xref: /openbmc/linux/arch/loongarch/Kconfig (revision 6548d543)
1# SPDX-License-Identifier: GPL-2.0
2config LOONGARCH
3	bool
4	default y
5	select ACPI
6	select ACPI_GENERIC_GSI if ACPI
7	select ACPI_MCFG if ACPI
8	select ACPI_PPTT if ACPI
9	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
10	select ARCH_BINFMT_ELF_STATE
11	select ARCH_DISABLE_KASAN_INLINE
12	select ARCH_ENABLE_MEMORY_HOTPLUG
13	select ARCH_ENABLE_MEMORY_HOTREMOVE
14	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
15	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
16	select ARCH_HAS_CPU_FINALIZE_INIT
17	select ARCH_HAS_FORTIFY_SOURCE
18	select ARCH_HAS_KCOV
19	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
20	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
21	select ARCH_HAS_PTE_SPECIAL
22	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
23	select ARCH_INLINE_READ_LOCK if !PREEMPTION
24	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
25	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
26	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
27	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
28	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
29	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
30	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
31	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
32	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
33	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
34	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
35	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
36	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
37	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
38	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
39	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
40	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
41	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
42	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
43	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
44	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
45	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
46	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
47	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
48	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
49	select ARCH_KEEP_MEMBLOCK
50	select ARCH_MIGHT_HAVE_PC_PARPORT
51	select ARCH_MIGHT_HAVE_PC_SERIO
52	select ARCH_SPARSEMEM_ENABLE
53	select ARCH_STACKWALK
54	select ARCH_SUPPORTS_ACPI
55	select ARCH_SUPPORTS_ATOMIC_RMW
56	select ARCH_SUPPORTS_HUGETLBFS
57	select ARCH_SUPPORTS_LTO_CLANG
58	select ARCH_SUPPORTS_LTO_CLANG_THIN
59	select ARCH_SUPPORTS_NUMA_BALANCING
60	select ARCH_USE_BUILTIN_BSWAP
61	select ARCH_USE_CMPXCHG_LOCKREF
62	select ARCH_USE_QUEUED_RWLOCKS
63	select ARCH_USE_QUEUED_SPINLOCKS
64	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
65	select ARCH_WANT_LD_ORPHAN_WARN
66	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
67	select ARCH_WANTS_NO_INSTR
68	select BUILDTIME_TABLE_SORT
69	select COMMON_CLK
70	select CPU_PM
71	select EFI
72	select GENERIC_CLOCKEVENTS
73	select GENERIC_CMOS_UPDATE
74	select GENERIC_CPU_AUTOPROBE
75	select GENERIC_ENTRY
76	select GENERIC_GETTIMEOFDAY
77	select GENERIC_IOREMAP if !ARCH_IOREMAP
78	select GENERIC_IRQ_MULTI_HANDLER
79	select GENERIC_IRQ_PROBE
80	select GENERIC_IRQ_SHOW
81	select GENERIC_LIB_ASHLDI3
82	select GENERIC_LIB_ASHRDI3
83	select GENERIC_LIB_CMPDI2
84	select GENERIC_LIB_LSHRDI3
85	select GENERIC_LIB_UCMPDI2
86	select GENERIC_LIB_DEVMEM_IS_ALLOWED
87	select GENERIC_PCI_IOMAP
88	select GENERIC_SCHED_CLOCK
89	select GENERIC_SMP_IDLE_THREAD
