xref: /openbmc/linux/arch/arm64/Kconfig (revision 6a0abce4)
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 && PCI)
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_DMA_COHERENT_TO_PFN
15	select ARCH_HAS_DMA_MMAP_PGPROT
16	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
17	select ARCH_HAS_ELF_RANDOMIZE
18	select ARCH_HAS_FAST_MULTIPLIER
19	select ARCH_HAS_FORTIFY_SOURCE
20	select ARCH_HAS_GCOV_PROFILE_ALL
21	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
22	select ARCH_HAS_KCOV
23	select ARCH_HAS_MEMBARRIER_SYNC_CORE
24	select ARCH_HAS_PTE_SPECIAL
25	select ARCH_HAS_SET_MEMORY
26	select ARCH_HAS_SG_CHAIN
27	select ARCH_HAS_STRICT_KERNEL_RWX
28	select ARCH_HAS_STRICT_MODULE_RWX
29	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
30	select ARCH_HAS_SYNC_DMA_FOR_CPU
31	select ARCH_HAS_SYSCALL_WRAPPER
32	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
33	select ARCH_HAVE_NMI_SAFE_CMPXCHG
34	select ARCH_INLINE_READ_LOCK if !PREEMPT
35	select ARCH_INLINE_READ_LOCK_BH if !PREEMPT
36	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT
37	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT
38	select ARCH_INLINE_READ_UNLOCK if !PREEMPT
39	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT
40	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT
41	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT
42	select ARCH_INLINE_WRITE_LOCK if !PREEMPT
43	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT
44	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT
45	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT
46	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT
47	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT
48	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT
49	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT
50	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPT
51	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPT
52	select ARCH_INLINE_SPIN_LOCK if !PREEMPT
53	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPT
54	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPT
55	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPT
56	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPT
57	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT
58	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT
59	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT
60	select ARCH_USE_CMPXCHG_LOCKREF
61	select ARCH_USE_QUEUED_RWLOCKS
62	select ARCH_USE_QUEUED_SPINLOCKS
63	select ARCH_SUPPORTS_MEMORY_FAILURE
64	select ARCH_SUPPORTS_ATOMIC_RMW
65	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG
66	select ARCH_SUPPORTS_NUMA_BALANCING
67	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
68	select ARCH_WANT_FRAME_POINTERS
69	select ARCH_HAS_UBSAN_SANITIZE_ALL
70	select ARM_AMBA
71	select ARM_ARCH_TIMER
72	select ARM_GIC
73	select AUDIT_ARCH_COMPAT_GENERIC
74	select ARM_GIC_V2M if PCI
75	select ARM_GIC_V3
76	select ARM_GIC_V3_ITS if PCI
77	select ARM_PSCI_FW
78	select BUILDTIME_EXTABLE_SORT
79	select CLONE_BACKWARDS
80	select COMMON_CLK
81	select CPU_PM if (SUSPEND || CPU_IDLE)
82	select CRC32
83	select DCACHE_WORD_ACCESS
84	select DMA_DIRECT_OPS
85	select EDAC_SUPPORT
86	select FRAME_POINTER
87	select GENERIC_ALLOCATOR
88	select GENERIC_ARCH_TOPOLOGY
89	select GENERIC_CLOCKEVENTS
90	select GENERIC_CLOCKEVENTS_BROADCAST
91	select GENERIC_CPU_AUTOPROBE
92	select GENERIC_EARLY_IOREMAP
93	select GENERIC_IDLE_POLL_SETUP
94	select GENERIC_IRQ_MULTI_HANDLER
95	select GENERIC_IRQ_PROBE
96	select GENERIC_IRQ_SHOW
97	select GENERIC_IRQ_SHOW_LEVEL
98	select GENERIC_PCI_IOMAP
99	select GENERIC_SCHED_CLOCK
100	select GENERIC_SMP_IDLE_THREAD
101	select GENERIC_STRNCPY_FROM_USER
102	select GENERIC_STRNLEN_USER
103	select GENERIC_TIME_VSYSCALL
104	select HANDLE_DOMAIN_IRQ
105	select HARDIRQS_SW_RESEND
106	select HAVE_ACPI_APEI if (ACPI && EFI)
107	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
108	select HAVE_ARCH_AUDITSYSCALL
109	select HAVE_ARCH_BITREVERSE
110	select HAVE_ARCH_HUGE_VMAP
111	select HAVE_ARCH_JUMP_LABEL
112	select HAVE_ARCH_JUMP_LABEL_RELATIVE
113	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
114	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
115	select HAVE_ARCH_KGDB
116	select HAVE_ARCH_MMAP_RND_BITS
117	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
118	select HAVE_ARCH_PREL32_RELOCATIONS
119	select HAVE_ARCH_SECCOMP_FILTER
120	select HAVE_ARCH_STACKLEAK
121	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
122	select HAVE_ARCH_TRACEHOOK
123	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
124	select HAVE_ARCH_VMAP_STACK
125	select HAVE_ARM_SMCCC
126	select HAVE_EBPF_JIT
127	select HAVE_C_RECORDMCOUNT
128	select HAVE_CMPXCHG_DOUBLE
129	select HAVE_CMPXCHG_LOCAL
130	select HAVE_CONTEXT_TRACKING
131	select HAVE_DEBUG_BUGVERBOSE
132	select HAVE_DEBUG_KMEMLEAK
133	select HAVE_DMA_CONTIGUOUS
134	select HAVE_DYNAMIC_FTRACE
135	select HAVE_EFFICIENT_UNALIGNED_ACCESS
136	select HAVE_FTRACE_MCOUNT_RECORD
137	select HAVE_FUNCTION_TRACER
138	select HAVE_FUNCTION_GRAPH_TRACER
139	select HAVE_GCC_PLUGINS
140	select HAVE_GENERIC_DMA_COHERENT
141	select HAVE_HW_BREAKPOINT if PERF_EVENTS
142	select HAVE_IRQ_TIME_ACCOUNTING
143	select HAVE_MEMBLOCK_NODE_MAP if NUMA
144	select HAVE_NMI
145	select HAVE_PATA_PLATFORM
146	select HAVE_PERF_EVENTS
147	select HAVE_PERF_REGS
148	select HAVE_PERF_USER_STACK_DUMP
149	select HAVE_REGS_AND_STACK_ACCESS_API
150	select HAVE_RCU_TABLE_FREE
151	select HAVE_RCU_TABLE_INVALIDATE
152	select HAVE_RSEQ
153	select HAVE_STACKPROTECTOR
154	select HAVE_SYSCALL_TRACEPOINTS
155	select HAVE_KPROBES
156	select HAVE_KRETPROBES
157	select IOMMU_DMA if IOMMU_SUPPORT
158	select IRQ_DOMAIN
159	select IRQ_FORCED_THREADING
160	select MODULES_USE_ELF_RELA
161	select MULTI_IRQ_HANDLER
162	select NEED_DMA_MAP_STATE
163	select NEED_SG_DMA_LENGTH
164	select OF
165	select OF_EARLY_FLATTREE
166	select OF_RESERVED_MEM
167	select PCI_ECAM if (ACPI && PCI)
