xref: /openbmc/linux/arch/arm64/Kconfig (revision 5ff32883)
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_STRICT_KERNEL_RWX
27	select ARCH_HAS_STRICT_MODULE_RWX
28	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
29	select ARCH_HAS_SYNC_DMA_FOR_CPU
30	select ARCH_HAS_SYSCALL_WRAPPER
31	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
32	select ARCH_HAVE_NMI_SAFE_CMPXCHG
33	select ARCH_INLINE_READ_LOCK if !PREEMPT
34	select ARCH_INLINE_READ_LOCK_BH if !PREEMPT
35	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT
36	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT
37	select ARCH_INLINE_READ_UNLOCK if !PREEMPT
38	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT
39	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT
40	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT
41	select ARCH_INLINE_WRITE_LOCK if !PREEMPT
42	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT
43	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT
44	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT
45	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT
46	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT
47	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT
48	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT
49	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPT
50	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPT
51	select ARCH_INLINE_SPIN_LOCK if !PREEMPT
52	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPT
53	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPT
54	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPT
55	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPT
56	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT
57	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT
58	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT
59	select ARCH_USE_CMPXCHG_LOCKREF
60	select ARCH_USE_QUEUED_RWLOCKS
61	select ARCH_USE_QUEUED_SPINLOCKS
62	select ARCH_SUPPORTS_MEMORY_FAILURE
63	select ARCH_SUPPORTS_ATOMIC_RMW
64	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG
65	select ARCH_SUPPORTS_NUMA_BALANCING
66	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
67	select ARCH_WANT_FRAME_POINTERS
68	select ARCH_HAS_UBSAN_SANITIZE_ALL
69	select ARM_AMBA
70	select ARM_ARCH_TIMER
71	select ARM_GIC
72	select AUDIT_ARCH_COMPAT_GENERIC
73	select ARM_GIC_V2M if PCI
74	select ARM_GIC_V3
75	select ARM_GIC_V3_ITS if PCI
76	select ARM_PSCI_FW
77	select BUILDTIME_EXTABLE_SORT
78	select CLONE_BACKWARDS
79	select COMMON_CLK
80	select CPU_PM if (SUSPEND || CPU_IDLE)
81	select CRC32
82	select DCACHE_WORD_ACCESS
83	select DMA_DIRECT_REMAP
84	select EDAC_SUPPORT
85	select FRAME_POINTER
86	select GENERIC_ALLOCATOR
87	select GENERIC_ARCH_TOPOLOGY
88	select GENERIC_CLOCKEVENTS
89	select GENERIC_CLOCKEVENTS_BROADCAST
90	select GENERIC_CPU_AUTOPROBE
91	select GENERIC_EARLY_IOREMAP
92	select GENERIC_IDLE_POLL_SETUP
93	select GENERIC_IRQ_MULTI_HANDLER
94	select GENERIC_IRQ_PROBE
95	select GENERIC_IRQ_SHOW
96	select GENERIC_IRQ_SHOW_LEVEL
97	select GENERIC_PCI_IOMAP
98	select GENERIC_SCHED_CLOCK
99	select GENERIC_SMP_IDLE_THREAD
100	select GENERIC_STRNCPY_FROM_USER
101	select GENERIC_STRNLEN_USER
102	select GENERIC_TIME_VSYSCALL
103	select HANDLE_DOMAIN_IRQ
104	select HARDIRQS_SW_RESEND
105	select HAVE_PCI
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_DOMAINS_GENERIC if PCI
168	select PCI_ECAM if (ACPI && PCI)
169	select PCI_SYSCALL if PCI
170	select POWER_RESET
171	select POWER_SUPPLY
172	select REFCOUNT_FULL
173	select SPARSE_IRQ
174	select SWIOTLB
175	select SYSCTL_EXCEPTION_TRACE
176	select THREAD_INFO_IN_TASK
177	help
178	  ARM 64-bit (AArch64) Linux support.
179
180config 64BIT
181	def_bool y
182
183config MMU
184	def_bool y
185
186config ARM64_PAGE_SHIFT
187	int
188	default 16 if ARM64_64K_PAGES
189	default 14 if ARM64_16K_PAGES
190	default 12
191
192config ARM64_CONT_SHIFT
193	int
194	default 5 if ARM64_64K_PAGES
195	default 7 if ARM64_16K_PAGES
196	default 4
197
198config ARCH_MMAP_RND_BITS_MIN
199       default 14 if ARM64_64K_PAGES
200       default 16 if ARM64_16K_PAGES
201       default 18
202
203# max bits determined by the following formula:
204#  VA_BITS - PAGE_SHIFT - 3
205config ARCH_MMAP_RND_BITS_MAX
206       default 19 if ARM64_VA_BITS=36
207       default 24 if ARM64_VA_BITS=39
208       default 27 if ARM64_VA_BITS=42
209       default 30 if ARM64_VA_BITS=47
210       default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
211       default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
212       default 33 if ARM64_VA_BITS=48
213       default 14 if ARM64_64K_PAGES
214       default 16 if ARM64_16K_PAGES
215       default 18
216
217config ARCH_MMAP_RND_COMPAT_BITS_MIN
218       default 7 if ARM64_64K_PAGES
219       default 9 if ARM64_16K_PAGES
220       default 11
221
222config ARCH_MMAP_RND_COMPAT_BITS_MAX
223       default 16
224
225config NO_IOPORT_MAP
226	def_bool y if !PCI
227
228config STACKTRACE_SUPPORT
229	def_bool y
230
231config ILLEGAL_POINTER_VALUE
232	hex
233	default 0xdead000000000000
234
235config LOCKDEP_SUPPORT
236	def_bool y
237
238config TRACE_IRQFLAGS_SUPPORT
239	def_bool y
240
241config RWSEM_XCHGADD_ALGORITHM
242	def_bool y
243
244config GENERIC_BUG
245	def_bool y
246	depends on BUG
247
248config GENERIC_BUG_RELATIVE_POINTERS
249	def_bool y
250	depends on GENERIC_BUG
251
252config GENERIC_HWEIGHT
253	def_bool y
254
255config GENERIC_CSUM
256        def_bool y
257
258config GENERIC_CALIBRATE_DELAY
259	def_bool y
260
261config ZONE_DMA32
262	def_bool y
263
264config HAVE_GENERIC_GUP
265	def_bool y
266
267config ARCH_ENABLE_MEMORY_HOTPLUG
268	def_bool y
269
270config SMP
271	def_bool y
272
273config KERNEL_MODE_NEON
274	def_bool y
275
276config FIX_EARLYCON_MEM
277	def_bool y
278
279config PGTABLE_LEVELS
280	int
281	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
282	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
283	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52)
284	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
285	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
286	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
287
288config ARCH_SUPPORTS_UPROBES
289	def_bool y
290
291config ARCH_PROC_KCORE_TEXT
292	def_bool y
293
294source "arch/arm64/Kconfig.platforms"
295
296menu "Kernel Features"
297
298menu "ARM errata workarounds via the alternatives framework"
