xref: /openbmc/linux/arch/arm64/Kconfig (revision ba61bb17)
1config ARM64
2	def_bool y
3	select ACPI_CCA_REQUIRED if ACPI
4	select ACPI_GENERIC_GSI if ACPI
5	select ACPI_GTDT if ACPI
6	select ACPI_IORT if ACPI
7	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
8	select ACPI_MCFG if ACPI
9	select ACPI_SPCR_TABLE if ACPI
10	select ACPI_PPTT if ACPI
11	select ARCH_CLOCKSOURCE_DATA
12	select ARCH_HAS_DEBUG_VIRTUAL
13	select ARCH_HAS_DEVMEM_IS_ALLOWED
14	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
15	select ARCH_HAS_ELF_RANDOMIZE
16	select ARCH_HAS_FAST_MULTIPLIER
17	select ARCH_HAS_FORTIFY_SOURCE
18	select ARCH_HAS_GCOV_PROFILE_ALL
19	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
20	select ARCH_HAS_KCOV
21	select ARCH_HAS_MEMBARRIER_SYNC_CORE
22	select ARCH_HAS_PTE_SPECIAL
23	select ARCH_HAS_SET_MEMORY
24	select ARCH_HAS_SG_CHAIN
25	select ARCH_HAS_STRICT_KERNEL_RWX
26	select ARCH_HAS_STRICT_MODULE_RWX
27	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
28	select ARCH_HAVE_NMI_SAFE_CMPXCHG
29	select ARCH_INLINE_READ_LOCK if !PREEMPT
30	select ARCH_INLINE_READ_LOCK_BH if !PREEMPT
31	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT
32	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT
33	select ARCH_INLINE_READ_UNLOCK if !PREEMPT
34	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT
35	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT
36	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT
37	select ARCH_INLINE_WRITE_LOCK if !PREEMPT
38	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT
39	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT
40	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT
41	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT
42	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT
43	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT
44	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT
45	select ARCH_USE_CMPXCHG_LOCKREF
46	select ARCH_USE_QUEUED_RWLOCKS
47	select ARCH_SUPPORTS_MEMORY_FAILURE
48	select ARCH_SUPPORTS_ATOMIC_RMW
49	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG
50	select ARCH_SUPPORTS_NUMA_BALANCING
51	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
52	select ARCH_WANT_FRAME_POINTERS
53	select ARCH_HAS_UBSAN_SANITIZE_ALL
54	select ARM_AMBA
55	select ARM_ARCH_TIMER
56	select ARM_GIC
57	select AUDIT_ARCH_COMPAT_GENERIC
58	select ARM_GIC_V2M if PCI
59	select ARM_GIC_V3
60	select ARM_GIC_V3_ITS if PCI
61	select ARM_PSCI_FW
62	select BUILDTIME_EXTABLE_SORT
63	select CLONE_BACKWARDS
64	select COMMON_CLK
65	select CPU_PM if (SUSPEND || CPU_IDLE)
66	select DCACHE_WORD_ACCESS
67	select DMA_DIRECT_OPS
68	select EDAC_SUPPORT
69	select FRAME_POINTER
70	select GENERIC_ALLOCATOR
71	select GENERIC_ARCH_TOPOLOGY
72	select GENERIC_CLOCKEVENTS
73	select GENERIC_CLOCKEVENTS_BROADCAST
74	select GENERIC_CPU_AUTOPROBE
75	select GENERIC_EARLY_IOREMAP
76	select GENERIC_IDLE_POLL_SETUP
77	select GENERIC_IRQ_PROBE
78	select GENERIC_IRQ_SHOW
79	select GENERIC_IRQ_SHOW_LEVEL
80	select GENERIC_PCI_IOMAP
81	select GENERIC_SCHED_CLOCK
82	select GENERIC_SMP_IDLE_THREAD
83	select GENERIC_STRNCPY_FROM_USER
84	select GENERIC_STRNLEN_USER
85	select GENERIC_TIME_VSYSCALL
86	select HANDLE_DOMAIN_IRQ
87	select HARDIRQS_SW_RESEND
88	select HAVE_ACPI_APEI if (ACPI && EFI)