168	select POWER_RESET
169	select POWER_SUPPLY
170	select REFCOUNT_FULL
171	select SPARSE_IRQ
172	select SWIOTLB
173	select SYSCTL_EXCEPTION_TRACE
174	select THREAD_INFO_IN_TASK
175	help
176	  ARM 64-bit (AArch64) Linux support.
177
178config 64BIT
179	def_bool y
180
181config MMU
182	def_bool y
183
184config ARM64_PAGE_SHIFT
185	int
186	default 16 if ARM64_64K_PAGES
187	default 14 if ARM64_16K_PAGES
188	default 12
189
190config ARM64_CONT_SHIFT
191	int
192	default 5 if ARM64_64K_PAGES
193	default 7 if ARM64_16K_PAGES
194	default 4
195
196config ARCH_MMAP_RND_BITS_MIN
197       default 14 if ARM64_64K_PAGES
198       default 16 if ARM64_16K_PAGES
199       default 18
200
201# max bits determined by the following formula:
202#  VA_BITS - PAGE_SHIFT - 3
203config ARCH_MMAP_RND_BITS_MAX
204       default 19 if ARM64_VA_BITS=36
205       default 24 if ARM64_VA_BITS=39
206       default 27 if ARM64_VA_BITS=42
207       default 30 if ARM64_VA_BITS=47
208       default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
209       default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
210       default 33 if ARM64_VA_BITS=48
211       default 14 if ARM64_64K_PAGES
212       default 16 if ARM64_16K_PAGES
213       default 18
214
215config ARCH_MMAP_RND_COMPAT_BITS_MIN
216       default 7 if ARM64_64K_PAGES
217       default 9 if ARM64_16K_PAGES
218       default 11
219
220config ARCH_MMAP_RND_COMPAT_BITS_MAX
221       default 16
222
223config NO_IOPORT_MAP
224	def_bool y if !PCI
225
226config STACKTRACE_SUPPORT
227	def_bool y
228
229config ILLEGAL_POINTER_VALUE
230	hex
231	default 0xdead000000000000
232
233config LOCKDEP_SUPPORT
234	def_bool y
235
236config TRACE_IRQFLAGS_SUPPORT
237	def_bool y
238
239config RWSEM_XCHGADD_ALGORITHM
240	def_bool y
241
242config GENERIC_BUG
243	def_bool y
244	depends on BUG
245
246config GENERIC_BUG_RELATIVE_POINTERS
247	def_bool y
248	depends on GENERIC_BUG
249
250config GENERIC_HWEIGHT
251	def_bool y
252
253config GENERIC_CSUM
254        def_bool y
255
256config GENERIC_CALIBRATE_DELAY
257	def_bool y
258
259config ZONE_DMA32
260	def_bool y
261
262config HAVE_GENERIC_GUP
263	def_bool y
264
265config ARCH_ENABLE_MEMORY_HOTPLUG
266	def_bool y
267
268config SMP
269	def_bool y
270
271config KERNEL_MODE_NEON
272	def_bool y
273
274config FIX_EARLYCON_MEM
275	def_bool y
276
277config PGTABLE_LEVELS
278	int
279	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
280	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
281	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52)
282	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
283	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
284	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
285
286config ARCH_SUPPORTS_UPROBES
287	def_bool y
288
289config ARCH_PROC_KCORE_TEXT
290	def_bool y
291
292source "arch/arm64/Kconfig.platforms"
293
294menu "Bus support"
295
296config PCI
297	bool "PCI support"
298	help
299	  This feature enables support for PCI bus system. If you say Y
300	  here, the kernel will include drivers and infrastructure code
301	  to support PCI bus devices.
302
303config PCI_DOMAINS
304	def_bool PCI
305
306config PCI_DOMAINS_GENERIC
307	def_bool PCI
308
309config PCI_SYSCALL
310	def_bool PCI
311
312source "drivers/pci/Kconfig"
313
314endmenu
315
316menu "Kernel Features"
317
318menu "ARM errata workarounds via the alternatives framework"
319
320config ARM64_WORKAROUND_CLEAN_CACHE
321	def_bool n
322
323config ARM64_ERRATUM_826319
324	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
325	default y
326	select ARM64_WORKAROUND_CLEAN_CACHE
327	help
328	  This option adds an alternative code sequence to work around ARM
329	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
330	  AXI master interface and an L2 cache.
331
332	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
333	  and is unable to accept a certain write via this interface, it will
334	  not progress on read data presented on the read data channel and the
335	  system can deadlock.
336
337	  The workaround promotes data cache clean instructions to
338	  data cache clean-and-invalidate.
339	  Please note that this does not necessarily enable the workaround,
340	  as it depends on the alternative framework, which will only patch
341	  the kernel if an affected CPU is detected.
342
343	  If unsure, say Y.
344
345config ARM64_ERRATUM_827319
346	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
347	default y
348	select ARM64_WORKAROUND_CLEAN_CACHE
349	help
350	  This option adds an alternative code sequence to work around ARM
351	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
352	  master interface and an L2 cache.
353
354	  Under certain conditions this erratum can cause a clean line eviction
355	  to occur at the same time as another transaction to the same address
356	  on the AMBA 5 CHI interface, which can cause data corruption if the
357	  interconnect reorders the two transactions.
358
359	  The workaround promotes data cache clean instructions to
360	  data cache clean-and-invalidate.
361	  Please note that this does not necessarily enable the workaround,
362	  as it depends on the alternative framework, which will only patch
363	  the kernel if an affected CPU is detected.
364
365	  If unsure, say Y.
366
367config ARM64_ERRATUM_824069
368	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
369	default y
370	select ARM64_WORKAROUND_CLEAN_CACHE
371	help
372	  This option adds an alternative code sequence to work around ARM
373	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
374	  to a coherent interconnect.
