xref: /openbmc/linux/arch/riscv/Kconfig (revision dfc53baa)
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	select ARCH_CLOCKSOURCE_INIT
16	select ARCH_SUPPORTS_ATOMIC_RMW
17	select ARCH_HAS_BINFMT_FLAT
18	select ARCH_HAS_DEBUG_VM_PGTABLE
19	select ARCH_HAS_DEBUG_VIRTUAL if MMU
20	select ARCH_HAS_DEBUG_WX
21	select ARCH_HAS_GCOV_PROFILE_ALL
22	select ARCH_HAS_GIGANTIC_PAGE
23	select ARCH_HAS_KCOV
24	select ARCH_HAS_MMIOWB
25	select ARCH_HAS_PTE_SPECIAL
26	select ARCH_HAS_SET_DIRECT_MAP
27	select ARCH_HAS_SET_MEMORY
28	select ARCH_HAS_STRICT_KERNEL_RWX if MMU
29	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
30	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
31	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
32	select ARCH_WANT_FRAME_POINTERS
33	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
34	select CLONE_BACKWARDS
35	select CLINT_TIMER if !MMU
36	select COMMON_CLK
37	select EDAC_SUPPORT
38	select GENERIC_ARCH_TOPOLOGY if SMP
39	select GENERIC_ATOMIC64 if !64BIT
40	select GENERIC_CLOCKEVENTS
41	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
42	select GENERIC_IOREMAP
43	select GENERIC_IRQ_MULTI_HANDLER
44	select GENERIC_IRQ_SHOW
45	select GENERIC_PCI_IOMAP
46	select GENERIC_PTDUMP if MMU
47	select GENERIC_SCHED_CLOCK
48	select GENERIC_SMP_IDLE_THREAD
49	select GENERIC_STRNCPY_FROM_USER if MMU
50	select GENERIC_STRNLEN_USER if MMU
51	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
52	select HANDLE_DOMAIN_IRQ
53	select HAVE_ARCH_AUDITSYSCALL
54	select HAVE_ARCH_JUMP_LABEL
55	select HAVE_ARCH_JUMP_LABEL_RELATIVE
56	select HAVE_ARCH_KASAN if MMU && 64BIT
57	select HAVE_ARCH_KGDB
58	select HAVE_ARCH_KGDB_QXFER_PKT
59	select HAVE_ARCH_MMAP_RND_BITS if MMU
60	select HAVE_ARCH_SECCOMP_FILTER
61	select HAVE_ARCH_TRACEHOOK
62	select HAVE_ASM_MODVERSIONS
63	select HAVE_CONTEXT_TRACKING
64	select HAVE_DEBUG_KMEMLEAK
65	select HAVE_DMA_CONTIGUOUS if MMU
66	select HAVE_EBPF_JIT if MMU
67	select HAVE_FUTEX_CMPXCHG if FUTEX
68	select HAVE_GCC_PLUGINS
69	select HAVE_GENERIC_VDSO if MMU && 64BIT
70	select HAVE_PCI
71	select HAVE_PERF_EVENTS
72	select HAVE_PERF_REGS
73	select HAVE_PERF_USER_STACK_DUMP
74	select HAVE_STACKPROTECTOR
75	select HAVE_SYSCALL_TRACEPOINTS
76	select IRQ_DOMAIN
77	select MODULES_USE_ELF_RELA if MODULES
78	select MODULE_SECTIONS if MODULES
79	select OF
80	select OF_EARLY_FLATTREE
81	select OF_IRQ
82	select PCI_DOMAINS_GENERIC if PCI
83	select PCI_MSI if PCI
84	select RISCV_INTC
85	select RISCV_TIMER if RISCV_SBI
86	select SPARSEMEM_STATIC if 32BIT
87	select SPARSE_IRQ
88	select SYSCTL_EXCEPTION_TRACE
89	select THREAD_INFO_IN_TASK
90
91config ARCH_MMAP_RND_BITS_MIN
92	default 18 if 64BIT
93	default 8
94
95# max bits determined by the following formula:
96#  VA_BITS - PAGE_SHIFT - 3
97config ARCH_MMAP_RND_BITS_MAX
98	default 24 if 64BIT # SV39 based
99	default 17
100
101# set if we run in machine mode, cleared if we run in supervisor mode
102config RISCV_M_MODE
103	bool
104	default !MMU
105
106# set if we are running in S-mode and can use SBI calls
107config RISCV_SBI
108	bool
109	depends on !RISCV_M_MODE
110	default y
111
112config MMU
113	bool "MMU-based Paged Memory Management Support"
114	default y
115	help
116	  Select if you want MMU-based virtualised addressing space
117	  support by paged memory management. If unsure, say 'Y'.