89	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
90	select HAVE_ARCH_AUDITSYSCALL
91	select HAVE_ARCH_BITREVERSE
92	select HAVE_ARCH_HUGE_VMAP
93	select HAVE_ARCH_JUMP_LABEL
94	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
95	select HAVE_ARCH_KGDB
96	select HAVE_ARCH_MMAP_RND_BITS
97	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
98	select HAVE_ARCH_SECCOMP_FILTER
99	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
100	select HAVE_ARCH_TRACEHOOK
101	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
102	select HAVE_ARCH_VMAP_STACK
103	select HAVE_ARM_SMCCC
104	select HAVE_EBPF_JIT
105	select HAVE_C_RECORDMCOUNT
106	select HAVE_CMPXCHG_DOUBLE
107	select HAVE_CMPXCHG_LOCAL
108	select HAVE_CONTEXT_TRACKING
109	select HAVE_DEBUG_BUGVERBOSE
110	select HAVE_DEBUG_KMEMLEAK
111	select HAVE_DMA_CONTIGUOUS
112	select HAVE_DYNAMIC_FTRACE
113	select HAVE_EFFICIENT_UNALIGNED_ACCESS
114	select HAVE_FTRACE_MCOUNT_RECORD
115	select HAVE_FUNCTION_TRACER
116	select HAVE_FUNCTION_GRAPH_TRACER
117	select HAVE_GCC_PLUGINS
118	select HAVE_GENERIC_DMA_COHERENT
119	select HAVE_HW_BREAKPOINT if PERF_EVENTS
120	select HAVE_IRQ_TIME_ACCOUNTING
121	select HAVE_MEMBLOCK
122	select HAVE_MEMBLOCK_NODE_MAP if NUMA
123	select HAVE_NMI
124	select HAVE_PATA_PLATFORM
125	select HAVE_PERF_EVENTS
126	select HAVE_PERF_REGS
127	select HAVE_PERF_USER_STACK_DUMP
128	select HAVE_REGS_AND_STACK_ACCESS_API
129	select HAVE_RCU_TABLE_FREE
130	select HAVE_STACKPROTECTOR
131	select HAVE_SYSCALL_TRACEPOINTS
132	select HAVE_KPROBES
133	select HAVE_KRETPROBES
134	select IOMMU_DMA if IOMMU_SUPPORT
135	select IRQ_DOMAIN
136	select IRQ_FORCED_THREADING
137	select MODULES_USE_ELF_RELA
138	select MULTI_IRQ_HANDLER
139	select NEED_DMA_MAP_STATE
140	select NEED_SG_DMA_LENGTH
141	select NO_BOOTMEM
142	select OF
143	select OF_EARLY_FLATTREE
144	select OF_RESERVED_MEM
145	select PCI_ECAM if ACPI
146	select POWER_RESET
147	select POWER_SUPPLY
148	select REFCOUNT_FULL
149	select SPARSE_IRQ
150	select SWIOTLB
151	select SYSCTL_EXCEPTION_TRACE
152	select THREAD_INFO_IN_TASK
153	help
154	  ARM 64-bit (AArch64) Linux support.
155
156config 64BIT
157	def_bool y
158
159config MMU
160	def_bool y
161
162config ARM64_PAGE_SHIFT
163	int
164	default 16 if ARM64_64K_PAGES
165	default 14 if ARM64_16K_PAGES
166	default 12
167
168config ARM64_CONT_SHIFT
169	int
170	default 5 if ARM64_64K_PAGES
171	default 7 if ARM64_16K_PAGES
172	default 4
173
174config ARCH_MMAP_RND_BITS_MIN
175       default 14 if ARM64_64K_PAGES
176       default 16 if ARM64_16K_PAGES
177       default 18
178
179# max bits determined by the following formula:
180#  VA_BITS - PAGE_SHIFT - 3
181config ARCH_MMAP_RND_BITS_MAX
182       default 19 if ARM64_VA_BITS=36
183       default 24 if ARM64_VA_BITS=39
184       default 27 if ARM64_VA_BITS=42
185       default 30 if ARM64_VA_BITS=47
186       default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
187       default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
188       default 33 if ARM64_VA_BITS=48
189       default 14 if ARM64_64K_PAGES
190       default 16 if ARM64_16K_PAGES
191       default 18
192
193config ARCH_MMAP_RND_COMPAT_BITS_MIN
194       default 7 if ARM64_64K_PAGES
195       default 9 if ARM64_16K_PAGES
196       default 11
197
198config ARCH_MMAP_RND_COMPAT_BITS_MAX
199       default 16
200
201config NO_IOPORT_MAP
202	def_bool y if !PCI
203
204config STACKTRACE_SUPPORT
205	def_bool y
206
207config ILLEGAL_POINTER_VALUE
208	hex
209	default 0xdead000000000000
210
211config LOCKDEP_SUPPORT
212	def_bool y
213
214config TRACE_IRQFLAGS_SUPPORT
215	def_bool y
216
217config RWSEM_XCHGADD_ALGORITHM
218	def_bool y
219
220config GENERIC_BUG
221	def_bool y
222	depends on BUG
223
224config GENERIC_BUG_RELATIVE_POINTERS
225	def_bool y
226	depends on GENERIC_BUG
227
228config GENERIC_HWEIGHT
229	def_bool y
230
231config GENERIC_CSUM
232        def_bool y
233
234config GENERIC_CALIBRATE_DELAY
235	def_bool y
236
237config ZONE_DMA32
238	def_bool y
239
240config HAVE_GENERIC_GUP
241	def_bool y
242
243config SMP
244	def_bool y
245
246config KERNEL_MODE_NEON
247	def_bool y
248
249config FIX_EARLYCON_MEM
250	def_bool y
251
252config PGTABLE_LEVELS
253	int
254	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
255	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
256	default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48
257	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
258	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
259	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
260
261config ARCH_SUPPORTS_UPROBES
262	def_bool y
263
264config ARCH_PROC_KCORE_TEXT
265	def_bool y
266
267config MULTI_IRQ_HANDLER
268	def_bool y
269
270source "init/Kconfig"
271
272source "kernel/Kconfig.freezer"
273
274source "arch/arm64/Kconfig.platforms"
275
276menu "Bus support"
277
278config PCI
279	bool "PCI support"
280	help
281	  This feature enables support for PCI bus system. If you say Y
282	  here, the kernel will include drivers and infrastructure code
283	  to support PCI bus devices.
284
285config PCI_DOMAINS
286	def_bool PCI
287
288config PCI_DOMAINS_GENERIC
289	def_bool PCI
290
291config PCI_SYSCALL
292	def_bool PCI
293
294source "drivers/pci/Kconfig"
295
296endmenu
297
298menu "Kernel Features"
299
300menu "ARM errata workarounds via the alternatives framework"
301
302config ARM64_ERRATUM_826319
303	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
304	default y
305	help
306	  This option adds an alternative code sequence to work around ARM
307	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
308	  AXI master interface and an L2 cache.
309
310	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
311	  and is unable to accept a certain write via this interface, it will
312	  not progress on read data presented on the read data channel and the
313	  system can deadlock.
314
315	  The workaround promotes data cache clean instructions to
316	  data cache clean-and-invalidate.
317	  Please note that this does not necessarily enable the workaround,
318	  as it depends on the alternative framework, which will only patch
319	  the kernel if an affected CPU is detected.
