xref: /linux/arch/arm64/Kconfig (revision 2993c9b04e616df0848b655d7202a707a70fc876)
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_PREP_COHERENT
17	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
18	select ARCH_HAS_FAST_MULTIPLIER
19	select ARCH_HAS_FORTIFY_SOURCE
20	select ARCH_HAS_GCOV_PROFILE_ALL
21	select ARCH_HAS_GIGANTIC_PAGE
22	select ARCH_HAS_KCOV
23	select ARCH_HAS_KEEPINITRD
24	select ARCH_HAS_MEMBARRIER_SYNC_CORE
25	select ARCH_HAS_PTE_DEVMAP
26	select ARCH_HAS_PTE_SPECIAL
27	select ARCH_HAS_SETUP_DMA_OPS
28	select ARCH_HAS_SET_DIRECT_MAP
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_DEFAULT_TOPDOWN_MMAP_LAYOUT
74	select ARCH_WANT_FRAME_POINTERS
75	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
76	select ARCH_HAS_UBSAN_SANITIZE_ALL
77	select ARM_AMBA
78	select ARM_ARCH_TIMER
79	select ARM_GIC
80	select AUDIT_ARCH_COMPAT_GENERIC
81	select ARM_GIC_V2M if PCI
82	select ARM_GIC_V3
83	select ARM_GIC_V3_ITS if PCI
84	select ARM_PSCI_FW
85	select BUILDTIME_EXTABLE_SORT
86	select CLONE_BACKWARDS
87	select COMMON_CLK
88	select CPU_PM if (SUSPEND || CPU_IDLE)
89	select CRC32
90	select DCACHE_WORD_ACCESS
91	select DMA_DIRECT_REMAP
92	select EDAC_SUPPORT
93	select FRAME_POINTER
94	select GENERIC_ALLOCATOR
95	select GENERIC_ARCH_TOPOLOGY
96	select GENERIC_CLOCKEVENTS
97	select GENERIC_CLOCKEVENTS_BROADCAST
98	select GENERIC_CPU_AUTOPROBE
99	select GENERIC_CPU_VULNERABILITIES
100	select GENERIC_EARLY_IOREMAP
101	select GENERIC_IDLE_POLL_SETUP
102	select GENERIC_IRQ_MULTI_HANDLER
103	select GENERIC_IRQ_PROBE
104	select GENERIC_IRQ_SHOW
105	select GENERIC_IRQ_SHOW_LEVEL
106	select GENERIC_PCI_IOMAP
107	select GENERIC_SCHED_CLOCK
108	select GENERIC_SMP_IDLE_THREAD
109	select GENERIC_STRNCPY_FROM_USER
110	select GENERIC_STRNLEN_USER
111	select GENERIC_TIME_VSYSCALL
112	select GENERIC_GETTIMEOFDAY
113	select HANDLE_DOMAIN_IRQ
114	select HARDIRQS_SW_RESEND
115	select HAVE_PCI
116	select HAVE_ACPI_APEI if (ACPI && EFI)
117	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
118	select HAVE_ARCH_AUDITSYSCALL
119	select HAVE_ARCH_BITREVERSE
120	select HAVE_ARCH_HUGE_VMAP
121	select HAVE_ARCH_JUMP_LABEL
122	select HAVE_ARCH_JUMP_LABEL_RELATIVE
123	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
124	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
125	select HAVE_ARCH_KGDB
126	select HAVE_ARCH_MMAP_RND_BITS
127	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
128	select HAVE_ARCH_PREL32_RELOCATIONS
129	select HAVE_ARCH_SECCOMP_FILTER
130	select HAVE_ARCH_STACKLEAK
131	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
132	select HAVE_ARCH_TRACEHOOK
133	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
134	select HAVE_ARCH_VMAP_STACK
135	select HAVE_ARM_SMCCC
136	select HAVE_ASM_MODVERSIONS
137	select HAVE_EBPF_JIT
138	select HAVE_C_RECORDMCOUNT
139	select HAVE_CMPXCHG_DOUBLE
140	select HAVE_CMPXCHG_LOCAL
141	select HAVE_CONTEXT_TRACKING
142	select HAVE_DEBUG_BUGVERBOSE
143	select HAVE_DEBUG_KMEMLEAK
144	select HAVE_DMA_CONTIGUOUS
145	select HAVE_DYNAMIC_FTRACE
146	select HAVE_EFFICIENT_UNALIGNED_ACCESS
147	select HAVE_FAST_GUP
148	select HAVE_FTRACE_MCOUNT_RECORD
149	select HAVE_FUNCTION_TRACER
150	select HAVE_FUNCTION_ERROR_INJECTION
151	select HAVE_FUNCTION_GRAPH_TRACER
152	select HAVE_GCC_PLUGINS
153	select HAVE_HW_BREAKPOINT if PERF_EVENTS
154	select HAVE_IRQ_TIME_ACCOUNTING
155	select HAVE_MEMBLOCK_NODE_MAP if NUMA
156	select HAVE_NMI
157	select HAVE_PATA_PLATFORM
158	select HAVE_PERF_EVENTS
159	select HAVE_PERF_REGS
160	select HAVE_PERF_USER_STACK_DUMP
161	select HAVE_REGS_AND_STACK_ACCESS_API
162	select HAVE_FUNCTION_ARG_ACCESS_API
163	select HAVE_RCU_TABLE_FREE
164	select HAVE_RSEQ
165	select HAVE_STACKPROTECTOR
166	select HAVE_SYSCALL_TRACEPOINTS
167	select HAVE_KPROBES
168	select HAVE_KRETPROBES
169	select HAVE_GENERIC_VDSO