118
119config ZONE_DMA32
120	bool
121	default y if 64BIT
122
123config VA_BITS
124	int
125	default 32 if 32BIT
126	default 39 if 64BIT
127
128config PA_BITS
129	int
130	default 34 if 32BIT
131	default 56 if 64BIT
132
133config PAGE_OFFSET
134	hex
135	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
136	default 0x80000000 if 64BIT && !MMU
137	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
138	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
139
140config ARCH_FLATMEM_ENABLE
141	def_bool y
142
143config ARCH_SPARSEMEM_ENABLE
144	def_bool y
145	depends on MMU
146	select SPARSEMEM_VMEMMAP_ENABLE
147
148config ARCH_SELECT_MEMORY_MODEL
149	def_bool ARCH_SPARSEMEM_ENABLE
150
151config ARCH_WANT_GENERAL_HUGETLB
152	def_bool y
153
154config ARCH_SUPPORTS_DEBUG_PAGEALLOC
155	def_bool y
156
157config SYS_SUPPORTS_HUGETLBFS
158	depends on MMU
159	def_bool y
160
161config STACKTRACE_SUPPORT
162	def_bool y
163
164config TRACE_IRQFLAGS_SUPPORT
165	def_bool y
166
167config GENERIC_BUG
168	def_bool y
169	depends on BUG
170	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
171
172config GENERIC_BUG_RELATIVE_POINTERS
173	bool
174
175config GENERIC_CALIBRATE_DELAY
176	def_bool y
177
178config GENERIC_CSUM
179	def_bool y
180
181config GENERIC_HWEIGHT
182	def_bool y
183
184config FIX_EARLYCON_MEM
185	def_bool MMU
186
187config PGTABLE_LEVELS
188	int
189	default 3 if 64BIT
190	default 2
191
192config LOCKDEP_SUPPORT
193	def_bool y
194
195source "arch/riscv/Kconfig.socs"
196
197menu "Platform type"
198
199choice
200	prompt "Base ISA"
201	default ARCH_RV64I
202	help
203	  This selects the base ISA that this kernel will target and must match
204	  the target platform.
205
206config ARCH_RV32I
207	bool "RV32I"
208	select 32BIT
209	select GENERIC_LIB_ASHLDI3
210	select GENERIC_LIB_ASHRDI3
211	select GENERIC_LIB_LSHRDI3
212	select GENERIC_LIB_UCMPDI2
213	select MMU
214
215config ARCH_RV64I
216	bool "RV64I"
217	select 64BIT
218	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
219	select HAVE_DYNAMIC_FTRACE if MMU
220	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
221	select HAVE_FTRACE_MCOUNT_RECORD
222	select HAVE_FUNCTION_GRAPH_TRACER
223	select HAVE_FUNCTION_TRACER
224	select SWIOTLB if MMU
225
226endchoice
227
228# We must be able to map all physical memory into the kernel, but the compiler
229# is still a bit more efficient when generating code if it's setup in a manner
230# such that it can only map 2GiB of memory.
231choice
232	prompt "Kernel Code Model"
233	default CMODEL_MEDLOW if 32BIT
234	default CMODEL_MEDANY if 64BIT
235
236	config CMODEL_MEDLOW
237		bool "medium low code model"
238	config CMODEL_MEDANY
239		bool "medium any code model"
240endchoice
241
242config MODULE_SECTIONS
243	bool
244	select HAVE_MOD_ARCH_SPECIFIC
245
246choice
247	prompt "Maximum Physical Memory"
248	default MAXPHYSMEM_2GB if 32BIT
249	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
250	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
251
252	config MAXPHYSMEM_2GB
253		bool "2GiB"
254	config MAXPHYSMEM_128GB
255		depends on 64BIT && CMODEL_MEDANY
256		bool "128GiB"
257endchoice
258
259
260config SMP
261	bool "Symmetric Multi-Processing"
262	help
263	  This enables support for systems with more than one CPU.  If
264	  you say N here, the kernel will run on single and
265	  multiprocessor machines, but will use only one CPU of a
266	  multiprocessor machine. If you say Y here, the kernel will run
267	  on many, but not all, single processor machines. On a single
268	  processor machine, the kernel will run faster if you say N
269	  here.