299
300config ARM64_WORKAROUND_CLEAN_CACHE
301	def_bool n
302
303config ARM64_ERRATUM_826319
304	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
305	default y
306	select ARM64_WORKAROUND_CLEAN_CACHE
307	help
308	  This option adds an alternative code sequence to work around ARM
309	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
310	  AXI master interface and an L2 cache.
311
312	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
313	  and is unable to accept a certain write via this interface, it will
314	  not progress on read data presented on the read data channel and the
315	  system can deadlock.
316
317	  The workaround promotes data cache clean instructions to
318	  data cache clean-and-invalidate.
319	  Please note that this does not necessarily enable the workaround,
320	  as it depends on the alternative framework, which will only patch
321	  the kernel if an affected CPU is detected.
322
323	  If unsure, say Y.
324
325config ARM64_ERRATUM_827319
326	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
327	default y
328	select ARM64_WORKAROUND_CLEAN_CACHE
329	help
330	  This option adds an alternative code sequence to work around ARM
331	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
332	  master interface and an L2 cache.
333
334	  Under certain conditions this erratum can cause a clean line eviction
335	  to occur at the same time as another transaction to the same address
336	  on the AMBA 5 CHI interface, which can cause data corruption if the
337	  interconnect reorders the two transactions.
338
339	  The workaround promotes data cache clean instructions to
340	  data cache clean-and-invalidate.
341	  Please note that this does not necessarily enable the workaround,
342	  as it depends on the alternative framework, which will only patch
343	  the kernel if an affected CPU is detected.
344
345	  If unsure, say Y.
346
347config ARM64_ERRATUM_824069
348	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
349	default y
350	select ARM64_WORKAROUND_CLEAN_CACHE
351	help
352	  This option adds an alternative code sequence to work around ARM
353	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
354	  to a coherent interconnect.
355
356	  If a Cortex-A53 processor is executing a store or prefetch for
357	  write instruction at the same time as a processor in another
358	  cluster is executing a cache maintenance operation to the same
359	  address, then this erratum might cause a clean cache line to be
360	  incorrectly marked as dirty.
361
362	  The workaround promotes data cache clean instructions to
363	  data cache clean-and-invalidate.
364	  Please note that this option does not necessarily enable the
365	  workaround, as it depends on the alternative framework, which will
366	  only patch the kernel if an affected CPU is detected.
367
368	  If unsure, say Y.
369
370config ARM64_ERRATUM_819472
371	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
372	default y
373	select ARM64_WORKAROUND_CLEAN_CACHE
374	help
375	  This option adds an alternative code sequence to work around ARM
376	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
377	  present when it is connected to a coherent interconnect.
378
379	  If the processor is executing a load and store exclusive sequence at
380	  the same time as a processor in another cluster is executing a cache
381	  maintenance operation to the same address, then this erratum might
382	  cause data corruption.
383
384	  The workaround promotes data cache clean instructions to
385	  data cache clean-and-invalidate.
386	  Please note that this does not necessarily enable the workaround,
387	  as it depends on the alternative framework, which will only patch
388	  the kernel if an affected CPU is detected.
389
390	  If unsure, say Y.
391
392config ARM64_ERRATUM_832075
393	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
394	default y
395	help
396	  This option adds an alternative code sequence to work around ARM
397	  erratum 832075 on Cortex-A57 parts up to r1p2.
398
399	  Affected Cortex-A57 parts might deadlock when exclusive load/store
400	  instructions to Write-Back memory are mixed with Device loads.
401
402	  The workaround is to promote device loads to use Load-Acquire
403	  semantics.
404	  Please note that this does not necessarily enable the workaround,
405	  as it depends on the alternative framework, which will only patch
406	  the kernel if an affected CPU is detected.
407
408	  If unsure, say Y.
409
410config ARM64_ERRATUM_834220
411	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
412	depends on KVM
413	default y
414	help
415	  This option adds an alternative code sequence to work around ARM
416	  erratum 834220 on Cortex-A57 parts up to r1p2.
417
418	  Affected Cortex-A57 parts might report a Stage 2 translation
419	  fault as the result of a Stage 1 fault for load crossing a
420	  page boundary when there is a permission or device memory
421	  alignment fault at Stage 1 and a translation fault at Stage 2.
422
423	  The workaround is to verify that the Stage 1 translation
424	  doesn't generate a fault before handling the Stage 2 fault.
425	  Please note that this does not necessarily enable the workaround,
426	  as it depends on the alternative framework, which will only patch
427	  the kernel if an affected CPU is detected.
428
429	  If unsure, say Y.
430
431config ARM64_ERRATUM_845719
432	bool "Cortex-A53: 845719: a load might read incorrect data"
433	depends on COMPAT
434	default y
435	help
436	  This option adds an alternative code sequence to work around ARM
437	  erratum 845719 on Cortex-A53 parts up to r0p4.
438
439	  When running a compat (AArch32) userspace on an affected Cortex-A53
440	  part, a load at EL0 from a virtual address that matches the bottom 32
441	  bits of the virtual address used by a recent load at (AArch64) EL1
442	  might return incorrect data.
