xref: /linux/arch/arm64/Kconfig (revision 63307d015b91e626c97bb82e88054af3d0b74643)
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 if COMPAT
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_1418040
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	help
484	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
485	  errata 1188873 and 1418040.
486
487	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
488	  cause register corruption when accessing the timer registers
489	  from AArch32 userspace.
490
491	  If unsure, say Y.
492
493config ARM64_ERRATUM_1165522
494	bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
495	default y
496	help
497	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
498
499	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
500	  corrupted TLBs by speculating an AT instruction during a guest
501	  context switch.
502
503	  If unsure, say Y.
504
505config ARM64_ERRATUM_1286807
506	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
507	default y
508	select ARM64_WORKAROUND_REPEAT_TLBI
509	help
510	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
511
512	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
513	  address for a cacheable mapping of a location is being
514	  accessed by a core while another core is remapping the virtual
515	  address to a new physical page using the recommended
516	  break-before-make sequence, then under very rare circumstances
517	  TLBI+DSB completes before a read using the translation being
518	  invalidated has been observed by other observers. The
519	  workaround repeats the TLBI+DSB operation.
520
521	  If unsure, say Y.
522
523config ARM64_ERRATUM_1463225
524	bool "Cortex-A76: Software Step might prevent interrupt recognition"
525	default y
526	help
527	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
528
529	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
530	  of a system call instruction (SVC) can prevent recognition of
531	  subsequent interrupts when software stepping is disabled in the
532	  exception handler of the system call and either kernel debugging
533	  is enabled or VHE is in use.
534
535	  Work around the erratum by triggering a dummy step exception
536	  when handling a system call from a task that is being stepped
537	  in a VHE configuration of the kernel.
538
539	  If unsure, say Y.
540
541config CAVIUM_ERRATUM_22375
542	bool "Cavium erratum 22375, 24313"
543	default y
544	help
545	  Enable workaround for errata 22375 and 24313.
546
547	  This implements two gicv3-its errata workarounds for ThunderX. Both
548	  with a small impact affecting only ITS table allocation.
549
550	    erratum 22375: only alloc 8MB table size
551	    erratum 24313: ignore memory access type
552
553	  The fixes are in ITS initialization and basically ignore memory access
554	  type and table size provided by the TYPER and BASER registers.
555
556	  If unsure, say Y.
557
558config CAVIUM_ERRATUM_23144
559	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
560	depends on NUMA
561	default y
562	help
563	  ITS SYNC command hang for cross node io and collections/cpu mapping.
564
565	  If unsure, say Y.
566
567config CAVIUM_ERRATUM_23154
568	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
569	default y
570	help
571	  The gicv3 of ThunderX requires a modified version for
572	  reading the IAR status to ensure data synchronization
573	  (access to icc_iar1_el1 is not sync'ed before and after).
574
575	  If unsure, say Y.
576
577config CAVIUM_ERRATUM_27456
578	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
579	default y
580	help
581	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
582	  instructions may cause the icache to become corrupted if it
583	  contains data for a non-current ASID.  The fix is to
584	  invalidate the icache when changing the mm context.
585
586	  If unsure, say Y.
587
588config CAVIUM_ERRATUM_30115
589	bool "Cavium erratum 30115: Guest may disable interrupts in host"
590	default y
591	help
592	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
593	  1.2, and T83 Pass 1.0, KVM guest execution may disable
594	  interrupts in host. Trapping both GICv3 group-0 and group-1
595	  accesses sidesteps the issue.
596
597	  If unsure, say Y.
598
599config QCOM_FALKOR_ERRATUM_1003
600	bool "Falkor E1003: Incorrect translation due to ASID change"
601	default y
602	help
603	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
604	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
605	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
606	  then only for entries in the walk cache, since the leaf translation
607	  is unchanged. Work around the erratum by invalidating the walk cache
608	  entries for the trampoline before entering the kernel proper.
609
610config ARM64_WORKAROUND_REPEAT_TLBI
611	bool
612
613config QCOM_FALKOR_ERRATUM_1009
614	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
615	default y
616	select ARM64_WORKAROUND_REPEAT_TLBI
617	help
618	  On Falkor v1, the CPU may prematurely complete a DSB following a
619	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
620	  one more time to fix the issue.
621
622	  If unsure, say Y.
623
624config QCOM_QDF2400_ERRATUM_0065
625	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
626	default y
627	help
628	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
629	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
630	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
631
632	  If unsure, say Y.
633
634config SOCIONEXT_SYNQUACER_PREITS
635	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
636	default y
637	help
638	  Socionext Synquacer SoCs implement a separate h/w block to generate
639	  MSI doorbell writes with non-zero values for the device ID.
640
641	  If unsure, say Y.
642
643config HISILICON_ERRATUM_161600802
644	bool "Hip07 161600802: Erroneous redistributor VLPI base"
645	default y
646	help
647	  The HiSilicon Hip07 SoC uses the wrong redistributor base
648	  when issued ITS commands such as VMOVP and VMAPP, and requires
649	  a 128kB offset to be applied to the target address in this commands.
