xref: /linux/arch/riscv/Kconfig (revision 2d2da475ac0eebfbf40e5c5ca8c0409d62d23424)
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_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
17	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
18	select ARCH_HAS_BINFMT_FLAT
19	select ARCH_HAS_CURRENT_STACK_POINTER
20	select ARCH_HAS_DEBUG_VM_PGTABLE
21	select ARCH_HAS_DEBUG_VIRTUAL if MMU
22	select ARCH_HAS_DEBUG_WX
23	select ARCH_HAS_FORTIFY_SOURCE
24	select ARCH_HAS_GCOV_PROFILE_ALL
25	select ARCH_HAS_GIGANTIC_PAGE
26	select ARCH_HAS_KCOV
27	select ARCH_HAS_MMIOWB
28	select ARCH_HAS_PTE_SPECIAL
29	select ARCH_HAS_SET_DIRECT_MAP if MMU
30	select ARCH_HAS_SET_MEMORY if MMU
31	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
32	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
33	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
34	select ARCH_HAS_UBSAN_SANITIZE_ALL
35	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
36	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
37	select ARCH_STACKWALK
38	select ARCH_SUPPORTS_ATOMIC_RMW
39	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
40	select ARCH_SUPPORTS_HUGETLBFS if MMU
41	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
42	select ARCH_USE_MEMTEST
43	select ARCH_USE_QUEUED_RWLOCKS
44	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
45	select ARCH_WANT_FRAME_POINTERS
46	select ARCH_WANT_GENERAL_HUGETLB
47	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
48	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
49	select BUILDTIME_TABLE_SORT if MMU
50	select CLONE_BACKWARDS
51	select CLINT_TIMER if !MMU
52	select COMMON_CLK
53	select CPU_PM if CPU_IDLE
54	select EDAC_SUPPORT
55	select GENERIC_ARCH_TOPOLOGY if SMP
56	select GENERIC_ATOMIC64 if !64BIT
57	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
58	select GENERIC_EARLY_IOREMAP
59	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
60	select GENERIC_IDLE_POLL_SETUP
61	select GENERIC_IOREMAP if MMU
62	select GENERIC_IRQ_MULTI_HANDLER
63	select GENERIC_IRQ_SHOW
64	select GENERIC_IRQ_SHOW_LEVEL
65	select GENERIC_LIB_DEVMEM_IS_ALLOWED
66	select GENERIC_PCI_IOMAP
67	select GENERIC_PTDUMP if MMU
68	select GENERIC_SCHED_CLOCK
69	select GENERIC_SMP_IDLE_THREAD
70	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
71	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
72	select HAVE_ARCH_AUDITSYSCALL
73	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
74	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
75	select HAVE_ARCH_KASAN if MMU && 64BIT
76	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
77	select HAVE_ARCH_KFENCE if MMU && 64BIT
78	select HAVE_ARCH_KGDB if !XIP_KERNEL
79	select HAVE_ARCH_KGDB_QXFER_PKT
80	select HAVE_ARCH_MMAP_RND_BITS if MMU
81	select HAVE_ARCH_SECCOMP_FILTER
82	select HAVE_ARCH_TRACEHOOK
83	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
84	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
85	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
86	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
87	select HAVE_ASM_MODVERSIONS
88	select HAVE_CONTEXT_TRACKING
89	select HAVE_DEBUG_KMEMLEAK
90	select HAVE_DMA_CONTIGUOUS if MMU
91	select HAVE_EBPF_JIT if MMU
92	select HAVE_FUNCTION_ERROR_INJECTION
93	select HAVE_GCC_PLUGINS
94	select HAVE_GENERIC_VDSO if MMU && 64BIT
95	select HAVE_IRQ_TIME_ACCOUNTING
96	select HAVE_KPROBES if !XIP_KERNEL
97	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
98	select HAVE_KRETPROBES if !XIP_KERNEL
99	select HAVE_MOVE_PMD
100	select HAVE_MOVE_PUD
101	select HAVE_PCI
102	select HAVE_PERF_EVENTS
103	select HAVE_PERF_REGS
104	select HAVE_PERF_USER_STACK_DUMP
105	select HAVE_REGS_AND_STACK_ACCESS_API
106	select HAVE_FUNCTION_ARG_ACCESS_API
107	select HAVE_STACKPROTECTOR
108	select HAVE_SYSCALL_TRACEPOINTS
109	select HAVE_RSEQ
110	select IRQ_DOMAIN
111	select IRQ_FORCED_THREADING
112	select MODULES_USE_ELF_RELA if MODULES
113	select MODULE_SECTIONS if MODULES
114	select OF
115	select OF_EARLY_FLATTREE
116	select OF_IRQ
117	select PCI_DOMAINS_GENERIC if PCI