375
376	  If a Cortex-A53 processor is executing a store or prefetch for
377	  write instruction at the same time as a processor in another
378	  cluster is executing a cache maintenance operation to the same
379	  address, then this erratum might cause a clean cache line to be
380	  incorrectly marked as dirty.
381
382	  The workaround promotes data cache clean instructions to
383	  data cache clean-and-invalidate.
384	  Please note that this option does not necessarily enable the
385	  workaround, as it depends on the alternative framework, which will
386	  only patch the kernel if an affected CPU is detected.
387
388	  If unsure, say Y.
389
390config ARM64_ERRATUM_819472
391	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
392	default y
393	select ARM64_WORKAROUND_CLEAN_CACHE
394	help
395	  This option adds an alternative code sequence to work around ARM
396	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
397	  present when it is connected to a coherent interconnect.
398
399	  If the processor is executing a load and store exclusive sequence at
400	  the same time as a processor in another cluster is executing a cache
401	  maintenance operation to the same address, then this erratum might
402	  cause data corruption.
403
404	  The workaround promotes data cache clean instructions to
405	  data cache clean-and-invalidate.
406	  Please note that this does not necessarily enable the workaround,
407	  as it depends on the alternative framework, which will only patch
408	  the kernel if an affected CPU is detected.
409
410	  If unsure, say Y.
411
412config ARM64_ERRATUM_832075
413	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
414	default y
415	help
416	  This option adds an alternative code sequence to work around ARM
417	  erratum 832075 on Cortex-A57 parts up to r1p2.
418
419	  Affected Cortex-A57 parts might deadlock when exclusive load/store
420	  instructions to Write-Back memory are mixed with Device loads.
421
422	  The workaround is to promote device loads to use Load-Acquire
423	  semantics.
424	  Please note that this does not necessarily enable the workaround,
425	  as it depends on the alternative framework, which will only patch
426	  the kernel if an affected CPU is detected.
427
428	  If unsure, say Y.
429
430config ARM64_ERRATUM_834220
431	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
432	depends on KVM
433	default y
434	help
435	  This option adds an alternative code sequence to work around ARM
436	  erratum 834220 on Cortex-A57 parts up to r1p2.
437
438	  Affected Cortex-A57 parts might report a Stage 2 translation
439	  fault as the result of a Stage 1 fault for load crossing a
440	  page boundary when there is a permission or device memory
441	  alignment fault at Stage 1 and a translation fault at Stage 2.
442
443	  The workaround is to verify that the Stage 1 translation
444	  doesn't generate a fault before handling the Stage 2 fault.
445	  Please note that this does not necessarily enable the workaround,
446	  as it depends on the alternative framework, which will only patch
447	  the kernel if an affected CPU is detected.
448
449	  If unsure, say Y.
450
451config ARM64_ERRATUM_845719
452	bool "Cortex-A53: 845719: a load might read incorrect data"
453	depends on COMPAT
454	default y
455	help
456	  This option adds an alternative code sequence to work around ARM
457	  erratum 845719 on Cortex-A53 parts up to r0p4.
458
459	  When running a compat (AArch32) userspace on an affected Cortex-A53
460	  part, a load at EL0 from a virtual address that matches the bottom 32
461	  bits of the virtual address used by a recent load at (AArch64) EL1
462	  might return incorrect data.
463
464	  The workaround is to write the contextidr_el1 register on exception
465	  return to a 32-bit task.
466	  Please note that this does not necessarily enable the workaround,
467	  as it depends on the alternative framework, which will only patch
468	  the kernel if an affected CPU is detected.
469
470	  If unsure, say Y.
471
472config ARM64_ERRATUM_843419
473	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
474	default y
475	select ARM64_MODULE_PLTS if MODULES
476	help
477	  This option links the kernel with '--fix-cortex-a53-843419' and
478	  enables PLT support to replace certain ADRP instructions, which can
479	  cause subsequent memory accesses to use an incorrect address on
480	  Cortex-A53 parts up to r0p4.
481
482	  If unsure, say Y.
483
484config ARM64_ERRATUM_1024718
485	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
486	default y
487	help
488	  This option adds work around for Arm Cortex-A55 Erratum 1024718.
489
490	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
491	  update of the hardware dirty bit when the DBM/AP bits are updated
492	  without a break-before-make. The work around is to disable the usage
493	  of hardware DBM locally on the affected cores. CPUs not affected by
494	  erratum will continue to use the feature.
495
496	  If unsure, say Y.
497
498config ARM64_ERRATUM_1188873
499	bool "Cortex-A76: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
500	default y
501	select ARM_ARCH_TIMER_OOL_WORKAROUND
502	help
503	  This option adds work arounds for ARM Cortex-A76 erratum 1188873
504
505	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could cause
506	  register corruption when accessing the timer registers from
507	  AArch32 userspace.
508
509	  If unsure, say Y.
510
511config ARM64_ERRATUM_1165522
512	bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
513	default y
514	help
515	  This option adds work arounds for ARM Cortex-A76 erratum 1165522
516
517	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
518	  corrupted TLBs by speculating an AT instruction during a guest
519	  context switch.
520
521	  If unsure, say Y.
522
523config ARM64_ERRATUM_1286807
524	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
525	default y
526	select ARM64_WORKAROUND_REPEAT_TLBI
527	help
528	  This option adds workaround for ARM Cortex-A76 erratum 1286807
529
530	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
531	  address for a cacheable mapping of a location is being
532	  accessed by a core while another core is remapping the virtual
533	  address to a new physical page using the recommended
534	  break-before-make sequence, then under very rare circumstances
535	  TLBI+DSB completes before a read using the translation being
536	  invalidated has been observed by other observers. The
537	  workaround repeats the TLBI+DSB operation.
538
539	  If unsure, say Y.
540
541config CAVIUM_ERRATUM_22375
542	bool "Cavium erratum 22375, 24313"
543	default y
544	help
545	  Enable workaround for erratum 22375, 24313.
546
547	  This implements two gicv3-its errata workarounds for ThunderX. Both
548	  with small impact affecting only ITS table allocation.
549
550	    erratum 22375: only alloc 8MB table size
551	    erratum 24313: ignore memory access type
552
553	  The fixes are in ITS initialization and basically ignore memory access
554	  type and table size provided by the TYPER and BASER registers.
555
556	  If unsure, say Y.
557
558config CAVIUM_ERRATUM_23144
559	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
560	depends on NUMA
561	default y
562	help
563	  ITS SYNC command hang for cross node io and collections/cpu mapping.
564
565	  If unsure, say Y.
566
567config CAVIUM_ERRATUM_23154
568	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
569	default y
570	help
571	  The gicv3 of ThunderX requires a modified version for
572	  reading the IAR status to ensure data synchronization
573	  (access to icc_iar1_el1 is not sync'ed before and after).