443
444	  The workaround is to write the contextidr_el1 register on exception
445	  return to a 32-bit task.
446	  Please note that this does not necessarily enable the workaround,
447	  as it depends on the alternative framework, which will only patch
448	  the kernel if an affected CPU is detected.
449
450	  If unsure, say Y.
451
452config ARM64_ERRATUM_843419
453	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
454	default y
455	select ARM64_MODULE_PLTS if MODULES
456	help
457	  This option links the kernel with '--fix-cortex-a53-843419' and
458	  enables PLT support to replace certain ADRP instructions, which can
459	  cause subsequent memory accesses to use an incorrect address on
460	  Cortex-A53 parts up to r0p4.
461
462	  If unsure, say Y.
463
464config ARM64_ERRATUM_1024718
465	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
466	default y
467	help
468	  This option adds work around for Arm Cortex-A55 Erratum 1024718.
469
470	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
471	  update of the hardware dirty bit when the DBM/AP bits are updated
472	  without a break-before-make. The work around is to disable the usage
473	  of hardware DBM locally on the affected cores. CPUs not affected by
474	  erratum will continue to use the feature.
475
476	  If unsure, say Y.
477
478config ARM64_ERRATUM_1188873
479	bool "Cortex-A76: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
480	default y
481	select ARM_ARCH_TIMER_OOL_WORKAROUND
482	help
483	  This option adds work arounds for ARM Cortex-A76 erratum 1188873
484
485	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could cause
486	  register corruption when accessing the timer registers from
487	  AArch32 userspace.
488
489	  If unsure, say Y.
490
491config ARM64_ERRATUM_1165522
492	bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
493	default y
494	help
495	  This option adds work arounds for ARM Cortex-A76 erratum 1165522
496
497	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
498	  corrupted TLBs by speculating an AT instruction during a guest
499	  context switch.
500
501	  If unsure, say Y.
502
503config ARM64_ERRATUM_1286807
504	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
505	default y
506	select ARM64_WORKAROUND_REPEAT_TLBI
507	help
508	  This option adds workaround for ARM Cortex-A76 erratum 1286807
509
510	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
511	  address for a cacheable mapping of a location is being
512	  accessed by a core while another core is remapping the virtual
513	  address to a new physical page using the recommended
514	  break-before-make sequence, then under very rare circumstances
515	  TLBI+DSB completes before a read using the translation being
516	  invalidated has been observed by other observers. The
517	  workaround repeats the TLBI+DSB operation.
518
519	  If unsure, say Y.
520
521config CAVIUM_ERRATUM_22375
522	bool "Cavium erratum 22375, 24313"
523	default y
524	help
525	  Enable workaround for erratum 22375, 24313.
526
527	  This implements two gicv3-its errata workarounds for ThunderX. Both
528	  with small impact affecting only ITS table allocation.
529
530	    erratum 22375: only alloc 8MB table size
531	    erratum 24313: ignore memory access type
532
533	  The fixes are in ITS initialization and basically ignore memory access
534	  type and table size provided by the TYPER and BASER registers.
535
536	  If unsure, say Y.
537
538config CAVIUM_ERRATUM_23144
539	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
540	depends on NUMA
541	default y
542	help
543	  ITS SYNC command hang for cross node io and collections/cpu mapping.
544
545	  If unsure, say Y.
546
547config CAVIUM_ERRATUM_23154
548	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
549	default y
550	help
551	  The gicv3 of ThunderX requires a modified version for
552	  reading the IAR status to ensure data synchronization
553	  (access to icc_iar1_el1 is not sync'ed before and after).
554
555	  If unsure, say Y.
556
557config CAVIUM_ERRATUM_27456
558	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
559	default y
560	help
561	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
562	  instructions may cause the icache to become corrupted if it
563	  contains data for a non-current ASID.  The fix is to
564	  invalidate the icache when changing the mm context.
565
566	  If unsure, say Y.
567
568config CAVIUM_ERRATUM_30115
569	bool "Cavium erratum 30115: Guest may disable interrupts in host"
570	default y
571	help
572	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
573	  1.2, and T83 Pass 1.0, KVM guest execution may disable
574	  interrupts in host. Trapping both GICv3 group-0 and group-1
575	  accesses sidesteps the issue.
576
577	  If unsure, say Y.
578
579config QCOM_FALKOR_ERRATUM_1003
580	bool "Falkor E1003: Incorrect translation due to ASID change"
581	default y
582	help
583	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
584	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
585	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
586	  then only for entries in the walk cache, since the leaf translation
587	  is unchanged. Work around the erratum by invalidating the walk cache
588	  entries for the trampoline before entering the kernel proper.
589
590config ARM64_WORKAROUND_REPEAT_TLBI
591	bool
592	help
593	  Enable the repeat TLBI workaround for Falkor erratum 1009 and
594	  Cortex-A76 erratum 1286807.
595
596config QCOM_FALKOR_ERRATUM_1009
597	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
598	default y
599	select ARM64_WORKAROUND_REPEAT_TLBI
600	help
601	  On Falkor v1, the CPU may prematurely complete a DSB following a
602	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
603	  one more time to fix the issue.
604
605	  If unsure, say Y.
606
607config QCOM_QDF2400_ERRATUM_0065
608	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
609	default y
610	help
611	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
612	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
613	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
614
615	  If unsure, say Y.
616
617config SOCIONEXT_SYNQUACER_PREITS
618	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
619	default y
620	help
621	  Socionext Synquacer SoCs implement a separate h/w block to generate
622	  MSI doorbell writes with non-zero values for the device ID.
623
624	  If unsure, say Y.
625
626config HISILICON_ERRATUM_161600802
627	bool "Hip07 161600802: Erroneous redistributor VLPI base"
628	default y
629	help
630	  The HiSilicon Hip07 SoC usees the wrong redistributor base
631	  when issued ITS commands such as VMOVP and VMAPP, and requires
632	  a 128kB offset to be applied to the target address in this commands.
