xref: /openbmc/linux/arch/arm64/Kconfig (revision ec8f24b7)
1# SPDX-License-Identifier: GPL-2.0-only
2config ARM64
3	def_bool y
4	select ACPI_CCA_REQUIRED if ACPI
5	select ACPI_GENERIC_GSI if ACPI
6	select ACPI_GTDT if ACPI
7	select ACPI_IORT if ACPI
8	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
9	select ACPI_MCFG if (ACPI && PCI)
10	select ACPI_SPCR_TABLE if ACPI
11	select ACPI_PPTT if ACPI
12	select ARCH_CLOCKSOURCE_DATA
13	select ARCH_HAS_DEBUG_VIRTUAL
14	select ARCH_HAS_DEVMEM_IS_ALLOWED
15	select ARCH_HAS_DMA_COHERENT_TO_PFN
16	select ARCH_HAS_DMA_MMAP_PGPROT
17	select ARCH_HAS_DMA_PREP_COHERENT
18	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
19	select ARCH_HAS_ELF_RANDOMIZE
20	select ARCH_HAS_FAST_MULTIPLIER
21	select ARCH_HAS_FORTIFY_SOURCE
22	select ARCH_HAS_GCOV_PROFILE_ALL
23	select ARCH_HAS_GIGANTIC_PAGE
24	select ARCH_HAS_KCOV
25	select ARCH_HAS_KEEPINITRD
26	select ARCH_HAS_MEMBARRIER_SYNC_CORE
27	select ARCH_HAS_PTE_SPECIAL
28	select ARCH_HAS_SETUP_DMA_OPS
29	select ARCH_HAS_SET_MEMORY
30	select ARCH_HAS_STRICT_KERNEL_RWX
31	select ARCH_HAS_STRICT_MODULE_RWX
32	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
33	select ARCH_HAS_SYNC_DMA_FOR_CPU
34	select ARCH_HAS_SYSCALL_WRAPPER
35	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
36	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
37	select ARCH_HAVE_NMI_SAFE_CMPXCHG
38	select ARCH_INLINE_READ_LOCK if !PREEMPT
39	select ARCH_INLINE_READ_LOCK_BH if !PREEMPT
40	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT
41	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT
42	select ARCH_INLINE_READ_UNLOCK if !PREEMPT
43	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT
44	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT
45	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT
46	select ARCH_INLINE_WRITE_LOCK if !PREEMPT
47	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT
48	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT
49	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT
50	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT
51	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT
52	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT
53	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT
54	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPT
55	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPT
56	select ARCH_INLINE_SPIN_LOCK if !PREEMPT
57	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPT
58	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPT
59	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPT
60	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPT
61	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT
62	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT
63	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT
64	select ARCH_KEEP_MEMBLOCK
65	select ARCH_USE_CMPXCHG_LOCKREF
66	select ARCH_USE_QUEUED_RWLOCKS
67	select ARCH_USE_QUEUED_SPINLOCKS
68	select ARCH_SUPPORTS_MEMORY_FAILURE
69	select ARCH_SUPPORTS_ATOMIC_RMW
70	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG
71	select ARCH_SUPPORTS_NUMA_BALANCING
72	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
73	select ARCH_WANT_FRAME_POINTERS
74	select ARCH_HAS_UBSAN_SANITIZE_ALL
75	select ARM_AMBA
76	select ARM_ARCH_TIMER
77	select ARM_GIC
78	select AUDIT_ARCH_COMPAT_GENERIC
79	select ARM_GIC_V2M if PCI
80	select ARM_GIC_V3
81	select ARM_GIC_V3_ITS if PCI
82	select ARM_PSCI_FW
83	select BUILDTIME_EXTABLE_SORT
84	select CLONE_BACKWARDS
85	select COMMON_CLK
86	select CPU_PM if (SUSPEND || CPU_IDLE)
87	select CRC32
88	select DCACHE_WORD_ACCESS
89	select DMA_DIRECT_REMAP
90	select EDAC_SUPPORT
91	select FRAME_POINTER
92	select GENERIC_ALLOCATOR
93	select GENERIC_ARCH_TOPOLOGY
94	select GENERIC_CLOCKEVENTS
95	select GENERIC_CLOCKEVENTS_BROADCAST
96	select GENERIC_CPU_AUTOPROBE
97	select GENERIC_CPU_VULNERABILITIES
98	select GENERIC_EARLY_IOREMAP
99	select GENERIC_IDLE_POLL_SETUP
100	select GENERIC_IRQ_MULTI_HANDLER
101	select GENERIC_IRQ_PROBE
102	select GENERIC_IRQ_SHOW
103	select GENERIC_IRQ_SHOW_LEVEL
104	select GENERIC_PCI_IOMAP
105	select GENERIC_SCHED_CLOCK
106	select GENERIC_SMP_IDLE_THREAD
107	select GENERIC_STRNCPY_FROM_USER
108	select GENERIC_STRNLEN_USER
109	select GENERIC_TIME_VSYSCALL
110	select HANDLE_DOMAIN_IRQ
111	select HARDIRQS_SW_RESEND
112	select HAVE_PCI
113	select HAVE_ACPI_APEI if (ACPI && EFI)
114	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
115	select HAVE_ARCH_AUDITSYSCALL
116	select HAVE_ARCH_BITREVERSE
117	select HAVE_ARCH_HUGE_VMAP
118	select HAVE_ARCH_JUMP_LABEL
119	select HAVE_ARCH_JUMP_LABEL_RELATIVE
120	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
121	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
122	select HAVE_ARCH_KGDB
123	select HAVE_ARCH_MMAP_RND_BITS
124	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
125	select HAVE_ARCH_PREL32_RELOCATIONS
126	select HAVE_ARCH_SECCOMP_FILTER
127	select HAVE_ARCH_STACKLEAK
128	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
129	select HAVE_ARCH_TRACEHOOK
130	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
131	select HAVE_ARCH_VMAP_STACK
132	select HAVE_ARM_SMCCC
133	select HAVE_EBPF_JIT
134	select HAVE_C_RECORDMCOUNT
135	select HAVE_CMPXCHG_DOUBLE
136	select HAVE_CMPXCHG_LOCAL
137	select HAVE_CONTEXT_TRACKING
138	select HAVE_DEBUG_BUGVERBOSE
139	select HAVE_DEBUG_KMEMLEAK
140	select HAVE_DMA_CONTIGUOUS
141	select HAVE_DYNAMIC_FTRACE
142	select HAVE_EFFICIENT_UNALIGNED_ACCESS
143	select HAVE_FTRACE_MCOUNT_RECORD
144	select HAVE_FUNCTION_TRACER
145	select HAVE_FUNCTION_GRAPH_TRACER
146	select HAVE_GCC_PLUGINS
147	select HAVE_HW_BREAKPOINT if PERF_EVENTS
148	select HAVE_IRQ_TIME_ACCOUNTING
149	select HAVE_MEMBLOCK_NODE_MAP if NUMA
150	select HAVE_NMI
151	select HAVE_PATA_PLATFORM
152	select HAVE_PERF_EVENTS
153	select HAVE_PERF_REGS
154	select HAVE_PERF_USER_STACK_DUMP
155	select HAVE_REGS_AND_STACK_ACCESS_API
156	select HAVE_FUNCTION_ARG_ACCESS_API
157	select HAVE_RCU_TABLE_FREE
158	select HAVE_RSEQ
159	select HAVE_STACKPROTECTOR
160	select HAVE_SYSCALL_TRACEPOINTS
161	select HAVE_KPROBES
162	select HAVE_KRETPROBES
163	select IOMMU_DMA if IOMMU_SUPPORT
164	select IRQ_DOMAIN
165	select IRQ_FORCED_THREADING
166	select MODULES_USE_ELF_RELA
167	select NEED_DMA_MAP_STATE
168	select NEED_SG_DMA_LENGTH
169	select OF
170	select OF_EARLY_FLATTREE
171	select PCI_DOMAINS_GENERIC if PCI
172	select PCI_ECAM if (ACPI && PCI)
