xref: /linux/arch/arm64/Kconfig (revision 2decec48b0fd28ffdbf4cc684bd04e735f0839dd)
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_SETUP_DMA_OPS
26	select ARCH_HAS_SET_MEMORY
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_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
33	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
34	select ARCH_HAVE_NMI_SAFE_CMPXCHG
35	select ARCH_INLINE_READ_LOCK if !PREEMPT
36	select ARCH_INLINE_READ_LOCK_BH if !PREEMPT
37	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT
38	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT
39	select ARCH_INLINE_READ_UNLOCK if !PREEMPT
40	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT
41	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT
42	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT
43	select ARCH_INLINE_WRITE_LOCK if !PREEMPT
44	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT
45	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT
46	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT
47	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT
48	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT
49	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT
50	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT
51	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPT
52	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPT
53	select ARCH_INLINE_SPIN_LOCK if !PREEMPT
54	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPT
55	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPT
56	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPT
57	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPT
58	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT
59	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT
60	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT
61	select ARCH_USE_CMPXCHG_LOCKREF
62	select ARCH_USE_QUEUED_RWLOCKS
63	select ARCH_USE_QUEUED_SPINLOCKS
64	select ARCH_SUPPORTS_MEMORY_FAILURE
65	select ARCH_SUPPORTS_ATOMIC_RMW
66	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG
67	select ARCH_SUPPORTS_NUMA_BALANCING
68	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
69	select ARCH_WANT_FRAME_POINTERS
70	select ARCH_HAS_UBSAN_SANITIZE_ALL
71	select ARM_AMBA
72	select ARM_ARCH_TIMER
73	select ARM_GIC
74	select AUDIT_ARCH_COMPAT_GENERIC
75	select ARM_GIC_V2M if PCI
76	select ARM_GIC_V3
77	select ARM_GIC_V3_ITS if PCI
78	select ARM_PSCI_FW
79	select BUILDTIME_EXTABLE_SORT
80	select CLONE_BACKWARDS
81	select COMMON_CLK
82	select CPU_PM if (SUSPEND || CPU_IDLE)
83	select CRC32
84	select DCACHE_WORD_ACCESS
85	select DMA_DIRECT_REMAP
86	select EDAC_SUPPORT
87	select FRAME_POINTER
88	select GENERIC_ALLOCATOR
89	select GENERIC_ARCH_TOPOLOGY
90	select GENERIC_CLOCKEVENTS
91	select GENERIC_CLOCKEVENTS_BROADCAST
92	select GENERIC_CPU_AUTOPROBE
93	select GENERIC_CPU_VULNERABILITIES
94	select GENERIC_EARLY_IOREMAP
95	select GENERIC_IDLE_POLL_SETUP
96	select GENERIC_IRQ_MULTI_HANDLER
97	select GENERIC_IRQ_PROBE
98	select GENERIC_IRQ_SHOW
99	select GENERIC_IRQ_SHOW_LEVEL
100	select GENERIC_PCI_IOMAP
101	select GENERIC_SCHED_CLOCK
102	select GENERIC_SMP_IDLE_THREAD
103	select GENERIC_STRNCPY_FROM_USER
104	select GENERIC_STRNLEN_USER
105	select GENERIC_TIME_VSYSCALL
106	select HANDLE_DOMAIN_IRQ
107	select HARDIRQS_SW_RESEND
108	select HAVE_PCI
109	select HAVE_ACPI_APEI if (ACPI && EFI)
110	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
111	select HAVE_ARCH_AUDITSYSCALL
112	select HAVE_ARCH_BITREVERSE
113	select HAVE_ARCH_HUGE_VMAP
114	select HAVE_ARCH_JUMP_LABEL
115	select HAVE_ARCH_JUMP_LABEL_RELATIVE
116	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
117	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
118	select HAVE_ARCH_KGDB
119	select HAVE_ARCH_MMAP_RND_BITS
120	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
121	select HAVE_ARCH_PREL32_RELOCATIONS
122	select HAVE_ARCH_SECCOMP_FILTER
123	select HAVE_ARCH_STACKLEAK
124	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
125	select HAVE_ARCH_TRACEHOOK
126	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
127	select HAVE_ARCH_VMAP_STACK
128	select HAVE_ARM_SMCCC
129	select HAVE_EBPF_JIT
130	select HAVE_C_RECORDMCOUNT
131	select HAVE_CMPXCHG_DOUBLE
132	select HAVE_CMPXCHG_LOCAL
133	select HAVE_CONTEXT_TRACKING
134	select HAVE_DEBUG_BUGVERBOSE
135	select HAVE_DEBUG_KMEMLEAK
136	select HAVE_DMA_CONTIGUOUS
137	select HAVE_DYNAMIC_FTRACE
138	select HAVE_EFFICIENT_UNALIGNED_ACCESS
139	select HAVE_FTRACE_MCOUNT_RECORD
140	select HAVE_FUNCTION_TRACER
141	select HAVE_FUNCTION_GRAPH_TRACER
142	select HAVE_GCC_PLUGINS
143	select HAVE_HW_BREAKPOINT if PERF_EVENTS
144	select HAVE_IRQ_TIME_ACCOUNTING
145	select HAVE_MEMBLOCK_NODE_MAP if NUMA
146	select HAVE_NMI
147	select HAVE_PATA_PLATFORM
148	select HAVE_PERF_EVENTS
149	select HAVE_PERF_REGS
150	select HAVE_PERF_USER_STACK_DUMP
151	select HAVE_REGS_AND_STACK_ACCESS_API
152	select HAVE_FUNCTION_ARG_ACCESS_API
153	select HAVE_RCU_TABLE_FREE
154	select HAVE_RSEQ
155	select HAVE_STACKPROTECTOR
156	select HAVE_SYSCALL_TRACEPOINTS
157	select HAVE_KPROBES
158	select HAVE_KRETPROBES
159	select IOMMU_DMA if IOMMU_SUPPORT
160	select IRQ_DOMAIN
161	select IRQ_FORCED_THREADING
162	select MODULES_USE_ELF_RELA
163	select NEED_DMA_MAP_STATE
164	select NEED_SG_DMA_LENGTH
165	select OF
166	select OF_EARLY_FLATTREE
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 GENERIC_BUG
242	def_bool y
243	depends on BUG
244
245config GENERIC_BUG_RELATIVE_POINTERS
246	def_bool y
247	depends on GENERIC_BUG
248
249config GENERIC_HWEIGHT
250	def_bool y
251
252config GENERIC_CSUM
253        def_bool y
254
255config GENERIC_CALIBRATE_DELAY
256	def_bool y
257
258config ZONE_DMA32
259	def_bool y
260
261config HAVE_GENERIC_GUP
262	def_bool y
263
264config ARCH_ENABLE_MEMORY_HOTPLUG
265	def_bool y
266
267config SMP
268	def_bool y
269
270config KERNEL_MODE_NEON
271	def_bool y
272
273config FIX_EARLYCON_MEM
274	def_bool y
275
276config PGTABLE_LEVELS
277	int
278	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
279	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
280	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52)
281	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
282	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
283	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
284
285config ARCH_SUPPORTS_UPROBES
286	def_bool y
287
288config ARCH_PROC_KCORE_TEXT
289	def_bool y
290
291source "arch/arm64/Kconfig.platforms"
292
293menu "Kernel Features"
294
295menu "ARM errata workarounds via the alternatives framework"