574
575	  If unsure, say Y.
576
577config CAVIUM_ERRATUM_27456
578	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
579	default y
580	help
581	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
582	  instructions may cause the icache to become corrupted if it
583	  contains data for a non-current ASID.  The fix is to
584	  invalidate the icache when changing the mm context.
585
586	  If unsure, say Y.
587
588config CAVIUM_ERRATUM_30115
589	bool "Cavium erratum 30115: Guest may disable interrupts in host"
590	default y
591	help
592	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
593	  1.2, and T83 Pass 1.0, KVM guest execution may disable
594	  interrupts in host. Trapping both GICv3 group-0 and group-1
595	  accesses sidesteps the issue.
596
597	  If unsure, say Y.
598
599config QCOM_FALKOR_ERRATUM_1003
600	bool "Falkor E1003: Incorrect translation due to ASID change"
601	default y
602	help
603	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
604	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
605	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
606	  then only for entries in the walk cache, since the leaf translation
607	  is unchanged. Work around the erratum by invalidating the walk cache
608	  entries for the trampoline before entering the kernel proper.
609
610config ARM64_WORKAROUND_REPEAT_TLBI
611	bool
612	help
613	  Enable the repeat TLBI workaround for Falkor erratum 1009 and
614	  Cortex-A76 erratum 1286807.
615
616config QCOM_FALKOR_ERRATUM_1009
617	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
618	default y
619	select ARM64_WORKAROUND_REPEAT_TLBI
620	help
621	  On Falkor v1, the CPU may prematurely complete a DSB following a
622	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
623	  one more time to fix the issue.
624
625	  If unsure, say Y.
626
627config QCOM_QDF2400_ERRATUM_0065
628	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
629	default y
630	help
631	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
632	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
633	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
634
635	  If unsure, say Y.
636
637config SOCIONEXT_SYNQUACER_PREITS
638	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
639	default y
640	help
641	  Socionext Synquacer SoCs implement a separate h/w block to generate
642	  MSI doorbell writes with non-zero values for the device ID.
643
644	  If unsure, say Y.
645
646config HISILICON_ERRATUM_161600802
647	bool "Hip07 161600802: Erroneous redistributor VLPI base"
648	default y
649	help
650	  The HiSilicon Hip07 SoC usees the wrong redistributor base
651	  when issued ITS commands such as VMOVP and VMAPP, and requires
652	  a 128kB offset to be applied to the target address in this commands.
653
654	  If unsure, say Y.
655
656config QCOM_FALKOR_ERRATUM_E1041
657	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
658	default y
659	help
660	  Falkor CPU may speculatively fetch instructions from an improper
661	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
662	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
663
664	  If unsure, say Y.
665
666endmenu
667
668
669choice
670	prompt "Page size"
671	default ARM64_4K_PAGES
672	help
673	  Page size (translation granule) configuration.
674
675config ARM64_4K_PAGES
676	bool "4KB"
677	help
678	  This feature enables 4KB pages support.
679
680config ARM64_16K_PAGES
681	bool "16KB"
682	help
683	  The system will use 16KB pages support. AArch32 emulation
684	  requires applications compiled with 16K (or a multiple of 16K)
685	  aligned segments.
686
687config ARM64_64K_PAGES
688	bool "64KB"
689	help
690	  This feature enables 64KB pages support (4KB by default)
691	  allowing only two levels of page tables and faster TLB
692	  look-up. AArch32 emulation requires applications compiled
693	  with 64K aligned segments.
694
695endchoice
696
697choice
698	prompt "Virtual address space size"
699	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
700	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
701	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
702	help
703	  Allows choosing one of multiple possible virtual address
704	  space sizes. The level of translation table is determined by
705	  a combination of page size and virtual address space size.
706
707config ARM64_VA_BITS_36
708	bool "36-bit" if EXPERT
709	depends on ARM64_16K_PAGES
710
711config ARM64_VA_BITS_39
712	bool "39-bit"
713	depends on ARM64_4K_PAGES
714
715config ARM64_VA_BITS_42
716	bool "42-bit"
717	depends on ARM64_64K_PAGES
718
719config ARM64_VA_BITS_47
720	bool "47-bit"
721	depends on ARM64_16K_PAGES
722
723config ARM64_VA_BITS_48
724	bool "48-bit"
725
726config ARM64_USER_VA_BITS_52
727	bool "52-bit (user)"
728	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
729	help
730	  Enable 52-bit virtual addressing for userspace when explicitly
731	  requested via a hint to mmap(). The kernel will continue to
732	  use 48-bit virtual addresses for its own mappings.
733
734	  NOTE: Enabling 52-bit virtual addressing in conjunction with
735	  ARMv8.3 Pointer Authentication will result in the PAC being
736	  reduced from 7 bits to 3 bits, which may have a significant
737	  impact on its susceptibility to brute-force attacks.
738
739	  If unsure, select 48-bit virtual addressing instead.
740
741endchoice
742
743config ARM64_FORCE_52BIT
744	bool "Force 52-bit virtual addresses for userspace"
745	depends on ARM64_USER_VA_BITS_52 && EXPERT
746	help
747	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
748	  to maintain compatibility with older software by providing 48-bit VAs
749	  unless a hint is supplied to mmap.
750
751	  This configuration option disables the 48-bit compatibility logic, and
752	  forces all userspace addresses to be 52-bit on HW that supports it. One
753	  should only enable this configuration option for stress testing userspace
754	  memory management code. If unsure say N here.
755
756config ARM64_VA_BITS
757	int
758	default 36 if ARM64_VA_BITS_36
759	default 39 if ARM64_VA_BITS_39
760	default 42 if ARM64_VA_BITS_42
761	default 47 if ARM64_VA_BITS_47
762	default 48 if ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52
763
764choice
765	prompt "Physical address space size"
766	default ARM64_PA_BITS_48
767	help
768	  Choose the maximum physical address range that the kernel will
769	  support.
770
771config ARM64_PA_BITS_48
772	bool "48-bit"
773
774config ARM64_PA_BITS_52
775	bool "52-bit (ARMv8.2)"
776	depends on ARM64_64K_PAGES
777	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
778	help
779	  Enable support for a 52-bit physical address space, introduced as
780	  part of the ARMv8.2-LPA extension.
781
782	  With this enabled, the kernel will also continue to work on CPUs that
783	  do not support ARMv8.2-LPA, but with some added memory overhead (and
784	  minor performance overhead).
