xref: /openbmc/linux/arch/riscv/Kconfig (revision 2cf1c348)
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_DEBUG_VM_PGTABLE
20	select ARCH_HAS_DEBUG_VIRTUAL if MMU
21	select ARCH_HAS_DEBUG_WX
22	select ARCH_HAS_FORTIFY_SOURCE
23	select ARCH_HAS_GCOV_PROFILE_ALL
24	select ARCH_HAS_GIGANTIC_PAGE
25	select ARCH_HAS_KCOV
26	select ARCH_HAS_MMIOWB
27	select ARCH_HAS_PTE_SPECIAL
28	select ARCH_HAS_SET_DIRECT_MAP if MMU
29	select ARCH_HAS_SET_MEMORY if MMU
30	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
31	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
32	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
33	select ARCH_HAS_UBSAN_SANITIZE_ALL
34	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
35	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
36	select ARCH_STACKWALK
37	select ARCH_SUPPORTS_ATOMIC_RMW
38	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
39	select ARCH_SUPPORTS_HUGETLBFS if MMU
40	select ARCH_USE_MEMTEST
41	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
42	select ARCH_WANT_FRAME_POINTERS
43	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
44	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
45	select BUILDTIME_TABLE_SORT if MMU
46	select CLONE_BACKWARDS
47	select CLINT_TIMER if !MMU
48	select COMMON_CLK
49	select EDAC_SUPPORT
50	select GENERIC_ARCH_TOPOLOGY if SMP
51	select GENERIC_ATOMIC64 if !64BIT
52	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
53	select GENERIC_EARLY_IOREMAP
54	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
55	select GENERIC_IDLE_POLL_SETUP
56	select GENERIC_IOREMAP if MMU
57	select GENERIC_IRQ_MULTI_HANDLER
58	select GENERIC_IRQ_SHOW
59	select GENERIC_IRQ_SHOW_LEVEL
60	select GENERIC_LIB_DEVMEM_IS_ALLOWED
61	select GENERIC_PCI_IOMAP
62	select GENERIC_PTDUMP if MMU
63	select GENERIC_SCHED_CLOCK
64	select GENERIC_SMP_IDLE_THREAD
65	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
66	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
67	select HAVE_ARCH_AUDITSYSCALL
68	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
69	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
70	select HAVE_ARCH_KASAN if MMU && 64BIT
71	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
72	select HAVE_ARCH_KFENCE if MMU && 64BIT
73	select HAVE_ARCH_KGDB if !XIP_KERNEL
74	select HAVE_ARCH_KGDB_QXFER_PKT
75	select HAVE_ARCH_MMAP_RND_BITS if MMU
76	select HAVE_ARCH_SECCOMP_FILTER
77	select HAVE_ARCH_TRACEHOOK
78	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
79	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
80	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
81	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
82	select HAVE_ASM_MODVERSIONS
83	select HAVE_CONTEXT_TRACKING
84	select HAVE_DEBUG_KMEMLEAK
85	select HAVE_DMA_CONTIGUOUS if MMU
86	select HAVE_EBPF_JIT if MMU
87	select HAVE_FUNCTION_ERROR_INJECTION
88	select HAVE_GCC_PLUGINS
89	select HAVE_GENERIC_VDSO if MMU && 64BIT
90	select HAVE_IRQ_TIME_ACCOUNTING
91	select HAVE_KPROBES if !XIP_KERNEL
92	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
93	select HAVE_KRETPROBES if !XIP_KERNEL
94	select HAVE_MOVE_PMD
95	select HAVE_MOVE_PUD
96	select HAVE_PCI
97	select HAVE_PERF_EVENTS
98	select HAVE_PERF_REGS
99	select HAVE_PERF_USER_STACK_DUMP
100	select HAVE_REGS_AND_STACK_ACCESS_API
101	select HAVE_FUNCTION_ARG_ACCESS_API
102	select HAVE_STACKPROTECTOR
103	select HAVE_SYSCALL_TRACEPOINTS
104	select IRQ_DOMAIN
105	select IRQ_FORCED_THREADING
106	select MODULES_USE_ELF_RELA if MODULES
107	select MODULE_SECTIONS if MODULES
108	select OF
109	select OF_EARLY_FLATTREE
110	select OF_IRQ
111	select PCI_DOMAINS_GENERIC if PCI
112	select PCI_MSI if PCI
113	select RISCV_INTC
114	select RISCV_TIMER if RISCV_SBI
115	select SPARSE_IRQ
116	select SYSCTL_EXCEPTION_TRACE
117	select THREAD_INFO_IN_TASK
118	select TRACE_IRQFLAGS_SUPPORT
119	select UACCESS_MEMCPY if !MMU
120	select ZONE_DMA32 if 64BIT
121
122config ARCH_MMAP_RND_BITS_MIN
123	default 18 if 64BIT
124	default 8
125
126# max bits determined by the following formula:
127#  VA_BITS - PAGE_SHIFT - 3
128config ARCH_MMAP_RND_BITS_MAX
129	default 24 if 64BIT # SV39 based
130	default 17
131
132# set if we run in machine mode, cleared if we run in supervisor mode
133config RISCV_M_MODE
134	bool
135	default !MMU
136
137# set if we are running in S-mode and can use SBI calls
138config RISCV_SBI
139	bool
140	depends on !RISCV_M_MODE
141	default y
142
143config MMU
144	bool "MMU-based Paged Memory Management Support"
145	default y
146	help
147	  Select if you want MMU-based virtualised addressing space
148	  support by paged memory management. If unsure, say 'Y'.