296
297config ARM64_WORKAROUND_CLEAN_CACHE
298	bool
299
300config ARM64_ERRATUM_826319
301	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
302	default y
303	select ARM64_WORKAROUND_CLEAN_CACHE
304	help
305	  This option adds an alternative code sequence to work around ARM
306	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
307	  AXI master interface and an L2 cache.
308
309	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
310	  and is unable to accept a certain write via this interface, it will
311	  not progress on read data presented on the read data channel and the
312	  system can deadlock.
313
314	  The workaround promotes data cache clean instructions to
315	  data cache clean-and-invalidate.
316	  Please note that this does not necessarily enable the workaround,
317	  as it depends on the alternative framework, which will only patch
318	  the kernel if an affected CPU is detected.
319
320	  If unsure, say Y.
321
322config ARM64_ERRATUM_827319
323	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
324	default y
325	select ARM64_WORKAROUND_CLEAN_CACHE
326	help
327	  This option adds an alternative code sequence to work around ARM
328	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
329	  master interface and an L2 cache.
330
331	  Under certain conditions this erratum can cause a clean line eviction
332	  to occur at the same time as another transaction to the same address
333	  on the AMBA 5 CHI interface, which can cause data corruption if the
334	  interconnect reorders the two transactions.
335
336	  The workaround promotes data cache clean instructions to
337	  data cache clean-and-invalidate.
338	  Please note that this does not necessarily enable the workaround,
339	  as it depends on the alternative framework, which will only patch
340	  the kernel if an affected CPU is detected.
341
342	  If unsure, say Y.
343
344config ARM64_ERRATUM_824069
345	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
346	default y
347	select ARM64_WORKAROUND_CLEAN_CACHE
348	help
349	  This option adds an alternative code sequence to work around ARM
350	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
351	  to a coherent interconnect.
352
353	  If a Cortex-A53 processor is executing a store or prefetch for
354	  write instruction at the same time as a processor in another
355	  cluster is executing a cache maintenance operation to the same
356	  address, then this erratum might cause a clean cache line to be
357	  incorrectly marked as dirty.
358
359	  The workaround promotes data cache clean instructions to
360	  data cache clean-and-invalidate.
361	  Please note that this option does not necessarily enable the
362	  workaround, as it depends on the alternative framework, which will
363	  only patch the kernel if an affected CPU is detected.
364
365	  If unsure, say Y.
366
367config ARM64_ERRATUM_819472
368	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
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 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
374	  present when it is connected to a coherent interconnect.
375
376	  If the processor is executing a load and store exclusive sequence at
377	  the same time as a processor in another cluster is executing a cache
378	  maintenance operation to the same address, then this erratum might
379	  cause data corruption.
380
381	  The workaround promotes data cache clean instructions to
382	  data cache clean-and-invalidate.
383	  Please note that this does not necessarily enable the workaround,
384	  as it depends on the alternative framework, which will only patch
385	  the kernel if an affected CPU is detected.
386
387	  If unsure, say Y.
388
389config ARM64_ERRATUM_832075
390	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
391	default y
392	help
393	  This option adds an alternative code sequence to work around ARM
394	  erratum 832075 on Cortex-A57 parts up to r1p2.
395
396	  Affected Cortex-A57 parts might deadlock when exclusive load/store
397	  instructions to Write-Back memory are mixed with Device loads.
398
399	  The workaround is to promote device loads to use Load-Acquire
400	  semantics.
401	  Please note that this does not necessarily enable the workaround,
402	  as it depends on the alternative framework, which will only patch
403	  the kernel if an affected CPU is detected.
404
405	  If unsure, say Y.
406
407config ARM64_ERRATUM_834220
408	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
409	depends on KVM
410	default y
411	help
412	  This option adds an alternative code sequence to work around ARM
413	  erratum 834220 on Cortex-A57 parts up to r1p2.
414
415	  Affected Cortex-A57 parts might report a Stage 2 translation
416	  fault as the result of a Stage 1 fault for load crossing a
417	  page boundary when there is a permission or device memory
418	  alignment fault at Stage 1 and a translation fault at Stage 2.
419
420	  The workaround is to verify that the Stage 1 translation
421	  doesn't generate a fault before handling the Stage 2 fault.
422	  Please note that this does not necessarily enable the workaround,
423	  as it depends on the alternative framework, which will only patch
424	  the kernel if an affected CPU is detected.
425
426	  If unsure, say Y.
427
428config ARM64_ERRATUM_845719
429	bool "Cortex-A53: 845719: a load might read incorrect data"
430	depends on COMPAT
431	default y
432	help
433	  This option adds an alternative code sequence to work around ARM
434	  erratum 845719 on Cortex-A53 parts up to r0p4.
435
436	  When running a compat (AArch32) userspace on an affected Cortex-A53
437	  part, a load at EL0 from a virtual address that matches the bottom 32
438	  bits of the virtual address used by a recent load at (AArch64) EL1
439	  might return incorrect data.
440
441	  The workaround is to write the contextidr_el1 register on exception
442	  return to a 32-bit task.
443	  Please note that this does not necessarily enable the workaround,
444	  as it depends on the alternative framework, which will only patch
445	  the kernel if an affected CPU is detected.