118	select PCI_MSI if PCI
119	select RISCV_INTC
120	select RISCV_TIMER if RISCV_SBI
121	select SPARSE_IRQ
122	select SYSCTL_EXCEPTION_TRACE
123	select THREAD_INFO_IN_TASK
124	select TRACE_IRQFLAGS_SUPPORT
125	select UACCESS_MEMCPY if !MMU
126	select ZONE_DMA32 if 64BIT
127
128config ARCH_MMAP_RND_BITS_MIN
129	default 18 if 64BIT
130	default 8
131
132# max bits determined by the following formula:
133#  VA_BITS - PAGE_SHIFT - 3
134config ARCH_MMAP_RND_BITS_MAX
135	default 24 if 64BIT # SV39 based
136	default 17
137
138# set if we run in machine mode, cleared if we run in supervisor mode
139config RISCV_M_MODE
140	bool
141	default !MMU
142
143# set if we are running in S-mode and can use SBI calls
144config RISCV_SBI
145	bool
146	depends on !RISCV_M_MODE
147	default y
148
149config MMU
150	bool "MMU-based Paged Memory Management Support"
151	default y
152	help
153	  Select if you want MMU-based virtualised addressing space
154	  support by paged memory management. If unsure, say 'Y'.
155
156config PAGE_OFFSET
157	hex
158	default 0xC0000000 if 32BIT
159	default 0x80000000 if 64BIT && !MMU
160	default 0xff60000000000000 if 64BIT
161
162config KASAN_SHADOW_OFFSET
163	hex
164	depends on KASAN_GENERIC
165	default 0xdfffffff00000000 if 64BIT
166	default 0xffffffff if 32BIT
167
168config ARCH_FLATMEM_ENABLE
169	def_bool !NUMA
170
171config ARCH_SPARSEMEM_ENABLE
172	def_bool y
173	depends on MMU
174	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
175	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
176
177config ARCH_SELECT_MEMORY_MODEL
178	def_bool ARCH_SPARSEMEM_ENABLE
179
180config ARCH_SUPPORTS_UPROBES
181	def_bool y
182
183config STACKTRACE_SUPPORT
184	def_bool y
185
186config GENERIC_BUG
187	def_bool y
188	depends on BUG
189	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
190
191config GENERIC_BUG_RELATIVE_POINTERS
192	bool
193
194config GENERIC_CALIBRATE_DELAY
195	def_bool y
196
197config GENERIC_CSUM
198	def_bool y
199
200config GENERIC_HWEIGHT
201	def_bool y
202
203config FIX_EARLYCON_MEM
204	def_bool MMU
205
206config PGTABLE_LEVELS
207	int
208	default 5 if 64BIT
209	default 2
210
211config LOCKDEP_SUPPORT
212	def_bool y
213
214source "arch/riscv/Kconfig.socs"
215source "arch/riscv/Kconfig.erratas"
216
217menu "Platform type"
218
219choice
220	prompt "Base ISA"
221	default ARCH_RV64I
222	help
223	  This selects the base ISA that this kernel will target and must match
224	  the target platform.
225
226config ARCH_RV32I
227	bool "RV32I"
228	select 32BIT
229	select GENERIC_LIB_ASHLDI3
230	select GENERIC_LIB_ASHRDI3
231	select GENERIC_LIB_LSHRDI3
232	select GENERIC_LIB_UCMPDI2
233	select MMU
234
235config ARCH_RV64I
236	bool "RV64I"
237	select 64BIT
238	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
239	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
240	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
241	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
242	select HAVE_FUNCTION_GRAPH_TRACER
243	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
244	select SWIOTLB if MMU
245
246endchoice
247
248# We must be able to map all physical memory into the kernel, but the compiler
249# is still a bit more efficient when generating code if it's setup in a manner
250# such that it can only map 2GiB of memory.
251choice
252	prompt "Kernel Code Model"
253	default CMODEL_MEDLOW if 32BIT
254	default CMODEL_MEDANY if 64BIT
255
256	config CMODEL_MEDLOW
257		bool "medium low code model"
258	config CMODEL_MEDANY
259		bool "medium any code model"
260endchoice
261
262config MODULE_SECTIONS
263	bool
264	select HAVE_MOD_ARCH_SPECIFIC
265
266config SMP
267	bool "Symmetric Multi-Processing"
268	help
269	  This enables support for systems with more than one CPU.  If
270	  you say N here, the kernel will run on single and
271	  multiprocessor machines, but will use only one CPU of a
272	  multiprocessor machine. If you say Y here, the kernel will run
273	  on many, but not all, single processor machines. On a single
274	  processor machine, the kernel will run faster if you say N
275	  here.
