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_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_FORTIFY_SOURCE
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 if MMU
28	select ARCH_HAS_SET_MEMORY if MMU
29	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
30	select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
31	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
32	select ARCH_HAS_UBSAN_SANITIZE_ALL
33	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
34	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
35	select ARCH_STACKWALK
36	select ARCH_SUPPORTS_ATOMIC_RMW
37	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
38	select ARCH_SUPPORTS_HUGETLBFS if MMU
39	select ARCH_USE_MEMTEST
40	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
41	select ARCH_WANT_FRAME_POINTERS
42	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
43	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
44	select BUILDTIME_TABLE_SORT if MMU
45	select CLONE_BACKWARDS
46	select CLINT_TIMER if !MMU
47	select COMMON_CLK
48	select EDAC_SUPPORT
49	select GENERIC_ARCH_TOPOLOGY if SMP
50	select GENERIC_ATOMIC64 if !64BIT
51	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
52	select GENERIC_EARLY_IOREMAP
53	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
54	select GENERIC_IDLE_POLL_SETUP
55	select GENERIC_IOREMAP if MMU
56	select GENERIC_IRQ_MULTI_HANDLER
57	select GENERIC_IRQ_SHOW
58	select GENERIC_IRQ_SHOW_LEVEL
59	select GENERIC_LIB_DEVMEM_IS_ALLOWED
60	select GENERIC_PCI_IOMAP
61	select GENERIC_PTDUMP if MMU
62	select GENERIC_SCHED_CLOCK
63	select GENERIC_SMP_IDLE_THREAD
64	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
65	select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
66	select HAVE_ARCH_AUDITSYSCALL
67	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
68	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL
69	select HAVE_ARCH_KASAN if MMU && 64BIT
70	select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
71	select HAVE_ARCH_KFENCE if MMU && 64BIT
72	select HAVE_ARCH_KGDB if !XIP_KERNEL
73	select HAVE_ARCH_KGDB_QXFER_PKT
74	select HAVE_ARCH_MMAP_RND_BITS if MMU
75	select HAVE_ARCH_SECCOMP_FILTER
76	select HAVE_ARCH_TRACEHOOK
77	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
78	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
79	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
80	select HAVE_ASM_MODVERSIONS
81	select HAVE_CONTEXT_TRACKING
82	select HAVE_DEBUG_KMEMLEAK
83	select HAVE_DMA_CONTIGUOUS if MMU
84	select HAVE_EBPF_JIT if MMU
85	select HAVE_FUNCTION_ERROR_INJECTION
86	select HAVE_FUTEX_CMPXCHG if FUTEX
87	select HAVE_GCC_PLUGINS
88	select HAVE_GENERIC_VDSO if MMU && 64BIT
89	select HAVE_IRQ_TIME_ACCOUNTING
90	select HAVE_KPROBES if !XIP_KERNEL
91	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
92	select HAVE_KRETPROBES if !XIP_KERNEL
93	select HAVE_MOVE_PMD
94	select HAVE_MOVE_PUD
95	select HAVE_PCI
96	select HAVE_PERF_EVENTS
97	select HAVE_PERF_REGS
98	select HAVE_PERF_USER_STACK_DUMP
99	select HAVE_REGS_AND_STACK_ACCESS_API
100	select HAVE_FUNCTION_ARG_ACCESS_API
101	select HAVE_STACKPROTECTOR
102	select HAVE_SYSCALL_TRACEPOINTS
103	select IRQ_DOMAIN
104	select IRQ_FORCED_THREADING
105	select MODULES_USE_ELF_RELA if MODULES
106	select MODULE_SECTIONS if MODULES
107	select OF
108	select OF_EARLY_FLATTREE
109	select OF_IRQ
110	select PCI_DOMAINS_GENERIC if PCI
111	select PCI_MSI if PCI
112	select RISCV_INTC
113	select RISCV_TIMER if RISCV_SBI
114	select SPARSE_IRQ
115	select SYSCTL_EXCEPTION_TRACE
116	select THREAD_INFO_IN_TASK
117	select TRACE_IRQFLAGS_SUPPORT
118	select UACCESS_MEMCPY if !MMU
119	select ZONE_DMA32 if 64BIT
120
121config ARCH_MMAP_RND_BITS_MIN
122	default 18 if 64BIT
123	default 8
124
125# max bits determined by the following formula:
126#  VA_BITS - PAGE_SHIFT - 3
127config ARCH_MMAP_RND_BITS_MAX
128	default 24 if 64BIT # SV39 based
129	default 17
130
131# set if we run in machine mode, cleared if we run in supervisor mode
132config RISCV_M_MODE
133	bool
134	default !MMU
135
136# set if we are running in S-mode and can use SBI calls
137config RISCV_SBI
138	bool
139	depends on !RISCV_M_MODE
140	default y
141
142config MMU
143	bool "MMU-based Paged Memory Management Support"
144	default y
145	help
146	  Select if you want MMU-based virtualised addressing space
147	  support by paged memory management. If unsure, say 'Y'.