320
321	  If unsure, say Y.
322
323config ARM64_ERRATUM_827319
324	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
325	default y
326	help
327	  This option adds an alternative code sequence to work around ARM
328	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
329	  master interface and an L2 cache.
330
331	  Under certain conditions this erratum can cause a clean line eviction
332	  to occur at the same time as another transaction to the same address
333	  on the AMBA 5 CHI interface, which can cause data corruption if the
334	  interconnect reorders the two transactions.
335
336	  The workaround promotes data cache clean instructions to
337	  data cache clean-and-invalidate.
338	  Please note that this does not necessarily enable the workaround,
339	  as it depends on the alternative framework, which will only patch
340	  the kernel if an affected CPU is detected.
341
342	  If unsure, say Y.
343
344config ARM64_ERRATUM_824069
345	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
346	default y
347	help
348	  This option adds an alternative code sequence to work around ARM
349	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
350	  to a coherent interconnect.
351
352	  If a Cortex-A53 processor is executing a store or prefetch for
353	  write instruction at the same time as a processor in another
354	  cluster is executing a cache maintenance operation to the same
355	  address, then this erratum might cause a clean cache line to be
356	  incorrectly marked as dirty.
357
358	  The workaround promotes data cache clean instructions to
359	  data cache clean-and-invalidate.
360	  Please note that this option does not necessarily enable the
361	  workaround, as it depends on the alternative framework, which will
362	  only patch the kernel if an affected CPU is detected.
363
364	  If unsure, say Y.
365
366config ARM64_ERRATUM_819472
367	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
368	default y
369	help
370	  This option adds an alternative code sequence to work around ARM
371	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
372	  present when it is connected to a coherent interconnect.
373
374	  If the processor is executing a load and store exclusive sequence at
375	  the same time as a processor in another cluster is executing a cache
376	  maintenance operation to the same address, then this erratum might
377	  cause data corruption.
378
379	  The workaround promotes data cache clean instructions to
380	  data cache clean-and-invalidate.
381	  Please note that this does not necessarily enable the workaround,
382	  as it depends on the alternative framework, which will only patch
383	  the kernel if an affected CPU is detected.
384
385	  If unsure, say Y.
386
387config ARM64_ERRATUM_832075
388	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
389	default y
390	help
391	  This option adds an alternative code sequence to work around ARM
392	  erratum 832075 on Cortex-A57 parts up to r1p2.
393
394	  Affected Cortex-A57 parts might deadlock when exclusive load/store
395	  instructions to Write-Back memory are mixed with Device loads.
396
397	  The workaround is to promote device loads to use Load-Acquire
398	  semantics.
399	  Please note that this does not necessarily enable the workaround,
400	  as it depends on the alternative framework, which will only patch
401	  the kernel if an affected CPU is detected.
402
403	  If unsure, say Y.
404
405config ARM64_ERRATUM_834220
406	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
407	depends on KVM
408	default y
409	help
410	  This option adds an alternative code sequence to work around ARM
411	  erratum 834220 on Cortex-A57 parts up to r1p2.
412
413	  Affected Cortex-A57 parts might report a Stage 2 translation
414	  fault as the result of a Stage 1 fault for load crossing a
415	  page boundary when there is a permission or device memory
416	  alignment fault at Stage 1 and a translation fault at Stage 2.
417
418	  The workaround is to verify that the Stage 1 translation
419	  doesn't generate a fault before handling the Stage 2 fault.
420	  Please note that this does not necessarily enable the workaround,
421	  as it depends on the alternative framework, which will only patch
422	  the kernel if an affected CPU is detected.
423
424	  If unsure, say Y.
425
426config ARM64_ERRATUM_845719
427	bool "Cortex-A53: 845719: a load might read incorrect data"
428	depends on COMPAT
429	default y
430	help
431	  This option adds an alternative code sequence to work around ARM
432	  erratum 845719 on Cortex-A53 parts up to r0p4.
433
434	  When running a compat (AArch32) userspace on an affected Cortex-A53
435	  part, a load at EL0 from a virtual address that matches the bottom 32
436	  bits of the virtual address used by a recent load at (AArch64) EL1
437	  might return incorrect data.
438
439	  The workaround is to write the contextidr_el1 register on exception
440	  return to a 32-bit task.
441	  Please note that this does not necessarily enable the workaround,
442	  as it depends on the alternative framework, which will only patch
443	  the kernel if an affected CPU is detected.
444
445	  If unsure, say Y.
446
447config ARM64_ERRATUM_843419
448	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
449	default y
450	select ARM64_MODULE_PLTS if MODULES
451	help
452	  This option links the kernel with '--fix-cortex-a53-843419' and
453	  enables PLT support to replace certain ADRP instructions, which can
454	  cause subsequent memory accesses to use an incorrect address on
455	  Cortex-A53 parts up to r0p4.
456
457	  If unsure, say Y.
458
459config ARM64_ERRATUM_1024718
460	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
461	default y
462	help
463	  This option adds work around for Arm Cortex-A55 Erratum 1024718.
464
465	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
466	  update of the hardware dirty bit when the DBM/AP bits are updated
467	  without a break-before-make. The work around is to disable the usage
468	  of hardware DBM locally on the affected cores. CPUs not affected by
469	  erratum will continue to use the feature.
470
471	  If unsure, say Y.
472
473config CAVIUM_ERRATUM_22375
474	bool "Cavium erratum 22375, 24313"
475	default y
476	help
477	  Enable workaround for erratum 22375, 24313.
478
479	  This implements two gicv3-its errata workarounds for ThunderX. Both
480	  with small impact affecting only ITS table allocation.
481
482	    erratum 22375: only alloc 8MB table size
483	    erratum 24313: ignore memory access type
484
485	  The fixes are in ITS initialization and basically ignore memory access
486	  type and table size provided by the TYPER and BASER registers.