785
786endchoice
787
788config ARM64_PA_BITS
789	int
790	default 48 if ARM64_PA_BITS_48
791	default 52 if ARM64_PA_BITS_52
792
793config CPU_BIG_ENDIAN
794       bool "Build big-endian kernel"
795       help
796         Say Y if you plan on running a kernel in big-endian mode.
797
798config SCHED_MC
799	bool "Multi-core scheduler support"
800	help
801	  Multi-core scheduler support improves the CPU scheduler's decision
802	  making when dealing with multi-core CPU chips at a cost of slightly
803	  increased overhead in some places. If unsure say N here.
804
805config SCHED_SMT
806	bool "SMT scheduler support"
807	help
808	  Improves the CPU scheduler's decision making when dealing with
809	  MultiThreading at a cost of slightly increased overhead in some
810	  places. If unsure say N here.
811
812config NR_CPUS
813	int "Maximum number of CPUs (2-4096)"
814	range 2 4096
815	# These have to remain sorted largest to smallest
816	default "64"
817
818config HOTPLUG_CPU
819	bool "Support for hot-pluggable CPUs"
820	select GENERIC_IRQ_MIGRATION
821	help
822	  Say Y here to experiment with turning CPUs off and on.  CPUs
823	  can be controlled through /sys/devices/system/cpu.
824
825# Common NUMA Features
826config NUMA
827	bool "Numa Memory Allocation and Scheduler Support"
828	select ACPI_NUMA if ACPI
829	select OF_NUMA
830	help
831	  Enable NUMA (Non Uniform Memory Access) support.
832
833	  The kernel will try to allocate memory used by a CPU on the
834	  local memory of the CPU and add some more
835	  NUMA awareness to the kernel.
836
837config NODES_SHIFT
838	int "Maximum NUMA Nodes (as a power of 2)"
839	range 1 10
840	default "2"
841	depends on NEED_MULTIPLE_NODES
842	help
843	  Specify the maximum number of NUMA Nodes available on the target
844	  system.  Increases memory reserved to accommodate various tables.
845
846config USE_PERCPU_NUMA_NODE_ID
847	def_bool y
848	depends on NUMA
849
850config HAVE_SETUP_PER_CPU_AREA
851	def_bool y
852	depends on NUMA
853
854config NEED_PER_CPU_EMBED_FIRST_CHUNK
855	def_bool y
856	depends on NUMA
857
858config HOLES_IN_ZONE
859	def_bool y
860
861source kernel/Kconfig.hz
862
863config ARCH_SUPPORTS_DEBUG_PAGEALLOC
864	def_bool y
865
866config ARCH_SPARSEMEM_ENABLE
867	def_bool y
868	select SPARSEMEM_VMEMMAP_ENABLE
869
870config ARCH_SPARSEMEM_DEFAULT
871	def_bool ARCH_SPARSEMEM_ENABLE
872
873config ARCH_SELECT_MEMORY_MODEL
874	def_bool ARCH_SPARSEMEM_ENABLE
875
876config ARCH_FLATMEM_ENABLE
877	def_bool !NUMA
878
879config HAVE_ARCH_PFN_VALID
880	def_bool y
881
882config HW_PERF_EVENTS
883	def_bool y
884	depends on ARM_PMU
885
886config SYS_SUPPORTS_HUGETLBFS
887	def_bool y
888
889config ARCH_WANT_HUGE_PMD_SHARE
890	def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
891
892config ARCH_HAS_CACHE_LINE_SIZE
893	def_bool y
894
895config SECCOMP
896	bool "Enable seccomp to safely compute untrusted bytecode"
897	---help---
898	  This kernel feature is useful for number crunching applications
899	  that may need to compute untrusted bytecode during their
900	  execution. By using pipes or other transports made available to
901	  the process as file descriptors supporting the read/write
902	  syscalls, it's possible to isolate those applications in
903	  their own address space using seccomp. Once seccomp is
904	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
905	  and the task is only allowed to execute a few safe syscalls
906	  defined by each seccomp mode.
907
908config PARAVIRT
909	bool "Enable paravirtualization code"
910	help
911	  This changes the kernel so it can modify itself when it is run
912	  under a hypervisor, potentially improving performance significantly
913	  over full virtualization.
914
915config PARAVIRT_TIME_ACCOUNTING
916	bool "Paravirtual steal time accounting"
917	select PARAVIRT
918	default n
919	help
920	  Select this option to enable fine granularity task steal time
921	  accounting. Time spent executing other tasks in parallel with
922	  the current vCPU is discounted from the vCPU power. To account for
923	  that, there can be a small performance impact.
924
925	  If in doubt, say N here.
926
927config KEXEC
928	depends on PM_SLEEP_SMP
929	select KEXEC_CORE
930	bool "kexec system call"
931	---help---
932	  kexec is a system call that implements the ability to shutdown your
933	  current kernel, and to start another kernel.  It is like a reboot
934	  but it is independent of the system firmware.   And like a reboot
935	  you can start any kernel with it, not just Linux.
936
937config KEXEC_FILE
938	bool "kexec file based system call"
939	select KEXEC_CORE
940	help
941	  This is new version of kexec system call. This system call is
942	  file based and takes file descriptors as system call argument
943	  for kernel and initramfs as opposed to list of segments as
944	  accepted by previous system call.
945
946config KEXEC_VERIFY_SIG
947	bool "Verify kernel signature during kexec_file_load() syscall"
948	depends on KEXEC_FILE
949	help
950	  Select this option to verify a signature with loaded kernel
951	  image. If configured, any attempt of loading a image without
952	  valid signature will fail.
953
954	  In addition to that option, you need to enable signature
955	  verification for the corresponding kernel image type being
956	  loaded in order for this to work.
957
958config KEXEC_IMAGE_VERIFY_SIG
959	bool "Enable Image signature verification support"
960	default y
961	depends on KEXEC_VERIFY_SIG
962	depends on EFI && SIGNED_PE_FILE_VERIFICATION
963	help
964	  Enable Image signature verification support.
965
966comment "Support for PE file signature verification disabled"
967	depends on KEXEC_VERIFY_SIG
968	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
969
970config CRASH_DUMP
971	bool "Build kdump crash kernel"
972	help
973	  Generate crash dump after being started by kexec. This should
974	  be normally only set in special crash dump kernels which are
975	  loaded in the main kernel with kexec-tools into a specially
976	  reserved region and then later executed after a crash by
977	  kdump/kexec.