270
271	  If you don't know what to do here, say N.
272
273config NR_CPUS
274	int "Maximum number of CPUs (2-32)"
275	range 2 32
276	depends on SMP
277	default "8"
278
279config HOTPLUG_CPU
280	bool "Support for hot-pluggable CPUs"
281	depends on SMP
282	select GENERIC_IRQ_MIGRATION
283	help
284
285	  Say Y here to experiment with turning CPUs off and on.  CPUs
286	  can be controlled through /sys/devices/system/cpu.
287
288	  Say N if you want to disable CPU hotplug.
289
290choice
291	prompt "CPU Tuning"
292	default TUNE_GENERIC
293
294config TUNE_GENERIC
295	bool "generic"
296
297endchoice
298
299config RISCV_ISA_C
300	bool "Emit compressed instructions when building Linux"
301	default y
302	help
303	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
304	   when building Linux, which results in compressed instructions in the
305	   Linux binary.
306
307	   If you don't know what to do here, say Y.
308
309menu "supported PMU type"
310	depends on PERF_EVENTS
311
312config RISCV_BASE_PMU
313	bool "Base Performance Monitoring Unit"
314	def_bool y
315	help
316	  A base PMU that serves as a reference implementation and has limited
317	  feature of perf.  It can run on any RISC-V machines so serves as the
318	  fallback, but this option can also be disable to reduce kernel size.
319
320endmenu
321
322config FPU
323	bool "FPU support"
324	default y
325	help
326	  Say N here if you want to disable all floating-point related procedure
327	  in the kernel.
328
329	  If you don't know what to do here, say Y.
330
331endmenu
332
333menu "Kernel features"
334
335source "kernel/Kconfig.hz"
336
337config SECCOMP
338	bool "Enable seccomp to safely compute untrusted bytecode"
339	help
340	  This kernel feature is useful for number crunching applications
341	  that may need to compute untrusted bytecode during their
342	  execution. By using pipes or other transports made available to
343	  the process as file descriptors supporting the read/write
344	  syscalls, it's possible to isolate those applications in
345	  their own address space using seccomp. Once seccomp is
346	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
347	  and the task is only allowed to execute a few safe syscalls
348	  defined by each seccomp mode.
349
350config RISCV_SBI_V01
351	bool "SBI v0.1 support"
352	default y
353	depends on RISCV_SBI
354	help
355	  This config allows kernel to use SBI v0.1 APIs. This will be
356	  deprecated in future once legacy M-mode software are no longer in use.
357endmenu
358
359menu "Boot options"
360
361config CMDLINE
362	string "Built-in kernel command line"
363	help
364	  For most platforms, the arguments for the kernel's command line
365	  are provided at run-time, during boot. However, there are cases
366	  where either no arguments are being provided or the provided
367	  arguments are insufficient or even invalid.
368
369	  When that occurs, it is possible to define a built-in command
370	  line here and choose how the kernel should use it later on.
371
372choice
373	prompt "Built-in command line usage" if CMDLINE != ""
374	default CMDLINE_FALLBACK
375	help
376	  Choose how the kernel will handle the provided built-in command
377	  line.
378
379config CMDLINE_FALLBACK
380	bool "Use bootloader kernel arguments if available"
381	help
382	  Use the built-in command line as fallback in case we get nothing
383	  during boot. This is the default behaviour.
384
385config CMDLINE_EXTEND
386	bool "Extend bootloader kernel arguments"
387	help
388	  The command-line arguments provided during boot will be
389	  appended to the built-in command line. This is useful in
390	  cases where the provided arguments are insufficient and
391	  you don't want to or cannot modify them.
392
393
394config CMDLINE_FORCE
395	bool "Always use the default kernel command string"
396	help
397	  Always use the built-in command line, even if we get one during
398	  boot. This is useful in case you need to override the provided
399	  command line on systems where you don't have or want control
400	  over it.
401
402endchoice
403
404endmenu
405
406config BUILTIN_DTB
407	def_bool n
408	depends on RISCV_M_MODE
409	depends on OF
410
411menu "Power management options"
412
413source "kernel/power/Kconfig"
414
415endmenu
416