650
651	  If unsure, say Y.
652
653config QCOM_FALKOR_ERRATUM_E1041
654	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
655	default y
656	help
657	  Falkor CPU may speculatively fetch instructions from an improper
658	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
659	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
660
661	  If unsure, say Y.
662
663config FUJITSU_ERRATUM_010001
664	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
665	default y
666	help
667	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
668	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
669	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
670	  This fault occurs under a specific hardware condition when a
671	  load/store instruction performs an address translation using:
672	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
673	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
674	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
675	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
676
677	  The workaround is to ensure these bits are clear in TCR_ELx.
678	  The workaround only affects the Fujitsu-A64FX.
679
680	  If unsure, say Y.
681
682endmenu
683
684
685choice
686	prompt "Page size"
687	default ARM64_4K_PAGES
688	help
689	  Page size (translation granule) configuration.
690
691config ARM64_4K_PAGES
692	bool "4KB"
693	help
694	  This feature enables 4KB pages support.
695
696config ARM64_16K_PAGES
697	bool "16KB"
698	help
699	  The system will use 16KB pages support. AArch32 emulation
700	  requires applications compiled with 16K (or a multiple of 16K)
701	  aligned segments.
702
703config ARM64_64K_PAGES
704	bool "64KB"
705	help
706	  This feature enables 64KB pages support (4KB by default)
707	  allowing only two levels of page tables and faster TLB
708	  look-up. AArch32 emulation requires applications compiled
709	  with 64K aligned segments.
710
711endchoice
712
713choice
714	prompt "Virtual address space size"
715	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
716	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
717	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
718	help
719	  Allows choosing one of multiple possible virtual address
720	  space sizes. The level of translation table is determined by
721	  a combination of page size and virtual address space size.
722
723config ARM64_VA_BITS_36
724	bool "36-bit" if EXPERT
725	depends on ARM64_16K_PAGES
726
727config ARM64_VA_BITS_39
728	bool "39-bit"
729	depends on ARM64_4K_PAGES
730
731config ARM64_VA_BITS_42
732	bool "42-bit"
733	depends on ARM64_64K_PAGES
734
735config ARM64_VA_BITS_47
736	bool "47-bit"
737	depends on ARM64_16K_PAGES
738
739config ARM64_VA_BITS_48
740	bool "48-bit"
741
742config ARM64_USER_VA_BITS_52
743	bool "52-bit (user)"
744	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
745	help
746	  Enable 52-bit virtual addressing for userspace when explicitly
747	  requested via a hint to mmap(). The kernel will continue to
748	  use 48-bit virtual addresses for its own mappings.
749
750	  NOTE: Enabling 52-bit virtual addressing in conjunction with
751	  ARMv8.3 Pointer Authentication will result in the PAC being
752	  reduced from 7 bits to 3 bits, which may have a significant
753	  impact on its susceptibility to brute-force attacks.
754
755	  If unsure, select 48-bit virtual addressing instead.
756
757endchoice
758
759config ARM64_FORCE_52BIT
760	bool "Force 52-bit virtual addresses for userspace"
761	depends on ARM64_USER_VA_BITS_52 && EXPERT
762	help
763	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
764	  to maintain compatibility with older software by providing 48-bit VAs
765	  unless a hint is supplied to mmap.
766
767	  This configuration option disables the 48-bit compatibility logic, and
768	  forces all userspace addresses to be 52-bit on HW that supports it. One
769	  should only enable this configuration option for stress testing userspace
770	  memory management code. If unsure say N here.
771
772config ARM64_VA_BITS
773	int
774	default 36 if ARM64_VA_BITS_36
775	default 39 if ARM64_VA_BITS_39
776	default 42 if ARM64_VA_BITS_42
777	default 47 if ARM64_VA_BITS_47
778	default 48 if ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52
779
780choice
781	prompt "Physical address space size"
782	default ARM64_PA_BITS_48
783	help
784	  Choose the maximum physical address range that the kernel will
785	  support.
786
787config ARM64_PA_BITS_48
788	bool "48-bit"
789
790config ARM64_PA_BITS_52
791	bool "52-bit (ARMv8.2)"
792	depends on ARM64_64K_PAGES
793	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
794	help
795	  Enable support for a 52-bit physical address space, introduced as
796	  part of the ARMv8.2-LPA extension.
797
798	  With this enabled, the kernel will also continue to work on CPUs that
799	  do not support ARMv8.2-LPA, but with some added memory overhead (and
800	  minor performance overhead).