173	select PCI_SYSCALL if PCI
174	select POWER_RESET
175	select POWER_SUPPLY
176	select REFCOUNT_FULL
177	select SPARSE_IRQ
178	select SWIOTLB
179	select SYSCTL_EXCEPTION_TRACE
180	select THREAD_INFO_IN_TASK
181	help
182	  ARM 64-bit (AArch64) Linux support.
183
184config 64BIT
185	def_bool y
186
187config MMU
188	def_bool y
189
190config ARM64_PAGE_SHIFT
191	int
192	default 16 if ARM64_64K_PAGES
193	default 14 if ARM64_16K_PAGES
194	default 12
195
196config ARM64_CONT_SHIFT
197	int
198	default 5 if ARM64_64K_PAGES
199	default 7 if ARM64_16K_PAGES
200	default 4
201
202config ARCH_MMAP_RND_BITS_MIN
203       default 14 if ARM64_64K_PAGES
204       default 16 if ARM64_16K_PAGES
205       default 18
206
207# max bits determined by the following formula:
208#  VA_BITS - PAGE_SHIFT - 3
209config ARCH_MMAP_RND_BITS_MAX
210       default 19 if ARM64_VA_BITS=36
211       default 24 if ARM64_VA_BITS=39
212       default 27 if ARM64_VA_BITS=42
213       default 30 if ARM64_VA_BITS=47
214       default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
215       default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
216       default 33 if ARM64_VA_BITS=48
217       default 14 if ARM64_64K_PAGES
218       default 16 if ARM64_16K_PAGES
219       default 18
220
221config ARCH_MMAP_RND_COMPAT_BITS_MIN
222       default 7 if ARM64_64K_PAGES
223       default 9 if ARM64_16K_PAGES
224       default 11
225
226config ARCH_MMAP_RND_COMPAT_BITS_MAX
227       default 16
228
229config NO_IOPORT_MAP
230	def_bool y if !PCI
231
232config STACKTRACE_SUPPORT
233	def_bool y
234
235config ILLEGAL_POINTER_VALUE
236	hex
237	default 0xdead000000000000
238
239config LOCKDEP_SUPPORT
240	def_bool y
241
242config TRACE_IRQFLAGS_SUPPORT
243	def_bool y
244
245config GENERIC_BUG
246	def_bool y
247	depends on BUG
248
249config GENERIC_BUG_RELATIVE_POINTERS
250	def_bool y
251	depends on GENERIC_BUG
252
253config GENERIC_HWEIGHT
254	def_bool y
255
256config GENERIC_CSUM
257        def_bool y
258
259config GENERIC_CALIBRATE_DELAY
260	def_bool y
261
262config ZONE_DMA32
263	def_bool y
264
265config HAVE_GENERIC_GUP
266	def_bool y
267
268config ARCH_ENABLE_MEMORY_HOTPLUG
269	def_bool y
270
271config SMP
272	def_bool y
273
274config KERNEL_MODE_NEON
275	def_bool y
276
277config FIX_EARLYCON_MEM
278	def_bool y
279
280config PGTABLE_LEVELS
281	int
282	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
283	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
284	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52)
285	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
286	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
287	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
288
289config ARCH_SUPPORTS_UPROBES
290	def_bool y
291
292config ARCH_PROC_KCORE_TEXT
293	def_bool y
294
295source "arch/arm64/Kconfig.platforms"
296
297menu "Kernel Features"
298
299menu "ARM errata workarounds via the alternatives framework"
300
301config ARM64_WORKAROUND_CLEAN_CACHE
302	bool
303
304config ARM64_ERRATUM_826319
305	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
306	default y
307	select ARM64_WORKAROUND_CLEAN_CACHE
308	help
309	  This option adds an alternative code sequence to work around ARM
310	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
311	  AXI master interface and an L2 cache.
312
313	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
314	  and is unable to accept a certain write via this interface, it will
315	  not progress on read data presented on the read data channel and the
316	  system can deadlock.
317
318	  The workaround promotes data cache clean instructions to
319	  data cache clean-and-invalidate.
320	  Please note that this does not necessarily enable the workaround,
321	  as it depends on the alternative framework, which will only patch
322	  the kernel if an affected CPU is detected.
323
324	  If unsure, say Y.
325
326config ARM64_ERRATUM_827319
327	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
328	default y
329	select ARM64_WORKAROUND_CLEAN_CACHE
330	help
331	  This option adds an alternative code sequence to work around ARM
332	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
333	  master interface and an L2 cache.
334
335	  Under certain conditions this erratum can cause a clean line eviction
336	  to occur at the same time as another transaction to the same address
337	  on the AMBA 5 CHI interface, which can cause data corruption if the
338	  interconnect reorders the two transactions.
339
340	  The workaround promotes data cache clean instructions to
341	  data cache clean-and-invalidate.
342	  Please note that this does not necessarily enable the workaround,
343	  as it depends on the alternative framework, which will only patch
344	  the kernel if an affected CPU is detected.
345
346	  If unsure, say Y.
347
348config ARM64_ERRATUM_824069
349	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
350	default y
351	select ARM64_WORKAROUND_CLEAN_CACHE
352	help
353	  This option adds an alternative code sequence to work around ARM
354	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
355	  to a coherent interconnect.