90	select GENERIC_TIME_VSYSCALL
91	select GENERIC_VDSO_TIME_NS
92	select GPIOLIB
93	select HAS_IOPORT
94	select HAVE_ARCH_AUDITSYSCALL
95	select HAVE_ARCH_JUMP_LABEL
96	select HAVE_ARCH_JUMP_LABEL_RELATIVE
97	select HAVE_ARCH_KASAN
98	select HAVE_ARCH_KFENCE
99	select HAVE_ARCH_KGDB if PERF_EVENTS
100	select HAVE_ARCH_MMAP_RND_BITS if MMU
101	select HAVE_ARCH_SECCOMP
102	select HAVE_ARCH_SECCOMP_FILTER
103	select HAVE_ARCH_TRACEHOOK
104	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
105	select HAVE_ASM_MODVERSIONS
106	select HAVE_CONTEXT_TRACKING_USER
107	select HAVE_C_RECORDMCOUNT
108	select HAVE_DEBUG_KMEMLEAK
109	select HAVE_DEBUG_STACKOVERFLOW
110	select HAVE_DMA_CONTIGUOUS
111	select HAVE_DYNAMIC_FTRACE
112	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
113	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
114	select HAVE_DYNAMIC_FTRACE_WITH_REGS
115	select HAVE_EBPF_JIT
116	select HAVE_EFFICIENT_UNALIGNED_ACCESS if !ARCH_STRICT_ALIGN
117	select HAVE_EXIT_THREAD
118	select HAVE_FAST_GUP
119	select HAVE_FTRACE_MCOUNT_RECORD
120	select HAVE_FUNCTION_ARG_ACCESS_API
121	select HAVE_FUNCTION_ERROR_INJECTION
122	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
123	select HAVE_FUNCTION_GRAPH_TRACER
124	select HAVE_FUNCTION_TRACER
125	select HAVE_GCC_PLUGINS
126	select HAVE_GENERIC_VDSO
127	select HAVE_HW_BREAKPOINT if PERF_EVENTS
128	select HAVE_IOREMAP_PROT
129	select HAVE_IRQ_EXIT_ON_IRQ_STACK
130	select HAVE_IRQ_TIME_ACCOUNTING
131	select HAVE_KPROBES
132	select HAVE_KPROBES_ON_FTRACE
133	select HAVE_KRETPROBES
134	select HAVE_MOD_ARCH_SPECIFIC
135	select HAVE_NMI
136	select HAVE_PCI
137	select HAVE_PERF_EVENTS
138	select HAVE_PERF_REGS
139	select HAVE_PERF_USER_STACK_DUMP
140	select HAVE_REGS_AND_STACK_ACCESS_API
141	select HAVE_RETHOOK
142	select HAVE_RSEQ
143	select HAVE_SAMPLE_FTRACE_DIRECT
144	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
145	select HAVE_SETUP_PER_CPU_AREA if NUMA
146	select HAVE_STACKPROTECTOR
147	select HAVE_SYSCALL_TRACEPOINTS
148	select HAVE_TIF_NOHZ
149	select HAVE_VIRT_CPU_ACCOUNTING_GEN if !SMP
150	select IRQ_FORCED_THREADING
151	select IRQ_LOONGARCH_CPU
152	select LOCK_MM_AND_FIND_VMA
153	select MMU_GATHER_MERGE_VMAS if MMU
154	select MODULES_USE_ELF_RELA if MODULES
155	select NEED_PER_CPU_EMBED_FIRST_CHUNK
156	select NEED_PER_CPU_PAGE_FIRST_CHUNK
157	select OF
158	select OF_EARLY_FLATTREE
159	select PCI
160	select PCI_DOMAINS_GENERIC
161	select PCI_ECAM if ACPI
162	select PCI_LOONGSON
163	select PCI_MSI_ARCH_FALLBACKS
164	select PCI_QUIRKS
165	select PERF_USE_VMALLOC
166	select RTC_LIB
167	select SMP
168	select SPARSE_IRQ
169	select SYSCTL_ARCH_UNALIGN_ALLOW
170	select SYSCTL_ARCH_UNALIGN_NO_WARN
171	select SYSCTL_EXCEPTION_TRACE
172	select SWIOTLB
173	select TRACE_IRQFLAGS_SUPPORT
174	select USE_PERCPU_NUMA_NODE_ID
175	select USER_STACKTRACE_SUPPORT
176	select ZONE_DMA32
177
178config 32BIT
179	bool
180
181config 64BIT
182	def_bool y
183
184config GENERIC_BUG
185	def_bool y
186	depends on BUG
187
188config GENERIC_BUG_RELATIVE_POINTERS
189	def_bool y
190	depends on GENERIC_BUG
191
192config GENERIC_CALIBRATE_DELAY
193	def_bool y
194
195config GENERIC_CSUM
196	def_bool y
197
198config GENERIC_HWEIGHT
199	def_bool y
200
201config L1_CACHE_SHIFT
202	int
203	default "6"
204
205config LOCKDEP_SUPPORT
206	bool
207	default y
208
209config STACKTRACE_SUPPORT
210	bool
211	default y
212
213# MACH_LOONGSON32 and MACH_LOONGSON64 are deliberately carried over from the
214# MIPS Loongson code, to preserve Loongson-specific code paths in drivers that
215# are shared between architectures, and specifically expecting the symbols.