978
979	  For more details see Documentation/kdump/kdump.txt
980
981config XEN_DOM0
982	def_bool y
983	depends on XEN
984
985config XEN
986	bool "Xen guest support on ARM64"
987	depends on ARM64 && OF
988	select SWIOTLB_XEN
989	select PARAVIRT
990	help
991	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
992
993config FORCE_MAX_ZONEORDER
994	int
995	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
996	default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
997	default "11"
998	help
999	  The kernel memory allocator divides physically contiguous memory
1000	  blocks into "zones", where each zone is a power of two number of
1001	  pages.  This option selects the largest power of two that the kernel
1002	  keeps in the memory allocator.  If you need to allocate very large
1003	  blocks of physically contiguous memory, then you may need to
1004	  increase this value.
1005
1006	  This config option is actually maximum order plus one. For example,
1007	  a value of 11 means that the largest free memory block is 2^10 pages.
1008
1009	  We make sure that we can allocate upto a HugePage size for each configuration.
1010	  Hence we have :
1011		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1012
1013	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1014	  4M allocations matching the default size used by generic code.
1015
1016config UNMAP_KERNEL_AT_EL0
1017	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1018	default y
1019	help
1020	  Speculation attacks against some high-performance processors can
1021	  be used to bypass MMU permission checks and leak kernel data to
1022	  userspace. This can be defended against by unmapping the kernel
1023	  when running in userspace, mapping it back in on exception entry
1024	  via a trampoline page in the vector table.
1025
1026	  If unsure, say Y.
1027
1028config HARDEN_BRANCH_PREDICTOR
1029	bool "Harden the branch predictor against aliasing attacks" if EXPERT
1030	default y
1031	help
1032	  Speculation attacks against some high-performance processors rely on
1033	  being able to manipulate the branch predictor for a victim context by
1034	  executing aliasing branches in the attacker context.  Such attacks
1035	  can be partially mitigated against by clearing internal branch
1036	  predictor state and limiting the prediction logic in some situations.
1037
1038	  This config option will take CPU-specific actions to harden the
1039	  branch predictor against aliasing attacks and may rely on specific
1040	  instruction sequences or control bits being set by the system
1041	  firmware.
1042
1043	  If unsure, say Y.
1044
1045config HARDEN_EL2_VECTORS
1046	bool "Harden EL2 vector mapping against system register leak" if EXPERT
1047	default y
1048	help
1049	  Speculation attacks against some high-performance processors can
1050	  be used to leak privileged information such as the vector base
1051	  register, resulting in a potential defeat of the EL2 layout
1052	  randomization.
1053
1054	  This config option will map the vectors to a fixed location,
1055	  independent of the EL2 code mapping, so that revealing VBAR_EL2
1056	  to an attacker does not give away any extra information. This
1057	  only gets enabled on affected CPUs.
1058
1059	  If unsure, say Y.
1060
1061config ARM64_SSBD
1062	bool "Speculative Store Bypass Disable" if EXPERT
1063	default y
1064	help
1065	  This enables mitigation of the bypassing of previous stores
1066	  by speculative loads.
1067
1068	  If unsure, say Y.
1069
1070config RODATA_FULL_DEFAULT_ENABLED
1071	bool "Apply r/o permissions of VM areas also to their linear aliases"
1072	default y
1073	help
1074	  Apply read-only attributes of VM areas to the linear alias of
1075	  the backing pages as well. This prevents code or read-only data
1076	  from being modified (inadvertently or intentionally) via another
1077	  mapping of the same memory page. This additional enhancement can
1078	  be turned off at runtime by passing rodata=[off|on] (and turned on
1079	  with rodata=full if this option is set to 'n')
1080
1081	  This requires the linear region to be mapped down to pages,
1082	  which may adversely affect performance in some cases.
1083
1084menuconfig ARMV8_DEPRECATED
1085	bool "Emulate deprecated/obsolete ARMv8 instructions"
1086	depends on COMPAT
1087	depends on SYSCTL
1088	help
1089	  Legacy software support may require certain instructions
1090	  that have been deprecated or obsoleted in the architecture.
1091
1092	  Enable this config to enable selective emulation of these
1093	  features.
1094
1095	  If unsure, say Y
1096
1097if ARMV8_DEPRECATED
1098
1099config SWP_EMULATION
1100	bool "Emulate SWP/SWPB instructions"
1101	help
1102	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1103	  they are always undefined. Say Y here to enable software
1104	  emulation of these instructions for userspace using LDXR/STXR.
1105
1106	  In some older versions of glibc [<=2.8] SWP is used during futex
1107	  trylock() operations with the assumption that the code will not
1108	  be preempted. This invalid assumption may be more likely to fail
1109	  with SWP emulation enabled, leading to deadlock of the user
1110	  application.
1111
1112	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1113	  on an external transaction monitoring block called a global
1114	  monitor to maintain update atomicity. If your system does not
1115	  implement a global monitor, this option can cause programs that
1116	  perform SWP operations to uncached memory to deadlock.
1117
1118	  If unsure, say Y
1119
1120config CP15_BARRIER_EMULATION
1121	bool "Emulate CP15 Barrier instructions"
1122	help
1123	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1124	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1125	  strongly recommended to use the ISB, DSB, and DMB
1126	  instructions instead.
1127
1128	  Say Y here to enable software emulation of these
1129	  instructions for AArch32 userspace code. When this option is
1130	  enabled, CP15 barrier usage is traced which can help
1131	  identify software that needs updating.
1132
1133	  If unsure, say Y
1134
1135config SETEND_EMULATION
1136	bool "Emulate SETEND instruction"
1137	help
1138	  The SETEND instruction alters the data-endianness of the
1139	  AArch32 EL0, and is deprecated in ARMv8.
1140
1141	  Say Y here to enable software emulation of the instruction
1142	  for AArch32 userspace code.
1143
1144	  Note: All the cpus on the system must have mixed endian support at EL0
1145	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1146	  endian - is hotplugged in after this feature has been enabled, there could
1147	  be unexpected results in the applications.
1148
1149	  If unsure, say Y
1150endif
1151
1152config ARM64_SW_TTBR0_PAN
1153	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1154	help
1155	  Enabling this option prevents the kernel from accessing
1156	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1157	  zeroed area and reserved ASID. The user access routines
1158	  restore the valid TTBR0_EL1 temporarily.