356
357	  If a Cortex-A53 processor is executing a store or prefetch for
358	  write instruction at the same time as a processor in another
359	  cluster is executing a cache maintenance operation to the same
360	  address, then this erratum might cause a clean cache line to be
361	  incorrectly marked as dirty.
362
363	  The workaround promotes data cache clean instructions to
364	  data cache clean-and-invalidate.
365	  Please note that this option does not necessarily enable the
366	  workaround, as it depends on the alternative framework, which will
367	  only patch the kernel if an affected CPU is detected.
368
369	  If unsure, say Y.
370
371config ARM64_ERRATUM_819472
372	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
373	default y
374	select ARM64_WORKAROUND_CLEAN_CACHE
375	help
376	  This option adds an alternative code sequence to work around ARM
377	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
378	  present when it is connected to a coherent interconnect.
379
380	  If the processor is executing a load and store exclusive sequence at
381	  the same time as a processor in another cluster is executing a cache
382	  maintenance operation to the same address, then this erratum might
383	  cause data corruption.
384
385	  The workaround promotes data cache clean instructions to
386	  data cache clean-and-invalidate.
387	  Please note that this does not necessarily enable the workaround,
388	  as it depends on the alternative framework, which will only patch
389	  the kernel if an affected CPU is detected.
390
391	  If unsure, say Y.
392
393config ARM64_ERRATUM_832075
394	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
395	default y
396	help
397	  This option adds an alternative code sequence to work around ARM
398	  erratum 832075 on Cortex-A57 parts up to r1p2.
399
400	  Affected Cortex-A57 parts might deadlock when exclusive load/store
401	  instructions to Write-Back memory are mixed with Device loads.
402
403	  The workaround is to promote device loads to use Load-Acquire
404	  semantics.
405	  Please note that this does not necessarily enable the workaround,
406	  as it depends on the alternative framework, which will only patch
407	  the kernel if an affected CPU is detected.
408
409	  If unsure, say Y.
410
411config ARM64_ERRATUM_834220
412	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
413	depends on KVM
414	default y
415	help
416	  This option adds an alternative code sequence to work around ARM
417	  erratum 834220 on Cortex-A57 parts up to r1p2.
418
419	  Affected Cortex-A57 parts might report a Stage 2 translation
420	  fault as the result of a Stage 1 fault for load crossing a
421	  page boundary when there is a permission or device memory
422	  alignment fault at Stage 1 and a translation fault at Stage 2.
423
424	  The workaround is to verify that the Stage 1 translation
425	  doesn't generate a fault before handling the Stage 2 fault.
426	  Please note that this does not necessarily enable the workaround,
427	  as it depends on the alternative framework, which will only patch
428	  the kernel if an affected CPU is detected.
429
430	  If unsure, say Y.
431
432config ARM64_ERRATUM_845719
433	bool "Cortex-A53: 845719: a load might read incorrect data"
434	depends on COMPAT
435	default y
436	help
437	  This option adds an alternative code sequence to work around ARM
438	  erratum 845719 on Cortex-A53 parts up to r0p4.
439
440	  When running a compat (AArch32) userspace on an affected Cortex-A53
441	  part, a load at EL0 from a virtual address that matches the bottom 32
442	  bits of the virtual address used by a recent load at (AArch64) EL1
443	  might return incorrect data.
444
445	  The workaround is to write the contextidr_el1 register on exception
446	  return to a 32-bit task.
447	  Please note that this does not necessarily enable the workaround,
448	  as it depends on the alternative framework, which will only patch
449	  the kernel if an affected CPU is detected.
450
451	  If unsure, say Y.
452
453config ARM64_ERRATUM_843419
454	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
455	default y
456	select ARM64_MODULE_PLTS if MODULES
457	help
458	  This option links the kernel with '--fix-cortex-a53-843419' and
459	  enables PLT support to replace certain ADRP instructions, which can
460	  cause subsequent memory accesses to use an incorrect address on
461	  Cortex-A53 parts up to r0p4.
462
463	  If unsure, say Y.
464
465config ARM64_ERRATUM_1024718
466	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
467	default y
468	help
469	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
470
471	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
472	  update of the hardware dirty bit when the DBM/AP bits are updated
473	  without a break-before-make. The workaround is to disable the usage
474	  of hardware DBM locally on the affected cores. CPUs not affected by
475	  this erratum will continue to use the feature.
476
477	  If unsure, say Y.
478
479config ARM64_ERRATUM_1188873
480	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
481	default y
482	depends on COMPAT
483	select ARM_ARCH_TIMER_OOL_WORKAROUND
484	help
485	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
486	  erratum 1188873.
487
488	  Affected Cortex-A76/Neoverse-N1 cores (r0p0, r1p0, r2p0) could
489	  cause register corruption when accessing the timer registers
490	  from AArch32 userspace.
491
492	  If unsure, say Y.
493
494config ARM64_ERRATUM_1165522
495	bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
496	default y
497	help
498	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
499
500	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
501	  corrupted TLBs by speculating an AT instruction during a guest
502	  context switch.
503
504	  If unsure, say Y.
505
506config ARM64_ERRATUM_1286807
507	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
508	default y
509	select ARM64_WORKAROUND_REPEAT_TLBI
510	help
511	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
512
513	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
514	  address for a cacheable mapping of a location is being
515	  accessed by a core while another core is remapping the virtual
516	  address to a new physical page using the recommended
517	  break-before-make sequence, then under very rare circumstances
518	  TLBI+DSB completes before a read using the translation being
519	  invalidated has been observed by other observers. The
520	  workaround repeats the TLBI+DSB operation.
521
522	  If unsure, say Y.
523
524config CAVIUM_ERRATUM_22375
525	bool "Cavium erratum 22375, 24313"
526	default y
527	help
528	  Enable workaround for errata 22375 and 24313.
529
530	  This implements two gicv3-its errata workarounds for ThunderX. Both
531	  with a small impact affecting only ITS table allocation.
532
533	    erratum 22375: only alloc 8MB table size
534	    erratum 24313: ignore memory access type
535
536	  The fixes are in ITS initialization and basically ignore memory access
537	  type and table size provided by the TYPER and BASER registers.
538
539	  If unsure, say Y.
540
541config CAVIUM_ERRATUM_23144
542	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
543	depends on NUMA
544	default y
545	help
546	  ITS SYNC command hang for cross node io and collections/cpu mapping.
547
548	  If unsure, say Y.
549
550config CAVIUM_ERRATUM_23154
551	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
552	default y
553	help
554	  The gicv3 of ThunderX requires a modified version for
555	  reading the IAR status to ensure data synchronization
556	  (access to icc_iar1_el1 is not sync'ed before and after).