216config MACH_LOONGSON32
217	def_bool 32BIT
218
219config MACH_LOONGSON64
220	def_bool 64BIT
221
222config FIX_EARLYCON_MEM
223	def_bool y
224
225config PAGE_SIZE_4KB
226	bool
227
228config PAGE_SIZE_16KB
229	bool
230
231config PAGE_SIZE_64KB
232	bool
233
234config PGTABLE_2LEVEL
235	bool
236
237config PGTABLE_3LEVEL
238	bool
239
240config PGTABLE_4LEVEL
241	bool
242
243config PGTABLE_LEVELS
244	int
245	default 2 if PGTABLE_2LEVEL
246	default 3 if PGTABLE_3LEVEL
247	default 4 if PGTABLE_4LEVEL
248
249config SCHED_OMIT_FRAME_POINTER
250	bool
251	default y
252
253config AS_HAS_EXPLICIT_RELOCS
254	def_bool $(as-instr,x:pcalau12i \$t0$(comma)%pc_hi20(x))
255
256config AS_HAS_FCSR_CLASS
257	def_bool $(as-instr,movfcsr2gr \$t0$(comma)\$fcsr0)
258
259config AS_HAS_LSX_EXTENSION
260	def_bool $(as-instr,vld \$vr0$(comma)\$a0$(comma)0)
261
262config AS_HAS_LASX_EXTENSION
263	def_bool $(as-instr,xvld \$xr0$(comma)\$a0$(comma)0)
264
265config AS_HAS_LBT_EXTENSION
266	def_bool $(as-instr,movscr2gr \$a0$(comma)\$scr0)
267
268menu "Kernel type and options"
269
270source "kernel/Kconfig.hz"
271
272choice
273	prompt "Page Table Layout"
274	default 16KB_2LEVEL if 32BIT
275	default 16KB_3LEVEL if 64BIT
276	help
277	  Allows choosing the page table layout, which is a combination
278	  of page size and page table levels. The size of virtual memory
279	  address space are determined by the page table layout.
280
281config 4KB_3LEVEL
282	bool "4KB with 3 levels"
283	select PAGE_SIZE_4KB
284	select PGTABLE_3LEVEL
285	help
286	  This option selects 4KB page size with 3 level page tables, which
287	  support a maximum of 39 bits of application virtual memory.
288
289config 4KB_4LEVEL
290	bool "4KB with 4 levels"
291	select PAGE_SIZE_4KB
292	select PGTABLE_4LEVEL
293	help
294	  This option selects 4KB page size with 4 level page tables, which
295	  support a maximum of 48 bits of application virtual memory.
296
297config 16KB_2LEVEL
298	bool "16KB with 2 levels"
299	select PAGE_SIZE_16KB
300	select PGTABLE_2LEVEL
301	help
302	  This option selects 16KB page size with 2 level page tables, which
303	  support a maximum of 36 bits of application virtual memory.
304
305config 16KB_3LEVEL
306	bool "16KB with 3 levels"
307	select PAGE_SIZE_16KB
308	select PGTABLE_3LEVEL
309	help
310	  This option selects 16KB page size with 3 level page tables, which
311	  support a maximum of 47 bits of application virtual memory.