633
634	  If unsure, say Y.
635
636config QCOM_FALKOR_ERRATUM_E1041
637	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
638	default y
639	help
640	  Falkor CPU may speculatively fetch instructions from an improper
641	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
642	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
643
644	  If unsure, say Y.
645
646endmenu
647
648
649choice
650	prompt "Page size"
651	default ARM64_4K_PAGES
652	help
653	  Page size (translation granule) configuration.
654
655config ARM64_4K_PAGES
656	bool "4KB"
657	help
658	  This feature enables 4KB pages support.
659
660config ARM64_16K_PAGES
661	bool "16KB"
662	help
663	  The system will use 16KB pages support. AArch32 emulation
664	  requires applications compiled with 16K (or a multiple of 16K)
665	  aligned segments.
666
667config ARM64_64K_PAGES
668	bool "64KB"
669	help
670	  This feature enables 64KB pages support (4KB by default)
671	  allowing only two levels of page tables and faster TLB
672	  look-up. AArch32 emulation requires applications compiled
673	  with 64K aligned segments.
674
675endchoice
676
677choice
678	prompt "Virtual address space size"
679	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
680	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
681	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
682	help
683	  Allows choosing one of multiple possible virtual address
684	  space sizes. The level of translation table is determined by
685	  a combination of page size and virtual address space size.
686
687config ARM64_VA_BITS_36
688	bool "36-bit" if EXPERT
689	depends on ARM64_16K_PAGES
690
691config ARM64_VA_BITS_39
692	bool "39-bit"
693	depends on ARM64_4K_PAGES
694
695config ARM64_VA_BITS_42
696	bool "42-bit"
697	depends on ARM64_64K_PAGES
698
699config ARM64_VA_BITS_47
700	bool "47-bit"
701	depends on ARM64_16K_PAGES
702
703config ARM64_VA_BITS_48
704	bool "48-bit"
705
706config ARM64_USER_VA_BITS_52
707	bool "52-bit (user)"
708	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
709	help
710	  Enable 52-bit virtual addressing for userspace when explicitly
711	  requested via a hint to mmap(). The kernel will continue to
712	  use 48-bit virtual addresses for its own mappings.
713
714	  NOTE: Enabling 52-bit virtual addressing in conjunction with
715	  ARMv8.3 Pointer Authentication will result in the PAC being
716	  reduced from 7 bits to 3 bits, which may have a significant
717	  impact on its susceptibility to brute-force attacks.
718
719	  If unsure, select 48-bit virtual addressing instead.
720
721endchoice
722
723config ARM64_FORCE_52BIT
724	bool "Force 52-bit virtual addresses for userspace"
725	depends on ARM64_USER_VA_BITS_52 && EXPERT
726	help
727	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
728	  to maintain compatibility with older software by providing 48-bit VAs
729	  unless a hint is supplied to mmap.
730
731	  This configuration option disables the 48-bit compatibility logic, and
732	  forces all userspace addresses to be 52-bit on HW that supports it. One
733	  should only enable this configuration option for stress testing userspace
734	  memory management code. If unsure say N here.
735
736config ARM64_VA_BITS
737	int
738	default 36 if ARM64_VA_BITS_36
739	default 39 if ARM64_VA_BITS_39
740	default 42 if ARM64_VA_BITS_42
741	default 47 if ARM64_VA_BITS_47
742	default 48 if ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52
743
744choice
745	prompt "Physical address space size"
746	default ARM64_PA_BITS_48
747	help
748	  Choose the maximum physical address range that the kernel will
749	  support.
750
751config ARM64_PA_BITS_48
752	bool "48-bit"
753
754config ARM64_PA_BITS_52
755	bool "52-bit (ARMv8.2)"
756	depends on ARM64_64K_PAGES
757	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
758	help
759	  Enable support for a 52-bit physical address space, introduced as
760	  part of the ARMv8.2-LPA extension.
761
762	  With this enabled, the kernel will also continue to work on CPUs that
763	  do not support ARMv8.2-LPA, but with some added memory overhead (and
764	  minor performance overhead).
765
766endchoice
767
768config ARM64_PA_BITS
769	int
770	default 48 if ARM64_PA_BITS_48
771	default 52 if ARM64_PA_BITS_52
772
773config CPU_BIG_ENDIAN
774       bool "Build big-endian kernel"
775       help
776         Say Y if you plan on running a kernel in big-endian mode.
777
778config SCHED_MC
779	bool "Multi-core scheduler support"
780	help
781	  Multi-core scheduler support improves the CPU scheduler's decision
782	  making when dealing with multi-core CPU chips at a cost of slightly
783	  increased overhead in some places. If unsure say N here.
784
785config SCHED_SMT
786	bool "SMT scheduler support"
787	help
788	  Improves the CPU scheduler's decision making when dealing with
789	  MultiThreading at a cost of slightly increased overhead in some
790	  places. If unsure say N here.
791
792config NR_CPUS
793	int "Maximum number of CPUs (2-4096)"
794	range 2 4096
795	# These have to remain sorted largest to smallest
796	default "64"
797
798config HOTPLUG_CPU
799	bool "Support for hot-pluggable CPUs"
800	select GENERIC_IRQ_MIGRATION
801	help
802	  Say Y here to experiment with turning CPUs off and on.  CPUs
803	  can be controlled through /sys/devices/system/cpu.
804
805# Common NUMA Features
806config NUMA
807	bool "Numa Memory Allocation and Scheduler Support"
808	select ACPI_NUMA if ACPI
809	select OF_NUMA
810	help
811	  Enable NUMA (Non Uniform Memory Access) support.
812
813	  The kernel will try to allocate memory used by a CPU on the
814	  local memory of the CPU and add some more
815	  NUMA awareness to the kernel.
816
817config NODES_SHIFT
818	int "Maximum NUMA Nodes (as a power of 2)"
819	range 1 10
820	default "2"
821	depends on NEED_MULTIPLE_NODES
822	help
823	  Specify the maximum number of NUMA Nodes available on the target
824	  system.  Increases memory reserved to accommodate various tables.