446
447	  If unsure, say Y.
448
449config ARM64_ERRATUM_843419
450	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
451	default y
452	select ARM64_MODULE_PLTS if MODULES
453	help
454	  This option links the kernel with '--fix-cortex-a53-843419' and
455	  enables PLT support to replace certain ADRP instructions, which can
456	  cause subsequent memory accesses to use an incorrect address on
457	  Cortex-A53 parts up to r0p4.
458
459	  If unsure, say Y.
460
461config ARM64_ERRATUM_1024718
462	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
463	default y
464	help
465	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
466
467	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
468	  update of the hardware dirty bit when the DBM/AP bits are updated
469	  without a break-before-make. The workaround is to disable the usage
470	  of hardware DBM locally on the affected cores. CPUs not affected by
471	  this erratum will continue to use the feature.
472
473	  If unsure, say Y.
474
475config ARM64_ERRATUM_1188873
476	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
477	default y
478	depends on COMPAT
479	select ARM_ARCH_TIMER_OOL_WORKAROUND
480	help
481	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
482	  erratum 1188873.
483
484	  Affected Cortex-A76/Neoverse-N1 cores (r0p0, r1p0, r2p0) could
485	  cause register corruption when accessing the timer registers
486	  from AArch32 userspace.
487
488	  If unsure, say Y.
489
490config ARM64_ERRATUM_1165522
491	bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
492	default y
493	help
494	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
495
496	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
497	  corrupted TLBs by speculating an AT instruction during a guest
498	  context switch.
499
500	  If unsure, say Y.
501
502config ARM64_ERRATUM_1286807
503	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
504	default y
505	select ARM64_WORKAROUND_REPEAT_TLBI
506	help
507	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
508
509	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
510	  address for a cacheable mapping of a location is being
511	  accessed by a core while another core is remapping the virtual
512	  address to a new physical page using the recommended
513	  break-before-make sequence, then under very rare circumstances
514	  TLBI+DSB completes before a read using the translation being
515	  invalidated has been observed by other observers. The
516	  workaround repeats the TLBI+DSB operation.
517
518	  If unsure, say Y.
519
520config CAVIUM_ERRATUM_22375
521	bool "Cavium erratum 22375, 24313"
522	default y
523	help
524	  Enable workaround for errata 22375 and 24313.
525
526	  This implements two gicv3-its errata workarounds for ThunderX. Both
527	  with a small impact affecting only ITS table allocation.
528
529	    erratum 22375: only alloc 8MB table size
530	    erratum 24313: ignore memory access type
531
532	  The fixes are in ITS initialization and basically ignore memory access
533	  type and table size provided by the TYPER and BASER registers.
534
535	  If unsure, say Y.
536
537config CAVIUM_ERRATUM_23144
538	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
539	depends on NUMA
540	default y
541	help
542	  ITS SYNC command hang for cross node io and collections/cpu mapping.
543
544	  If unsure, say Y.
545
546config CAVIUM_ERRATUM_23154
547	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
548	default y
549	help
550	  The gicv3 of ThunderX requires a modified version for
551	  reading the IAR status to ensure data synchronization
552	  (access to icc_iar1_el1 is not sync'ed before and after).
553
554	  If unsure, say Y.
555
556config CAVIUM_ERRATUM_27456
557	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
558	default y
559	help
560	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
561	  instructions may cause the icache to become corrupted if it
562	  contains data for a non-current ASID.  The fix is to
563	  invalidate the icache when changing the mm context.
564
565	  If unsure, say Y.
566
567config CAVIUM_ERRATUM_30115
568	bool "Cavium erratum 30115: Guest may disable interrupts in host"
569	default y
570	help
571	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
572	  1.2, and T83 Pass 1.0, KVM guest execution may disable
573	  interrupts in host. Trapping both GICv3 group-0 and group-1
574	  accesses sidesteps the issue.
575
576	  If unsure, say Y.
577
578config QCOM_FALKOR_ERRATUM_1003
579	bool "Falkor E1003: Incorrect translation due to ASID change"
580	default y
581	help
582	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
583	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
584	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
585	  then only for entries in the walk cache, since the leaf translation
586	  is unchanged. Work around the erratum by invalidating the walk cache
587	  entries for the trampoline before entering the kernel proper.
588
589config ARM64_WORKAROUND_REPEAT_TLBI
590	bool
591
592config QCOM_FALKOR_ERRATUM_1009
593	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
594	default y
595	select ARM64_WORKAROUND_REPEAT_TLBI
596	help
597	  On Falkor v1, the CPU may prematurely complete a DSB following a
598	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
599	  one more time to fix the issue.
600
601	  If unsure, say Y.
602
603config QCOM_QDF2400_ERRATUM_0065
604	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
605	default y
606	help
607	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
608	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
609	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
610
611	  If unsure, say Y.
612
613config SOCIONEXT_SYNQUACER_PREITS
614	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
615	default y
616	help
617	  Socionext Synquacer SoCs implement a separate h/w block to generate
618	  MSI doorbell writes with non-zero values for the device ID.
619
620	  If unsure, say Y.
621
622config HISILICON_ERRATUM_161600802
623	bool "Hip07 161600802: Erroneous redistributor VLPI base"
624	default y
625	help
626	  The HiSilicon Hip07 SoC uses the wrong redistributor base
627	  when issued ITS commands such as VMOVP and VMAPP, and requires
628	  a 128kB offset to be applied to the target address in this commands.
629
630	  If unsure, say Y.
631
632config QCOM_FALKOR_ERRATUM_E1041
633	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
634	default y
635	help
636	  Falkor CPU may speculatively fetch instructions from an improper
637	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
638	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
639
640	  If unsure, say Y.
641
642config FUJITSU_ERRATUM_010001
643	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
644	default y
645	help
646	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
647	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
648	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
649	  This fault occurs under a specific hardware condition when a
650	  load/store instruction performs an address translation using:
651	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
652	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
653	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
654	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
655
656	  The workaround is to ensure these bits are clear in TCR_ELx.
657	  The workaround only affects the Fujitsu-A64FX.
658
659	  If unsure, say Y.
660
661endmenu
662
663
664choice
665	prompt "Page size"
666	default ARM64_4K_PAGES
667	help
668	  Page size (translation granule) configuration.
669
670config ARM64_4K_PAGES
671	bool "4KB"
672	help
673	  This feature enables 4KB pages support.
674
675config ARM64_16K_PAGES
676	bool "16KB"
677	help
678	  The system will use 16KB pages support. AArch32 emulation
679	  requires applications compiled with 16K (or a multiple of 16K)
680	  aligned segments.