170	select IOMMU_DMA if IOMMU_SUPPORT
171	select IRQ_DOMAIN
172	select IRQ_FORCED_THREADING
173	select MODULES_USE_ELF_RELA
174	select NEED_DMA_MAP_STATE
175	select NEED_SG_DMA_LENGTH
176	select OF
177	select OF_EARLY_FLATTREE
178	select PCI_DOMAINS_GENERIC if PCI
179	select PCI_ECAM if (ACPI && PCI)
180	select PCI_SYSCALL if PCI
181	select POWER_RESET
182	select POWER_SUPPLY
183	select REFCOUNT_FULL
184	select SPARSE_IRQ
185	select SWIOTLB
186	select SYSCTL_EXCEPTION_TRACE
187	select THREAD_INFO_IN_TASK
188	help
189	  ARM 64-bit (AArch64) Linux support.
190
191config 64BIT
192	def_bool y
193
194config MMU
195	def_bool y
196
197config ARM64_PAGE_SHIFT
198	int
199	default 16 if ARM64_64K_PAGES
200	default 14 if ARM64_16K_PAGES
201	default 12
202
203config ARM64_CONT_SHIFT
204	int
205	default 5 if ARM64_64K_PAGES
206	default 7 if ARM64_16K_PAGES
207	default 4
208
209config ARCH_MMAP_RND_BITS_MIN
210       default 14 if ARM64_64K_PAGES
211       default 16 if ARM64_16K_PAGES
212       default 18
213
214# max bits determined by the following formula:
215#  VA_BITS - PAGE_SHIFT - 3
216config ARCH_MMAP_RND_BITS_MAX
217       default 19 if ARM64_VA_BITS=36
218       default 24 if ARM64_VA_BITS=39
219       default 27 if ARM64_VA_BITS=42
220       default 30 if ARM64_VA_BITS=47
221       default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
222       default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
223       default 33 if ARM64_VA_BITS=48
224       default 14 if ARM64_64K_PAGES
225       default 16 if ARM64_16K_PAGES
226       default 18
227
228config ARCH_MMAP_RND_COMPAT_BITS_MIN
229       default 7 if ARM64_64K_PAGES
230       default 9 if ARM64_16K_PAGES
231       default 11
232
233config ARCH_MMAP_RND_COMPAT_BITS_MAX
234       default 16
235
236config NO_IOPORT_MAP
237	def_bool y if !PCI
238
239config STACKTRACE_SUPPORT
240	def_bool y
241
242config ILLEGAL_POINTER_VALUE
243	hex
244	default 0xdead000000000000
245
246config LOCKDEP_SUPPORT
247	def_bool y
248
249config TRACE_IRQFLAGS_SUPPORT
250	def_bool y
251
252config GENERIC_BUG
253	def_bool y
254	depends on BUG
255
256config GENERIC_BUG_RELATIVE_POINTERS
257	def_bool y
258	depends on GENERIC_BUG
259
260config GENERIC_HWEIGHT
261	def_bool y
262
263config GENERIC_CSUM
264        def_bool y
265
266config GENERIC_CALIBRATE_DELAY
267	def_bool y
268
269config ZONE_DMA32
270	bool "Support DMA32 zone" if EXPERT
271	default y
272
273config ARCH_ENABLE_MEMORY_HOTPLUG
274	def_bool y
275
276config SMP
277	def_bool y
278
279config KERNEL_MODE_NEON
280	def_bool y
281
282config FIX_EARLYCON_MEM
283	def_bool y
284
285config PGTABLE_LEVELS
286	int
287	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
288	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
289	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
290	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
291	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
292	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
293
294config ARCH_SUPPORTS_UPROBES
295	def_bool y
296
297config ARCH_PROC_KCORE_TEXT
298	def_bool y
299
300config KASAN_SHADOW_OFFSET
301	hex
302	depends on KASAN
303	default 0xdfffa00000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
304	default 0xdfffd00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
305	default 0xdffffe8000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
306	default 0xdfffffd000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
307	default 0xdffffffa00000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
308	default 0xefff900000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
309	default 0xefffc80000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
310	default 0xeffffe4000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
311	default 0xefffffc800000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