801
802endchoice
803
804config ARM64_PA_BITS
805	int
806	default 48 if ARM64_PA_BITS_48
807	default 52 if ARM64_PA_BITS_52
808
809config CPU_BIG_ENDIAN
810       bool "Build big-endian kernel"
811       help
812         Say Y if you plan on running a kernel in big-endian mode.
813
814config SCHED_MC
815	bool "Multi-core scheduler support"
816	help
817	  Multi-core scheduler support improves the CPU scheduler's decision
818	  making when dealing with multi-core CPU chips at a cost of slightly
819	  increased overhead in some places. If unsure say N here.
820
821config SCHED_SMT
822	bool "SMT scheduler support"
823	help
824	  Improves the CPU scheduler's decision making when dealing with
825	  MultiThreading at a cost of slightly increased overhead in some
826	  places. If unsure say N here.
827
828config NR_CPUS
829	int "Maximum number of CPUs (2-4096)"
830	range 2 4096
831	default "256"
832
833config HOTPLUG_CPU
834	bool "Support for hot-pluggable CPUs"
835	select GENERIC_IRQ_MIGRATION
836	help
837	  Say Y here to experiment with turning CPUs off and on.  CPUs
838	  can be controlled through /sys/devices/system/cpu.
839
840# Common NUMA Features
841config NUMA
842	bool "Numa Memory Allocation and Scheduler Support"
843	select ACPI_NUMA if ACPI
844	select OF_NUMA
845	help
846	  Enable NUMA (Non Uniform Memory Access) support.
847
848	  The kernel will try to allocate memory used by a CPU on the
849	  local memory of the CPU and add some more
850	  NUMA awareness to the kernel.
851
852config NODES_SHIFT
853	int "Maximum NUMA Nodes (as a power of 2)"
854	range 1 10
855	default "2"
856	depends on NEED_MULTIPLE_NODES
857	help
858	  Specify the maximum number of NUMA Nodes available on the target
859	  system.  Increases memory reserved to accommodate various tables.
860
861config USE_PERCPU_NUMA_NODE_ID
862	def_bool y
863	depends on NUMA
864
865config HAVE_SETUP_PER_CPU_AREA
866	def_bool y
867	depends on NUMA
868
869config NEED_PER_CPU_EMBED_FIRST_CHUNK
870	def_bool y
871	depends on NUMA
872
873config HOLES_IN_ZONE
874	def_bool y
875
876source "kernel/Kconfig.hz"
877
878config ARCH_SUPPORTS_DEBUG_PAGEALLOC
879	def_bool y
880
881config ARCH_SPARSEMEM_ENABLE
882	def_bool y
883	select SPARSEMEM_VMEMMAP_ENABLE
884
885config ARCH_SPARSEMEM_DEFAULT
886	def_bool ARCH_SPARSEMEM_ENABLE
887
888config ARCH_SELECT_MEMORY_MODEL
889	def_bool ARCH_SPARSEMEM_ENABLE
890
891config ARCH_FLATMEM_ENABLE
892	def_bool !NUMA
893
894config HAVE_ARCH_PFN_VALID
895	def_bool y
896
897config HW_PERF_EVENTS
898	def_bool y
899	depends on ARM_PMU
900
901config SYS_SUPPORTS_HUGETLBFS
902	def_bool y
903
904config ARCH_WANT_HUGE_PMD_SHARE
905	def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
906
907config ARCH_HAS_CACHE_LINE_SIZE
908	def_bool y
909
910config ARCH_ENABLE_SPLIT_PMD_PTLOCK
911	def_bool y if PGTABLE_LEVELS > 2
912
913config SECCOMP
914	bool "Enable seccomp to safely compute untrusted bytecode"
915	---help---
916	  This kernel feature is useful for number crunching applications
917	  that may need to compute untrusted bytecode during their
918	  execution. By using pipes or other transports made available to
919	  the process as file descriptors supporting the read/write
920	  syscalls, it's possible to isolate those applications in
921	  their own address space using seccomp. Once seccomp is
922	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
923	  and the task is only allowed to execute a few safe syscalls
924	  defined by each seccomp mode.
925
926config PARAVIRT
927	bool "Enable paravirtualization code"
928	help
929	  This changes the kernel so it can modify itself when it is run
930	  under a hypervisor, potentially improving performance significantly
931	  over full virtualization.
932
933config PARAVIRT_TIME_ACCOUNTING
934	bool "Paravirtual steal time accounting"
935	select PARAVIRT
936	default n
937	help
938	  Select this option to enable fine granularity task steal time
939	  accounting. Time spent executing other tasks in parallel with
940	  the current vCPU is discounted from the vCPU power. To account for
941	  that, there can be a small performance impact.