487
488	  If unsure, say Y.
489
490config CAVIUM_ERRATUM_23144
491	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
492	depends on NUMA
493	default y
494	help
495	  ITS SYNC command hang for cross node io and collections/cpu mapping.
496
497	  If unsure, say Y.
498
499config CAVIUM_ERRATUM_23154
500	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
501	default y
502	help
503	  The gicv3 of ThunderX requires a modified version for
504	  reading the IAR status to ensure data synchronization
505	  (access to icc_iar1_el1 is not sync'ed before and after).
506
507	  If unsure, say Y.
508
509config CAVIUM_ERRATUM_27456
510	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
511	default y
512	help
513	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
514	  instructions may cause the icache to become corrupted if it
515	  contains data for a non-current ASID.  The fix is to
516	  invalidate the icache when changing the mm context.
517
518	  If unsure, say Y.
519
520config CAVIUM_ERRATUM_30115
521	bool "Cavium erratum 30115: Guest may disable interrupts in host"
522	default y
523	help
524	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
525	  1.2, and T83 Pass 1.0, KVM guest execution may disable
526	  interrupts in host. Trapping both GICv3 group-0 and group-1
527	  accesses sidesteps the issue.
528
529	  If unsure, say Y.
530
531config QCOM_FALKOR_ERRATUM_1003
532	bool "Falkor E1003: Incorrect translation due to ASID change"
533	default y
534	help
535	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
536	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
537	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
538	  then only for entries in the walk cache, since the leaf translation
539	  is unchanged. Work around the erratum by invalidating the walk cache
540	  entries for the trampoline before entering the kernel proper.
541
542config QCOM_FALKOR_ERRATUM_1009
543	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
544	default y
545	help
546	  On Falkor v1, the CPU may prematurely complete a DSB following a
547	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
548	  one more time to fix the issue.
549
550	  If unsure, say Y.
551
552config QCOM_QDF2400_ERRATUM_0065
553	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
554	default y
555	help
556	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
557	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
558	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
559
560	  If unsure, say Y.
561
562config SOCIONEXT_SYNQUACER_PREITS
563	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
564	default y
565	help
566	  Socionext Synquacer SoCs implement a separate h/w block to generate
567	  MSI doorbell writes with non-zero values for the device ID.
568
569	  If unsure, say Y.
570
571config HISILICON_ERRATUM_161600802
572	bool "Hip07 161600802: Erroneous redistributor VLPI base"
573	default y
574	help
575	  The HiSilicon Hip07 SoC usees the wrong redistributor base
576	  when issued ITS commands such as VMOVP and VMAPP, and requires
577	  a 128kB offset to be applied to the target address in this commands.
578
579	  If unsure, say Y.
580
581config QCOM_FALKOR_ERRATUM_E1041
582	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
583	default y
584	help
585	  Falkor CPU may speculatively fetch instructions from an improper
586	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
587	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
588
589	  If unsure, say Y.
590
591endmenu
592
593
594choice
595	prompt "Page size"
596	default ARM64_4K_PAGES
597	help
598	  Page size (translation granule) configuration.
599
600config ARM64_4K_PAGES
601	bool "4KB"
602	help
603	  This feature enables 4KB pages support.
604
605config ARM64_16K_PAGES
606	bool "16KB"
607	help
608	  The system will use 16KB pages support. AArch32 emulation
609	  requires applications compiled with 16K (or a multiple of 16K)
610	  aligned segments.
611
612config ARM64_64K_PAGES
613	bool "64KB"
614	help
615	  This feature enables 64KB pages support (4KB by default)
616	  allowing only two levels of page tables and faster TLB
617	  look-up. AArch32 emulation requires applications compiled
618	  with 64K aligned segments.
619
620endchoice
621
622choice
623	prompt "Virtual address space size"
624	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
625	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
626	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
627	help
628	  Allows choosing one of multiple possible virtual address
629	  space sizes. The level of translation table is determined by
630	  a combination of page size and virtual address space size.
631
632config ARM64_VA_BITS_36
633	bool "36-bit" if EXPERT
634	depends on ARM64_16K_PAGES
635
636config ARM64_VA_BITS_39
637	bool "39-bit"
638	depends on ARM64_4K_PAGES
639
640config ARM64_VA_BITS_42
641	bool "42-bit"
642	depends on ARM64_64K_PAGES
643
644config ARM64_VA_BITS_47
645	bool "47-bit"
646	depends on ARM64_16K_PAGES
647
648config ARM64_VA_BITS_48
649	bool "48-bit"
650
651endchoice
652
653config ARM64_VA_BITS
654	int
655	default 36 if ARM64_VA_BITS_36
656	default 39 if ARM64_VA_BITS_39
657	default 42 if ARM64_VA_BITS_42
658	default 47 if ARM64_VA_BITS_47
659	default 48 if ARM64_VA_BITS_48
660
661choice
662	prompt "Physical address space size"
663	default ARM64_PA_BITS_48
664	help
665	  Choose the maximum physical address range that the kernel will
666	  support.
667
668config ARM64_PA_BITS_48
669	bool "48-bit"
670
671config ARM64_PA_BITS_52
672	bool "52-bit (ARMv8.2)"
673	depends on ARM64_64K_PAGES
674	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
675	help
676	  Enable support for a 52-bit physical address space, introduced as
677	  part of the ARMv8.2-LPA extension.
678
679	  With this enabled, the kernel will also continue to work on CPUs that
680	  do not support ARMv8.2-LPA, but with some added memory overhead (and
681	  minor performance overhead).