1159
1160menu "ARMv8.1 architectural features"
1161
1162config ARM64_HW_AFDBM
1163	bool "Support for hardware updates of the Access and Dirty page flags"
1164	default y
1165	help
1166	  The ARMv8.1 architecture extensions introduce support for
1167	  hardware updates of the access and dirty information in page
1168	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1169	  capable processors, accesses to pages with PTE_AF cleared will
1170	  set this bit instead of raising an access flag fault.
1171	  Similarly, writes to read-only pages with the DBM bit set will
1172	  clear the read-only bit (AP[2]) instead of raising a
1173	  permission fault.
1174
1175	  Kernels built with this configuration option enabled continue
1176	  to work on pre-ARMv8.1 hardware and the performance impact is
1177	  minimal. If unsure, say Y.
1178
1179config ARM64_PAN
1180	bool "Enable support for Privileged Access Never (PAN)"
1181	default y
1182	help
1183	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1184	 prevents the kernel or hypervisor from accessing user-space (EL0)
1185	 memory directly.
1186
1187	 Choosing this option will cause any unprotected (not using
1188	 copy_to_user et al) memory access to fail with a permission fault.
1189
1190	 The feature is detected at runtime, and will remain as a 'nop'
1191	 instruction if the cpu does not implement the feature.
1192
1193config ARM64_LSE_ATOMICS
1194	bool "Atomic instructions"
1195	default y
1196	help
1197	  As part of the Large System Extensions, ARMv8.1 introduces new
1198	  atomic instructions that are designed specifically to scale in
1199	  very large systems.
1200
1201	  Say Y here to make use of these instructions for the in-kernel
1202	  atomic routines. This incurs a small overhead on CPUs that do
1203	  not support these instructions and requires the kernel to be
1204	  built with binutils >= 2.25 in order for the new instructions
1205	  to be used.
1206
1207config ARM64_VHE
1208	bool "Enable support for Virtualization Host Extensions (VHE)"
1209	default y
1210	help
1211	  Virtualization Host Extensions (VHE) allow the kernel to run
1212	  directly at EL2 (instead of EL1) on processors that support
1213	  it. This leads to better performance for KVM, as they reduce
1214	  the cost of the world switch.
1215
1216	  Selecting this option allows the VHE feature to be detected
1217	  at runtime, and does not affect processors that do not
1218	  implement this feature.
1219
1220endmenu
1221
1222menu "ARMv8.2 architectural features"
1223
1224config ARM64_UAO
1225	bool "Enable support for User Access Override (UAO)"
1226	default y
1227	help
1228	  User Access Override (UAO; part of the ARMv8.2 Extensions)
1229	  causes the 'unprivileged' variant of the load/store instructions to
1230	  be overridden to be privileged.
1231
1232	  This option changes get_user() and friends to use the 'unprivileged'
1233	  variant of the load/store instructions. This ensures that user-space
1234	  really did have access to the supplied memory. When addr_limit is
1235	  set to kernel memory the UAO bit will be set, allowing privileged
1236	  access to kernel memory.
1237
1238	  Choosing this option will cause copy_to_user() et al to use user-space
1239	  memory permissions.
1240
1241	  The feature is detected at runtime, the kernel will use the
1242	  regular load/store instructions if the cpu does not implement the
1243	  feature.
1244
1245config ARM64_PMEM
1246	bool "Enable support for persistent memory"
1247	select ARCH_HAS_PMEM_API
1248	select ARCH_HAS_UACCESS_FLUSHCACHE
1249	help
1250	  Say Y to enable support for the persistent memory API based on the
1251	  ARMv8.2 DCPoP feature.
1252
1253	  The feature is detected at runtime, and the kernel will use DC CVAC
1254	  operations if DC CVAP is not supported (following the behaviour of
1255	  DC CVAP itself if the system does not define a point of persistence).
1256
1257config ARM64_RAS_EXTN
1258	bool "Enable support for RAS CPU Extensions"
1259	default y
1260	help
1261	  CPUs that support the Reliability, Availability and Serviceability
1262	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1263	  errors, classify them and report them to software.
1264
1265	  On CPUs with these extensions system software can use additional
1266	  barriers to determine if faults are pending and read the
1267	  classification from a new set of registers.
1268
1269	  Selecting this feature will allow the kernel to use these barriers
1270	  and access the new registers if the system supports the extension.
1271	  Platform RAS features may additionally depend on firmware support.
1272
1273config ARM64_CNP
1274	bool "Enable support for Common Not Private (CNP) translations"
1275	default y
1276	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1277	help
1278	  Common Not Private (CNP) allows translation table entries to
1279	  be shared between different PEs in the same inner shareable
1280	  domain, so the hardware can use this fact to optimise the
1281	  caching of such entries in the TLB.
1282
1283	  Selecting this option allows the CNP feature to be detected
1284	  at runtime, and does not affect PEs that do not implement
1285	  this feature.
1286
1287endmenu
1288
1289menu "ARMv8.3 architectural features"
1290
1291config ARM64_PTR_AUTH
1292	bool "Enable support for pointer authentication"
1293	default y
1294	help
1295	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1296	  instructions for signing and authenticating pointers against secret
1297	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1298	  and other attacks.
1299
1300	  This option enables these instructions at EL0 (i.e. for userspace).
1301
1302	  Choosing this option will cause the kernel to initialise secret keys
1303	  for each process at exec() time, with these keys being
1304	  context-switched along with the process.
1305
1306	  The feature is detected at runtime. If the feature is not present in
1307	  hardware it will not be advertised to userspace nor will it be
1308	  enabled.
1309
1310endmenu
1311
1312config ARM64_SVE
1313	bool "ARM Scalable Vector Extension support"
1314	default y
1315	depends on !KVM || ARM64_VHE
1316	help
1317	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1318	  execution state which complements and extends the SIMD functionality
1319	  of the base architecture to support much larger vectors and to enable
1320	  additional vectorisation opportunities.
1321
1322	  To enable use of this extension on CPUs that implement it, say Y.
1323
1324	  Note that for architectural reasons, firmware _must_ implement SVE
1325	  support when running on SVE capable hardware.  The required support
1326	  is present in:
1327
1328	    * version 1.5 and later of the ARM Trusted Firmware
1329	    * the AArch64 boot wrapper since commit 5e1261e08abf
1330	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1331
1332	  For other firmware implementations, consult the firmware documentation
1333	  or vendor.
1334
1335	  If you need the kernel to boot on SVE-capable hardware with broken
1336	  firmware, you may need to say N here until you get your firmware
1337	  fixed.  Otherwise, you may experience firmware panics or lockups when
1338	  booting the kernel.  If unsure and you are not observing these
1339	  symptoms, you should assume that it is safe to say Y.