942
943	  If in doubt, say N here.
944
945config KEXEC
946	depends on PM_SLEEP_SMP
947	select KEXEC_CORE
948	bool "kexec system call"
949	---help---
950	  kexec is a system call that implements the ability to shutdown your
951	  current kernel, and to start another kernel.  It is like a reboot
952	  but it is independent of the system firmware.   And like a reboot
953	  you can start any kernel with it, not just Linux.
954
955config KEXEC_FILE
956	bool "kexec file based system call"
957	select KEXEC_CORE
958	help
959	  This is new version of kexec system call. This system call is
960	  file based and takes file descriptors as system call argument
961	  for kernel and initramfs as opposed to list of segments as
962	  accepted by previous system call.
963
964config KEXEC_VERIFY_SIG
965	bool "Verify kernel signature during kexec_file_load() syscall"
966	depends on KEXEC_FILE
967	help
968	  Select this option to verify a signature with loaded kernel
969	  image. If configured, any attempt of loading a image without
970	  valid signature will fail.
971
972	  In addition to that option, you need to enable signature
973	  verification for the corresponding kernel image type being
974	  loaded in order for this to work.
975
976config KEXEC_IMAGE_VERIFY_SIG
977	bool "Enable Image signature verification support"
978	default y
979	depends on KEXEC_VERIFY_SIG
980	depends on EFI && SIGNED_PE_FILE_VERIFICATION
981	help
982	  Enable Image signature verification support.
983
984comment "Support for PE file signature verification disabled"
985	depends on KEXEC_VERIFY_SIG
986	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
987
988config CRASH_DUMP
989	bool "Build kdump crash kernel"
990	help
991	  Generate crash dump after being started by kexec. This should
992	  be normally only set in special crash dump kernels which are
993	  loaded in the main kernel with kexec-tools into a specially
994	  reserved region and then later executed after a crash by
995	  kdump/kexec.
996
997	  For more details see Documentation/kdump/kdump.txt
998
999config XEN_DOM0
1000	def_bool y
1001	depends on XEN
1002
1003config XEN
1004	bool "Xen guest support on ARM64"
1005	depends on ARM64 && OF
1006	select SWIOTLB_XEN
1007	select PARAVIRT
1008	help
1009	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1010
1011config FORCE_MAX_ZONEORDER
1012	int
1013	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
1014	default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
1015	default "11"
1016	help
1017	  The kernel memory allocator divides physically contiguous memory
1018	  blocks into "zones", where each zone is a power of two number of
1019	  pages.  This option selects the largest power of two that the kernel
1020	  keeps in the memory allocator.  If you need to allocate very large
1021	  blocks of physically contiguous memory, then you may need to
1022	  increase this value.
1023
1024	  This config option is actually maximum order plus one. For example,
1025	  a value of 11 means that the largest free memory block is 2^10 pages.
1026
1027	  We make sure that we can allocate upto a HugePage size for each configuration.
1028	  Hence we have :
1029		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1030
1031	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1032	  4M allocations matching the default size used by generic code.
1033
1034config UNMAP_KERNEL_AT_EL0
1035	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1036	default y
1037	help
1038	  Speculation attacks against some high-performance processors can
1039	  be used to bypass MMU permission checks and leak kernel data to
1040	  userspace. This can be defended against by unmapping the kernel
1041	  when running in userspace, mapping it back in on exception entry
1042	  via a trampoline page in the vector table.
1043
1044	  If unsure, say Y.
1045
1046config HARDEN_BRANCH_PREDICTOR
1047	bool "Harden the branch predictor against aliasing attacks" if EXPERT
1048	default y
1049	help
1050	  Speculation attacks against some high-performance processors rely on
1051	  being able to manipulate the branch predictor for a victim context by
1052	  executing aliasing branches in the attacker context.  Such attacks
1053	  can be partially mitigated against by clearing internal branch
1054	  predictor state and limiting the prediction logic in some situations.
1055
1056	  This config option will take CPU-specific actions to harden the
1057	  branch predictor against aliasing attacks and may rely on specific
1058	  instruction sequences or control bits being set by the system
1059	  firmware.
1060
1061	  If unsure, say Y.
1062
1063config HARDEN_EL2_VECTORS
1064	bool "Harden EL2 vector mapping against system register leak" if EXPERT
1065	default y
1066	help
1067	  Speculation attacks against some high-performance processors can
1068	  be used to leak privileged information such as the vector base
1069	  register, resulting in a potential defeat of the EL2 layout
1070	  randomization.
1071
1072	  This config option will map the vectors to a fixed location,
1073	  independent of the EL2 code mapping, so that revealing VBAR_EL2
1074	  to an attacker does not give away any extra information. This
1075	  only gets enabled on affected CPUs.