681
682config ARM64_64K_PAGES
683	bool "64KB"
684	help
685	  This feature enables 64KB pages support (4KB by default)
686	  allowing only two levels of page tables and faster TLB
687	  look-up. AArch32 emulation requires applications compiled
688	  with 64K aligned segments.
689
690endchoice
691
692choice
693	prompt "Virtual address space size"
694	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
695	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
696	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
697	help
698	  Allows choosing one of multiple possible virtual address
699	  space sizes. The level of translation table is determined by
700	  a combination of page size and virtual address space size.
701
702config ARM64_VA_BITS_36
703	bool "36-bit" if EXPERT
704	depends on ARM64_16K_PAGES
705
706config ARM64_VA_BITS_39
707	bool "39-bit"
708	depends on ARM64_4K_PAGES
709
710config ARM64_VA_BITS_42
711	bool "42-bit"
712	depends on ARM64_64K_PAGES
713
714config ARM64_VA_BITS_47
715	bool "47-bit"
716	depends on ARM64_16K_PAGES
717
718config ARM64_VA_BITS_48
719	bool "48-bit"
720
721config ARM64_USER_VA_BITS_52
722	bool "52-bit (user)"
723	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
724	help
725	  Enable 52-bit virtual addressing for userspace when explicitly
726	  requested via a hint to mmap(). The kernel will continue to
727	  use 48-bit virtual addresses for its own mappings.
728
729	  NOTE: Enabling 52-bit virtual addressing in conjunction with
730	  ARMv8.3 Pointer Authentication will result in the PAC being
731	  reduced from 7 bits to 3 bits, which may have a significant
732	  impact on its susceptibility to brute-force attacks.
733
734	  If unsure, select 48-bit virtual addressing instead.
735
736endchoice
737
738config ARM64_FORCE_52BIT
739	bool "Force 52-bit virtual addresses for userspace"
740	depends on ARM64_USER_VA_BITS_52 && EXPERT
741	help
742	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
743	  to maintain compatibility with older software by providing 48-bit VAs
744	  unless a hint is supplied to mmap.
745
746	  This configuration option disables the 48-bit compatibility logic, and
747	  forces all userspace addresses to be 52-bit on HW that supports it. One
748	  should only enable this configuration option for stress testing userspace
749	  memory management code. If unsure say N here.
750
751config ARM64_VA_BITS
752	int
753	default 36 if ARM64_VA_BITS_36
754	default 39 if ARM64_VA_BITS_39
755	default 42 if ARM64_VA_BITS_42
756	default 47 if ARM64_VA_BITS_47
757	default 48 if ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52
758
759choice
760	prompt "Physical address space size"
761	default ARM64_PA_BITS_48
762	help
763	  Choose the maximum physical address range that the kernel will
764	  support.
765
766config ARM64_PA_BITS_48
767	bool "48-bit"
768
769config ARM64_PA_BITS_52
770	bool "52-bit (ARMv8.2)"
771	depends on ARM64_64K_PAGES
772	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
773	help
774	  Enable support for a 52-bit physical address space, introduced as
775	  part of the ARMv8.2-LPA extension.
776
777	  With this enabled, the kernel will also continue to work on CPUs that
778	  do not support ARMv8.2-LPA, but with some added memory overhead (and
779	  minor performance overhead).
780
781endchoice
782
783config ARM64_PA_BITS
784	int
785	default 48 if ARM64_PA_BITS_48
786	default 52 if ARM64_PA_BITS_52
787
788config CPU_BIG_ENDIAN
789       bool "Build big-endian kernel"
790       help
791         Say Y if you plan on running a kernel in big-endian mode.
792
793config SCHED_MC
794	bool "Multi-core scheduler support"
795	help
796	  Multi-core scheduler support improves the CPU scheduler's decision
797	  making when dealing with multi-core CPU chips at a cost of slightly
798	  increased overhead in some places. If unsure say N here.
799
800config SCHED_SMT
801	bool "SMT scheduler support"
802	help
803	  Improves the CPU scheduler's decision making when dealing with
804	  MultiThreading at a cost of slightly increased overhead in some
805	  places. If unsure say N here.
806
807config NR_CPUS
808	int "Maximum number of CPUs (2-4096)"
809	range 2 4096
810	default "256"
811
812config HOTPLUG_CPU
813	bool "Support for hot-pluggable CPUs"
814	select GENERIC_IRQ_MIGRATION
815	help
816	  Say Y here to experiment with turning CPUs off and on.  CPUs
817	  can be controlled through /sys/devices/system/cpu.
818
819# Common NUMA Features
820config NUMA
821	bool "Numa Memory Allocation and Scheduler Support"
822	select ACPI_NUMA if ACPI
823	select OF_NUMA
824	help
825	  Enable NUMA (Non Uniform Memory Access) support.
826
827	  The kernel will try to allocate memory used by a CPU on the
828	  local memory of the CPU and add some more
829	  NUMA awareness to the kernel.
830
831config NODES_SHIFT
832	int "Maximum NUMA Nodes (as a power of 2)"
833	range 1 10
834	default "2"
835	depends on NEED_MULTIPLE_NODES
836	help
837	  Specify the maximum number of NUMA Nodes available on the target
838	  system.  Increases memory reserved to accommodate various tables.