276
277	  If you don't know what to do here, say N.
278
279config NR_CPUS
280	int "Maximum number of CPUs (2-32)"
281	range 2 32
282	depends on SMP
283	default "8"
284
285config HOTPLUG_CPU
286	bool "Support for hot-pluggable CPUs"
287	depends on SMP
288	select GENERIC_IRQ_MIGRATION
289	help
290
291	  Say Y here to experiment with turning CPUs off and on.  CPUs
292	  can be controlled through /sys/devices/system/cpu.
293
294	  Say N if you want to disable CPU hotplug.
295
296choice
297	prompt "CPU Tuning"
298	default TUNE_GENERIC
299
300config TUNE_GENERIC
301	bool "generic"
302
303endchoice
304
305# Common NUMA Features
306config NUMA
307	bool "NUMA Memory Allocation and Scheduler Support"
308	depends on SMP && MMU
309	select GENERIC_ARCH_NUMA
310	select OF_NUMA
311	select ARCH_SUPPORTS_NUMA_BALANCING
312	select USE_PERCPU_NUMA_NODE_ID
313	select NEED_PER_CPU_EMBED_FIRST_CHUNK
314	help
315	  Enable NUMA (Non-Uniform Memory Access) support.
316
317	  The kernel will try to allocate memory used by a CPU on the
318	  local memory of the CPU and add some more NUMA awareness to the kernel.
319
320config NODES_SHIFT
321	int "Maximum NUMA Nodes (as a power of 2)"
322	range 1 10
323	default "2"
324	depends on NUMA
325	help
326	  Specify the maximum number of NUMA Nodes available on the target
327	  system.  Increases memory reserved to accommodate various tables.
328
329config RISCV_ISA_C
330	bool "Emit compressed instructions when building Linux"
331	default y
332	help
333	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
334	   when building Linux, which results in compressed instructions in the
335	   Linux binary.
336
337	   If you don't know what to do here, say Y.
338
339config FPU
340	bool "FPU support"
341	default y
342	help
343	  Say N here if you want to disable all floating-point related procedure
344	  in the kernel.
345
346	  If you don't know what to do here, say Y.
347
348endmenu
349
350menu "Kernel features"
351
352source "kernel/Kconfig.hz"
353
354config RISCV_SBI_V01
355	bool "SBI v0.1 support"
356	depends on RISCV_SBI
357	help
358	  This config allows kernel to use SBI v0.1 APIs. This will be
359	  deprecated in future once legacy M-mode software are no longer in use.
360
361config RISCV_BOOT_SPINWAIT
362	bool "Spinwait booting method"
363	depends on SMP
364	default y
365	help
366	  This enables support for booting Linux via spinwait method. In the
367	  spinwait method, all cores randomly jump to Linux. One of the cores
368	  gets chosen via lottery and all other keep spinning on a percpu
369	  variable. This method cannot support CPU hotplug and sparse hartid
370	  scheme. It should be only enabled for M-mode Linux or platforms relying
371	  on older firmware without SBI HSM extension. All other platforms should
372	  rely on ordered booting via SBI HSM extension which gets chosen
373	  dynamically at runtime if the firmware supports it.
374
375config KEXEC
376	bool "Kexec system call"
377	select KEXEC_CORE
378	select HOTPLUG_CPU if SMP
379	depends on MMU
380	help
381	  kexec is a system call that implements the ability to shutdown your
382	  current kernel, and to start another kernel. It is like a reboot
383	  but it is independent of the system firmware. And like a reboot
384	  you can start any kernel with it, not just Linux.
385
386	  The name comes from the similarity to the exec system call.
387
388config CRASH_DUMP
389	bool "Build kdump crash kernel"
390	help
391	  Generate crash dump after being started by kexec. This should
392	  be normally only set in special crash dump kernels which are
393	  loaded in the main kernel with kexec-tools into a specially
394	  reserved region and then later executed after a crash by
395	  kdump/kexec.
396
397	  For more details see Documentation/admin-guide/kdump/kdump.rst
398
399endmenu
400
401menu "Boot options"
402
403config CMDLINE
404	string "Built-in kernel command line"
405	help
406	  For most platforms, the arguments for the kernel's command line
407	  are provided at run-time, during boot. However, there are cases
408	  where either no arguments are being provided or the provided
409	  arguments are insufficient or even invalid.