1076
1077	  If unsure, say Y.
1078
1079config ARM64_SSBD
1080	bool "Speculative Store Bypass Disable" if EXPERT
1081	default y
1082	help
1083	  This enables mitigation of the bypassing of previous stores
1084	  by speculative loads.
1085
1086	  If unsure, say Y.
1087
1088config RODATA_FULL_DEFAULT_ENABLED
1089	bool "Apply r/o permissions of VM areas also to their linear aliases"
1090	default y
1091	help
1092	  Apply read-only attributes of VM areas to the linear alias of
1093	  the backing pages as well. This prevents code or read-only data
1094	  from being modified (inadvertently or intentionally) via another
1095	  mapping of the same memory page. This additional enhancement can
1096	  be turned off at runtime by passing rodata=[off|on] (and turned on
1097	  with rodata=full if this option is set to 'n')
1098
1099	  This requires the linear region to be mapped down to pages,
1100	  which may adversely affect performance in some cases.
1101
1102config ARM64_SW_TTBR0_PAN
1103	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1104	help
1105	  Enabling this option prevents the kernel from accessing
1106	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1107	  zeroed area and reserved ASID. The user access routines
1108	  restore the valid TTBR0_EL1 temporarily.
1109
1110menuconfig COMPAT
1111	bool "Kernel support for 32-bit EL0"
1112	depends on ARM64_4K_PAGES || EXPERT
1113	select COMPAT_BINFMT_ELF if BINFMT_ELF
1114	select HAVE_UID16
1115	select OLD_SIGSUSPEND3
1116	select COMPAT_OLD_SIGACTION
1117	help
1118	  This option enables support for a 32-bit EL0 running under a 64-bit
1119	  kernel at EL1. AArch32-specific components such as system calls,
1120	  the user helper functions, VFP support and the ptrace interface are
1121	  handled appropriately by the kernel.
1122
1123	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1124	  that you will only be able to execute AArch32 binaries that were compiled
1125	  with page size aligned segments.
1126
1127	  If you want to execute 32-bit userspace applications, say Y.
1128
1129if COMPAT
1130
1131config KUSER_HELPERS
1132	bool "Enable kuser helpers page for 32 bit applications"
1133	default y
1134	help
1135	  Warning: disabling this option may break 32-bit user programs.
1136
1137	  Provide kuser helpers to compat tasks. The kernel provides
1138	  helper code to userspace in read only form at a fixed location
1139	  to allow userspace to be independent of the CPU type fitted to
1140	  the system. This permits binaries to be run on ARMv4 through
1141	  to ARMv8 without modification.
1142
1143	  See Documentation/arm/kernel_user_helpers.txt for details.
1144
1145	  However, the fixed address nature of these helpers can be used
1146	  by ROP (return orientated programming) authors when creating
1147	  exploits.
1148
1149	  If all of the binaries and libraries which run on your platform
1150	  are built specifically for your platform, and make no use of
1151	  these helpers, then you can turn this option off to hinder
1152	  such exploits. However, in that case, if a binary or library
1153	  relying on those helpers is run, it will not function correctly.
1154
1155	  Say N here only if you are absolutely certain that you do not
1156	  need these helpers; otherwise, the safe option is to say Y.
1157
1158
1159menuconfig ARMV8_DEPRECATED
1160	bool "Emulate deprecated/obsolete ARMv8 instructions"
1161	depends on SYSCTL
1162	help
1163	  Legacy software support may require certain instructions
1164	  that have been deprecated or obsoleted in the architecture.
1165
1166	  Enable this config to enable selective emulation of these
1167	  features.
1168
1169	  If unsure, say Y
1170
1171if ARMV8_DEPRECATED
1172
1173config SWP_EMULATION
1174	bool "Emulate SWP/SWPB instructions"
1175	help
1176	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1177	  they are always undefined. Say Y here to enable software
1178	  emulation of these instructions for userspace using LDXR/STXR.
1179
1180	  In some older versions of glibc [<=2.8] SWP is used during futex
1181	  trylock() operations with the assumption that the code will not
1182	  be preempted. This invalid assumption may be more likely to fail
1183	  with SWP emulation enabled, leading to deadlock of the user
1184	  application.
1185
1186	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1187	  on an external transaction monitoring block called a global
1188	  monitor to maintain update atomicity. If your system does not
1189	  implement a global monitor, this option can cause programs that
1190	  perform SWP operations to uncached memory to deadlock.
1191
1192	  If unsure, say Y
1193
1194config CP15_BARRIER_EMULATION
1195	bool "Emulate CP15 Barrier instructions"
1196	help
1197	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1198	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1199	  strongly recommended to use the ISB, DSB, and DMB
1200	  instructions instead.
1201
1202	  Say Y here to enable software emulation of these
1203	  instructions for AArch32 userspace code. When this option is
1204	  enabled, CP15 barrier usage is traced which can help
1205	  identify software that needs updating.