839
840config USE_PERCPU_NUMA_NODE_ID
841	def_bool y
842	depends on NUMA
843
844config HAVE_SETUP_PER_CPU_AREA
845	def_bool y
846	depends on NUMA
847
848config NEED_PER_CPU_EMBED_FIRST_CHUNK
849	def_bool y
850	depends on NUMA
851
852config HOLES_IN_ZONE
853	def_bool y
854
855source "kernel/Kconfig.hz"
856
857config ARCH_SUPPORTS_DEBUG_PAGEALLOC
858	def_bool y
859
860config ARCH_SPARSEMEM_ENABLE
861	def_bool y
862	select SPARSEMEM_VMEMMAP_ENABLE
863
864config ARCH_SPARSEMEM_DEFAULT
865	def_bool ARCH_SPARSEMEM_ENABLE
866
867config ARCH_SELECT_MEMORY_MODEL
868	def_bool ARCH_SPARSEMEM_ENABLE
869
870config ARCH_FLATMEM_ENABLE
871	def_bool !NUMA
872
873config HAVE_ARCH_PFN_VALID
874	def_bool y
875
876config HW_PERF_EVENTS
877	def_bool y
878	depends on ARM_PMU
879
880config SYS_SUPPORTS_HUGETLBFS
881	def_bool y
882
883config ARCH_WANT_HUGE_PMD_SHARE
884	def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
885
886config ARCH_HAS_CACHE_LINE_SIZE
887	def_bool y
888
889config ARCH_ENABLE_SPLIT_PMD_PTLOCK
890	def_bool y if PGTABLE_LEVELS > 2
891
892config SECCOMP
893	bool "Enable seccomp to safely compute untrusted bytecode"
894	---help---
895	  This kernel feature is useful for number crunching applications
896	  that may need to compute untrusted bytecode during their
897	  execution. By using pipes or other transports made available to
898	  the process as file descriptors supporting the read/write
899	  syscalls, it's possible to isolate those applications in
900	  their own address space using seccomp. Once seccomp is
901	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
902	  and the task is only allowed to execute a few safe syscalls
903	  defined by each seccomp mode.
904
905config PARAVIRT
906	bool "Enable paravirtualization code"
907	help
908	  This changes the kernel so it can modify itself when it is run
909	  under a hypervisor, potentially improving performance significantly
910	  over full virtualization.
911
912config PARAVIRT_TIME_ACCOUNTING
913	bool "Paravirtual steal time accounting"
914	select PARAVIRT
915	default n
916	help
917	  Select this option to enable fine granularity task steal time
918	  accounting. Time spent executing other tasks in parallel with
919	  the current vCPU is discounted from the vCPU power. To account for
920	  that, there can be a small performance impact.
921
922	  If in doubt, say N here.
923
924config KEXEC
925	depends on PM_SLEEP_SMP
926	select KEXEC_CORE
927	bool "kexec system call"
928	---help---
929	  kexec is a system call that implements the ability to shutdown your
930	  current kernel, and to start another kernel.  It is like a reboot
931	  but it is independent of the system firmware.   And like a reboot
932	  you can start any kernel with it, not just Linux.
933
934config KEXEC_FILE
935	bool "kexec file based system call"
936	select KEXEC_CORE
937	help
938	  This is new version of kexec system call. This system call is
939	  file based and takes file descriptors as system call argument
940	  for kernel and initramfs as opposed to list of segments as
941	  accepted by previous system call.
942
943config KEXEC_VERIFY_SIG
944	bool "Verify kernel signature during kexec_file_load() syscall"
945	depends on KEXEC_FILE
946	help
947	  Select this option to verify a signature with loaded kernel
948	  image. If configured, any attempt of loading a image without
949	  valid signature will fail.
950
951	  In addition to that option, you need to enable signature
952	  verification for the corresponding kernel image type being
953	  loaded in order for this to work.
954
955config KEXEC_IMAGE_VERIFY_SIG
956	bool "Enable Image signature verification support"
957	default y
958	depends on KEXEC_VERIFY_SIG
959	depends on EFI && SIGNED_PE_FILE_VERIFICATION
960	help
961	  Enable Image signature verification support.
962
963comment "Support for PE file signature verification disabled"
964	depends on KEXEC_VERIFY_SIG
965	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
966
967config CRASH_DUMP
968	bool "Build kdump crash kernel"
969	help
970	  Generate crash dump after being started by kexec. This should
971	  be normally only set in special crash dump kernels which are
972	  loaded in the main kernel with kexec-tools into a specially
973	  reserved region and then later executed after a crash by
974	  kdump/kexec.
975
976	  For more details see Documentation/kdump/kdump.txt
977
978config XEN_DOM0
979	def_bool y
980	depends on XEN
981
982config XEN
983	bool "Xen guest support on ARM64"
984	depends on ARM64 && OF
985	select SWIOTLB_XEN
986	select PARAVIRT
987	help
988	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
989
990config FORCE_MAX_ZONEORDER
991	int
992	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
993	default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
994	default "11"
995	help
996	  The kernel memory allocator divides physically contiguous memory
997	  blocks into "zones", where each zone is a power of two number of
998	  pages.  This option selects the largest power of two that the kernel
999	  keeps in the memory allocator.  If you need to allocate very large
1000	  blocks of physically contiguous memory, then you may need to
1001	  increase this value.
1002
1003	  This config option is actually maximum order plus one. For example,
1004	  a value of 11 means that the largest free memory block is 2^10 pages.
1005
1006	  We make sure that we can allocate upto a HugePage size for each configuration.
1007	  Hence we have :
1008		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1009
1010	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1011	  4M allocations matching the default size used by generic code.
1012
1013config UNMAP_KERNEL_AT_EL0
1014	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1015	default y
1016	help
1017	  Speculation attacks against some high-performance processors can
1018	  be used to bypass MMU permission checks and leak kernel data to
1019	  userspace. This can be defended against by unmapping the kernel
1020	  when running in userspace, mapping it back in on exception entry
1021	  via a trampoline page in the vector table.
1022
1023	  If unsure, say Y.
1024
1025config HARDEN_BRANCH_PREDICTOR
1026	bool "Harden the branch predictor against aliasing attacks" if EXPERT
1027	default y
1028	help
1029	  Speculation attacks against some high-performance processors rely on
1030	  being able to manipulate the branch predictor for a victim context by
1031	  executing aliasing branches in the attacker context.  Such attacks
1032	  can be partially mitigated against by clearing internal branch
1033	  predictor state and limiting the prediction logic in some situations.
1034
1035	  This config option will take CPU-specific actions to harden the
1036	  branch predictor against aliasing attacks and may rely on specific
1037	  instruction sequences or control bits being set by the system
1038	  firmware.
1039
1040	  If unsure, say Y.
1041
1042config HARDEN_EL2_VECTORS
1043	bool "Harden EL2 vector mapping against system register leak" if EXPERT
1044	default y
1045	help
1046	  Speculation attacks against some high-performance processors can
1047	  be used to leak privileged information such as the vector base
1048	  register, resulting in a potential defeat of the EL2 layout
1049	  randomization.