149
150config PAGE_OFFSET
151	hex
152	default 0xC0000000 if 32BIT
153	default 0x80000000 if 64BIT && !MMU
154	default 0xffffaf8000000000 if 64BIT
155
156config KASAN_SHADOW_OFFSET
157	hex
158	depends on KASAN_GENERIC
159	default 0xdfffffff00000000 if 64BIT
160	default 0xffffffff if 32BIT
161
162config ARCH_FLATMEM_ENABLE
163	def_bool !NUMA
164
165config ARCH_SPARSEMEM_ENABLE
166	def_bool y
167	depends on MMU
168	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
169	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
170
171config ARCH_SELECT_MEMORY_MODEL
172	def_bool ARCH_SPARSEMEM_ENABLE
173
174config ARCH_WANT_GENERAL_HUGETLB
175	def_bool y
176
177config ARCH_SUPPORTS_UPROBES
178	def_bool y
179
180config STACKTRACE_SUPPORT
181	def_bool y
182
183config GENERIC_BUG
184	def_bool y
185	depends on BUG
186	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
187
188config GENERIC_BUG_RELATIVE_POINTERS
189	bool
190
191config GENERIC_CALIBRATE_DELAY
192	def_bool y
193
194config GENERIC_CSUM
195	def_bool y
196
197config GENERIC_HWEIGHT
198	def_bool y
199
200config FIX_EARLYCON_MEM
201	def_bool MMU
202
203config PGTABLE_LEVELS
204	int
205	default 4 if 64BIT
206	default 2
207
208config LOCKDEP_SUPPORT
209	def_bool y
210
211source "arch/riscv/Kconfig.socs"
212source "arch/riscv/Kconfig.erratas"
213
214menu "Platform type"
215
216choice
217	prompt "Base ISA"
218	default ARCH_RV64I
219	help
220	  This selects the base ISA that this kernel will target and must match
221	  the target platform.
222
223config ARCH_RV32I
224	bool "RV32I"
225	select 32BIT
226	select GENERIC_LIB_ASHLDI3
227	select GENERIC_LIB_ASHRDI3
228	select GENERIC_LIB_LSHRDI3
229	select GENERIC_LIB_UCMPDI2
230	select MMU
231
232config ARCH_RV64I
233	bool "RV64I"
234	select 64BIT
235	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
236	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
237	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
238	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
239	select HAVE_FUNCTION_GRAPH_TRACER
240	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
241	select SWIOTLB if MMU
242
243endchoice
244
245# We must be able to map all physical memory into the kernel, but the compiler
246# is still a bit more efficient when generating code if it's setup in a manner
247# such that it can only map 2GiB of memory.
248choice
249	prompt "Kernel Code Model"
250	default CMODEL_MEDLOW if 32BIT
251	default CMODEL_MEDANY if 64BIT
252
253	config CMODEL_MEDLOW
254		bool "medium low code model"
255	config CMODEL_MEDANY
256		bool "medium any code model"
257endchoice
258
259config MODULE_SECTIONS
260	bool
261	select HAVE_MOD_ARCH_SPECIFIC
262
263config SMP
264	bool "Symmetric Multi-Processing"
265	help
266	  This enables support for systems with more than one CPU.  If
267	  you say N here, the kernel will run on single and
268	  multiprocessor machines, but will use only one CPU of a
269	  multiprocessor machine. If you say Y here, the kernel will run
270	  on many, but not all, single processor machines. On a single
271	  processor machine, the kernel will run faster if you say N
272	  here.