557
558	  If unsure, say Y.
559
560config CAVIUM_ERRATUM_27456
561	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
562	default y
563	help
564	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
565	  instructions may cause the icache to become corrupted if it
566	  contains data for a non-current ASID.  The fix is to
567	  invalidate the icache when changing the mm context.
568
569	  If unsure, say Y.
570
571config CAVIUM_ERRATUM_30115
572	bool "Cavium erratum 30115: Guest may disable interrupts in host"
573	default y
574	help
575	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
576	  1.2, and T83 Pass 1.0, KVM guest execution may disable
577	  interrupts in host. Trapping both GICv3 group-0 and group-1
578	  accesses sidesteps the issue.
579
580	  If unsure, say Y.
581
582config QCOM_FALKOR_ERRATUM_1003
583	bool "Falkor E1003: Incorrect translation due to ASID change"
584	default y
585	help
586	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
587	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
588	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
589	  then only for entries in the walk cache, since the leaf translation
590	  is unchanged. Work around the erratum by invalidating the walk cache
591	  entries for the trampoline before entering the kernel proper.
592
593config ARM64_WORKAROUND_REPEAT_TLBI
594	bool
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 uses 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
646config FUJITSU_ERRATUM_010001
647	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
648	default y
649	help
650	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
651	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
652	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
653	  This fault occurs under a specific hardware condition when a
654	  load/store instruction performs an address translation using:
655	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
656	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
657	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
658	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
659
660	  The workaround is to ensure these bits are clear in TCR_ELx.
661	  The workaround only affects the Fujitsu-A64FX.
662
663	  If unsure, say Y.
664
665endmenu
666
667
668choice
669	prompt "Page size"
670	default ARM64_4K_PAGES
671	help
672	  Page size (translation granule) configuration.
673
674config ARM64_4K_PAGES
675	bool "4KB"
676	help
677	  This feature enables 4KB pages support.
678
679config ARM64_16K_PAGES
680	bool "16KB"
681	help
682	  The system will use 16KB pages support. AArch32 emulation
683	  requires applications compiled with 16K (or a multiple of 16K)
684	  aligned segments.
685
686config ARM64_64K_PAGES
687	bool "64KB"
688	help
689	  This feature enables 64KB pages support (4KB by default)
690	  allowing only two levels of page tables and faster TLB
691	  look-up. AArch32 emulation requires applications compiled
692	  with 64K aligned segments.
693
694endchoice
695
696choice
697	prompt "Virtual address space size"
698	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
699	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
700	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
701	help
702	  Allows choosing one of multiple possible virtual address
703	  space sizes. The level of translation table is determined by
704	  a combination of page size and virtual address space size.
705
706config ARM64_VA_BITS_36
707	bool "36-bit" if EXPERT
708	depends on ARM64_16K_PAGES
709
710config ARM64_VA_BITS_39
711	bool "39-bit"
712	depends on ARM64_4K_PAGES
713
714config ARM64_VA_BITS_42
715	bool "42-bit"
716	depends on ARM64_64K_PAGES
717
718config ARM64_VA_BITS_47
719	bool "47-bit"
720	depends on ARM64_16K_PAGES
721
722config ARM64_VA_BITS_48
723	bool "48-bit"
724
725config ARM64_USER_VA_BITS_52
726	bool "52-bit (user)"
727	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
728	help
729	  Enable 52-bit virtual addressing for userspace when explicitly
730	  requested via a hint to mmap(). The kernel will continue to
731	  use 48-bit virtual addresses for its own mappings.
732
733	  NOTE: Enabling 52-bit virtual addressing in conjunction with
734	  ARMv8.3 Pointer Authentication will result in the PAC being
735	  reduced from 7 bits to 3 bits, which may have a significant
736	  impact on its susceptibility to brute-force attacks.
737
738	  If unsure, select 48-bit virtual addressing instead.
739
740endchoice
741
742config ARM64_FORCE_52BIT
743	bool "Force 52-bit virtual addresses for userspace"
744	depends on ARM64_USER_VA_BITS_52 && EXPERT
745	help
746	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
747	  to maintain compatibility with older software by providing 48-bit VAs
748	  unless a hint is supplied to mmap.
749
750	  This configuration option disables the 48-bit compatibility logic, and
751	  forces all userspace addresses to be 52-bit on HW that supports it. One
752	  should only enable this configuration option for stress testing userspace
753	  memory management code. If unsure say N here.
754
755config ARM64_VA_BITS
756	int
757	default 36 if ARM64_VA_BITS_36
758	default 39 if ARM64_VA_BITS_39
759	default 42 if ARM64_VA_BITS_42
760	default 47 if ARM64_VA_BITS_47
761	default 48 if ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52
762
763choice
764	prompt "Physical address space size"
765	default ARM64_PA_BITS_48
766	help
767	  Choose the maximum physical address range that the kernel will
768	  support.
769
770config ARM64_PA_BITS_48
771	bool "48-bit"
772
773config ARM64_PA_BITS_52
774	bool "52-bit (ARMv8.2)"
775	depends on ARM64_64K_PAGES
776	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
777	help
778	  Enable support for a 52-bit physical address space, introduced as
779	  part of the ARMv8.2-LPA extension.
780
781	  With this enabled, the kernel will also continue to work on CPUs that
782	  do not support ARMv8.2-LPA, but with some added memory overhead (and
783	  minor performance overhead).
784
785endchoice
786
787config ARM64_PA_BITS
788	int
789	default 48 if ARM64_PA_BITS_48
790	default 52 if ARM64_PA_BITS_52
791
792config CPU_BIG_ENDIAN
793       bool "Build big-endian kernel"
794       help
795         Say Y if you plan on running a kernel in big-endian mode.
796
797config SCHED_MC
798	bool "Multi-core scheduler support"
799	help
800	  Multi-core scheduler support improves the CPU scheduler's decision
801	  making when dealing with multi-core CPU chips at a cost of slightly
802	  increased overhead in some places. If unsure say N here.
803
804config SCHED_SMT
805	bool "SMT scheduler support"
806	help
807	  Improves the CPU scheduler's decision making when dealing with
808	  MultiThreading at a cost of slightly increased overhead in some
809	  places. If unsure say N here.
810
811config NR_CPUS
812	int "Maximum number of CPUs (2-4096)"
813	range 2 4096
814	default "256"
815
816config HOTPLUG_CPU
817	bool "Support for hot-pluggable CPUs"
818	select GENERIC_IRQ_MIGRATION
819	help
820	  Say Y here to experiment with turning CPUs off and on.  CPUs
821	  can be controlled through /sys/devices/system/cpu.