1050
1051	  This config option will map the vectors to a fixed location,
1052	  independent of the EL2 code mapping, so that revealing VBAR_EL2
1053	  to an attacker does not give away any extra information. This
1054	  only gets enabled on affected CPUs.
1055
1056	  If unsure, say Y.
1057
1058config ARM64_SSBD
1059	bool "Speculative Store Bypass Disable" if EXPERT
1060	default y
1061	help
1062	  This enables mitigation of the bypassing of previous stores
1063	  by speculative loads.
1064
1065	  If unsure, say Y.
1066
1067config RODATA_FULL_DEFAULT_ENABLED
1068	bool "Apply r/o permissions of VM areas also to their linear aliases"
1069	default y
1070	help
1071	  Apply read-only attributes of VM areas to the linear alias of
1072	  the backing pages as well. This prevents code or read-only data
1073	  from being modified (inadvertently or intentionally) via another
1074	  mapping of the same memory page. This additional enhancement can
1075	  be turned off at runtime by passing rodata=[off|on] (and turned on
1076	  with rodata=full if this option is set to 'n')
1077
1078	  This requires the linear region to be mapped down to pages,
1079	  which may adversely affect performance in some cases.
1080
1081config ARM64_SW_TTBR0_PAN
1082	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1083	help
1084	  Enabling this option prevents the kernel from accessing
1085	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1086	  zeroed area and reserved ASID. The user access routines
1087	  restore the valid TTBR0_EL1 temporarily.
1088
1089menuconfig COMPAT
1090	bool "Kernel support for 32-bit EL0"
1091	depends on ARM64_4K_PAGES || EXPERT
1092	select COMPAT_BINFMT_ELF if BINFMT_ELF
1093	select HAVE_UID16
1094	select OLD_SIGSUSPEND3
1095	select COMPAT_OLD_SIGACTION
1096	help
1097	  This option enables support for a 32-bit EL0 running under a 64-bit
1098	  kernel at EL1. AArch32-specific components such as system calls,
1099	  the user helper functions, VFP support and the ptrace interface are
1100	  handled appropriately by the kernel.
1101
1102	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1103	  that you will only be able to execute AArch32 binaries that were compiled
1104	  with page size aligned segments.
1105
1106	  If you want to execute 32-bit userspace applications, say Y.
1107
1108if COMPAT
1109
1110config KUSER_HELPERS
1111	bool "Enable kuser helpers page for 32 bit applications"
1112	default y
1113	help
1114	  Warning: disabling this option may break 32-bit user programs.
1115
1116	  Provide kuser helpers to compat tasks. The kernel provides
1117	  helper code to userspace in read only form at a fixed location
1118	  to allow userspace to be independent of the CPU type fitted to
1119	  the system. This permits binaries to be run on ARMv4 through
1120	  to ARMv8 without modification.
1121
1122	  See Documentation/arm/kernel_user_helpers.txt for details.
1123
1124	  However, the fixed address nature of these helpers can be used
1125	  by ROP (return orientated programming) authors when creating
1126	  exploits.
1127
1128	  If all of the binaries and libraries which run on your platform
1129	  are built specifically for your platform, and make no use of
1130	  these helpers, then you can turn this option off to hinder
1131	  such exploits. However, in that case, if a binary or library
1132	  relying on those helpers is run, it will not function correctly.
1133
1134	  Say N here only if you are absolutely certain that you do not
1135	  need these helpers; otherwise, the safe option is to say Y.
1136
1137
1138menuconfig ARMV8_DEPRECATED
1139	bool "Emulate deprecated/obsolete ARMv8 instructions"
1140	depends on SYSCTL
1141	help
1142	  Legacy software support may require certain instructions
1143	  that have been deprecated or obsoleted in the architecture.
1144
1145	  Enable this config to enable selective emulation of these
1146	  features.
1147
1148	  If unsure, say Y
1149
1150if ARMV8_DEPRECATED
1151
1152config SWP_EMULATION
1153	bool "Emulate SWP/SWPB instructions"
1154	help
1155	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1156	  they are always undefined. Say Y here to enable software
1157	  emulation of these instructions for userspace using LDXR/STXR.
1158
1159	  In some older versions of glibc [<=2.8] SWP is used during futex
1160	  trylock() operations with the assumption that the code will not
1161	  be preempted. This invalid assumption may be more likely to fail
1162	  with SWP emulation enabled, leading to deadlock of the user
1163	  application.
1164
1165	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1166	  on an external transaction monitoring block called a global
1167	  monitor to maintain update atomicity. If your system does not
1168	  implement a global monitor, this option can cause programs that
1169	  perform SWP operations to uncached memory to deadlock.
1170
1171	  If unsure, say Y
1172
1173config CP15_BARRIER_EMULATION
1174	bool "Emulate CP15 Barrier instructions"
1175	help
1176	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1177	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1178	  strongly recommended to use the ISB, DSB, and DMB
1179	  instructions instead.
1180
1181	  Say Y here to enable software emulation of these
1182	  instructions for AArch32 userspace code. When this option is
1183	  enabled, CP15 barrier usage is traced which can help
1184	  identify software that needs updating.
1185
1186	  If unsure, say Y
1187
1188config SETEND_EMULATION
1189	bool "Emulate SETEND instruction"
1190	help
1191	  The SETEND instruction alters the data-endianness of the
1192	  AArch32 EL0, and is deprecated in ARMv8.
1193
1194	  Say Y here to enable software emulation of the instruction
1195	  for AArch32 userspace code.
1196
1197	  Note: All the cpus on the system must have mixed endian support at EL0
1198	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1199	  endian - is hotplugged in after this feature has been enabled, there could
1200	  be unexpected results in the applications.
1201
1202	  If unsure, say Y
1203endif
1204
1205endif
1206
1207menu "ARMv8.1 architectural features"
1208
1209config ARM64_HW_AFDBM
1210	bool "Support for hardware updates of the Access and Dirty page flags"
1211	default y
1212	help
1213	  The ARMv8.1 architecture extensions introduce support for
1214	  hardware updates of the access and dirty information in page
1215	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1216	  capable processors, accesses to pages with PTE_AF cleared will
1217	  set this bit instead of raising an access flag fault.
1218	  Similarly, writes to read-only pages with the DBM bit set will
1219	  clear the read-only bit (AP[2]) instead of raising a
1220	  permission fault.