273
274	  If you don't know what to do here, say N.
275
276config NR_CPUS
277	int "Maximum number of CPUs (2-32)"
278	range 2 32
279	depends on SMP
280	default "8"
281
282config HOTPLUG_CPU
283	bool "Support for hot-pluggable CPUs"
284	depends on SMP
285	select GENERIC_IRQ_MIGRATION
286	help
287
288	  Say Y here to experiment with turning CPUs off and on.  CPUs
289	  can be controlled through /sys/devices/system/cpu.
290
291	  Say N if you want to disable CPU hotplug.
292
293choice
294	prompt "CPU Tuning"
295	default TUNE_GENERIC
296
297config TUNE_GENERIC
298	bool "generic"
299
300endchoice
301
302# Common NUMA Features
303config NUMA
304	bool "NUMA Memory Allocation and Scheduler Support"
305	depends on SMP && MMU
306	select GENERIC_ARCH_NUMA
307	select OF_NUMA
308	select ARCH_SUPPORTS_NUMA_BALANCING
309	select USE_PERCPU_NUMA_NODE_ID
310	select NEED_PER_CPU_EMBED_FIRST_CHUNK
311	help
312	  Enable NUMA (Non-Uniform Memory Access) support.
313
314	  The kernel will try to allocate memory used by a CPU on the
315	  local memory of the CPU and add some more NUMA awareness to the kernel.
316
317config NODES_SHIFT
318	int "Maximum NUMA Nodes (as a power of 2)"
319	range 1 10
320	default "2"
321	depends on NUMA
322	help
323	  Specify the maximum number of NUMA Nodes available on the target
324	  system.  Increases memory reserved to accommodate various tables.
325
326config RISCV_ISA_C
327	bool "Emit compressed instructions when building Linux"
328	default y
329	help
330	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
331	   when building Linux, which results in compressed instructions in the
332	   Linux binary.
333
334	   If you don't know what to do here, say Y.
335
336menu "supported PMU type"
337	depends on PERF_EVENTS
338
339config RISCV_BASE_PMU
340	bool "Base Performance Monitoring Unit"
341	def_bool y
342	help
343	  A base PMU that serves as a reference implementation and has limited
344	  feature of perf.  It can run on any RISC-V machines so serves as the
345	  fallback, but this option can also be disable to reduce kernel size.
346
347endmenu
348
349config FPU
350	bool "FPU support"
351	default y
352	help
353	  Say N here if you want to disable all floating-point related procedure
354	  in the kernel.
355
356	  If you don't know what to do here, say Y.
357
358endmenu
359
360menu "Kernel features"
361
362source "kernel/Kconfig.hz"
363
364config RISCV_SBI_V01
365	bool "SBI v0.1 support"
366	depends on RISCV_SBI
367	help
368	  This config allows kernel to use SBI v0.1 APIs. This will be
369	  deprecated in future once legacy M-mode software are no longer in use.
370
371config RISCV_BOOT_SPINWAIT
372	bool "Spinwait booting method"
373	depends on SMP
374	default y
375	help
376	  This enables support for booting Linux via spinwait method. In the
377	  spinwait method, all cores randomly jump to Linux. One of the cores
378	  gets chosen via lottery and all other keep spinning on a percpu
379	  variable. This method cannot support CPU hotplug and sparse hartid
380	  scheme. It should be only enabled for M-mode Linux or platforms relying
381	  on older firmware without SBI HSM extension. All other platforms should
382	  rely on ordered booting via SBI HSM extension which gets chosen
383	  dynamically at runtime if the firmware supports it.
384
385config KEXEC
386	bool "Kexec system call"
387	select KEXEC_CORE
388	select HOTPLUG_CPU if SMP
389	depends on MMU
390	help
391	  kexec is a system call that implements the ability to shutdown your
392	  current kernel, and to start another kernel. It is like a reboot
393	  but it is independent of the system firmware. And like a reboot
394	  you can start any kernel with it, not just Linux.
395
396	  The name comes from the similarity to the exec system call.
397
398config CRASH_DUMP
399	bool "Build kdump crash kernel"
400	help
401	  Generate crash dump after being started by kexec. This should
402	  be normally only set in special crash dump kernels which are
403	  loaded in the main kernel with kexec-tools into a specially
404	  reserved region and then later executed after a crash by
405	  kdump/kexec.
406
407	  For more details see Documentation/admin-guide/kdump/kdump.rst
408
409endmenu
410
411menu "Boot options"
412
413config CMDLINE
414	string "Built-in kernel command line"
415	help
416	  For most platforms, the arguments for the kernel's command line
417	  are provided at run-time, during boot. However, there are cases
418	  where either no arguments are being provided or the provided
419	  arguments are insufficient or even invalid.