822
823# Common NUMA Features
824config NUMA
825	bool "Numa Memory Allocation and Scheduler Support"
826	select ACPI_NUMA if ACPI
827	select OF_NUMA
828	help
829	  Enable NUMA (Non Uniform Memory Access) support.
830
831	  The kernel will try to allocate memory used by a CPU on the
832	  local memory of the CPU and add some more
833	  NUMA awareness to the kernel.
834
835config NODES_SHIFT
836	int "Maximum NUMA Nodes (as a power of 2)"
837	range 1 10
838	default "2"
839	depends on NEED_MULTIPLE_NODES
840	help
841	  Specify the maximum number of NUMA Nodes available on the target
842	  system.  Increases memory reserved to accommodate various tables.
843
844config USE_PERCPU_NUMA_NODE_ID
845	def_bool y
846	depends on NUMA
847
848config HAVE_SETUP_PER_CPU_AREA
849	def_bool y
850	depends on NUMA
851
852config NEED_PER_CPU_EMBED_FIRST_CHUNK
853	def_bool y
854	depends on NUMA
855
856config HOLES_IN_ZONE
857	def_bool y
858
859source "kernel/Kconfig.hz"
860
861config ARCH_SUPPORTS_DEBUG_PAGEALLOC
862	def_bool y
863
864config ARCH_SPARSEMEM_ENABLE
865	def_bool y
866	select SPARSEMEM_VMEMMAP_ENABLE
867
868config ARCH_SPARSEMEM_DEFAULT
869	def_bool ARCH_SPARSEMEM_ENABLE
870
871config ARCH_SELECT_MEMORY_MODEL
872	def_bool ARCH_SPARSEMEM_ENABLE
873
874config ARCH_FLATMEM_ENABLE
875	def_bool !NUMA
876
877config HAVE_ARCH_PFN_VALID
878	def_bool y
879
880config HW_PERF_EVENTS
881	def_bool y
882	depends on ARM_PMU
883
884config SYS_SUPPORTS_HUGETLBFS
885	def_bool y
886
887config ARCH_WANT_HUGE_PMD_SHARE
888	def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
889
890config ARCH_HAS_CACHE_LINE_SIZE
891	def_bool y
892
893config ARCH_ENABLE_SPLIT_PMD_PTLOCK
894	def_bool y if PGTABLE_LEVELS > 2
895
896config SECCOMP
897	bool "Enable seccomp to safely compute untrusted bytecode"
898	---help---
899	  This kernel feature is useful for number crunching applications
900	  that may need to compute untrusted bytecode during their
901	  execution. By using pipes or other transports made available to
902	  the process as file descriptors supporting the read/write
903	  syscalls, it's possible to isolate those applications in
904	  their own address space using seccomp. Once seccomp is
905	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
906	  and the task is only allowed to execute a few safe syscalls
907	  defined by each seccomp mode.
908
909config PARAVIRT
910	bool "Enable paravirtualization code"
911	help
912	  This changes the kernel so it can modify itself when it is run
913	  under a hypervisor, potentially improving performance significantly
914	  over full virtualization.
915
916config PARAVIRT_TIME_ACCOUNTING
917	bool "Paravirtual steal time accounting"
918	select PARAVIRT
919	default n
920	help
921	  Select this option to enable fine granularity task steal time
922	  accounting. Time spent executing other tasks in parallel with
923	  the current vCPU is discounted from the vCPU power. To account for
924	  that, there can be a small performance impact.
925
926	  If in doubt, say N here.
927
928config KEXEC
929	depends on PM_SLEEP_SMP
930	select KEXEC_CORE
931	bool "kexec system call"
932	---help---
933	  kexec is a system call that implements the ability to shutdown your
934	  current kernel, and to start another kernel.  It is like a reboot
935	  but it is independent of the system firmware.   And like a reboot
936	  you can start any kernel with it, not just Linux.
937
938config KEXEC_FILE
939	bool "kexec file based system call"
940	select KEXEC_CORE
941	help
942	  This is new version of kexec system call. This system call is
943	  file based and takes file descriptors as system call argument
944	  for kernel and initramfs as opposed to list of segments as
945	  accepted by previous system call.
946
947config KEXEC_VERIFY_SIG
948	bool "Verify kernel signature during kexec_file_load() syscall"
949	depends on KEXEC_FILE
950	help
951	  Select this option to verify a signature with loaded kernel
952	  image. If configured, any attempt of loading a image without
953	  valid signature will fail.
954
955	  In addition to that option, you need to enable signature
956	  verification for the corresponding kernel image type being
957	  loaded in order for this to work.
958
959config KEXEC_IMAGE_VERIFY_SIG
960	bool "Enable Image signature verification support"
961	default y
962	depends on KEXEC_VERIFY_SIG
963	depends on EFI && SIGNED_PE_FILE_VERIFICATION
964	help
965	  Enable Image signature verification support.
966
967comment "Support for PE file signature verification disabled"
968	depends on KEXEC_VERIFY_SIG
969	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
970
971config CRASH_DUMP
972	bool "Build kdump crash kernel"
973	help
974	  Generate crash dump after being started by kexec. This should
975	  be normally only set in special crash dump kernels which are
976	  loaded in the main kernel with kexec-tools into a specially
977	  reserved region and then later executed after a crash by
978	  kdump/kexec.
979
980	  For more details see Documentation/kdump/kdump.txt
981
982config XEN_DOM0
983	def_bool y
984	depends on XEN
985
986config XEN
987	bool "Xen guest support on ARM64"
988	depends on ARM64 && OF
989	select SWIOTLB_XEN
990	select PARAVIRT
991	help
992	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
993
994config FORCE_MAX_ZONEORDER
995	int
996	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
997	default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
998	default "11"
999	help
1000	  The kernel memory allocator divides physically contiguous memory
1001	  blocks into "zones", where each zone is a power of two number of
1002	  pages.  This option selects the largest power of two that the kernel
1003	  keeps in the memory allocator.  If you need to allocate very large
1004	  blocks of physically contiguous memory, then you may need to
1005	  increase this value.
1006
1007	  This config option is actually maximum order plus one. For example,
1008	  a value of 11 means that the largest free memory block is 2^10 pages.
1009
1010	  We make sure that we can allocate upto a HugePage size for each configuration.
1011	  Hence we have :
1012		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1013
1014	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1015	  4M allocations matching the default size used by generic code.
1016
1017config UNMAP_KERNEL_AT_EL0
1018	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1019	default y
1020	help
1021	  Speculation attacks against some high-performance processors can
1022	  be used to bypass MMU permission checks and leak kernel data to
1023	  userspace. This can be defended against by unmapping the kernel
1024	  when running in userspace, mapping it back in on exception entry
1025	  via a trampoline page in the vector table.