825
826config USE_PERCPU_NUMA_NODE_ID
827	def_bool y
828	depends on NUMA
829
830config HAVE_SETUP_PER_CPU_AREA
831	def_bool y
832	depends on NUMA
833
834config NEED_PER_CPU_EMBED_FIRST_CHUNK
835	def_bool y
836	depends on NUMA
837
838config HOLES_IN_ZONE
839	def_bool y
840
841source "kernel/Kconfig.hz"
842
843config ARCH_SUPPORTS_DEBUG_PAGEALLOC
844	def_bool y
845
846config ARCH_SPARSEMEM_ENABLE
847	def_bool y
848	select SPARSEMEM_VMEMMAP_ENABLE
849
850config ARCH_SPARSEMEM_DEFAULT
851	def_bool ARCH_SPARSEMEM_ENABLE
852
853config ARCH_SELECT_MEMORY_MODEL
854	def_bool ARCH_SPARSEMEM_ENABLE
855
856config ARCH_FLATMEM_ENABLE
857	def_bool !NUMA
858
859config HAVE_ARCH_PFN_VALID
860	def_bool y
861
862config HW_PERF_EVENTS
863	def_bool y
864	depends on ARM_PMU
865
866config SYS_SUPPORTS_HUGETLBFS
867	def_bool y
868
869config ARCH_WANT_HUGE_PMD_SHARE
870	def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
871
872config ARCH_HAS_CACHE_LINE_SIZE
873	def_bool y
874
875config SECCOMP
876	bool "Enable seccomp to safely compute untrusted bytecode"
877	---help---
878	  This kernel feature is useful for number crunching applications
879	  that may need to compute untrusted bytecode during their
880	  execution. By using pipes or other transports made available to
881	  the process as file descriptors supporting the read/write
882	  syscalls, it's possible to isolate those applications in
883	  their own address space using seccomp. Once seccomp is
884	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
885	  and the task is only allowed to execute a few safe syscalls
886	  defined by each seccomp mode.
887
888config PARAVIRT
889	bool "Enable paravirtualization code"
890	help
891	  This changes the kernel so it can modify itself when it is run
892	  under a hypervisor, potentially improving performance significantly
893	  over full virtualization.
894
895config PARAVIRT_TIME_ACCOUNTING
896	bool "Paravirtual steal time accounting"
897	select PARAVIRT
898	default n
899	help
900	  Select this option to enable fine granularity task steal time
901	  accounting. Time spent executing other tasks in parallel with
902	  the current vCPU is discounted from the vCPU power. To account for
903	  that, there can be a small performance impact.
904
905	  If in doubt, say N here.
906
907config KEXEC
908	depends on PM_SLEEP_SMP
909	select KEXEC_CORE
910	bool "kexec system call"
911	---help---
912	  kexec is a system call that implements the ability to shutdown your
913	  current kernel, and to start another kernel.  It is like a reboot
914	  but it is independent of the system firmware.   And like a reboot
915	  you can start any kernel with it, not just Linux.
916
917config KEXEC_FILE
918	bool "kexec file based system call"
919	select KEXEC_CORE
920	help
921	  This is new version of kexec system call. This system call is
922	  file based and takes file descriptors as system call argument
923	  for kernel and initramfs as opposed to list of segments as
924	  accepted by previous system call.
925
926config KEXEC_VERIFY_SIG
927	bool "Verify kernel signature during kexec_file_load() syscall"
928	depends on KEXEC_FILE
929	help
930	  Select this option to verify a signature with loaded kernel
931	  image. If configured, any attempt of loading a image without
932	  valid signature will fail.
933
934	  In addition to that option, you need to enable signature
935	  verification for the corresponding kernel image type being
936	  loaded in order for this to work.
937
938config KEXEC_IMAGE_VERIFY_SIG
939	bool "Enable Image signature verification support"
940	default y
941	depends on KEXEC_VERIFY_SIG
942	depends on EFI && SIGNED_PE_FILE_VERIFICATION
943	help
944	  Enable Image signature verification support.
945
946comment "Support for PE file signature verification disabled"
947	depends on KEXEC_VERIFY_SIG
948	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
949
950config CRASH_DUMP
951	bool "Build kdump crash kernel"
952	help
953	  Generate crash dump after being started by kexec. This should
954	  be normally only set in special crash dump kernels which are
955	  loaded in the main kernel with kexec-tools into a specially
956	  reserved region and then later executed after a crash by
957	  kdump/kexec.
958
959	  For more details see Documentation/kdump/kdump.txt
960
961config XEN_DOM0
962	def_bool y
963	depends on XEN
964
965config XEN
966	bool "Xen guest support on ARM64"
967	depends on ARM64 && OF
968	select SWIOTLB_XEN
969	select PARAVIRT
970	help
971	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
972
973config FORCE_MAX_ZONEORDER
974	int
975	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
976	default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
977	default "11"
978	help
979	  The kernel memory allocator divides physically contiguous memory
980	  blocks into "zones", where each zone is a power of two number of
981	  pages.  This option selects the largest power of two that the kernel
982	  keeps in the memory allocator.  If you need to allocate very large
983	  blocks of physically contiguous memory, then you may need to
984	  increase this value.
985
986	  This config option is actually maximum order plus one. For example,
987	  a value of 11 means that the largest free memory block is 2^10 pages.
988
989	  We make sure that we can allocate upto a HugePage size for each configuration.
990	  Hence we have :
991		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
992
993	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
994	  4M allocations matching the default size used by generic code.
995
996config UNMAP_KERNEL_AT_EL0
997	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
998	default y
999	help
1000	  Speculation attacks against some high-performance processors can
1001	  be used to bypass MMU permission checks and leak kernel data to
1002	  userspace. This can be defended against by unmapping the kernel
1003	  when running in userspace, mapping it back in on exception entry
1004	  via a trampoline page in the vector table.