410
411	  When that occurs, it is possible to define a built-in command
412	  line here and choose how the kernel should use it later on.
413
414choice
415	prompt "Built-in command line usage" if CMDLINE != ""
416	default CMDLINE_FALLBACK
417	help
418	  Choose how the kernel will handle the provided built-in command
419	  line.
420
421config CMDLINE_FALLBACK
422	bool "Use bootloader kernel arguments if available"
423	help
424	  Use the built-in command line as fallback in case we get nothing
425	  during boot. This is the default behaviour.
426
427config CMDLINE_EXTEND
428	bool "Extend bootloader kernel arguments"
429	help
430	  The command-line arguments provided during boot will be
431	  appended to the built-in command line. This is useful in
432	  cases where the provided arguments are insufficient and
433	  you don't want to or cannot modify them.
434
435
436config CMDLINE_FORCE
437	bool "Always use the default kernel command string"
438	help
439	  Always use the built-in command line, even if we get one during
440	  boot. This is useful in case you need to override the provided
441	  command line on systems where you don't have or want control
442	  over it.
443
444endchoice
445
446config EFI_STUB
447	bool
448
449config EFI
450	bool "UEFI runtime support"
451	depends on OF && !XIP_KERNEL
452	select LIBFDT
453	select UCS2_STRING
454	select EFI_PARAMS_FROM_FDT
455	select EFI_STUB
456	select EFI_GENERIC_STUB
457	select EFI_RUNTIME_WRAPPERS
458	select RISCV_ISA_C
459	depends on MMU
460	default y
461	help
462	  This option provides support for runtime services provided
463	  by UEFI firmware (such as non-volatile variables, realtime
464	  clock, and platform reset). A UEFI stub is also provided to
465	  allow the kernel to be booted as an EFI application. This
466	  is only useful on systems that have UEFI firmware.
467
468config CC_HAVE_STACKPROTECTOR_TLS
469	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
470
471config STACKPROTECTOR_PER_TASK
472	def_bool y
473	depends on !RANDSTRUCT
474	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
475
476config PHYS_RAM_BASE_FIXED
477	bool "Explicitly specified physical RAM address"
478	default n
479
480config PHYS_RAM_BASE
481	hex "Platform Physical RAM address"
482	depends on PHYS_RAM_BASE_FIXED
483	default "0x80000000"
484	help
485	  This is the physical address of RAM in the system. It has to be
486	  explicitly specified to run early relocations of read-write data
487	  from flash to RAM.
488
489config XIP_KERNEL
490	bool "Kernel Execute-In-Place from ROM"
491	depends on MMU && SPARSEMEM
492	# This prevents XIP from being enabled by all{yes,mod}config, which
493	# fail to build since XIP doesn't support large kernels.
494	depends on !COMPILE_TEST
495	select PHYS_RAM_BASE_FIXED
496	help
497	  Execute-In-Place allows the kernel to run from non-volatile storage
498	  directly addressable by the CPU, such as NOR flash. This saves RAM
499	  space since the text section of the kernel is not loaded from flash
500	  to RAM.  Read-write sections, such as the data section and stack,
501	  are still copied to RAM.  The XIP kernel is not compressed since
502	  it has to run directly from flash, so it will take more space to
503	  store it.  The flash address used to link the kernel object files,
504	  and for storing it, is configuration dependent. Therefore, if you
505	  say Y here, you must know the proper physical address where to
506	  store the kernel image depending on your own flash memory usage.
507
508	  Also note that the make target becomes "make xipImage" rather than
509	  "make zImage" or "make Image".  The final kernel binary to put in
510	  ROM memory will be arch/riscv/boot/xipImage.
511
512	  SPARSEMEM is required because the kernel text and rodata that are
513	  flash resident are not backed by memmap, then any attempt to get
514	  a struct page on those regions will trigger a fault.
515
516	  If unsure, say N.
517
518config XIP_PHYS_ADDR
519	hex "XIP Kernel Physical Location"
520	depends on XIP_KERNEL
521	default "0x21000000"
522	help
523	  This is the physical address in your flash memory the kernel will
524	  be linked for and stored to.  This address is dependent on your
525	  own flash usage.
526
527endmenu
528
529config BUILTIN_DTB
530	bool
531	depends on OF
532	default y if XIP_KERNEL
533
534menu "Power management options"
535
536source "kernel/power/Kconfig"
537
538endmenu
539
540menu "CPU Power Management"
541
542source "drivers/cpuidle/Kconfig"
543
544endmenu
545
546source "arch/riscv/kvm/Kconfig"
547