1026
1027	  If unsure, say Y.
1028
1029config HARDEN_BRANCH_PREDICTOR
1030	bool "Harden the branch predictor against aliasing attacks" if EXPERT
1031	default y
1032	help
1033	  Speculation attacks against some high-performance processors rely on
1034	  being able to manipulate the branch predictor for a victim context by
1035	  executing aliasing branches in the attacker context.  Such attacks
1036	  can be partially mitigated against by clearing internal branch
1037	  predictor state and limiting the prediction logic in some situations.
1038
1039	  This config option will take CPU-specific actions to harden the
1040	  branch predictor against aliasing attacks and may rely on specific
1041	  instruction sequences or control bits being set by the system
1042	  firmware.
1043
1044	  If unsure, say Y.
1045
1046config HARDEN_EL2_VECTORS
1047	bool "Harden EL2 vector mapping against system register leak" if EXPERT
1048	default y
1049	help
1050	  Speculation attacks against some high-performance processors can
1051	  be used to leak privileged information such as the vector base
1052	  register, resulting in a potential defeat of the EL2 layout
1053	  randomization.
1054
1055	  This config option will map the vectors to a fixed location,
1056	  independent of the EL2 code mapping, so that revealing VBAR_EL2
1057	  to an attacker does not give away any extra information. This
1058	  only gets enabled on affected CPUs.
1059
1060	  If unsure, say Y.
1061
1062config ARM64_SSBD
1063	bool "Speculative Store Bypass Disable" if EXPERT
1064	default y
1065	help
1066	  This enables mitigation of the bypassing of previous stores
1067	  by speculative loads.
1068
1069	  If unsure, say Y.
1070
1071config RODATA_FULL_DEFAULT_ENABLED
1072	bool "Apply r/o permissions of VM areas also to their linear aliases"
1073	default y
1074	help
1075	  Apply read-only attributes of VM areas to the linear alias of
1076	  the backing pages as well. This prevents code or read-only data
1077	  from being modified (inadvertently or intentionally) via another
1078	  mapping of the same memory page. This additional enhancement can
1079	  be turned off at runtime by passing rodata=[off|on] (and turned on
1080	  with rodata=full if this option is set to 'n')
1081
1082	  This requires the linear region to be mapped down to pages,
1083	  which may adversely affect performance in some cases.
1084
1085config ARM64_SW_TTBR0_PAN
1086	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1087	help
1088	  Enabling this option prevents the kernel from accessing
1089	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1090	  zeroed area and reserved ASID. The user access routines
1091	  restore the valid TTBR0_EL1 temporarily.
1092
1093menuconfig COMPAT
1094	bool "Kernel support for 32-bit EL0"
1095	depends on ARM64_4K_PAGES || EXPERT
1096	select COMPAT_BINFMT_ELF if BINFMT_ELF
1097	select HAVE_UID16
1098	select OLD_SIGSUSPEND3
1099	select COMPAT_OLD_SIGACTION
1100	help
1101	  This option enables support for a 32-bit EL0 running under a 64-bit
1102	  kernel at EL1. AArch32-specific components such as system calls,
1103	  the user helper functions, VFP support and the ptrace interface are
1104	  handled appropriately by the kernel.
1105
1106	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1107	  that you will only be able to execute AArch32 binaries that were compiled
1108	  with page size aligned segments.
1109
1110	  If you want to execute 32-bit userspace applications, say Y.
1111
1112if COMPAT
1113
1114config KUSER_HELPERS
1115	bool "Enable kuser helpers page for 32 bit applications"
1116	default y
1117	help
1118	  Warning: disabling this option may break 32-bit user programs.
1119
1120	  Provide kuser helpers to compat tasks. The kernel provides
1121	  helper code to userspace in read only form at a fixed location
1122	  to allow userspace to be independent of the CPU type fitted to
1123	  the system. This permits binaries to be run on ARMv4 through
1124	  to ARMv8 without modification.
1125
1126	  See Documentation/arm/kernel_user_helpers.txt for details.
1127
1128	  However, the fixed address nature of these helpers can be used
1129	  by ROP (return orientated programming) authors when creating
1130	  exploits.
1131
1132	  If all of the binaries and libraries which run on your platform
1133	  are built specifically for your platform, and make no use of
1134	  these helpers, then you can turn this option off to hinder
1135	  such exploits. However, in that case, if a binary or library
1136	  relying on those helpers is run, it will not function correctly.
1137
1138	  Say N here only if you are absolutely certain that you do not
1139	  need these helpers; otherwise, the safe option is to say Y.
1140
1141
1142menuconfig ARMV8_DEPRECATED
1143	bool "Emulate deprecated/obsolete ARMv8 instructions"
1144	depends on SYSCTL
1145	help
1146	  Legacy software support may require certain instructions
1147	  that have been deprecated or obsoleted in the architecture.
1148
1149	  Enable this config to enable selective emulation of these
1150	  features.
1151
1152	  If unsure, say Y
1153
1154if ARMV8_DEPRECATED
1155
1156config SWP_EMULATION
1157	bool "Emulate SWP/SWPB instructions"
1158	help
1159	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1160	  they are always undefined. Say Y here to enable software
1161	  emulation of these instructions for userspace using LDXR/STXR.
1162
1163	  In some older versions of glibc [<=2.8] SWP is used during futex
1164	  trylock() operations with the assumption that the code will not
1165	  be preempted. This invalid assumption may be more likely to fail
1166	  with SWP emulation enabled, leading to deadlock of the user
1167	  application.
1168
1169	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1170	  on an external transaction monitoring block called a global
1171	  monitor to maintain update atomicity. If your system does not
1172	  implement a global monitor, this option can cause programs that
1173	  perform SWP operations to uncached memory to deadlock.
1174
1175	  If unsure, say Y
1176
1177config CP15_BARRIER_EMULATION
1178	bool "Emulate CP15 Barrier instructions"
1179	help
1180	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1181	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1182	  strongly recommended to use the ISB, DSB, and DMB
1183	  instructions instead.
1184
1185	  Say Y here to enable software emulation of these
1186	  instructions for AArch32 userspace code. When this option is
1187	  enabled, CP15 barrier usage is traced which can help
1188	  identify software that needs updating.
1189
1190	  If unsure, say Y
1191
1192config SETEND_EMULATION
1193	bool "Emulate SETEND instruction"
1194	help
1195	  The SETEND instruction alters the data-endianness of the
1196	  AArch32 EL0, and is deprecated in ARMv8.
1197
1198	  Say Y here to enable software emulation of the instruction
1199	  for AArch32 userspace code.
1200
1201	  Note: All the cpus on the system must have mixed endian support at EL0
1202	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1203	  endian - is hotplugged in after this feature has been enabled, there could
1204	  be unexpected results in the applications.