420
421	  When that occurs, it is possible to define a built-in command
422	  line here and choose how the kernel should use it later on.
423
424choice
425	prompt "Built-in command line usage" if CMDLINE != ""
426	default CMDLINE_FALLBACK
427	help
428	  Choose how the kernel will handle the provided built-in command
429	  line.
430
431config CMDLINE_FALLBACK
432	bool "Use bootloader kernel arguments if available"
433	help
434	  Use the built-in command line as fallback in case we get nothing
435	  during boot. This is the default behaviour.
436
437config CMDLINE_EXTEND
438	bool "Extend bootloader kernel arguments"
439	help
440	  The command-line arguments provided during boot will be
441	  appended to the built-in command line. This is useful in
442	  cases where the provided arguments are insufficient and
443	  you don't want to or cannot modify them.
444
445
446config CMDLINE_FORCE
447	bool "Always use the default kernel command string"
448	help
449	  Always use the built-in command line, even if we get one during
450	  boot. This is useful in case you need to override the provided
451	  command line on systems where you don't have or want control
452	  over it.
453
454endchoice
455
456config EFI_STUB
457	bool
458
459config EFI
460	bool "UEFI runtime support"
461	depends on OF && !XIP_KERNEL
462	select LIBFDT
463	select UCS2_STRING
464	select EFI_PARAMS_FROM_FDT
465	select EFI_STUB
466	select EFI_GENERIC_STUB
467	select EFI_RUNTIME_WRAPPERS
468	select RISCV_ISA_C
469	depends on MMU
470	default y
471	help
472	  This option provides support for runtime services provided
473	  by UEFI firmware (such as non-volatile variables, realtime
474	  clock, and platform reset). A UEFI stub is also provided to
475	  allow the kernel to be booted as an EFI application. This
476	  is only useful on systems that have UEFI firmware.
477
478config CC_HAVE_STACKPROTECTOR_TLS
479	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
480
481config STACKPROTECTOR_PER_TASK
482	def_bool y
483	depends on !GCC_PLUGIN_RANDSTRUCT
484	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
485
486config PHYS_RAM_BASE_FIXED
487	bool "Explicitly specified physical RAM address"
488	default n
489
490config PHYS_RAM_BASE
491	hex "Platform Physical RAM address"
492	depends on PHYS_RAM_BASE_FIXED
493	default "0x80000000"
494	help
495	  This is the physical address of RAM in the system. It has to be
496	  explicitly specified to run early relocations of read-write data
497	  from flash to RAM.
498
499config XIP_KERNEL
500	bool "Kernel Execute-In-Place from ROM"
501	depends on MMU && SPARSEMEM
502	# This prevents XIP from being enabled by all{yes,mod}config, which
503	# fail to build since XIP doesn't support large kernels.
504	depends on !COMPILE_TEST
505	select PHYS_RAM_BASE_FIXED
506	help
507	  Execute-In-Place allows the kernel to run from non-volatile storage
508	  directly addressable by the CPU, such as NOR flash. This saves RAM
509	  space since the text section of the kernel is not loaded from flash
510	  to RAM.  Read-write sections, such as the data section and stack,
511	  are still copied to RAM.  The XIP kernel is not compressed since
512	  it has to run directly from flash, so it will take more space to
513	  store it.  The flash address used to link the kernel object files,
514	  and for storing it, is configuration dependent. Therefore, if you
515	  say Y here, you must know the proper physical address where to
516	  store the kernel image depending on your own flash memory usage.
517
518	  Also note that the make target becomes "make xipImage" rather than
519	  "make zImage" or "make Image".  The final kernel binary to put in
520	  ROM memory will be arch/riscv/boot/xipImage.
521
522	  SPARSEMEM is required because the kernel text and rodata that are
523	  flash resident are not backed by memmap, then any attempt to get
524	  a struct page on those regions will trigger a fault.
525
526	  If unsure, say N.
527
528config XIP_PHYS_ADDR
529	hex "XIP Kernel Physical Location"
530	depends on XIP_KERNEL
531	default "0x21000000"
532	help
533	  This is the physical address in your flash memory the kernel will
534	  be linked for and stored to.  This address is dependent on your
535	  own flash usage.
536
537endmenu
538
539config BUILTIN_DTB
540	bool
541	depends on OF
542	default y if XIP_KERNEL
543
544menu "Power management options"
545
546source "kernel/power/Kconfig"
547
548endmenu
549
550source "arch/riscv/kvm/Kconfig"
551