148
149config VA_BITS
150	int
151	default 32 if 32BIT
152	default 39 if 64BIT
153
154config PA_BITS
155	int
156	default 34 if 32BIT
157	default 56 if 64BIT
158
159config PAGE_OFFSET
160	hex
161	default 0xC0000000 if 32BIT && MAXPHYSMEM_1GB
162	default 0x80000000 if 64BIT && !MMU
163	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
164	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
165
166config KASAN_SHADOW_OFFSET
167	hex
168	depends on KASAN_GENERIC
169	default 0xdfffffc800000000 if 64BIT
170	default 0xffffffff if 32BIT
171
172config ARCH_FLATMEM_ENABLE
173	def_bool !NUMA
174
175config ARCH_SPARSEMEM_ENABLE
176	def_bool y
177	depends on MMU
178	select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
179	select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
180
181config ARCH_SELECT_MEMORY_MODEL
182	def_bool ARCH_SPARSEMEM_ENABLE
183
184config ARCH_WANT_GENERAL_HUGETLB
185	def_bool y
186
187config ARCH_SUPPORTS_UPROBES
188	def_bool y
189
190config STACKTRACE_SUPPORT
191	def_bool y
192
193config GENERIC_BUG
194	def_bool y
195	depends on BUG
196	select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
197
198config GENERIC_BUG_RELATIVE_POINTERS
199	bool
200
201config GENERIC_CALIBRATE_DELAY
202	def_bool y
203
204config GENERIC_CSUM
205	def_bool y
206
207config GENERIC_HWEIGHT
208	def_bool y
209
210config FIX_EARLYCON_MEM
211	def_bool MMU
212
213config PGTABLE_LEVELS
214	int
215	default 3 if 64BIT
216	default 2
217
218config LOCKDEP_SUPPORT
219	def_bool y
220
221source "arch/riscv/Kconfig.socs"
222source "arch/riscv/Kconfig.erratas"
223
224menu "Platform type"
225
226choice
227	prompt "Base ISA"
228	default ARCH_RV64I
229	help
230	  This selects the base ISA that this kernel will target and must match
231	  the target platform.
232
233config ARCH_RV32I
234	bool "RV32I"
235	select 32BIT
236	select GENERIC_LIB_ASHLDI3
237	select GENERIC_LIB_ASHRDI3
238	select GENERIC_LIB_LSHRDI3
239	select GENERIC_LIB_UCMPDI2
240	select MMU
241
242config ARCH_RV64I
243	bool "RV64I"
244	select 64BIT
245	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
246	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8)
247	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
248	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
249	select HAVE_FUNCTION_GRAPH_TRACER
250	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
251	select SWIOTLB if MMU
252
253endchoice
254
255# We must be able to map all physical memory into the kernel, but the compiler
256# is still a bit more efficient when generating code if it's setup in a manner
257# such that it can only map 2GiB of memory.
258choice
259	prompt "Kernel Code Model"
260	default CMODEL_MEDLOW if 32BIT
261	default CMODEL_MEDANY if 64BIT
262
263	config CMODEL_MEDLOW
264		bool "medium low code model"
265	config CMODEL_MEDANY
266		bool "medium any code model"
267endchoice
268
269config MODULE_SECTIONS
270	bool
271	select HAVE_MOD_ARCH_SPECIFIC
272
273choice
274	prompt "Maximum Physical Memory"
275	default MAXPHYSMEM_1GB if 32BIT
276	default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
277	default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
278
279	config MAXPHYSMEM_1GB
280		depends on 32BIT
281		bool "1GiB"
282	config MAXPHYSMEM_2GB
283		depends on 64BIT && CMODEL_MEDLOW
284		bool "2GiB"
285	config MAXPHYSMEM_128GB
286		depends on 64BIT && CMODEL_MEDANY
287		bool "128GiB"
288endchoice
289
290
291config SMP
292	bool "Symmetric Multi-Processing"
293	help
294	  This enables support for systems with more than one CPU.  If
295	  you say N here, the kernel will run on single and
296	  multiprocessor machines, but will use only one CPU of a
297	  multiprocessor machine. If you say Y here, the kernel will run
298	  on many, but not all, single processor machines. On a single
299	  processor machine, the kernel will run faster if you say N
300	  here.
