xref: /openbmc/linux/arch/riscv/Kconfig (revision aeefc1a0)
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_SUPPORTS_DEBUG_PAGEALLOC if MMU
18	select ARCH_HAS_BINFMT_FLAT
19	select ARCH_HAS_DEBUG_VM_PGTABLE
20	select ARCH_HAS_DEBUG_VIRTUAL if MMU
21	select ARCH_HAS_DEBUG_WX
22	select ARCH_HAS_GCOV_PROFILE_ALL
23	select ARCH_HAS_GIGANTIC_PAGE
24	select ARCH_HAS_KCOV
25	select ARCH_HAS_MMIOWB
26	select ARCH_HAS_PTE_SPECIAL
27	select ARCH_HAS_SET_DIRECT_MAP
28	select ARCH_HAS_SET_MEMORY
29	select ARCH_HAS_STRICT_KERNEL_RWX if MMU
30	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
31	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
32	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
33	select ARCH_WANT_FRAME_POINTERS
34	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
35	select CLONE_BACKWARDS
36	select CLINT_TIMER if !MMU
37	select COMMON_CLK
38	select EDAC_SUPPORT
39	select GENERIC_ARCH_TOPOLOGY if SMP
40	select GENERIC_ATOMIC64 if !64BIT
41	select GENERIC_EARLY_IOREMAP
42	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
43	select GENERIC_IOREMAP
44	select GENERIC_IRQ_MULTI_HANDLER
45	select GENERIC_IRQ_SHOW
46	select GENERIC_PCI_IOMAP
47	select GENERIC_PTDUMP if MMU
48	select GENERIC_SCHED_CLOCK
49	select GENERIC_SMP_IDLE_THREAD
50	select GENERIC_STRNCPY_FROM_USER if MMU
51	select GENERIC_STRNLEN_USER if MMU
52	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
53	select HANDLE_DOMAIN_IRQ
54	select HAVE_ARCH_AUDITSYSCALL
55	select HAVE_ARCH_JUMP_LABEL
56	select HAVE_ARCH_JUMP_LABEL_RELATIVE
57	select HAVE_ARCH_KASAN if MMU && 64BIT
58	select HAVE_ARCH_KGDB
59	select HAVE_ARCH_KGDB_QXFER_PKT
60	select HAVE_ARCH_MMAP_RND_BITS if MMU
61	select HAVE_ARCH_SECCOMP_FILTER
62	select HAVE_ARCH_TRACEHOOK
63	select HAVE_ASM_MODVERSIONS
64	select HAVE_CONTEXT_TRACKING
65	select HAVE_DEBUG_KMEMLEAK
66	select HAVE_DMA_CONTIGUOUS if MMU
67	select HAVE_EBPF_JIT if MMU
68	select HAVE_FUTEX_CMPXCHG if FUTEX
69	select HAVE_GCC_PLUGINS
70	select HAVE_GENERIC_VDSO if MMU && 64BIT
71	select HAVE_PCI
72	select HAVE_PERF_EVENTS
73	select HAVE_PERF_REGS
74	select HAVE_PERF_USER_STACK_DUMP
75	select HAVE_STACKPROTECTOR
76	select HAVE_SYSCALL_TRACEPOINTS
77	select IRQ_DOMAIN
78	select MODULES_USE_ELF_RELA if MODULES
79	select MODULE_SECTIONS if MODULES
80	select OF
81	select OF_EARLY_FLATTREE
82	select OF_IRQ
83	select PCI_DOMAINS_GENERIC if PCI
84	select PCI_MSI if PCI
85	select RISCV_INTC
86	select RISCV_TIMER if RISCV_SBI
87	select SPARSEMEM_STATIC if 32BIT
88	select SPARSE_IRQ
89	select SYSCTL_EXCEPTION_TRACE
90	select THREAD_INFO_IN_TASK
91	select UACCESS_MEMCPY if !MMU
92
93config ARCH_MMAP_RND_BITS_MIN
94	default 18 if 64BIT
95	default 8
96
97# max bits determined by the following formula:
98#  VA_BITS - PAGE_SHIFT - 3
99config ARCH_MMAP_RND_BITS_MAX
100	default 24 if 64BIT # SV39 based
101	default 17
102
103# set if we run in machine mode, cleared if we run in supervisor mode
104config RISCV_M_MODE
105	bool
106	default !MMU
107
108# set if we are running in S-mode and can use SBI calls
109config RISCV_SBI
110	bool
111	depends on !RISCV_M_MODE
112	default y
113
114config MMU
115	bool "MMU-based Paged Memory Management Support"
116	default y
117	help
118	  Select if you want MMU-based virtualised addressing space
119	  support by paged memory management. If unsure, say 'Y'.