1206
1207	  If unsure, say Y
1208
1209config SETEND_EMULATION
1210	bool "Emulate SETEND instruction"
1211	help
1212	  The SETEND instruction alters the data-endianness of the
1213	  AArch32 EL0, and is deprecated in ARMv8.
1214
1215	  Say Y here to enable software emulation of the instruction
1216	  for AArch32 userspace code.
1217
1218	  Note: All the cpus on the system must have mixed endian support at EL0
1219	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1220	  endian - is hotplugged in after this feature has been enabled, there could
1221	  be unexpected results in the applications.
1222
1223	  If unsure, say Y
1224endif
1225
1226endif
1227
1228menu "ARMv8.1 architectural features"
1229
1230config ARM64_HW_AFDBM
1231	bool "Support for hardware updates of the Access and Dirty page flags"
1232	default y
1233	help
1234	  The ARMv8.1 architecture extensions introduce support for
1235	  hardware updates of the access and dirty information in page
1236	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1237	  capable processors, accesses to pages with PTE_AF cleared will
1238	  set this bit instead of raising an access flag fault.
1239	  Similarly, writes to read-only pages with the DBM bit set will
1240	  clear the read-only bit (AP[2]) instead of raising a
1241	  permission fault.
1242
1243	  Kernels built with this configuration option enabled continue
1244	  to work on pre-ARMv8.1 hardware and the performance impact is
1245	  minimal. If unsure, say Y.
1246
1247config ARM64_PAN
1248	bool "Enable support for Privileged Access Never (PAN)"
1249	default y
1250	help
1251	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1252	 prevents the kernel or hypervisor from accessing user-space (EL0)
1253	 memory directly.
1254
1255	 Choosing this option will cause any unprotected (not using
1256	 copy_to_user et al) memory access to fail with a permission fault.
1257
1258	 The feature is detected at runtime, and will remain as a 'nop'
1259	 instruction if the cpu does not implement the feature.
1260
1261config ARM64_LSE_ATOMICS
1262	bool "Atomic instructions"
1263	default y
1264	help
1265	  As part of the Large System Extensions, ARMv8.1 introduces new
1266	  atomic instructions that are designed specifically to scale in
1267	  very large systems.
1268
1269	  Say Y here to make use of these instructions for the in-kernel
1270	  atomic routines. This incurs a small overhead on CPUs that do
1271	  not support these instructions and requires the kernel to be
1272	  built with binutils >= 2.25 in order for the new instructions
1273	  to be used.
1274
1275config ARM64_VHE
1276	bool "Enable support for Virtualization Host Extensions (VHE)"
1277	default y
1278	help
1279	  Virtualization Host Extensions (VHE) allow the kernel to run
1280	  directly at EL2 (instead of EL1) on processors that support
1281	  it. This leads to better performance for KVM, as they reduce
1282	  the cost of the world switch.
1283
1284	  Selecting this option allows the VHE feature to be detected
1285	  at runtime, and does not affect processors that do not
1286	  implement this feature.
1287
1288endmenu
1289
1290menu "ARMv8.2 architectural features"
1291
1292config ARM64_UAO
1293	bool "Enable support for User Access Override (UAO)"
1294	default y
1295	help
1296	  User Access Override (UAO; part of the ARMv8.2 Extensions)
1297	  causes the 'unprivileged' variant of the load/store instructions to
1298	  be overridden to be privileged.
1299
1300	  This option changes get_user() and friends to use the 'unprivileged'
1301	  variant of the load/store instructions. This ensures that user-space
1302	  really did have access to the supplied memory. When addr_limit is
1303	  set to kernel memory the UAO bit will be set, allowing privileged
1304	  access to kernel memory.
1305
1306	  Choosing this option will cause copy_to_user() et al to use user-space
1307	  memory permissions.
1308
1309	  The feature is detected at runtime, the kernel will use the
1310	  regular load/store instructions if the cpu does not implement the
1311	  feature.
1312
1313config ARM64_PMEM
1314	bool "Enable support for persistent memory"
1315	select ARCH_HAS_PMEM_API
1316	select ARCH_HAS_UACCESS_FLUSHCACHE
1317	help
1318	  Say Y to enable support for the persistent memory API based on the
1319	  ARMv8.2 DCPoP feature.
1320
1321	  The feature is detected at runtime, and the kernel will use DC CVAC
1322	  operations if DC CVAP is not supported (following the behaviour of
1323	  DC CVAP itself if the system does not define a point of persistence).
1324
1325config ARM64_RAS_EXTN
1326	bool "Enable support for RAS CPU Extensions"
1327	default y
1328	help
1329	  CPUs that support the Reliability, Availability and Serviceability
1330	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1331	  errors, classify them and report them to software.