1221
1222	  Kernels built with this configuration option enabled continue
1223	  to work on pre-ARMv8.1 hardware and the performance impact is
1224	  minimal. If unsure, say Y.
1225
1226config ARM64_PAN
1227	bool "Enable support for Privileged Access Never (PAN)"
1228	default y
1229	help
1230	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1231	 prevents the kernel or hypervisor from accessing user-space (EL0)
1232	 memory directly.
1233
1234	 Choosing this option will cause any unprotected (not using
1235	 copy_to_user et al) memory access to fail with a permission fault.
1236
1237	 The feature is detected at runtime, and will remain as a 'nop'
1238	 instruction if the cpu does not implement the feature.
1239
1240config ARM64_LSE_ATOMICS
1241	bool "Atomic instructions"
1242	default y
1243	help
1244	  As part of the Large System Extensions, ARMv8.1 introduces new
1245	  atomic instructions that are designed specifically to scale in
1246	  very large systems.
1247
1248	  Say Y here to make use of these instructions for the in-kernel
1249	  atomic routines. This incurs a small overhead on CPUs that do
1250	  not support these instructions and requires the kernel to be
1251	  built with binutils >= 2.25 in order for the new instructions
1252	  to be used.
1253
1254config ARM64_VHE
1255	bool "Enable support for Virtualization Host Extensions (VHE)"
1256	default y
1257	help
1258	  Virtualization Host Extensions (VHE) allow the kernel to run
1259	  directly at EL2 (instead of EL1) on processors that support
1260	  it. This leads to better performance for KVM, as they reduce
1261	  the cost of the world switch.
1262
1263	  Selecting this option allows the VHE feature to be detected
1264	  at runtime, and does not affect processors that do not
1265	  implement this feature.
1266
1267endmenu
1268
1269menu "ARMv8.2 architectural features"
1270
1271config ARM64_UAO
1272	bool "Enable support for User Access Override (UAO)"
1273	default y
1274	help
1275	  User Access Override (UAO; part of the ARMv8.2 Extensions)
1276	  causes the 'unprivileged' variant of the load/store instructions to
1277	  be overridden to be privileged.
1278
1279	  This option changes get_user() and friends to use the 'unprivileged'
1280	  variant of the load/store instructions. This ensures that user-space
1281	  really did have access to the supplied memory. When addr_limit is
1282	  set to kernel memory the UAO bit will be set, allowing privileged
1283	  access to kernel memory.
1284
1285	  Choosing this option will cause copy_to_user() et al to use user-space
1286	  memory permissions.
1287
1288	  The feature is detected at runtime, the kernel will use the
1289	  regular load/store instructions if the cpu does not implement the
1290	  feature.
1291
1292config ARM64_PMEM
1293	bool "Enable support for persistent memory"
1294	select ARCH_HAS_PMEM_API
1295	select ARCH_HAS_UACCESS_FLUSHCACHE
1296	help
1297	  Say Y to enable support for the persistent memory API based on the
1298	  ARMv8.2 DCPoP feature.
1299
1300	  The feature is detected at runtime, and the kernel will use DC CVAC
1301	  operations if DC CVAP is not supported (following the behaviour of
1302	  DC CVAP itself if the system does not define a point of persistence).
1303
1304config ARM64_RAS_EXTN
1305	bool "Enable support for RAS CPU Extensions"
1306	default y
1307	help
1308	  CPUs that support the Reliability, Availability and Serviceability
1309	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1310	  errors, classify them and report them to software.
1311
1312	  On CPUs with these extensions system software can use additional
1313	  barriers to determine if faults are pending and read the
1314	  classification from a new set of registers.
1315
1316	  Selecting this feature will allow the kernel to use these barriers
1317	  and access the new registers if the system supports the extension.
1318	  Platform RAS features may additionally depend on firmware support.
1319
1320config ARM64_CNP
1321	bool "Enable support for Common Not Private (CNP) translations"
1322	default y
1323	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1324	help
1325	  Common Not Private (CNP) allows translation table entries to
1326	  be shared between different PEs in the same inner shareable
1327	  domain, so the hardware can use this fact to optimise the
1328	  caching of such entries in the TLB.
1329
1330	  Selecting this option allows the CNP feature to be detected
1331	  at runtime, and does not affect PEs that do not implement
1332	  this feature.
1333
1334endmenu
1335
1336menu "ARMv8.3 architectural features"
1337
1338config ARM64_PTR_AUTH
1339	bool "Enable support for pointer authentication"
1340	default y
1341	help
1342	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1343	  instructions for signing and authenticating pointers against secret
1344	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1345	  and other attacks.
1346
1347	  This option enables these instructions at EL0 (i.e. for userspace).
1348
1349	  Choosing this option will cause the kernel to initialise secret keys
1350	  for each process at exec() time, with these keys being
1351	  context-switched along with the process.
1352
1353	  The feature is detected at runtime. If the feature is not present in
1354	  hardware it will not be advertised to userspace nor will it be
1355	  enabled.
1356
1357endmenu
1358
1359config ARM64_SVE
1360	bool "ARM Scalable Vector Extension support"
1361	default y
1362	depends on !KVM || ARM64_VHE
1363	help
1364	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1365	  execution state which complements and extends the SIMD functionality
1366	  of the base architecture to support much larger vectors and to enable
1367	  additional vectorisation opportunities.
1368
1369	  To enable use of this extension on CPUs that implement it, say Y.
1370
1371	  On CPUs that support the SVE2 extensions, this option will enable
1372	  those too.
1373
1374	  Note that for architectural reasons, firmware _must_ implement SVE
1375	  support when running on SVE capable hardware.  The required support
1376	  is present in:
1377
1378	    * version 1.5 and later of the ARM Trusted Firmware
1379	    * the AArch64 boot wrapper since commit 5e1261e08abf
1380	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1381
1382	  For other firmware implementations, consult the firmware documentation
1383	  or vendor.
1384
1385	  If you need the kernel to boot on SVE-capable hardware with broken
1386	  firmware, you may need to say N here until you get your firmware
1387	  fixed.  Otherwise, you may experience firmware panics or lockups when
1388	  booting the kernel.  If unsure and you are not observing these
1389	  symptoms, you should assume that it is safe to say Y.
1390
1391	  CPUs that support SVE are architecturally required to support the
1392	  Virtualization Host Extensions (VHE), so the kernel makes no
1393	  provision for supporting SVE alongside KVM without VHE enabled.