312
313config 64KB_2LEVEL
314	bool "64KB with 2 levels"
315	select PAGE_SIZE_64KB
316	select PGTABLE_2LEVEL
317	help
318	  This option selects 64KB page size with 2 level page tables, which
319	  support a maximum of 42 bits of application virtual memory.
320
321config 64KB_3LEVEL
322	bool "64KB with 3 levels"
323	select PAGE_SIZE_64KB
324	select PGTABLE_3LEVEL
325	help
326	  This option selects 64KB page size with 3 level page tables, which
327	  support a maximum of 55 bits of application virtual memory.
328
329endchoice
330
331config CMDLINE
332	string "Built-in kernel command line"
333	help
334	  For most platforms, the arguments for the kernel's command line
335	  are provided at run-time, during boot. However, there are cases
336	  where either no arguments are being provided or the provided
337	  arguments are insufficient or even invalid.
338
339	  When that occurs, it is possible to define a built-in command
340	  line here and choose how the kernel should use it later on.
341
342choice
343	prompt "Kernel command line type"
344	default CMDLINE_BOOTLOADER
345	help
346	  Choose how the kernel will handle the provided built-in command
347	  line.
348
349config CMDLINE_BOOTLOADER
350	bool "Use bootloader kernel arguments if available"
351	help
352	  Prefer the command-line passed by the boot loader if available.
353	  Use the built-in command line as fallback in case we get nothing
354	  during boot. This is the default behaviour.
355
356config CMDLINE_EXTEND
357	bool "Use built-in to extend bootloader kernel arguments"
358	help
359	  The command-line arguments provided during boot will be
360	  appended to the built-in command line. This is useful in
361	  cases where the provided arguments are insufficient and
362	  you don't want to or cannot modify them.
363
364config CMDLINE_FORCE
365	bool "Always use the built-in kernel command string"
366	help
367	  Always use the built-in command line, even if we get one during
368	  boot. This is useful in case you need to override the provided
369	  command line on systems where you don't have or want control
370	  over it.
371
372endchoice
373
374config DMI
375	bool "Enable DMI scanning"
376	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
377	default y
378	help
379	  This enables SMBIOS/DMI feature for systems, and scanning of
380	  DMI to identify machine quirks.
381
382config EFI
383	bool "EFI runtime service support"
384	select UCS2_STRING
385	select EFI_RUNTIME_WRAPPERS
386	help
387	  This enables the kernel to use EFI runtime services that are
388	  available (such as the EFI variable services).
389
390config EFI_STUB
391	bool "EFI boot stub support"
392	default y
393	depends on EFI
394	select EFI_GENERIC_STUB
395	help
396	  This kernel feature allows the kernel to be loaded directly by
397	  EFI firmware without the use of a bootloader.
398
399config SCHED_SMT
400	bool "SMT scheduler support"
401	default y
402	help
403	  Improves scheduler's performance when there are multiple
404	  threads in one physical core.
405
406config SMP
407	bool "Multi-Processing support"
408	help
409	  This enables support for systems with more than one CPU. If you have
410	  a system with only one CPU, say N. If you have a system with more
411	  than one CPU, say Y.
412
413	  If you say N here, the kernel will run on uni- and multiprocessor
414	  machines, but will use only one CPU of a multiprocessor machine. If
415	  you say Y here, the kernel will run on many, but not all,
416	  uniprocessor machines. On a uniprocessor machine, the kernel
417	  will run faster if you say N here.
418
419	  See also the SMP-HOWTO available at <http://www.tldp.org/docs.html#howto>.
420
421	  If you don't know what to do here, say N.
422
423config HOTPLUG_CPU
424	bool "Support for hot-pluggable CPUs"
425	depends on SMP
426	select GENERIC_IRQ_MIGRATION
427	help
428	  Say Y here to allow turning CPUs off and on. CPUs can be
429	  controlled through /sys/devices/system/cpu.