1205
1206	  If unsure, say Y
1207endif
1208
1209endif
1210
1211menu "ARMv8.1 architectural features"
1212
1213config ARM64_HW_AFDBM
1214	bool "Support for hardware updates of the Access and Dirty page flags"
1215	default y
1216	help
1217	  The ARMv8.1 architecture extensions introduce support for
1218	  hardware updates of the access and dirty information in page
1219	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1220	  capable processors, accesses to pages with PTE_AF cleared will
1221	  set this bit instead of raising an access flag fault.
1222	  Similarly, writes to read-only pages with the DBM bit set will
1223	  clear the read-only bit (AP[2]) instead of raising a
1224	  permission fault.
1225
1226	  Kernels built with this configuration option enabled continue
1227	  to work on pre-ARMv8.1 hardware and the performance impact is
1228	  minimal. If unsure, say Y.
1229
1230config ARM64_PAN
1231	bool "Enable support for Privileged Access Never (PAN)"
1232	default y
1233	help
1234	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1235	 prevents the kernel or hypervisor from accessing user-space (EL0)
1236	 memory directly.
1237
1238	 Choosing this option will cause any unprotected (not using
1239	 copy_to_user et al) memory access to fail with a permission fault.
1240
1241	 The feature is detected at runtime, and will remain as a 'nop'
1242	 instruction if the cpu does not implement the feature.
1243
1244config ARM64_LSE_ATOMICS
1245	bool "Atomic instructions"
1246	default y
1247	help
1248	  As part of the Large System Extensions, ARMv8.1 introduces new
1249	  atomic instructions that are designed specifically to scale in
1250	  very large systems.
1251
1252	  Say Y here to make use of these instructions for the in-kernel
1253	  atomic routines. This incurs a small overhead on CPUs that do
1254	  not support these instructions and requires the kernel to be
1255	  built with binutils >= 2.25 in order for the new instructions
1256	  to be used.
1257
1258config ARM64_VHE
1259	bool "Enable support for Virtualization Host Extensions (VHE)"
1260	default y
1261	help
1262	  Virtualization Host Extensions (VHE) allow the kernel to run
1263	  directly at EL2 (instead of EL1) on processors that support
1264	  it. This leads to better performance for KVM, as they reduce
1265	  the cost of the world switch.
1266
1267	  Selecting this option allows the VHE feature to be detected
1268	  at runtime, and does not affect processors that do not
1269	  implement this feature.
1270
1271endmenu
1272
1273menu "ARMv8.2 architectural features"
1274
1275config ARM64_UAO
1276	bool "Enable support for User Access Override (UAO)"
1277	default y
1278	help
1279	  User Access Override (UAO; part of the ARMv8.2 Extensions)
1280	  causes the 'unprivileged' variant of the load/store instructions to
1281	  be overridden to be privileged.
1282
1283	  This option changes get_user() and friends to use the 'unprivileged'
1284	  variant of the load/store instructions. This ensures that user-space
1285	  really did have access to the supplied memory. When addr_limit is
1286	  set to kernel memory the UAO bit will be set, allowing privileged
1287	  access to kernel memory.
1288
1289	  Choosing this option will cause copy_to_user() et al to use user-space
1290	  memory permissions.
1291
1292	  The feature is detected at runtime, the kernel will use the
1293	  regular load/store instructions if the cpu does not implement the
1294	  feature.
1295
1296config ARM64_PMEM
1297	bool "Enable support for persistent memory"
1298	select ARCH_HAS_PMEM_API
1299	select ARCH_HAS_UACCESS_FLUSHCACHE
1300	help
1301	  Say Y to enable support for the persistent memory API based on the
1302	  ARMv8.2 DCPoP feature.
1303
1304	  The feature is detected at runtime, and the kernel will use DC CVAC
1305	  operations if DC CVAP is not supported (following the behaviour of
1306	  DC CVAP itself if the system does not define a point of persistence).
1307
1308config ARM64_RAS_EXTN
1309	bool "Enable support for RAS CPU Extensions"
1310	default y
1311	help
1312	  CPUs that support the Reliability, Availability and Serviceability
1313	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1314	  errors, classify them and report them to software.
1315
1316	  On CPUs with these extensions system software can use additional
1317	  barriers to determine if faults are pending and read the
1318	  classification from a new set of registers.
1319
1320	  Selecting this feature will allow the kernel to use these barriers
1321	  and access the new registers if the system supports the extension.
1322	  Platform RAS features may additionally depend on firmware support.
1323
1324config ARM64_CNP
1325	bool "Enable support for Common Not Private (CNP) translations"
1326	default y
1327	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1328	help
1329	  Common Not Private (CNP) allows translation table entries to
1330	  be shared between different PEs in the same inner shareable
1331	  domain, so the hardware can use this fact to optimise the
1332	  caching of such entries in the TLB.
1333
1334	  Selecting this option allows the CNP feature to be detected
1335	  at runtime, and does not affect PEs that do not implement
1336	  this feature.
1337
1338endmenu
1339
1340menu "ARMv8.3 architectural features"
1341
1342config ARM64_PTR_AUTH
1343	bool "Enable support for pointer authentication"
1344	default y
1345	depends on !KVM || ARM64_VHE
1346	help
1347	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1348	  instructions for signing and authenticating pointers against secret
1349	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1350	  and other attacks.
1351
1352	  This option enables these instructions at EL0 (i.e. for userspace).
1353
1354	  Choosing this option will cause the kernel to initialise secret keys
1355	  for each process at exec() time, with these keys being
1356	  context-switched along with the process.
1357
1358	  The feature is detected at runtime. If the feature is not present in
1359	  hardware it will not be advertised to userspace/KVM guest nor will it
1360	  be enabled. However, KVM guest also require VHE mode and hence
1361	  CONFIG_ARM64_VHE=y option to use this feature.
1362
1363endmenu
1364
1365config ARM64_SVE
1366	bool "ARM Scalable Vector Extension support"
1367	default y
1368	depends on !KVM || ARM64_VHE
1369	help
1370	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1371	  execution state which complements and extends the SIMD functionality
1372	  of the base architecture to support much larger vectors and to enable
1373	  additional vectorisation opportunities.
1374
1375	  To enable use of this extension on CPUs that implement it, say Y.
1376
1377	  On CPUs that support the SVE2 extensions, this option will enable
1378	  those too.
1379
1380	  Note that for architectural reasons, firmware _must_ implement SVE
1381	  support when running on SVE capable hardware.  The required support
1382	  is present in:
1383
1384	    * version 1.5 and later of the ARM Trusted Firmware
1385	    * the AArch64 boot wrapper since commit 5e1261e08abf
1386	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1387
1388	  For other firmware implementations, consult the firmware documentation
1389	  or vendor.