1394	  Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
1395	  KVM in the same kernel image.
1396
1397config ARM64_MODULE_PLTS
1398	bool
1399	select HAVE_MOD_ARCH_SPECIFIC
1400
1401config ARM64_PSEUDO_NMI
1402	bool "Support for NMI-like interrupts"
1403	select CONFIG_ARM_GIC_V3
1404	help
1405	  Adds support for mimicking Non-Maskable Interrupts through the use of
1406	  GIC interrupt priority. This support requires version 3 or later of
1407	  ARM GIC.
1408
1409	  This high priority configuration for interrupts needs to be
1410	  explicitly enabled by setting the kernel parameter
1411	  "irqchip.gicv3_pseudo_nmi" to 1.
1412
1413	  If unsure, say N
1414
1415config RELOCATABLE
1416	bool
1417	help
1418	  This builds the kernel as a Position Independent Executable (PIE),
1419	  which retains all relocation metadata required to relocate the
1420	  kernel binary at runtime to a different virtual address than the
1421	  address it was linked at.
1422	  Since AArch64 uses the RELA relocation format, this requires a
1423	  relocation pass at runtime even if the kernel is loaded at the
1424	  same address it was linked at.
1425
1426config RANDOMIZE_BASE
1427	bool "Randomize the address of the kernel image"
1428	select ARM64_MODULE_PLTS if MODULES
1429	select RELOCATABLE
1430	help
1431	  Randomizes the virtual address at which the kernel image is
1432	  loaded, as a security feature that deters exploit attempts
1433	  relying on knowledge of the location of kernel internals.
1434
1435	  It is the bootloader's job to provide entropy, by passing a
1436	  random u64 value in /chosen/kaslr-seed at kernel entry.
1437
1438	  When booting via the UEFI stub, it will invoke the firmware's
1439	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1440	  to the kernel proper. In addition, it will randomise the physical
1441	  location of the kernel Image as well.
1442
1443	  If unsure, say N.
1444
1445config RANDOMIZE_MODULE_REGION_FULL
1446	bool "Randomize the module region over a 4 GB range"
1447	depends on RANDOMIZE_BASE
1448	default y
1449	help
1450	  Randomizes the location of the module region inside a 4 GB window
1451	  covering the core kernel. This way, it is less likely for modules
1452	  to leak information about the location of core kernel data structures
1453	  but it does imply that function calls between modules and the core
1454	  kernel will need to be resolved via veneers in the module PLT.
1455
1456	  When this option is not set, the module region will be randomized over
1457	  a limited range that contains the [_stext, _etext] interval of the
1458	  core kernel, so branch relocations are always in range.
1459
1460config CC_HAVE_STACKPROTECTOR_SYSREG
1461	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1462
1463config STACKPROTECTOR_PER_TASK
1464	def_bool y
1465	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1466
1467endmenu
1468
1469menu "Boot options"
1470
1471config ARM64_ACPI_PARKING_PROTOCOL
1472	bool "Enable support for the ARM64 ACPI parking protocol"
1473	depends on ACPI
1474	help
1475	  Enable support for the ARM64 ACPI parking protocol. If disabled
1476	  the kernel will not allow booting through the ARM64 ACPI parking
1477	  protocol even if the corresponding data is present in the ACPI
1478	  MADT table.
1479
1480config CMDLINE
1481	string "Default kernel command string"
1482	default ""
1483	help
1484	  Provide a set of default command-line options at build time by
1485	  entering them here. As a minimum, you should specify the the
1486	  root device (e.g. root=/dev/nfs).
1487
1488config CMDLINE_FORCE
1489	bool "Always use the default kernel command string"
1490	help
1491	  Always use the default kernel command string, even if the boot
1492	  loader passes other arguments to the kernel.
1493	  This is useful if you cannot or don't want to change the
1494	  command-line options your boot loader passes to the kernel.
1495
1496config EFI_STUB
1497	bool
1498
1499config EFI
1500	bool "UEFI runtime support"
1501	depends on OF && !CPU_BIG_ENDIAN
1502	depends on KERNEL_MODE_NEON
1503	select ARCH_SUPPORTS_ACPI
1504	select LIBFDT
1505	select UCS2_STRING
1506	select EFI_PARAMS_FROM_FDT
1507	select EFI_RUNTIME_WRAPPERS
1508	select EFI_STUB
1509	select EFI_ARMSTUB
1510	default y
1511	help
1512	  This option provides support for runtime services provided
1513	  by UEFI firmware (such as non-volatile variables, realtime
1514          clock, and platform reset). A UEFI stub is also provided to
1515	  allow the kernel to be booted as an EFI application. This
1516	  is only useful on systems that have UEFI firmware.
1517
1518config DMI
1519	bool "Enable support for SMBIOS (DMI) tables"
1520	depends on EFI
1521	default y
1522	help
1523	  This enables SMBIOS/DMI feature for systems.
1524
1525	  This option is only useful on systems that have UEFI firmware.
1526	  However, even with this option, the resultant kernel should
1527	  continue to boot on existing non-UEFI platforms.
1528
1529endmenu
1530
1531config SYSVIPC_COMPAT
1532	def_bool y
1533	depends on COMPAT && SYSVIPC
1534
1535config ARCH_ENABLE_HUGEPAGE_MIGRATION
1536	def_bool y
1537	depends on HUGETLB_PAGE && MIGRATION
1538
1539menu "Power management options"
1540
1541source "kernel/power/Kconfig"
1542
1543config ARCH_HIBERNATION_POSSIBLE
1544	def_bool y
1545	depends on CPU_PM
1546
1547config ARCH_HIBERNATION_HEADER
1548	def_bool y
1549	depends on HIBERNATION
1550
1551config ARCH_SUSPEND_POSSIBLE
1552	def_bool y
1553
1554endmenu
1555
1556menu "CPU Power Management"
1557
1558source "drivers/cpuidle/Kconfig"
1559
1560source "drivers/cpufreq/Kconfig"
1561
1562endmenu
1563
1564source "drivers/firmware/Kconfig"
1565
1566source "drivers/acpi/Kconfig"
1567
1568source "arch/arm64/kvm/Kconfig"
1569
1570if CRYPTO
1571source "arch/arm64/crypto/Kconfig"
1572endif
1573