
92	default 2
93
94config HAVE_KPROBES
95	def_bool n
96
97menu "Platform type"
98
99choice
100	prompt "Base ISA"
101	default ARCH_RV64I
102	help
103	  This selects the base ISA that this kernel will traget and must match
104	  the target platform.
105
106config ARCH_RV32I
107	bool "RV32I"
108	select 32BIT
109	select GENERIC_LIB_ASHLDI3
110	select GENERIC_LIB_ASHRDI3
111	select GENERIC_LIB_LSHRDI3
112	select GENERIC_LIB_UCMPDI2
113
114config ARCH_RV64I
115	bool "RV64I"
116	select 64BIT
117	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
118	select HAVE_FUNCTION_TRACER
119	select HAVE_FUNCTION_GRAPH_TRACER
120	select HAVE_FTRACE_MCOUNT_RECORD
121	select HAVE_DYNAMIC_FTRACE
122	select HAVE_DYNAMIC_FTRACE_WITH_REGS
123	select SWIOTLB
124
125endchoice
126
127# We must be able to map all physical memory into the kernel, but the compiler
128# is still a bit more efficient when generating code if it's setup in a manner
129# such that it can only map 2GiB of memory.
130choice
131	prompt "Kernel Code Model"
132	default CMODEL_MEDLOW if 32BIT
133	default CMODEL_MEDANY if 64BIT
134
135	config CMODEL_MEDLOW
136		bool "medium low code model"
137	config CMODEL_MEDANY
138		bool "medium any code model"
139endchoice
140
141config MODULE_SECTIONS
142	bool
143	select HAVE_MOD_ARCH_SPECIFIC
144
145choice
146	prompt "Maximum Physical Memory"
147	default MAXPHYSMEM_2GB if 32BIT
148	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
149	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
150
151	config MAXPHYSMEM_2GB
152		bool "2GiB"
153	config MAXPHYSMEM_128GB
154		depends on 64BIT && CMODEL_MEDANY
155		select MODULE_SECTIONS if MODULES
156		bool "128GiB"
157endchoice
158
159
160config SMP
161	bool "Symmetric Multi-Processing"
162	help
163	  This enables support for systems with more than one CPU.  If
164	  you say N here, the kernel will run on single and
165	  multiprocessor machines, but will use only one CPU of a
166	  multiprocessor machine. If you say Y here, the kernel will run
167	  on many, but not all, single processor machines. On a single
168	  processor machine, the kernel will run faster if you say N
169	  here.
170
171	  If you don't know what to do here, say N.
172
173config NR_CPUS
174	int "Maximum number of CPUs (2-32)"
175	range 2 32
176	depends on SMP
177	default "8"
178
179choice
180	prompt "CPU Tuning"
181	default TUNE_GENERIC
182
183config TUNE_GENERIC
184	bool "generic"
185
186endchoice
187
188config RISCV_ISA_C
189	bool "Emit compressed instructions when building Linux"
190	default y
191	help
192	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
193	   when building Linux, which results in compressed instructions in the
194	   Linux binary.
195
196	   If you don't know what to do here, say Y.
197
198config RISCV_ISA_A
199	def_bool y
200
201menu "supported PMU type"
202	depends on PERF_EVENTS
203
204config RISCV_BASE_PMU
205	bool "Base Performance Monitoring Unit"
206	def_bool y
207	help
208	  A base PMU that serves as a reference implementation and has limited
209	  feature of perf.  It can run on any RISC-V machines so serves as the
210	  fallback, but this option can also be disable to reduce kernel size.
211
212endmenu
213
214config FPU
215	bool "FPU support"
216	default y
217	help
218	  Say N here if you want to disable all floating-point related procedure
219	  in the kernel.
220
221	  If you don't know what to do here, say Y.
222
223endmenu
224
225menu "Kernel features"
226
227source "kernel/Kconfig.hz"
228
229endmenu
230
231menu "Boot options"
232
233config CMDLINE
234	string "Built-in kernel command line"
235	help
236	  For most platforms, the arguments for the kernel's command line
237	  are provided at run-time, during boot. However, there are cases
238	  where either no arguments are being provided or the provided
239	  arguments are insufficient or even invalid.
240
241	  When that occurs, it is possible to define a built-in command
242	  line here and choose how the kernel should use it later on.
243
244choice
245	prompt "Built-in command line usage" if CMDLINE != ""
246	default CMDLINE_FALLBACK
247	help
248	  Choose how the kernel will handle the provided built-in command
249	  line.
250
251config CMDLINE_FALLBACK
252	bool "Use bootloader kernel arguments if available"
253	help
254	  Use the built-in command line as fallback in case we get nothing
255	  during boot. This is the default behaviour.
256
257config CMDLINE_EXTEND
258	bool "Extend bootloader kernel arguments"
259	help
260	  The command-line arguments provided during boot will be
261	  appended to the built-in command line. This is useful in
262	  cases where the provided arguments are insufficient and
263	  you don't want to or cannot modify them.
264
265
266config CMDLINE_FORCE
267	bool "Always use the default kernel command string"
268	help
269	  Always use the built-in command line, even if we get one during
270	  boot. This is useful in case you need to override the provided
271	  command line on systems where you don't have or want control
272	  over it.
273
274endchoice
275
276endmenu
277
278menu "Power management options"
279
280source "kernel/power/Kconfig"
281
282endmenu
283