301
302	  If you don't know what to do here, say N.
303
304config NR_CPUS
305	int "Maximum number of CPUs (2-32)"
306	range 2 32
307	depends on SMP
308	default "8"
309
310config HOTPLUG_CPU
311	bool "Support for hot-pluggable CPUs"
312	depends on SMP
313	select GENERIC_IRQ_MIGRATION
314	help
315
316	  Say Y here to experiment with turning CPUs off and on.  CPUs
317	  can be controlled through /sys/devices/system/cpu.
318
319	  Say N if you want to disable CPU hotplug.
320
321choice
322	prompt "CPU Tuning"
323	default TUNE_GENERIC
324
325config TUNE_GENERIC
326	bool "generic"
327
328endchoice
329
330# Common NUMA Features
331config NUMA
332	bool "NUMA Memory Allocation and Scheduler Support"
333	depends on SMP && MMU
334	select GENERIC_ARCH_NUMA
335	select OF_NUMA
336	select ARCH_SUPPORTS_NUMA_BALANCING
337	help
338	  Enable NUMA (Non-Uniform Memory Access) support.
339
340	  The kernel will try to allocate memory used by a CPU on the
341	  local memory of the CPU and add some more NUMA awareness to the kernel.
342
343config NODES_SHIFT
344	int "Maximum NUMA Nodes (as a power of 2)"
345	range 1 10
346	default "2"
347	depends on NUMA
348	help
349	  Specify the maximum number of NUMA Nodes available on the target
350	  system.  Increases memory reserved to accommodate various tables.
351
352config USE_PERCPU_NUMA_NODE_ID
353	def_bool y
354	depends on NUMA
355
356config NEED_PER_CPU_EMBED_FIRST_CHUNK
357	def_bool y
358	depends on NUMA
359
360config RISCV_ISA_C
361	bool "Emit compressed instructions when building Linux"
362	default y
363	help
364	   Adds "C" to the ISA subsets that the toolchain is allowed to emit
365	   when building Linux, which results in compressed instructions in the
366	   Linux binary.
367
368	   If you don't know what to do here, say Y.
369
370menu "supported PMU type"
371	depends on PERF_EVENTS
372
373config RISCV_BASE_PMU
374	bool "Base Performance Monitoring Unit"
375	def_bool y
376	help
377	  A base PMU that serves as a reference implementation and has limited
378	  feature of perf.  It can run on any RISC-V machines so serves as the
379	  fallback, but this option can also be disable to reduce kernel size.
380
381endmenu
382
383config FPU
384	bool "FPU support"
385	default y
386	help
387	  Say N here if you want to disable all floating-point related procedure
388	  in the kernel.
389
390	  If you don't know what to do here, say Y.
391
392endmenu
393
394menu "Kernel features"
395
396source "kernel/Kconfig.hz"
397
398config RISCV_SBI_V01
399	bool "SBI v0.1 support"
400	default y
401	depends on RISCV_SBI
402	help
403	  This config allows kernel to use SBI v0.1 APIs. This will be
404	  deprecated in future once legacy M-mode software are no longer in use.
405
406config KEXEC
407	bool "Kexec system call"
408	select KEXEC_CORE
409	select HOTPLUG_CPU if SMP
410	depends on MMU
411	help
412	  kexec is a system call that implements the ability to shutdown your
413	  current kernel, and to start another kernel. It is like a reboot
414	  but it is independent of the system firmware. And like a reboot
415	  you can start any kernel with it, not just Linux.
416
417	  The name comes from the similarity to the exec system call.
418
419config CRASH_DUMP
420	bool "Build kdump crash kernel"
421	help
422	  Generate crash dump after being started by kexec. This should
423	  be normally only set in special crash dump kernels which are
424	  loaded in the main kernel with kexec-tools into a specially
425	  reserved region and then later executed after a crash by
426	  kdump/kexec.
427
428	  For more details see Documentation/admin-guide/kdump/kdump.rst
429
430endmenu
431
432menu "Boot options"
433
434config CMDLINE
435	string "Built-in kernel command line"
436	help
437	  For most platforms, the arguments for the kernel's command line
438	  are provided at run-time, during boot. However, there are cases
439	  where either no arguments are being provided or the provided
440	  arguments are insufficient or even invalid.