1005
1006	  If unsure, say Y.
1007
1008config HARDEN_BRANCH_PREDICTOR
1009	bool "Harden the branch predictor against aliasing attacks" if EXPERT
1010	default y
1011	help
1012	  Speculation attacks against some high-performance processors rely on
1013	  being able to manipulate the branch predictor for a victim context by
1014	  executing aliasing branches in the attacker context.  Such attacks
1015	  can be partially mitigated against by clearing internal branch
1016	  predictor state and limiting the prediction logic in some situations.
1017
1018	  This config option will take CPU-specific actions to harden the
1019	  branch predictor against aliasing attacks and may rely on specific
1020	  instruction sequences or control bits being set by the system
1021	  firmware.
1022
1023	  If unsure, say Y.
1024
1025config HARDEN_EL2_VECTORS
1026	bool "Harden EL2 vector mapping against system register leak" if EXPERT
1027	default y
1028	help
1029	  Speculation attacks against some high-performance processors can
1030	  be used to leak privileged information such as the vector base
1031	  register, resulting in a potential defeat of the EL2 layout
1032	  randomization.
1033
1034	  This config option will map the vectors to a fixed location,
1035	  independent of the EL2 code mapping, so that revealing VBAR_EL2
1036	  to an attacker does not give away any extra information. This
1037	  only gets enabled on affected CPUs.
1038
1039	  If unsure, say Y.
1040
1041config ARM64_SSBD
1042	bool "Speculative Store Bypass Disable" if EXPERT
1043	default y
1044	help
1045	  This enables mitigation of the bypassing of previous stores
1046	  by speculative loads.
1047
1048	  If unsure, say Y.
1049
1050config RODATA_FULL_DEFAULT_ENABLED
1051	bool "Apply r/o permissions of VM areas also to their linear aliases"
1052	default y
1053	help
1054	  Apply read-only attributes of VM areas to the linear alias of
1055	  the backing pages as well. This prevents code or read-only data
1056	  from being modified (inadvertently or intentionally) via another
1057	  mapping of the same memory page. This additional enhancement can
1058	  be turned off at runtime by passing rodata=[off|on] (and turned on
1059	  with rodata=full if this option is set to 'n')
1060
1061	  This requires the linear region to be mapped down to pages,
1062	  which may adversely affect performance in some cases.
1063
1064menuconfig ARMV8_DEPRECATED
1065	bool "Emulate deprecated/obsolete ARMv8 instructions"
1066	depends on COMPAT
1067	depends on SYSCTL
1068	help
1069	  Legacy software support may require certain instructions
1070	  that have been deprecated or obsoleted in the architecture.
1071
1072	  Enable this config to enable selective emulation of these
1073	  features.
1074
1075	  If unsure, say Y
1076
1077if ARMV8_DEPRECATED
1078
1079config SWP_EMULATION
1080	bool "Emulate SWP/SWPB instructions"
1081	help
1082	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1083	  they are always undefined. Say Y here to enable software
1084	  emulation of these instructions for userspace using LDXR/STXR.
1085
1086	  In some older versions of glibc [<=2.8] SWP is used during futex
1087	  trylock() operations with the assumption that the code will not
1088	  be preempted. This invalid assumption may be more likely to fail
1089	  with SWP emulation enabled, leading to deadlock of the user
1090	  application.
1091
1092	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1093	  on an external transaction monitoring block called a global
1094	  monitor to maintain update atomicity. If your system does not
1095	  implement a global monitor, this option can cause programs that
1096	  perform SWP operations to uncached memory to deadlock.
1097
1098	  If unsure, say Y
1099
1100config CP15_BARRIER_EMULATION
1101	bool "Emulate CP15 Barrier instructions"
1102	help
1103	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1104	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1105	  strongly recommended to use the ISB, DSB, and DMB
1106	  instructions instead.
1107
1108	  Say Y here to enable software emulation of these
1109	  instructions for AArch32 userspace code. When this option is
1110	  enabled, CP15 barrier usage is traced which can help
1111	  identify software that needs updating.
1112
1113	  If unsure, say Y
1114
1115config SETEND_EMULATION
1116	bool "Emulate SETEND instruction"
1117	help
1118	  The SETEND instruction alters the data-endianness of the
1119	  AArch32 EL0, and is deprecated in ARMv8.
1120
1121	  Say Y here to enable software emulation of the instruction
1122	  for AArch32 userspace code.
1123
1124	  Note: All the cpus on the system must have mixed endian support at EL0
1125	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1126	  endian - is hotplugged in after this feature has been enabled, there could
1127	  be unexpected results in the applications.
1128
1129	  If unsure, say Y
1130endif
1131
1132config ARM64_SW_TTBR0_PAN
1133	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1134	help
1135	  Enabling this option prevents the kernel from accessing
1136	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1137	  zeroed area and reserved ASID. The user access routines
1138	  restore the valid TTBR0_EL1 temporarily.
1139
1140menu "ARMv8.1 architectural features"
1141
1142config ARM64_HW_AFDBM
1143	bool "Support for hardware updates of the Access and Dirty page flags"
1144	default y
1145	help
1146	  The ARMv8.1 architecture extensions introduce support for
1147	  hardware updates of the access and dirty information in page
1148	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1149	  capable processors, accesses to pages with PTE_AF cleared will
1150	  set this bit instead of raising an access flag fault.
1151	  Similarly, writes to read-only pages with the DBM bit set will
1152	  clear the read-only bit (AP[2]) instead of raising a
1153	  permission fault.
1154
1155	  Kernels built with this configuration option enabled continue
1156	  to work on pre-ARMv8.1 hardware and the performance impact is
1157	  minimal. If unsure, say Y.
1158
1159config ARM64_PAN
1160	bool "Enable support for Privileged Access Never (PAN)"
1161	default y
1162	help
1163	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1164	 prevents the kernel or hypervisor from accessing user-space (EL0)
1165	 memory directly.
1166
1167	 Choosing this option will cause any unprotected (not using
1168	 copy_to_user et al) memory access to fail with a permission fault.
1169
1170	 The feature is detected at runtime, and will remain as a 'nop'
1171	 instruction if the cpu does not implement the feature.