682
683endchoice
684
685config ARM64_PA_BITS
686	int
687	default 48 if ARM64_PA_BITS_48
688	default 52 if ARM64_PA_BITS_52
689
690config CPU_BIG_ENDIAN
691       bool "Build big-endian kernel"
692       help
693         Say Y if you plan on running a kernel in big-endian mode.
694
695config SCHED_MC
696	bool "Multi-core scheduler support"
697	help
698	  Multi-core scheduler support improves the CPU scheduler's decision
699	  making when dealing with multi-core CPU chips at a cost of slightly
700	  increased overhead in some places. If unsure say N here.
701
702config SCHED_SMT
703	bool "SMT scheduler support"
704	help
705	  Improves the CPU scheduler's decision making when dealing with
706	  MultiThreading at a cost of slightly increased overhead in some
707	  places. If unsure say N here.
708
709config NR_CPUS
710	int "Maximum number of CPUs (2-4096)"
711	range 2 4096
712	# These have to remain sorted largest to smallest
713	default "64"
714
715config HOTPLUG_CPU
716	bool "Support for hot-pluggable CPUs"
717	select GENERIC_IRQ_MIGRATION
718	help
719	  Say Y here to experiment with turning CPUs off and on.  CPUs
720	  can be controlled through /sys/devices/system/cpu.
721
722# Common NUMA Features
723config NUMA
724	bool "Numa Memory Allocation and Scheduler Support"
725	select ACPI_NUMA if ACPI
726	select OF_NUMA
727	help
728	  Enable NUMA (Non Uniform Memory Access) support.
729
730	  The kernel will try to allocate memory used by a CPU on the
731	  local memory of the CPU and add some more
732	  NUMA awareness to the kernel.
733
734config NODES_SHIFT
735	int "Maximum NUMA Nodes (as a power of 2)"
736	range 1 10
737	default "2"
738	depends on NEED_MULTIPLE_NODES
739	help
740	  Specify the maximum number of NUMA Nodes available on the target
741	  system.  Increases memory reserved to accommodate various tables.
742
743config USE_PERCPU_NUMA_NODE_ID
744	def_bool y
745	depends on NUMA
746
747config HAVE_SETUP_PER_CPU_AREA
748	def_bool y
749	depends on NUMA
750
751config NEED_PER_CPU_EMBED_FIRST_CHUNK
752	def_bool y
753	depends on NUMA
754
755config HOLES_IN_ZONE
756	def_bool y
757	depends on NUMA
758
759source kernel/Kconfig.preempt
760source kernel/Kconfig.hz
761
762config ARCH_SUPPORTS_DEBUG_PAGEALLOC
763	def_bool y
764
765config ARCH_HAS_HOLES_MEMORYMODEL
766	def_bool y if SPARSEMEM
767
768config ARCH_SPARSEMEM_ENABLE
769	def_bool y
770	select SPARSEMEM_VMEMMAP_ENABLE
771
772config ARCH_SPARSEMEM_DEFAULT
773	def_bool ARCH_SPARSEMEM_ENABLE
774
775config ARCH_SELECT_MEMORY_MODEL
776	def_bool ARCH_SPARSEMEM_ENABLE
777
778config HAVE_ARCH_PFN_VALID
779	def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
780
781config HW_PERF_EVENTS
782	def_bool y
783	depends on ARM_PMU
784
785config SYS_SUPPORTS_HUGETLBFS
786	def_bool y
787
788config ARCH_WANT_HUGE_PMD_SHARE
789	def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
790
791config ARCH_HAS_CACHE_LINE_SIZE
792	def_bool y
793
794source "mm/Kconfig"
795
796config SECCOMP
797	bool "Enable seccomp to safely compute untrusted bytecode"
798	---help---
799	  This kernel feature is useful for number crunching applications
800	  that may need to compute untrusted bytecode during their
801	  execution. By using pipes or other transports made available to
802	  the process as file descriptors supporting the read/write
803	  syscalls, it's possible to isolate those applications in
804	  their own address space using seccomp. Once seccomp is
805	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
806	  and the task is only allowed to execute a few safe syscalls
807	  defined by each seccomp mode.
808
809config PARAVIRT
810	bool "Enable paravirtualization code"
811	help
812	  This changes the kernel so it can modify itself when it is run
813	  under a hypervisor, potentially improving performance significantly
814	  over full virtualization.
815
816config PARAVIRT_TIME_ACCOUNTING
817	bool "Paravirtual steal time accounting"
818	select PARAVIRT
819	default n
820	help
821	  Select this option to enable fine granularity task steal time
822	  accounting. Time spent executing other tasks in parallel with
823	  the current vCPU is discounted from the vCPU power. To account for
824	  that, there can be a small performance impact.
825
826	  If in doubt, say N here.
827
828config KEXEC
829	depends on PM_SLEEP_SMP
830	select KEXEC_CORE
831	bool "kexec system call"
832	---help---
833	  kexec is a system call that implements the ability to shutdown your
834	  current kernel, and to start another kernel.  It is like a reboot
835	  but it is independent of the system firmware.   And like a reboot
836	  you can start any kernel with it, not just Linux.
837
838config CRASH_DUMP
839	bool "Build kdump crash kernel"
840	help
841	  Generate crash dump after being started by kexec. This should
842	  be normally only set in special crash dump kernels which are
843	  loaded in the main kernel with kexec-tools into a specially
844	  reserved region and then later executed after a crash by
845	  kdump/kexec.
846
847	  For more details see Documentation/kdump/kdump.txt
848
849config XEN_DOM0
850	def_bool y
851	depends on XEN
852
853config XEN
854	bool "Xen guest support on ARM64"
855	depends on ARM64 && OF
856	select SWIOTLB_XEN
857	select PARAVIRT
858	help
859	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
860
861config FORCE_MAX_ZONEORDER
862	int
863	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
864	default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
865	default "11"
866	help
867	  The kernel memory allocator divides physically contiguous memory
868	  blocks into "zones", where each zone is a power of two number of
869	  pages.  This option selects the largest power of two that the kernel
870	  keeps in the memory allocator.  If you need to allocate very large
871	  blocks of physically contiguous memory, then you may need to
872	  increase this value.