1332
1333	  On CPUs with these extensions system software can use additional
1334	  barriers to determine if faults are pending and read the
1335	  classification from a new set of registers.
1336
1337	  Selecting this feature will allow the kernel to use these barriers
1338	  and access the new registers if the system supports the extension.
1339	  Platform RAS features may additionally depend on firmware support.
1340
1341config ARM64_CNP
1342	bool "Enable support for Common Not Private (CNP) translations"
1343	default y
1344	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1345	help
1346	  Common Not Private (CNP) allows translation table entries to
1347	  be shared between different PEs in the same inner shareable
1348	  domain, so the hardware can use this fact to optimise the
1349	  caching of such entries in the TLB.
1350
1351	  Selecting this option allows the CNP feature to be detected
1352	  at runtime, and does not affect PEs that do not implement
1353	  this feature.
1354
1355endmenu
1356
1357menu "ARMv8.3 architectural features"
1358
1359config ARM64_PTR_AUTH
1360	bool "Enable support for pointer authentication"
1361	default y
1362	depends on !KVM || ARM64_VHE
1363	help
1364	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1365	  instructions for signing and authenticating pointers against secret
1366	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1367	  and other attacks.
1368
1369	  This option enables these instructions at EL0 (i.e. for userspace).
1370
1371	  Choosing this option will cause the kernel to initialise secret keys
1372	  for each process at exec() time, with these keys being
1373	  context-switched along with the process.
1374
1375	  The feature is detected at runtime. If the feature is not present in
1376	  hardware it will not be advertised to userspace/KVM guest nor will it
1377	  be enabled. However, KVM guest also require VHE mode and hence
1378	  CONFIG_ARM64_VHE=y option to use this feature.
1379
1380endmenu
1381
1382config ARM64_SVE
1383	bool "ARM Scalable Vector Extension support"
1384	default y
1385	depends on !KVM || ARM64_VHE
1386	help
1387	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1388	  execution state which complements and extends the SIMD functionality
1389	  of the base architecture to support much larger vectors and to enable
1390	  additional vectorisation opportunities.
1391
1392	  To enable use of this extension on CPUs that implement it, say Y.
1393
1394	  On CPUs that support the SVE2 extensions, this option will enable
1395	  those too.
1396
1397	  Note that for architectural reasons, firmware _must_ implement SVE
1398	  support when running on SVE capable hardware.  The required support
1399	  is present in:
1400
1401	    * version 1.5 and later of the ARM Trusted Firmware
1402	    * the AArch64 boot wrapper since commit 5e1261e08abf
1403	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1404
1405	  For other firmware implementations, consult the firmware documentation
1406	  or vendor.
1407
1408	  If you need the kernel to boot on SVE-capable hardware with broken
1409	  firmware, you may need to say N here until you get your firmware
1410	  fixed.  Otherwise, you may experience firmware panics or lockups when
1411	  booting the kernel.  If unsure and you are not observing these
1412	  symptoms, you should assume that it is safe to say Y.
1413
1414	  CPUs that support SVE are architecturally required to support the
1415	  Virtualization Host Extensions (VHE), so the kernel makes no
1416	  provision for supporting SVE alongside KVM without VHE enabled.
1417	  Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
1418	  KVM in the same kernel image.
1419
1420config ARM64_MODULE_PLTS
1421	bool
1422	select HAVE_MOD_ARCH_SPECIFIC
1423
1424config ARM64_PSEUDO_NMI
1425	bool "Support for NMI-like interrupts"
1426	depends on BROKEN # 1556553607-46531-1-git-send-email-julien.thierry@arm.com
1427	select CONFIG_ARM_GIC_V3
1428	help
1429	  Adds support for mimicking Non-Maskable Interrupts through the use of
1430	  GIC interrupt priority. This support requires version 3 or later of
1431	  ARM GIC.
1432
1433	  This high priority configuration for interrupts needs to be
1434	  explicitly enabled by setting the kernel parameter
1435	  "irqchip.gicv3_pseudo_nmi" to 1.
1436
1437	  If unsure, say N
1438
1439config RELOCATABLE
1440	bool
1441	help
1442	  This builds the kernel as a Position Independent Executable (PIE),
1443	  which retains all relocation metadata required to relocate the
1444	  kernel binary at runtime to a different virtual address than the
1445	  address it was linked at.
1446	  Since AArch64 uses the RELA relocation format, this requires a
1447	  relocation pass at runtime even if the kernel is loaded at the
1448	  same address it was linked at.
1449
1450config RANDOMIZE_BASE
1451	bool "Randomize the address of the kernel image"
1452	select ARM64_MODULE_PLTS if MODULES
1453	select RELOCATABLE
1454	help
1455	  Randomizes the virtual address at which the kernel image is
1456	  loaded, as a security feature that deters exploit attempts
1457	  relying on knowledge of the location of kernel internals.