1172
1173config ARM64_LSE_ATOMICS
1174	bool "Atomic instructions"
1175	default y
1176	help
1177	  As part of the Large System Extensions, ARMv8.1 introduces new
1178	  atomic instructions that are designed specifically to scale in
1179	  very large systems.
1180
1181	  Say Y here to make use of these instructions for the in-kernel
1182	  atomic routines. This incurs a small overhead on CPUs that do
1183	  not support these instructions and requires the kernel to be
1184	  built with binutils >= 2.25 in order for the new instructions
1185	  to be used.
1186
1187config ARM64_VHE
1188	bool "Enable support for Virtualization Host Extensions (VHE)"
1189	default y
1190	help
1191	  Virtualization Host Extensions (VHE) allow the kernel to run
1192	  directly at EL2 (instead of EL1) on processors that support
1193	  it. This leads to better performance for KVM, as they reduce
1194	  the cost of the world switch.
1195
1196	  Selecting this option allows the VHE feature to be detected
1197	  at runtime, and does not affect processors that do not
1198	  implement this feature.
1199
1200endmenu
1201
1202menu "ARMv8.2 architectural features"
1203
1204config ARM64_UAO
1205	bool "Enable support for User Access Override (UAO)"
1206	default y
1207	help
1208	  User Access Override (UAO; part of the ARMv8.2 Extensions)
1209	  causes the 'unprivileged' variant of the load/store instructions to
1210	  be overridden to be privileged.
1211
1212	  This option changes get_user() and friends to use the 'unprivileged'
1213	  variant of the load/store instructions. This ensures that user-space
1214	  really did have access to the supplied memory. When addr_limit is
1215	  set to kernel memory the UAO bit will be set, allowing privileged
1216	  access to kernel memory.
1217
1218	  Choosing this option will cause copy_to_user() et al to use user-space
1219	  memory permissions.
1220
1221	  The feature is detected at runtime, the kernel will use the
1222	  regular load/store instructions if the cpu does not implement the
1223	  feature.
1224
1225config ARM64_PMEM
1226	bool "Enable support for persistent memory"
1227	select ARCH_HAS_PMEM_API
1228	select ARCH_HAS_UACCESS_FLUSHCACHE
1229	help
1230	  Say Y to enable support for the persistent memory API based on the
1231	  ARMv8.2 DCPoP feature.
1232
1233	  The feature is detected at runtime, and the kernel will use DC CVAC
1234	  operations if DC CVAP is not supported (following the behaviour of
1235	  DC CVAP itself if the system does not define a point of persistence).
1236
1237config ARM64_RAS_EXTN
1238	bool "Enable support for RAS CPU Extensions"
1239	default y
1240	help
1241	  CPUs that support the Reliability, Availability and Serviceability
1242	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1243	  errors, classify them and report them to software.
1244
1245	  On CPUs with these extensions system software can use additional
1246	  barriers to determine if faults are pending and read the
1247	  classification from a new set of registers.
1248
1249	  Selecting this feature will allow the kernel to use these barriers
1250	  and access the new registers if the system supports the extension.
1251	  Platform RAS features may additionally depend on firmware support.
1252
1253config ARM64_CNP
1254	bool "Enable support for Common Not Private (CNP) translations"
1255	default y
1256	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1257	help
1258	  Common Not Private (CNP) allows translation table entries to
1259	  be shared between different PEs in the same inner shareable
1260	  domain, so the hardware can use this fact to optimise the
1261	  caching of such entries in the TLB.
1262
1263	  Selecting this option allows the CNP feature to be detected
1264	  at runtime, and does not affect PEs that do not implement
1265	  this feature.
1266
1267endmenu
1268
1269menu "ARMv8.3 architectural features"
1270
1271config ARM64_PTR_AUTH
1272	bool "Enable support for pointer authentication"
1273	default y
1274	help
1275	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1276	  instructions for signing and authenticating pointers against secret
1277	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1278	  and other attacks.
1279
1280	  This option enables these instructions at EL0 (i.e. for userspace).
1281
1282	  Choosing this option will cause the kernel to initialise secret keys
1283	  for each process at exec() time, with these keys being
1284	  context-switched along with the process.
1285
1286	  The feature is detected at runtime. If the feature is not present in
1287	  hardware it will not be advertised to userspace nor will it be
1288	  enabled.
1289
1290endmenu
1291
1292config ARM64_SVE
1293	bool "ARM Scalable Vector Extension support"
1294	default y
1295	depends on !KVM || ARM64_VHE
1296	help
1297	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1298	  execution state which complements and extends the SIMD functionality
1299	  of the base architecture to support much larger vectors and to enable
1300	  additional vectorisation opportunities.
1301
1302	  To enable use of this extension on CPUs that implement it, say Y.
1303
1304	  Note that for architectural reasons, firmware _must_ implement SVE
1305	  support when running on SVE capable hardware.  The required support
1306	  is present in:
1307
1308	    * version 1.5 and later of the ARM Trusted Firmware
1309	    * the AArch64 boot wrapper since commit 5e1261e08abf
1310	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1311
1312	  For other firmware implementations, consult the firmware documentation
1313	  or vendor.
1314
1315	  If you need the kernel to boot on SVE-capable hardware with broken
1316	  firmware, you may need to say N here until you get your firmware
1317	  fixed.  Otherwise, you may experience firmware panics or lockups when
1318	  booting the kernel.  If unsure and you are not observing these
1319	  symptoms, you should assume that it is safe to say Y.
1320
1321	  CPUs that support SVE are architecturally required to support the
1322	  Virtualization Host Extensions (VHE), so the kernel makes no
1323	  provision for supporting SVE alongside KVM without VHE enabled.
1324	  Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
1325	  KVM in the same kernel image.
1326
1327config ARM64_MODULE_PLTS
1328	bool
1329	select HAVE_MOD_ARCH_SPECIFIC
1330
1331config RELOCATABLE
1332	bool
1333	help
1334	  This builds the kernel as a Position Independent Executable (PIE),
1335	  which retains all relocation metadata required to relocate the
1336	  kernel binary at runtime to a different virtual address than the
1337	  address it was linked at.