312	default 0xeffffff900000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
313	default 0xffffffffffffffff
314
315source "arch/arm64/Kconfig.platforms"
316
317menu "Kernel Features"
318
319menu "ARM errata workarounds via the alternatives framework"
320
321config ARM64_WORKAROUND_CLEAN_CACHE
322	bool
323
324config ARM64_ERRATUM_826319
325	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
326	default y
327	select ARM64_WORKAROUND_CLEAN_CACHE
328	help
329	  This option adds an alternative code sequence to work around ARM
330	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
331	  AXI master interface and an L2 cache.
332
333	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
334	  and is unable to accept a certain write via this interface, it will
335	  not progress on read data presented on the read data channel and the
336	  system can deadlock.
337
338	  The workaround promotes data cache clean instructions to
339	  data cache clean-and-invalidate.
340	  Please note that this does not necessarily enable the workaround,
341	  as it depends on the alternative framework, which will only patch
342	  the kernel if an affected CPU is detected.
343
344	  If unsure, say Y.
345
346config ARM64_ERRATUM_827319
347	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
348	default y
349	select ARM64_WORKAROUND_CLEAN_CACHE
350	help
351	  This option adds an alternative code sequence to work around ARM
352	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
353	  master interface and an L2 cache.
354
355	  Under certain conditions this erratum can cause a clean line eviction
356	  to occur at the same time as another transaction to the same address
357	  on the AMBA 5 CHI interface, which can cause data corruption if the
358	  interconnect reorders the two transactions.
359
360	  The workaround promotes data cache clean instructions to
361	  data cache clean-and-invalidate.
362	  Please note that this does not necessarily enable the workaround,
363	  as it depends on the alternative framework, which will only patch
364	  the kernel if an affected CPU is detected.
365
366	  If unsure, say Y.
367
368config ARM64_ERRATUM_824069
369	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
370	default y
371	select ARM64_WORKAROUND_CLEAN_CACHE
372	help
373	  This option adds an alternative code sequence to work around ARM
374	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
375	  to a coherent interconnect.
376
377	  If a Cortex-A53 processor is executing a store or prefetch for
378	  write instruction at the same time as a processor in another
379	  cluster is executing a cache maintenance operation to the same
380	  address, then this erratum might cause a clean cache line to be
381	  incorrectly marked as dirty.
382
383	  The workaround promotes data cache clean instructions to
384	  data cache clean-and-invalidate.
385	  Please note that this option does not necessarily enable the
386	  workaround, as it depends on the alternative framework, which will
387	  only patch the kernel if an affected CPU is detected.
388
389	  If unsure, say Y.
390
391config ARM64_ERRATUM_819472
392	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
393	default y
394	select ARM64_WORKAROUND_CLEAN_CACHE
395	help
396	  This option adds an alternative code sequence to work around ARM
397	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
398	  present when it is connected to a coherent interconnect.
399
400	  If the processor is executing a load and store exclusive sequence at
401	  the same time as a processor in another cluster is executing a cache
402	  maintenance operation to the same address, then this erratum might
403	  cause data corruption.
404
405	  The workaround promotes data cache clean instructions to
406	  data cache clean-and-invalidate.