873
874	  This config option is actually maximum order plus one. For example,
875	  a value of 11 means that the largest free memory block is 2^10 pages.
876
877	  We make sure that we can allocate upto a HugePage size for each configuration.
878	  Hence we have :
879		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
880
881	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
882	  4M allocations matching the default size used by generic code.
883
884config UNMAP_KERNEL_AT_EL0
885	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
886	default y
887	help
888	  Speculation attacks against some high-performance processors can
889	  be used to bypass MMU permission checks and leak kernel data to
890	  userspace. This can be defended against by unmapping the kernel
891	  when running in userspace, mapping it back in on exception entry
892	  via a trampoline page in the vector table.
893
894	  If unsure, say Y.
895
896config HARDEN_BRANCH_PREDICTOR
897	bool "Harden the branch predictor against aliasing attacks" if EXPERT
898	default y
899	help
900	  Speculation attacks against some high-performance processors rely on
901	  being able to manipulate the branch predictor for a victim context by
902	  executing aliasing branches in the attacker context.  Such attacks
903	  can be partially mitigated against by clearing internal branch
904	  predictor state and limiting the prediction logic in some situations.
905
906	  This config option will take CPU-specific actions to harden the
907	  branch predictor against aliasing attacks and may rely on specific
908	  instruction sequences or control bits being set by the system
909	  firmware.
910
911	  If unsure, say Y.
912
913config HARDEN_EL2_VECTORS
914	bool "Harden EL2 vector mapping against system register leak" if EXPERT
915	default y
916	help
917	  Speculation attacks against some high-performance processors can
918	  be used to leak privileged information such as the vector base
919	  register, resulting in a potential defeat of the EL2 layout
920	  randomization.
921
922	  This config option will map the vectors to a fixed location,
923	  independent of the EL2 code mapping, so that revealing VBAR_EL2
924	  to an attacker does not give away any extra information. This
925	  only gets enabled on affected CPUs.
926
927	  If unsure, say Y.
928
929config ARM64_SSBD
930	bool "Speculative Store Bypass Disable" if EXPERT
931	default y
932	help
933	  This enables mitigation of the bypassing of previous stores
934	  by speculative loads.
935
936	  If unsure, say Y.
937
938menuconfig ARMV8_DEPRECATED
939	bool "Emulate deprecated/obsolete ARMv8 instructions"
940	depends on COMPAT
941	depends on SYSCTL
942	help
943	  Legacy software support may require certain instructions
944	  that have been deprecated or obsoleted in the architecture.
945
946	  Enable this config to enable selective emulation of these
947	  features.
948
949	  If unsure, say Y
950
951if ARMV8_DEPRECATED
952
953config SWP_EMULATION
954	bool "Emulate SWP/SWPB instructions"
955	help
956	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
957	  they are always undefined. Say Y here to enable software
958	  emulation of these instructions for userspace using LDXR/STXR.
959
960	  In some older versions of glibc [<=2.8] SWP is used during futex
961	  trylock() operations with the assumption that the code will not
962	  be preempted. This invalid assumption may be more likely to fail
963	  with SWP emulation enabled, leading to deadlock of the user
964	  application.
965
966	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
967	  on an external transaction monitoring block called a global
968	  monitor to maintain update atomicity. If your system does not
969	  implement a global monitor, this option can cause programs that
970	  perform SWP operations to uncached memory to deadlock.
971
972	  If unsure, say Y
973
974config CP15_BARRIER_EMULATION
975	bool "Emulate CP15 Barrier instructions"
976	help
977	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
978	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
979	  strongly recommended to use the ISB, DSB, and DMB
980	  instructions instead.
981
982	  Say Y here to enable software emulation of these
983	  instructions for AArch32 userspace code. When this option is
984	  enabled, CP15 barrier usage is traced which can help
985	  identify software that needs updating.
986
987	  If unsure, say Y
988
989config SETEND_EMULATION
990	bool "Emulate SETEND instruction"
991	help
992	  The SETEND instruction alters the data-endianness of the
993	  AArch32 EL0, and is deprecated in ARMv8.
994
995	  Say Y here to enable software emulation of the instruction
996	  for AArch32 userspace code.
997
998	  Note: All the cpus on the system must have mixed endian support at EL0
999	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1000	  endian - is hotplugged in after this feature has been enabled, there could
1001	  be unexpected results in the applications.
1002
1003	  If unsure, say Y
1004endif
1005
1006config ARM64_SW_TTBR0_PAN
1007	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1008	help
1009	  Enabling this option prevents the kernel from accessing
1010	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1011	  zeroed area and reserved ASID. The user access routines
1012	  restore the valid TTBR0_EL1 temporarily.
1013
1014menu "ARMv8.1 architectural features"
1015
1016config ARM64_HW_AFDBM
1017	bool "Support for hardware updates of the Access and Dirty page flags"
1018	default y
1019	help
1020	  The ARMv8.1 architecture extensions introduce support for
1021	  hardware updates of the access and dirty information in page
1022	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1023	  capable processors, accesses to pages with PTE_AF cleared will
1024	  set this bit instead of raising an access flag fault.
1025	  Similarly, writes to read-only pages with the DBM bit set will
1026	  clear the read-only bit (AP[2]) instead of raising a
1027	  permission fault.
1028
1029	  Kernels built with this configuration option enabled continue
1030	  to work on pre-ARMv8.1 hardware and the performance impact is
1031	  minimal. If unsure, say Y.