1340
1341	  CPUs that support SVE are architecturally required to support the
1342	  Virtualization Host Extensions (VHE), so the kernel makes no
1343	  provision for supporting SVE alongside KVM without VHE enabled.
1344	  Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
1345	  KVM in the same kernel image.
1346
1347config ARM64_MODULE_PLTS
1348	bool
1349	select HAVE_MOD_ARCH_SPECIFIC
1350
1351config RELOCATABLE
1352	bool
1353	help
1354	  This builds the kernel as a Position Independent Executable (PIE),
1355	  which retains all relocation metadata required to relocate the
1356	  kernel binary at runtime to a different virtual address than the
1357	  address it was linked at.
1358	  Since AArch64 uses the RELA relocation format, this requires a
1359	  relocation pass at runtime even if the kernel is loaded at the
1360	  same address it was linked at.
1361
1362config RANDOMIZE_BASE
1363	bool "Randomize the address of the kernel image"
1364	select ARM64_MODULE_PLTS if MODULES
1365	select RELOCATABLE
1366	help
1367	  Randomizes the virtual address at which the kernel image is
1368	  loaded, as a security feature that deters exploit attempts
1369	  relying on knowledge of the location of kernel internals.
1370
1371	  It is the bootloader's job to provide entropy, by passing a
1372	  random u64 value in /chosen/kaslr-seed at kernel entry.
1373
1374	  When booting via the UEFI stub, it will invoke the firmware's
1375	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1376	  to the kernel proper. In addition, it will randomise the physical
1377	  location of the kernel Image as well.
1378
1379	  If unsure, say N.
1380
1381config RANDOMIZE_MODULE_REGION_FULL
1382	bool "Randomize the module region over a 4 GB range"
1383	depends on RANDOMIZE_BASE
1384	default y
1385	help
1386	  Randomizes the location of the module region inside a 4 GB window
1387	  covering the core kernel. This way, it is less likely for modules
1388	  to leak information about the location of core kernel data structures
1389	  but it does imply that function calls between modules and the core
1390	  kernel will need to be resolved via veneers in the module PLT.
1391
1392	  When this option is not set, the module region will be randomized over
1393	  a limited range that contains the [_stext, _etext] interval of the
1394	  core kernel, so branch relocations are always in range.
1395
1396config CC_HAVE_STACKPROTECTOR_SYSREG
1397	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1398
1399config STACKPROTECTOR_PER_TASK
1400	def_bool y
1401	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1402
1403endmenu
1404
1405menu "Boot options"
1406
1407config ARM64_ACPI_PARKING_PROTOCOL
1408	bool "Enable support for the ARM64 ACPI parking protocol"
1409	depends on ACPI
1410	help
1411	  Enable support for the ARM64 ACPI parking protocol. If disabled
1412	  the kernel will not allow booting through the ARM64 ACPI parking
1413	  protocol even if the corresponding data is present in the ACPI
1414	  MADT table.
1415
1416config CMDLINE
1417	string "Default kernel command string"
1418	default ""
1419	help
1420	  Provide a set of default command-line options at build time by
1421	  entering them here. As a minimum, you should specify the the
1422	  root device (e.g. root=/dev/nfs).
1423
1424config CMDLINE_FORCE
1425	bool "Always use the default kernel command string"
1426	help
1427	  Always use the default kernel command string, even if the boot
1428	  loader passes other arguments to the kernel.
1429	  This is useful if you cannot or don't want to change the
1430	  command-line options your boot loader passes to the kernel.
1431
1432config EFI_STUB
1433	bool
1434
1435config EFI
1436	bool "UEFI runtime support"
1437	depends on OF && !CPU_BIG_ENDIAN
1438	depends on KERNEL_MODE_NEON
1439	select ARCH_SUPPORTS_ACPI
1440	select LIBFDT
1441	select UCS2_STRING
1442	select EFI_PARAMS_FROM_FDT
1443	select EFI_RUNTIME_WRAPPERS
1444	select EFI_STUB
1445	select EFI_ARMSTUB
1446	default y
1447	help
1448	  This option provides support for runtime services provided
1449	  by UEFI firmware (such as non-volatile variables, realtime
1450          clock, and platform reset). A UEFI stub is also provided to
1451	  allow the kernel to be booted as an EFI application. This
1452	  is only useful on systems that have UEFI firmware.
1453
1454config DMI
1455	bool "Enable support for SMBIOS (DMI) tables"
1456	depends on EFI
1457	default y
1458	help
1459	  This enables SMBIOS/DMI feature for systems.
1460
1461	  This option is only useful on systems that have UEFI firmware.
1462	  However, even with this option, the resultant kernel should
1463	  continue to boot on existing non-UEFI platforms.
1464
1465endmenu
1466
1467config COMPAT
1468	bool "Kernel support for 32-bit EL0"
1469	depends on ARM64_4K_PAGES || EXPERT
1470	select COMPAT_BINFMT_ELF if BINFMT_ELF
1471	select HAVE_UID16
1472	select OLD_SIGSUSPEND3
1473	select COMPAT_OLD_SIGACTION
1474	help
1475	  This option enables support for a 32-bit EL0 running under a 64-bit
1476	  kernel at EL1. AArch32-specific components such as system calls,
1477	  the user helper functions, VFP support and the ptrace interface are
1478	  handled appropriately by the kernel.
1479
1480	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1481	  that you will only be able to execute AArch32 binaries that were compiled
1482	  with page size aligned segments.
1483
1484	  If you want to execute 32-bit userspace applications, say Y.
1485
1486config SYSVIPC_COMPAT
1487	def_bool y
1488	depends on COMPAT && SYSVIPC
1489
1490menu "Power management options"
1491
1492source "kernel/power/Kconfig"
1493
1494config ARCH_HIBERNATION_POSSIBLE
1495	def_bool y
1496	depends on CPU_PM
1497
1498config ARCH_HIBERNATION_HEADER
1499	def_bool y
1500	depends on HIBERNATION
1501
1502config ARCH_SUSPEND_POSSIBLE
1503	def_bool y
1504
1505endmenu
1506
1507menu "CPU Power Management"
1508
1509source "drivers/cpuidle/Kconfig"
1510
1511source "drivers/cpufreq/Kconfig"
1512
1513endmenu
1514
1515source "drivers/firmware/Kconfig"
1516
1517source "drivers/acpi/Kconfig"
1518
1519source "arch/arm64/kvm/Kconfig"
1520
1521if CRYPTO
1522source "arch/arm64/crypto/Kconfig"
1523endif
1524