430	  (Note: power management support will enable this option
431	    automatically on SMP systems. )
432	  Say N if you want to disable CPU hotplug.
433
434config NR_CPUS
435	int "Maximum number of CPUs (2-256)"
436	range 2 256
437	depends on SMP
438	default "64"
439	help
440	  This allows you to specify the maximum number of CPUs which this
441	  kernel will support.
442
443config NUMA
444	bool "NUMA Support"
445	select SMP
446	select ACPI_NUMA if ACPI
447	help
448	  Say Y to compile the kernel with NUMA (Non-Uniform Memory Access)
449	  support.  This option improves performance on systems with more
450	  than one NUMA node; on single node systems it is generally better
451	  to leave it disabled.
452
453config NODES_SHIFT
454	int
455	default "6"
456	depends on NUMA
457
458config ARCH_FORCE_MAX_ORDER
459	int "Maximum zone order"
460	default "13" if PAGE_SIZE_64KB
461	default "11" if PAGE_SIZE_16KB
462	default "10"
463	help
464	  The kernel memory allocator divides physically contiguous memory
465	  blocks into "zones", where each zone is a power of two number of
466	  pages.  This option selects the largest power of two that the kernel
467	  keeps in the memory allocator.  If you need to allocate very large
468	  blocks of physically contiguous memory, then you may need to
469	  increase this value.
470
471	  The page size is not necessarily 4KB.  Keep this in mind
472	  when choosing a value for this option.
473
474config ARCH_IOREMAP
475	bool "Enable LoongArch DMW-based ioremap()"
476	help
477	  We use generic TLB-based ioremap() by default since it has page
478	  protection support. However, you can enable LoongArch DMW-based
479	  ioremap() for better performance.
480
481config ARCH_WRITECOMBINE
482	bool "Enable WriteCombine (WUC) for ioremap()"
483	help
484	  LoongArch maintains cache coherency in hardware, but when paired
485	  with LS7A chipsets the WUC attribute (Weak-ordered UnCached, which
486	  is similar to WriteCombine) is out of the scope of cache coherency
487	  machanism for PCIe devices (this is a PCIe protocol violation, which
488	  may be fixed in newer chipsets).
489
490	  This means WUC can only used for write-only memory regions now, so
491	  this option is disabled by default, making WUC silently fallback to
492	  SUC for ioremap(). You can enable this option if the kernel is ensured
493	  to run on hardware without this bug.
494
495	  You can override this setting via writecombine=on/off boot parameter.
496
497config ARCH_STRICT_ALIGN
498	bool "Enable -mstrict-align to prevent unaligned accesses" if EXPERT
499	default y
500	help
501	  Not all LoongArch cores support h/w unaligned access, we can use
502	  -mstrict-align build parameter to prevent unaligned accesses.
503
504	  CPUs with h/w unaligned access support:
505	  Loongson-2K2000/2K3000/3A5000/3C5000/3D5000.
506
507	  CPUs without h/w unaligned access support:
508	  Loongson-2K500/2K1000.
509
510	  This option is enabled by default to make the kernel be able to run
511	  on all LoongArch systems. But you can disable it manually if you want
512	  to run kernel only on systems with h/w unaligned access support in
513	  order to optimise for performance.
514
515config CPU_HAS_FPU
516	bool
517	default y
518
519config CPU_HAS_LSX
520	bool "Support for the Loongson SIMD Extension"
521	depends on AS_HAS_LSX_EXTENSION
522	help
523	  Loongson SIMD Extension (LSX) introduces 128 bit wide vector registers
524	  and a set of SIMD instructions to operate on them. When this option
525	  is enabled the kernel will support allocating & switching LSX
526	  vector register contexts. If you know that your kernel will only be
527	  running on CPUs which do not support LSX or that your userland will
528	  not be making use of it then you may wish to say N here to reduce
529	  the size & complexity of your kernel.