1390
1391	  If you need the kernel to boot on SVE-capable hardware with broken
1392	  firmware, you may need to say N here until you get your firmware
1393	  fixed.  Otherwise, you may experience firmware panics or lockups when
1394	  booting the kernel.  If unsure and you are not observing these
1395	  symptoms, you should assume that it is safe to say Y.
1396
1397	  CPUs that support SVE are architecturally required to support the
1398	  Virtualization Host Extensions (VHE), so the kernel makes no
1399	  provision for supporting SVE alongside KVM without VHE enabled.
1400	  Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
1401	  KVM in the same kernel image.
1402
1403config ARM64_MODULE_PLTS
1404	bool
1405	select HAVE_MOD_ARCH_SPECIFIC
1406
1407config ARM64_PSEUDO_NMI
1408	bool "Support for NMI-like interrupts"
1409	select CONFIG_ARM_GIC_V3
1410	help
1411	  Adds support for mimicking Non-Maskable Interrupts through the use of
1412	  GIC interrupt priority. This support requires version 3 or later of
1413	  ARM GIC.
1414
1415	  This high priority configuration for interrupts needs to be
1416	  explicitly enabled by setting the kernel parameter
1417	  "irqchip.gicv3_pseudo_nmi" to 1.
1418
1419	  If unsure, say N
1420
1421config RELOCATABLE
1422	bool
1423	help
1424	  This builds the kernel as a Position Independent Executable (PIE),
1425	  which retains all relocation metadata required to relocate the
1426	  kernel binary at runtime to a different virtual address than the
1427	  address it was linked at.
1428	  Since AArch64 uses the RELA relocation format, this requires a
1429	  relocation pass at runtime even if the kernel is loaded at the
1430	  same address it was linked at.
1431
1432config RANDOMIZE_BASE
1433	bool "Randomize the address of the kernel image"
1434	select ARM64_MODULE_PLTS if MODULES
1435	select RELOCATABLE
1436	help
1437	  Randomizes the virtual address at which the kernel image is
1438	  loaded, as a security feature that deters exploit attempts
1439	  relying on knowledge of the location of kernel internals.
1440
1441	  It is the bootloader's job to provide entropy, by passing a
1442	  random u64 value in /chosen/kaslr-seed at kernel entry.
1443
1444	  When booting via the UEFI stub, it will invoke the firmware's
1445	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1446	  to the kernel proper. In addition, it will randomise the physical
1447	  location of the kernel Image as well.
1448
1449	  If unsure, say N.
1450
1451config RANDOMIZE_MODULE_REGION_FULL
1452	bool "Randomize the module region over a 4 GB range"
1453	depends on RANDOMIZE_BASE
1454	default y
1455	help
1456	  Randomizes the location of the module region inside a 4 GB window
1457	  covering the core kernel. This way, it is less likely for modules
1458	  to leak information about the location of core kernel data structures
1459	  but it does imply that function calls between modules and the core
1460	  kernel will need to be resolved via veneers in the module PLT.
1461
1462	  When this option is not set, the module region will be randomized over
1463	  a limited range that contains the [_stext, _etext] interval of the
1464	  core kernel, so branch relocations are always in range.
1465
1466config CC_HAVE_STACKPROTECTOR_SYSREG
1467	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1468
1469config STACKPROTECTOR_PER_TASK
1470	def_bool y
1471	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1472
1473endmenu
1474
1475menu "Boot options"
1476
1477config ARM64_ACPI_PARKING_PROTOCOL
1478	bool "Enable support for the ARM64 ACPI parking protocol"
1479	depends on ACPI
1480	help
1481	  Enable support for the ARM64 ACPI parking protocol. If disabled
1482	  the kernel will not allow booting through the ARM64 ACPI parking
1483	  protocol even if the corresponding data is present in the ACPI
1484	  MADT table.
1485
1486config CMDLINE
1487	string "Default kernel command string"
1488	default ""
1489	help
1490	  Provide a set of default command-line options at build time by
1491	  entering them here. As a minimum, you should specify the the
1492	  root device (e.g. root=/dev/nfs).
1493
1494config CMDLINE_FORCE
1495	bool "Always use the default kernel command string"
1496	help
1497	  Always use the default kernel command string, even if the boot
1498	  loader passes other arguments to the kernel.
1499	  This is useful if you cannot or don't want to change the
1500	  command-line options your boot loader passes to the kernel.
1501
1502config EFI_STUB
1503	bool
1504
1505config EFI
1506	bool "UEFI runtime support"
1507	depends on OF && !CPU_BIG_ENDIAN
1508	depends on KERNEL_MODE_NEON
1509	select ARCH_SUPPORTS_ACPI
1510	select LIBFDT
1511	select UCS2_STRING
1512	select EFI_PARAMS_FROM_FDT
1513	select EFI_RUNTIME_WRAPPERS
1514	select EFI_STUB
1515	select EFI_ARMSTUB
1516	default y
1517	help
1518	  This option provides support for runtime services provided
1519	  by UEFI firmware (such as non-volatile variables, realtime
1520          clock, and platform reset). A UEFI stub is also provided to
1521	  allow the kernel to be booted as an EFI application. This
1522	  is only useful on systems that have UEFI firmware.
1523
1524config DMI
1525	bool "Enable support for SMBIOS (DMI) tables"
1526	depends on EFI
1527	default y
1528	help
1529	  This enables SMBIOS/DMI feature for systems.
1530
1531	  This option is only useful on systems that have UEFI firmware.
1532	  However, even with this option, the resultant kernel should
1533	  continue to boot on existing non-UEFI platforms.
1534
1535endmenu
1536
1537config SYSVIPC_COMPAT
1538	def_bool y
1539	depends on COMPAT && SYSVIPC
1540
1541config ARCH_ENABLE_HUGEPAGE_MIGRATION
1542	def_bool y
1543	depends on HUGETLB_PAGE && MIGRATION
1544
1545menu "Power management options"
1546
1547source "kernel/power/Kconfig"
1548
1549config ARCH_HIBERNATION_POSSIBLE
1550	def_bool y
1551	depends on CPU_PM
1552
1553config ARCH_HIBERNATION_HEADER
1554	def_bool y
1555	depends on HIBERNATION
1556
1557config ARCH_SUSPEND_POSSIBLE
1558	def_bool y
1559
1560endmenu
1561
1562menu "CPU Power Management"
1563
1564source "drivers/cpuidle/Kconfig"
1565
1566source "drivers/cpufreq/Kconfig"
1567
1568endmenu
1569
1570source "drivers/firmware/Kconfig"
1571
1572source "drivers/acpi/Kconfig"
1573
1574source "arch/arm64/kvm/Kconfig"
1575
1576if CRYPTO
1577source "arch/arm64/crypto/Kconfig"
1578endif
1579