1032
1033config ARM64_PAN
1034	bool "Enable support for Privileged Access Never (PAN)"
1035	default y
1036	help
1037	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1038	 prevents the kernel or hypervisor from accessing user-space (EL0)
1039	 memory directly.
1040
1041	 Choosing this option will cause any unprotected (not using
1042	 copy_to_user et al) memory access to fail with a permission fault.
1043
1044	 The feature is detected at runtime, and will remain as a 'nop'
1045	 instruction if the cpu does not implement the feature.
1046
1047config ARM64_LSE_ATOMICS
1048	bool "Atomic instructions"
1049	default y
1050	help
1051	  As part of the Large System Extensions, ARMv8.1 introduces new
1052	  atomic instructions that are designed specifically to scale in
1053	  very large systems.
1054
1055	  Say Y here to make use of these instructions for the in-kernel
1056	  atomic routines. This incurs a small overhead on CPUs that do
1057	  not support these instructions and requires the kernel to be
1058	  built with binutils >= 2.25 in order for the new instructions
1059	  to be used.
1060
1061config ARM64_VHE
1062	bool "Enable support for Virtualization Host Extensions (VHE)"
1063	default y
1064	help
1065	  Virtualization Host Extensions (VHE) allow the kernel to run
1066	  directly at EL2 (instead of EL1) on processors that support
1067	  it. This leads to better performance for KVM, as they reduce
1068	  the cost of the world switch.
1069
1070	  Selecting this option allows the VHE feature to be detected
1071	  at runtime, and does not affect processors that do not
1072	  implement this feature.
1073
1074endmenu
1075
1076menu "ARMv8.2 architectural features"
1077
1078config ARM64_UAO
1079	bool "Enable support for User Access Override (UAO)"
1080	default y
1081	help
1082	  User Access Override (UAO; part of the ARMv8.2 Extensions)
1083	  causes the 'unprivileged' variant of the load/store instructions to
1084	  be overridden to be privileged.
1085
1086	  This option changes get_user() and friends to use the 'unprivileged'
1087	  variant of the load/store instructions. This ensures that user-space
1088	  really did have access to the supplied memory. When addr_limit is
1089	  set to kernel memory the UAO bit will be set, allowing privileged
1090	  access to kernel memory.
1091
1092	  Choosing this option will cause copy_to_user() et al to use user-space
1093	  memory permissions.
1094
1095	  The feature is detected at runtime, the kernel will use the
1096	  regular load/store instructions if the cpu does not implement the
1097	  feature.
1098
1099config ARM64_PMEM
1100	bool "Enable support for persistent memory"
1101	select ARCH_HAS_PMEM_API
1102	select ARCH_HAS_UACCESS_FLUSHCACHE
1103	help
1104	  Say Y to enable support for the persistent memory API based on the
1105	  ARMv8.2 DCPoP feature.
1106
1107	  The feature is detected at runtime, and the kernel will use DC CVAC
1108	  operations if DC CVAP is not supported (following the behaviour of
1109	  DC CVAP itself if the system does not define a point of persistence).
1110
1111config ARM64_RAS_EXTN
1112	bool "Enable support for RAS CPU Extensions"
1113	default y
1114	help
1115	  CPUs that support the Reliability, Availability and Serviceability
1116	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1117	  errors, classify them and report them to software.
1118
1119	  On CPUs with these extensions system software can use additional
1120	  barriers to determine if faults are pending and read the
1121	  classification from a new set of registers.
1122
1123	  Selecting this feature will allow the kernel to use these barriers
1124	  and access the new registers if the system supports the extension.
1125	  Platform RAS features may additionally depend on firmware support.
1126
1127endmenu
1128
1129config ARM64_SVE
1130	bool "ARM Scalable Vector Extension support"
1131	default y
1132	depends on !KVM || ARM64_VHE
1133	help
1134	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1135	  execution state which complements and extends the SIMD functionality
1136	  of the base architecture to support much larger vectors and to enable
1137	  additional vectorisation opportunities.
1138
1139	  To enable use of this extension on CPUs that implement it, say Y.
1140
1141	  Note that for architectural reasons, firmware _must_ implement SVE
1142	  support when running on SVE capable hardware.  The required support
1143	  is present in:
1144
1145	    * version 1.5 and later of the ARM Trusted Firmware
1146	    * the AArch64 boot wrapper since commit 5e1261e08abf
1147	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1148
1149	  For other firmware implementations, consult the firmware documentation
1150	  or vendor.
1151
1152	  If you need the kernel to boot on SVE-capable hardware with broken
1153	  firmware, you may need to say N here until you get your firmware
1154	  fixed.  Otherwise, you may experience firmware panics or lockups when
1155	  booting the kernel.  If unsure and you are not observing these
1156	  symptoms, you should assume that it is safe to say Y.
1157
1158	  CPUs that support SVE are architecturally required to support the
1159	  Virtualization Host Extensions (VHE), so the kernel makes no
1160	  provision for supporting SVE alongside KVM without VHE enabled.
1161	  Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
1162	  KVM in the same kernel image.
1163
1164config ARM64_MODULE_PLTS
1165	bool
1166	select HAVE_MOD_ARCH_SPECIFIC
1167
1168config RELOCATABLE
1169	bool
1170	help
1171	  This builds the kernel as a Position Independent Executable (PIE),
1172	  which retains all relocation metadata required to relocate the
1173	  kernel binary at runtime to a different virtual address than the
1174	  address it was linked at.
1175	  Since AArch64 uses the RELA relocation format, this requires a
1176	  relocation pass at runtime even if the kernel is loaded at the
1177	  same address it was linked at.