1338	  Since AArch64 uses the RELA relocation format, this requires a
1339	  relocation pass at runtime even if the kernel is loaded at the
1340	  same address it was linked at.
1341
1342config RANDOMIZE_BASE
1343	bool "Randomize the address of the kernel image"
1344	select ARM64_MODULE_PLTS if MODULES
1345	select RELOCATABLE
1346	help
1347	  Randomizes the virtual address at which the kernel image is
1348	  loaded, as a security feature that deters exploit attempts
1349	  relying on knowledge of the location of kernel internals.
1350
1351	  It is the bootloader's job to provide entropy, by passing a
1352	  random u64 value in /chosen/kaslr-seed at kernel entry.
1353
1354	  When booting via the UEFI stub, it will invoke the firmware's
1355	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1356	  to the kernel proper. In addition, it will randomise the physical
1357	  location of the kernel Image as well.
1358
1359	  If unsure, say N.
1360
1361config RANDOMIZE_MODULE_REGION_FULL
1362	bool "Randomize the module region over a 4 GB range"
1363	depends on RANDOMIZE_BASE
1364	default y
1365	help
1366	  Randomizes the location of the module region inside a 4 GB window
1367	  covering the core kernel. This way, it is less likely for modules
1368	  to leak information about the location of core kernel data structures
1369	  but it does imply that function calls between modules and the core
1370	  kernel will need to be resolved via veneers in the module PLT.
1371
1372	  When this option is not set, the module region will be randomized over
1373	  a limited range that contains the [_stext, _etext] interval of the
1374	  core kernel, so branch relocations are always in range.
1375
1376config CC_HAVE_STACKPROTECTOR_SYSREG
1377	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1378
1379config STACKPROTECTOR_PER_TASK
1380	def_bool y
1381	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1382
1383endmenu
1384
1385menu "Boot options"
1386
1387config ARM64_ACPI_PARKING_PROTOCOL
1388	bool "Enable support for the ARM64 ACPI parking protocol"
1389	depends on ACPI
1390	help
1391	  Enable support for the ARM64 ACPI parking protocol. If disabled
1392	  the kernel will not allow booting through the ARM64 ACPI parking
1393	  protocol even if the corresponding data is present in the ACPI
1394	  MADT table.
1395
1396config CMDLINE
1397	string "Default kernel command string"
1398	default ""
1399	help
1400	  Provide a set of default command-line options at build time by
1401	  entering them here. As a minimum, you should specify the the
1402	  root device (e.g. root=/dev/nfs).
1403
1404config CMDLINE_FORCE
1405	bool "Always use the default kernel command string"
1406	help
1407	  Always use the default kernel command string, even if the boot
1408	  loader passes other arguments to the kernel.
1409	  This is useful if you cannot or don't want to change the
1410	  command-line options your boot loader passes to the kernel.
1411
1412config EFI_STUB
1413	bool
1414
1415config EFI
1416	bool "UEFI runtime support"
1417	depends on OF && !CPU_BIG_ENDIAN
1418	depends on KERNEL_MODE_NEON
1419	select ARCH_SUPPORTS_ACPI
1420	select LIBFDT
1421	select UCS2_STRING
1422	select EFI_PARAMS_FROM_FDT
1423	select EFI_RUNTIME_WRAPPERS
1424	select EFI_STUB
1425	select EFI_ARMSTUB
1426	default y
1427	help
1428	  This option provides support for runtime services provided
1429	  by UEFI firmware (such as non-volatile variables, realtime
1430          clock, and platform reset). A UEFI stub is also provided to
1431	  allow the kernel to be booted as an EFI application. This
1432	  is only useful on systems that have UEFI firmware.
1433
1434config DMI
1435	bool "Enable support for SMBIOS (DMI) tables"
1436	depends on EFI
1437	default y
1438	help
1439	  This enables SMBIOS/DMI feature for systems.
1440
1441	  This option is only useful on systems that have UEFI firmware.
1442	  However, even with this option, the resultant kernel should
1443	  continue to boot on existing non-UEFI platforms.
1444
1445endmenu
1446
1447config COMPAT
1448	bool "Kernel support for 32-bit EL0"
1449	depends on ARM64_4K_PAGES || EXPERT
1450	select COMPAT_BINFMT_ELF if BINFMT_ELF
1451	select HAVE_UID16
1452	select OLD_SIGSUSPEND3
1453	select COMPAT_OLD_SIGACTION
1454	help
1455	  This option enables support for a 32-bit EL0 running under a 64-bit
1456	  kernel at EL1. AArch32-specific components such as system calls,
1457	  the user helper functions, VFP support and the ptrace interface are
1458	  handled appropriately by the kernel.
1459
1460	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1461	  that you will only be able to execute AArch32 binaries that were compiled
1462	  with page size aligned segments.
1463
1464	  If you want to execute 32-bit userspace applications, say Y.
1465
1466config SYSVIPC_COMPAT
1467	def_bool y
1468	depends on COMPAT && SYSVIPC
1469
1470menu "Power management options"
1471
1472source "kernel/power/Kconfig"
1473
1474config ARCH_HIBERNATION_POSSIBLE
1475	def_bool y
1476	depends on CPU_PM
1477
1478config ARCH_HIBERNATION_HEADER
1479	def_bool y
1480	depends on HIBERNATION
1481
1482config ARCH_SUSPEND_POSSIBLE
1483	def_bool y
1484
1485endmenu
1486
1487menu "CPU Power Management"
1488
1489source "drivers/cpuidle/Kconfig"
1490
1491source "drivers/cpufreq/Kconfig"
1492
1493endmenu
1494
1495source "drivers/firmware/Kconfig"
1496
1497source "drivers/acpi/Kconfig"
1498
1499source "arch/arm64/kvm/Kconfig"
1500
1501if CRYPTO
1502source "arch/arm64/crypto/Kconfig"
1503endif
1504