120
121config ZONE_DMA32
122	bool
123	default y if 64BIT
124
125config VA_BITS
126	int
127	default 32 if 32BIT
128	default 39 if 64BIT
129
130config PA_BITS
131	int
132	default 34 if 32BIT
133	default 56 if 64BIT
134
135config PAGE_OFFSET
136	hex
137	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
138	default 0x80000000 if 64BIT && !MMU
139	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
140	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
141
142config ARCH_FLATMEM_ENABLE
143	def_bool y
144
145config ARCH_SPARSEMEM_ENABLE
146	def_bool y
147	depends on MMU
148	select SPARSEMEM_VMEMMAP_ENABLE
149
150config ARCH_SELECT_MEMORY_MODEL
151	def_bool ARCH_SPARSEMEM_ENABLE
152
153config ARCH_WANT_GENERAL_HUGETLB
154	def_bool y
155
156config SYS_SUPPORTS_HUGETLBFS
157	depends on MMU
158	def_bool y
159
160config STACKTRACE_SUPPORT
161	def_bool y
162
163config TRACE_IRQFLAGS_SUPPORT
164	def_bool y
165
166config GENERIC_BUG
167	def_bool y
168	depends on BUG
169	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
170
171config GENERIC_BUG_RELATIVE_POINTERS
172	bool
173
174config GENERIC_CALIBRATE_DELAY
175	def_bool y
176
177config GENERIC_CSUM
178	def_bool y
179
180config GENERIC_HWEIGHT
181	def_bool y
182
183config FIX_EARLYCON_MEM
184	def_bool MMU
185
186config PGTABLE_LEVELS
187	int
188	default 3 if 64BIT
189	default 2
190
191config LOCKDEP_SUPPORT
192	def_bool y
193
194source "arch/riscv/Kconfig.socs"
195
196menu "Platform type"
197
198choice
199	prompt "Base ISA"
200	default ARCH_RV64I
201	help
202	  This selects the base ISA that this kernel will target and must match
203	  the target platform.
204
205config ARCH_RV32I
206	bool "RV32I"
207	select 32BIT
208	select GENERIC_LIB_ASHLDI3
209	select GENERIC_LIB_ASHRDI3
210	select GENERIC_LIB_LSHRDI3
211	select GENERIC_LIB_UCMPDI2
212	select MMU
213
214config ARCH_RV64I
215	bool "RV64I"
216	select 64BIT
217	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
218	select HAVE_DYNAMIC_FTRACE if MMU
219	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
220	select HAVE_FTRACE_MCOUNT_RECORD
221	select HAVE_FUNCTION_GRAPH_TRACER
222	select HAVE_FUNCTION_TRACER
223	select SWIOTLB if MMU
224
225endchoice
226
227# We must be able to map all physical memory into the kernel, but the compiler
228# is still a bit more efficient when generating code if it's setup in a manner
229# such that it can only map 2GiB of memory.
230choice
231	prompt "Kernel Code Model"
232	default CMODEL_MEDLOW if 32BIT
233	default CMODEL_MEDANY if 64BIT
234
235	config CMODEL_MEDLOW
236		bool "medium low code model"
237	config CMODEL_MEDANY
238		bool "medium any code model"
239endchoice
240
241config MODULE_SECTIONS
242	bool
243	select HAVE_MOD_ARCH_SPECIFIC
244
245choice
246	prompt "Maximum Physical Memory"
247	default MAXPHYSMEM_2GB if 32BIT
248	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
249	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
250
251	config MAXPHYSMEM_2GB
252		bool "2GiB"
253	config MAXPHYSMEM_128GB
254		depends on 64BIT && CMODEL_MEDANY
255		bool "128GiB"
256endchoice
257
258
259config SMP
260	bool "Symmetric Multi-Processing"
261	help
262	  This enables support for systems with more than one CPU.  If
263	  you say N here, the kernel will run on single and
264	  multiprocessor machines, but will use only one CPU of a
265	  multiprocessor machine. If you say Y here, the kernel will run
266	  on many, but not all, single processor machines. On a single
267	  processor machine, the kernel will run faster if you say N
268	  here.