1178
1179config RANDOMIZE_BASE
1180	bool "Randomize the address of the kernel image"
1181	select ARM64_MODULE_PLTS if MODULES
1182	select RELOCATABLE
1183	help
1184	  Randomizes the virtual address at which the kernel image is
1185	  loaded, as a security feature that deters exploit attempts
1186	  relying on knowledge of the location of kernel internals.
1187
1188	  It is the bootloader's job to provide entropy, by passing a
1189	  random u64 value in /chosen/kaslr-seed at kernel entry.
1190
1191	  When booting via the UEFI stub, it will invoke the firmware's
1192	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1193	  to the kernel proper. In addition, it will randomise the physical
1194	  location of the kernel Image as well.
1195
1196	  If unsure, say N.
1197
1198config RANDOMIZE_MODULE_REGION_FULL
1199	bool "Randomize the module region over a 4 GB range"
1200	depends on RANDOMIZE_BASE
1201	default y
1202	help
1203	  Randomizes the location of the module region inside a 4 GB window
1204	  covering the core kernel. This way, it is less likely for modules
1205	  to leak information about the location of core kernel data structures
1206	  but it does imply that function calls between modules and the core
1207	  kernel will need to be resolved via veneers in the module PLT.
1208
1209	  When this option is not set, the module region will be randomized over
1210	  a limited range that contains the [_stext, _etext] interval of the
1211	  core kernel, so branch relocations are always in range.
1212
1213endmenu
1214
1215menu "Boot options"
1216
1217config ARM64_ACPI_PARKING_PROTOCOL
1218	bool "Enable support for the ARM64 ACPI parking protocol"
1219	depends on ACPI
1220	help
1221	  Enable support for the ARM64 ACPI parking protocol. If disabled
1222	  the kernel will not allow booting through the ARM64 ACPI parking
1223	  protocol even if the corresponding data is present in the ACPI
1224	  MADT table.
1225
1226config CMDLINE
1227	string "Default kernel command string"
1228	default ""
1229	help
1230	  Provide a set of default command-line options at build time by
1231	  entering them here. As a minimum, you should specify the the
1232	  root device (e.g. root=/dev/nfs).
1233
1234config CMDLINE_FORCE
1235	bool "Always use the default kernel command string"
1236	help
1237	  Always use the default kernel command string, even if the boot
1238	  loader passes other arguments to the kernel.
1239	  This is useful if you cannot or don't want to change the
1240	  command-line options your boot loader passes to the kernel.
1241
1242config EFI_STUB
1243	bool
1244
1245config EFI
1246	bool "UEFI runtime support"
1247	depends on OF && !CPU_BIG_ENDIAN
1248	depends on KERNEL_MODE_NEON
1249	select LIBFDT
1250	select UCS2_STRING
1251	select EFI_PARAMS_FROM_FDT
1252	select EFI_RUNTIME_WRAPPERS
1253	select EFI_STUB
1254	select EFI_ARMSTUB
1255	default y
1256	help
1257	  This option provides support for runtime services provided
1258	  by UEFI firmware (such as non-volatile variables, realtime
1259          clock, and platform reset). A UEFI stub is also provided to
1260	  allow the kernel to be booted as an EFI application. This
1261	  is only useful on systems that have UEFI firmware.
1262
1263config DMI
1264	bool "Enable support for SMBIOS (DMI) tables"
1265	depends on EFI
1266	default y
1267	help
1268	  This enables SMBIOS/DMI feature for systems.
1269
1270	  This option is only useful on systems that have UEFI firmware.
1271	  However, even with this option, the resultant kernel should
1272	  continue to boot on existing non-UEFI platforms.
1273
1274endmenu
1275
1276menu "Userspace binary formats"
1277
1278source "fs/Kconfig.binfmt"
1279
1280config COMPAT
1281	bool "Kernel support for 32-bit EL0"
1282	depends on ARM64_4K_PAGES || EXPERT
1283	select COMPAT_BINFMT_ELF if BINFMT_ELF
1284	select HAVE_UID16
1285	select OLD_SIGSUSPEND3
1286	select COMPAT_OLD_SIGACTION
1287	help
1288	  This option enables support for a 32-bit EL0 running under a 64-bit
1289	  kernel at EL1. AArch32-specific components such as system calls,
1290	  the user helper functions, VFP support and the ptrace interface are
1291	  handled appropriately by the kernel.
1292
1293	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1294	  that you will only be able to execute AArch32 binaries that were compiled
1295	  with page size aligned segments.
1296
1297	  If you want to execute 32-bit userspace applications, say Y.
1298
1299config SYSVIPC_COMPAT
1300	def_bool y
1301	depends on COMPAT && SYSVIPC
1302
1303endmenu
1304
1305menu "Power management options"
1306
1307source "kernel/power/Kconfig"
1308
1309config ARCH_HIBERNATION_POSSIBLE
1310	def_bool y
1311	depends on CPU_PM
1312
1313config ARCH_HIBERNATION_HEADER
1314	def_bool y
1315	depends on HIBERNATION
1316
1317config ARCH_SUSPEND_POSSIBLE
1318	def_bool y
1319
1320endmenu
1321
1322menu "CPU Power Management"
1323
1324source "drivers/cpuidle/Kconfig"
1325
1326source "drivers/cpufreq/Kconfig"
1327
1328endmenu
1329
1330source "net/Kconfig"
1331
1332source "drivers/Kconfig"
1333
1334source "drivers/firmware/Kconfig"
1335
1336source "drivers/acpi/Kconfig"
1337
1338source "fs/Kconfig"
1339
1340source "arch/arm64/kvm/Kconfig"
1341
1342source "arch/arm64/Kconfig.debug"
1343
1344source "security/Kconfig"
1345
1346source "crypto/Kconfig"
1347if CRYPTO
1348source "arch/arm64/crypto/Kconfig"
1349endif
1350
1351source "lib/Kconfig"
1352