441
442	  When that occurs, it is possible to define a built-in command
443	  line here and choose how the kernel should use it later on.
444
445choice
446	prompt "Built-in command line usage" if CMDLINE != ""
447	default CMDLINE_FALLBACK
448	help
449	  Choose how the kernel will handle the provided built-in command
450	  line.
451
452config CMDLINE_FALLBACK
453	bool "Use bootloader kernel arguments if available"
454	help
455	  Use the built-in command line as fallback in case we get nothing
456	  during boot. This is the default behaviour.
457
458config CMDLINE_EXTEND
459	bool "Extend bootloader kernel arguments"
460	help
461	  The command-line arguments provided during boot will be
462	  appended to the built-in command line. This is useful in
463	  cases where the provided arguments are insufficient and
464	  you don't want to or cannot modify them.
465
466
467config CMDLINE_FORCE
468	bool "Always use the default kernel command string"
469	help
470	  Always use the built-in command line, even if we get one during
471	  boot. This is useful in case you need to override the provided
472	  command line on systems where you don't have or want control
473	  over it.
474
475endchoice
476
477config EFI_STUB
478	bool
479
480config EFI
481	bool "UEFI runtime support"
482	depends on OF && !XIP_KERNEL
483	select LIBFDT
484	select UCS2_STRING
485	select EFI_PARAMS_FROM_FDT
486	select EFI_STUB
487	select EFI_GENERIC_STUB
488	select EFI_RUNTIME_WRAPPERS
489	select RISCV_ISA_C
490	depends on MMU
491	default y
492	help
493	  This option provides support for runtime services provided
494	  by UEFI firmware (such as non-volatile variables, realtime
495	  clock, and platform reset). A UEFI stub is also provided to
496	  allow the kernel to be booted as an EFI application. This
497	  is only useful on systems that have UEFI firmware.
498
499config CC_HAVE_STACKPROTECTOR_TLS
500	def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)
501
502config STACKPROTECTOR_PER_TASK
503	def_bool y
504	depends on !GCC_PLUGIN_RANDSTRUCT
505	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS
506
507config PHYS_RAM_BASE_FIXED
508	bool "Explicitly specified physical RAM address"
509	default n
510
511config PHYS_RAM_BASE
512	hex "Platform Physical RAM address"
513	depends on PHYS_RAM_BASE_FIXED
514	default "0x80000000"
515	help
516	  This is the physical address of RAM in the system. It has to be
517	  explicitly specified to run early relocations of read-write data
518	  from flash to RAM.
519
520config XIP_KERNEL
521	bool "Kernel Execute-In-Place from ROM"
522	depends on MMU && SPARSEMEM
523	# This prevents XIP from being enabled by all{yes,mod}config, which
524	# fail to build since XIP doesn't support large kernels.
525	depends on !COMPILE_TEST
526	select PHYS_RAM_BASE_FIXED
527	help
528	  Execute-In-Place allows the kernel to run from non-volatile storage
529	  directly addressable by the CPU, such as NOR flash. This saves RAM
530	  space since the text section of the kernel is not loaded from flash
531	  to RAM.  Read-write sections, such as the data section and stack,
532	  are still copied to RAM.  The XIP kernel is not compressed since
533	  it has to run directly from flash, so it will take more space to
534	  store it.  The flash address used to link the kernel object files,
535	  and for storing it, is configuration dependent. Therefore, if you
536	  say Y here, you must know the proper physical address where to
537	  store the kernel image depending on your own flash memory usage.
538
539	  Also note that the make target becomes "make xipImage" rather than
540	  "make zImage" or "make Image".  The final kernel binary to put in
541	  ROM memory will be arch/riscv/boot/xipImage.
542
543	  SPARSEMEM is required because the kernel text and rodata that are
544	  flash resident are not backed by memmap, then any attempt to get
545	  a struct page on those regions will trigger a fault.
546
547	  If unsure, say N.
548
549config XIP_PHYS_ADDR
550	hex "XIP Kernel Physical Location"
551	depends on XIP_KERNEL
552	default "0x21000000"
553	help
554	  This is the physical address in your flash memory the kernel will
555	  be linked for and stored to.  This address is dependent on your
556	  own flash usage.
557
558endmenu
559
560config BUILTIN_DTB
561	bool
562	depends on OF
563	default y if XIP_KERNEL
564
565menu "Power management options"
566
567source "kernel/power/Kconfig"
568
569endmenu
570
571source "arch/riscv/kvm/Kconfig"
572