269
270	  If you don't know what to do here, say N.
271
272config NR_CPUS
273	int "Maximum number of CPUs (2-32)"
274	range 2 32
275	depends on SMP
276	default "8"
277
278config HOTPLUG_CPU
279	bool "Support for hot-pluggable CPUs"
280	depends on SMP
281	select GENERIC_IRQ_MIGRATION
282	help
283
284	  Say Y here to experiment with turning CPUs off and on.  CPUs
285	  can be controlled through /sys/devices/system/cpu.
286
287	  Say N if you want to disable CPU hotplug.
288
289choice
290	prompt "CPU Tuning"
291	default TUNE_GENERIC
292
293config TUNE_GENERIC
294	bool "generic"
295
296endchoice
297
298config RISCV_ISA_C
299	bool "Emit compressed instructions when building Linux"
300	default y
301	help
302	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
303	   when building Linux, which results in compressed instructions in the
304	   Linux binary.
305
306	   If you don't know what to do here, say Y.
307
308menu "supported PMU type"
309	depends on PERF_EVENTS
310
311config RISCV_BASE_PMU
312	bool "Base Performance Monitoring Unit"
313	def_bool y
314	help
315	  A base PMU that serves as a reference implementation and has limited
316	  feature of perf.  It can run on any RISC-V machines so serves as the
317	  fallback, but this option can also be disable to reduce kernel size.
318
319endmenu
320
321config FPU
322	bool "FPU support"
323	default y
324	help
325	  Say N here if you want to disable all floating-point related procedure
326	  in the kernel.
327
328	  If you don't know what to do here, say Y.
329
330endmenu
331
332menu "Kernel features"
333
334source "kernel/Kconfig.hz"
335
336config RISCV_SBI_V01
337	bool "SBI v0.1 support"
338	default y
339	depends on RISCV_SBI
340	help
341	  This config allows kernel to use SBI v0.1 APIs. This will be
342	  deprecated in future once legacy M-mode software are no longer in use.
343endmenu
344
345menu "Boot options"
346
347config CMDLINE
348	string "Built-in kernel command line"
349	help
350	  For most platforms, the arguments for the kernel's command line
351	  are provided at run-time, during boot. However, there are cases
352	  where either no arguments are being provided or the provided
353	  arguments are insufficient or even invalid.
354
355	  When that occurs, it is possible to define a built-in command
356	  line here and choose how the kernel should use it later on.
357
358choice
359	prompt "Built-in command line usage" if CMDLINE != ""
360	default CMDLINE_FALLBACK
361	help
362	  Choose how the kernel will handle the provided built-in command
363	  line.
364
365config CMDLINE_FALLBACK
366	bool "Use bootloader kernel arguments if available"
367	help
368	  Use the built-in command line as fallback in case we get nothing
369	  during boot. This is the default behaviour.
370
371config CMDLINE_EXTEND
372	bool "Extend bootloader kernel arguments"
373	help
374	  The command-line arguments provided during boot will be
375	  appended to the built-in command line. This is useful in
376	  cases where the provided arguments are insufficient and
377	  you don't want to or cannot modify them.
378
379
380config CMDLINE_FORCE
381	bool "Always use the default kernel command string"
382	help
383	  Always use the built-in command line, even if we get one during
384	  boot. This is useful in case you need to override the provided
385	  command line on systems where you don't have or want control
386	  over it.
387
388endchoice
389
390config EFI_STUB
391	bool
392
393config EFI
394	bool "UEFI runtime support"
395	depends on OF
396	select LIBFDT
397	select UCS2_STRING
398	select EFI_PARAMS_FROM_FDT
399	select EFI_STUB
400	select EFI_GENERIC_STUB
401	select EFI_RUNTIME_WRAPPERS
402	select RISCV_ISA_C
403	depends on MMU
404	default y
405	help
406	  This option provides support for runtime services provided
407	  by UEFI firmware (such as non-volatile variables, realtime
408	  clock, and platform reset). A UEFI stub is also provided to
409	  allow the kernel to be booted as an EFI application. This
410	  is only useful on systems that have UEFI firmware.
411
412endmenu
413
414config BUILTIN_DTB
415	def_bool n
416	depends on RISCV_M_MODE
417	depends on OF
418
419menu "Power management options"
420
421source "kernel/power/Kconfig"
422
423endmenu
424
425source "drivers/firmware/Kconfig"
426