1458
1459	  It is the bootloader's job to provide entropy, by passing a
1460	  random u64 value in /chosen/kaslr-seed at kernel entry.
1461
1462	  When booting via the UEFI stub, it will invoke the firmware's
1463	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1464	  to the kernel proper. In addition, it will randomise the physical
1465	  location of the kernel Image as well.
1466
1467	  If unsure, say N.
1468
1469config RANDOMIZE_MODULE_REGION_FULL
1470	bool "Randomize the module region over a 4 GB range"
1471	depends on RANDOMIZE_BASE
1472	default y
1473	help
1474	  Randomizes the location of the module region inside a 4 GB window
1475	  covering the core kernel. This way, it is less likely for modules
1476	  to leak information about the location of core kernel data structures
1477	  but it does imply that function calls between modules and the core
1478	  kernel will need to be resolved via veneers in the module PLT.
1479
1480	  When this option is not set, the module region will be randomized over
1481	  a limited range that contains the [_stext, _etext] interval of the
1482	  core kernel, so branch relocations are always in range.
1483
1484config CC_HAVE_STACKPROTECTOR_SYSREG
1485	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1486
1487config STACKPROTECTOR_PER_TASK
1488	def_bool y
1489	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1490
1491endmenu
1492
1493menu "Boot options"
1494
1495config ARM64_ACPI_PARKING_PROTOCOL
1496	bool "Enable support for the ARM64 ACPI parking protocol"
1497	depends on ACPI
1498	help
1499	  Enable support for the ARM64 ACPI parking protocol. If disabled
1500	  the kernel will not allow booting through the ARM64 ACPI parking
1501	  protocol even if the corresponding data is present in the ACPI
1502	  MADT table.
1503
1504config CMDLINE
1505	string "Default kernel command string"
1506	default ""
1507	help
1508	  Provide a set of default command-line options at build time by
1509	  entering them here. As a minimum, you should specify the the
1510	  root device (e.g. root=/dev/nfs).
1511
1512config CMDLINE_FORCE
1513	bool "Always use the default kernel command string"
1514	help
1515	  Always use the default kernel command string, even if the boot
1516	  loader passes other arguments to the kernel.
1517	  This is useful if you cannot or don't want to change the
1518	  command-line options your boot loader passes to the kernel.
1519
1520config EFI_STUB
1521	bool
1522
1523config EFI
1524	bool "UEFI runtime support"
1525	depends on OF && !CPU_BIG_ENDIAN
1526	depends on KERNEL_MODE_NEON
1527	select ARCH_SUPPORTS_ACPI
1528	select LIBFDT
1529	select UCS2_STRING
1530	select EFI_PARAMS_FROM_FDT
1531	select EFI_RUNTIME_WRAPPERS
1532	select EFI_STUB
1533	select EFI_ARMSTUB
1534	default y
1535	help
1536	  This option provides support for runtime services provided
1537	  by UEFI firmware (such as non-volatile variables, realtime
1538          clock, and platform reset). A UEFI stub is also provided to
1539	  allow the kernel to be booted as an EFI application. This
1540	  is only useful on systems that have UEFI firmware.
1541
1542config DMI
1543	bool "Enable support for SMBIOS (DMI) tables"
1544	depends on EFI
1545	default y
1546	help
1547	  This enables SMBIOS/DMI feature for systems.
1548
1549	  This option is only useful on systems that have UEFI firmware.
1550	  However, even with this option, the resultant kernel should
1551	  continue to boot on existing non-UEFI platforms.
1552
1553endmenu
1554
1555config SYSVIPC_COMPAT
1556	def_bool y
1557	depends on COMPAT && SYSVIPC
1558
1559config ARCH_ENABLE_HUGEPAGE_MIGRATION
1560	def_bool y
1561	depends on HUGETLB_PAGE && MIGRATION
1562
1563menu "Power management options"
1564
1565source "kernel/power/Kconfig"
1566
1567config ARCH_HIBERNATION_POSSIBLE
1568	def_bool y
1569	depends on CPU_PM
1570
1571config ARCH_HIBERNATION_HEADER
1572	def_bool y
1573	depends on HIBERNATION
1574
1575config ARCH_SUSPEND_POSSIBLE
1576	def_bool y
1577
1578endmenu
1579
1580menu "CPU Power Management"
1581
1582source "drivers/cpuidle/Kconfig"
1583
1584source "drivers/cpufreq/Kconfig"
1585
1586endmenu
1587
1588source "drivers/firmware/Kconfig"
1589
1590source "drivers/acpi/Kconfig"
1591
1592source "arch/arm64/kvm/Kconfig"
1593
1594if CRYPTO
1595source "arch/arm64/crypto/Kconfig"
1596endif
1597