530
531	  If unsure, say Y.
532
533config CPU_HAS_LASX
534	bool "Support for the Loongson Advanced SIMD Extension"
535	depends on CPU_HAS_LSX
536	depends on AS_HAS_LASX_EXTENSION
537	help
538	  Loongson Advanced SIMD Extension (LASX) introduces 256 bit wide vector
539	  registers and a set of SIMD instructions to operate on them. When this
540	  option is enabled the kernel will support allocating & switching LASX
541	  vector register contexts. If you know that your kernel will only be
542	  running on CPUs which do not support LASX or that your userland will
543	  not be making use of it then you may wish to say N here to reduce
544	  the size & complexity of your kernel.
545
546	  If unsure, say Y.
547
548config CPU_HAS_LBT
549	bool "Support for the Loongson Binary Translation Extension"
550	depends on AS_HAS_LBT_EXTENSION
551	help
552	  Loongson Binary Translation (LBT) introduces 4 scratch registers (SCR0
553	  to SCR3), x86/ARM eflags (eflags) and x87 fpu stack pointer (ftop).
554	  Enabling this option allows the kernel to allocate and switch registers
555	  specific to LBT.
556
557	  If you want to use this feature, such as the Loongson Architecture
558	  Translator (LAT), say Y.
559
560config CPU_HAS_PREFETCH
561	bool
562	default y
563
564config ARCH_SUPPORTS_KEXEC
565	def_bool y
566
567config ARCH_SUPPORTS_CRASH_DUMP
568	def_bool y
569
570config ARCH_SELECTS_CRASH_DUMP
571	def_bool y
572	depends on CRASH_DUMP
573	select RELOCATABLE
574
575config RELOCATABLE
576	bool "Relocatable kernel"
577	help
578	  This builds the kernel as a Position Independent Executable (PIE),
579	  which retains all relocation metadata required, so as to relocate
580	  the kernel binary at runtime to a different virtual address from
581	  its link address.
582
583config RANDOMIZE_BASE
584	bool "Randomize the address of the kernel (KASLR)"
585	depends on RELOCATABLE
586	help
587	   Randomizes the physical and virtual address at which the
588	   kernel image is loaded, as a security feature that
589	   deters exploit attempts relying on knowledge of the location
590	   of kernel internals.
591
592	   The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET.
593
594	   If unsure, say N.
595
596config RANDOMIZE_BASE_MAX_OFFSET
597	hex "Maximum KASLR offset" if EXPERT
598	depends on RANDOMIZE_BASE
599	range 0x0 0x10000000
600	default "0x01000000"
601	help
602	  When KASLR is active, this provides the maximum offset that will
603	  be applied to the kernel image. It should be set according to the
604	  amount of physical RAM available in the target system.
605
606	  This is limited by the size of the lower address memory, 256MB.
607
608endmenu
609
610config ARCH_SELECT_MEMORY_MODEL
611	def_bool y
612
613config ARCH_FLATMEM_ENABLE
614	def_bool y
615	depends on !NUMA
616
617config ARCH_SPARSEMEM_ENABLE
618	def_bool y
619	select SPARSEMEM_VMEMMAP_ENABLE
620	help
621	  Say Y to support efficient handling of sparse physical memory,
622	  for architectures which are either NUMA (Non-Uniform Memory Access)
623	  or have huge holes in the physical address space for other reasons.
624	  See <file:Documentation/mm/numa.rst> for more.
625
626config ARCH_MEMORY_PROBE
627	def_bool y
628	depends on MEMORY_HOTPLUG
629
630config MMU
631	bool
632	default y
633
634config ARCH_MMAP_RND_BITS_MIN
635	default 12
636
637config ARCH_MMAP_RND_BITS_MAX
638	default 18
639
640config ARCH_SUPPORTS_UPROBES
641	def_bool y
642
643config KASAN_SHADOW_OFFSET
644	hex
645	default 0x0
646	depends on KASAN
647
648menu "Power management options"
649
650config ARCH_SUSPEND_POSSIBLE
651	def_bool y
652
653config ARCH_HIBERNATION_POSSIBLE
654	def_bool y
655
656source "kernel/power/Kconfig"
657source "drivers/acpi/Kconfig"
658
659endmenu
660