407	  Please note that this does not necessarily enable the workaround,
408	  as it depends on the alternative framework, which will only patch
409	  the kernel if an affected CPU is detected.
410
411	  If unsure, say Y.
412
413config ARM64_ERRATUM_832075
414	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
415	default y
416	help
417	  This option adds an alternative code sequence to work around ARM
418	  erratum 832075 on Cortex-A57 parts up to r1p2.
419
420	  Affected Cortex-A57 parts might deadlock when exclusive load/store
421	  instructions to Write-Back memory are mixed with Device loads.
422
423	  The workaround is to promote device loads to use Load-Acquire
424	  semantics.
425	  Please note that this does not necessarily enable the workaround,
426	  as it depends on the alternative framework, which will only patch
427	  the kernel if an affected CPU is detected.
428
429	  If unsure, say Y.
430
431config ARM64_ERRATUM_834220
432	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
433	depends on KVM
434	default y
435	help
436	  This option adds an alternative code sequence to work around ARM
437	  erratum 834220 on Cortex-A57 parts up to r1p2.
438
439	  Affected Cortex-A57 parts might report a Stage 2 translation
440	  fault as the result of a Stage 1 fault for load crossing a
441	  page boundary when there is a permission or device memory
442	  alignment fault at Stage 1 and a translation fault at Stage 2.
443
444	  The workaround is to verify that the Stage 1 translation
445	  doesn't generate a fault before handling the Stage 2 fault.
446	  Please note that this does not necessarily enable the workaround,
447	  as it depends on the alternative framework, which will only patch
448	  the kernel if an affected CPU is detected.
449
450	  If unsure, say Y.
451
452config ARM64_ERRATUM_845719
453	bool "Cortex-A53: 845719: a load might read incorrect data"
454	depends on COMPAT
455	default y
456	help
457	  This option adds an alternative code sequence to work around ARM
458	  erratum 845719 on Cortex-A53 parts up to r0p4.
459
460	  When running a compat (AArch32) userspace on an affected Cortex-A53
461	  part, a load at EL0 from a virtual address that matches the bottom 32
462	  bits of the virtual address used by a recent load at (AArch64) EL1
463	  might return incorrect data.
464
465	  The workaround is to write the contextidr_el1 register on exception
466	  return to a 32-bit task.
467	  Please note that this does not necessarily enable the workaround,
468	  as it depends on the alternative framework, which will only patch
469	  the kernel if an affected CPU is detected.
470
471	  If unsure, say Y.
472
473config ARM64_ERRATUM_843419
474	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
475	default y
476	select ARM64_MODULE_PLTS if MODULES
477	help
478	  This option links the kernel with '--fix-cortex-a53-843419' and
479	  enables PLT support to replace certain ADRP instructions, which can
480	  cause subsequent memory accesses to use an incorrect address on
481	  Cortex-A53 parts up to r0p4.
482
483	  If unsure, say Y.
484
485config ARM64_ERRATUM_1024718
486	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
487	default y
488	help
489	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
490
491	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
492	  update of the hardware dirty bit when the DBM/AP bits are updated
493	  without a break-before-make. The workaround is to disable the usage
494	  of hardware DBM locally on the affected cores. CPUs not affected by
495	  this erratum will continue to use the feature.
496
497	  If unsure, say Y.
498
499config ARM64_ERRATUM_1418040
500	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
501	default y
502	depends on COMPAT
503	help
504	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
505	  errata 1188873 and 1418040.
506
507	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
508	  cause register corruption when accessing the timer registers
509	  from AArch32 userspace.
510
511	  If unsure, say Y.
512
513config ARM64_ERRATUM_1165522
514	bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
515	default y
516	help
517	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
518
519	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
520	  corrupted TLBs by speculating an AT instruction during a guest
521	  context switch.
522
523	  If unsure, say Y.
524
525config ARM64_ERRATUM_1286807
526	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
527	default y
528	select ARM64_WORKAROUND_REPEAT_TLBI
529	help
530	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
531
532	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
533	  address for a cacheable mapping of a location is being
534	  accessed by a core while another core is remapping the virtual
535	  address to a new physical page using the recommended
536	  break-before-make sequence, then under very rare circumstances
537	  TLBI+DSB completes before a read using the translation being
538	  invalidated has been observed by other observers. The
539	  workaround repeats the TLBI+DSB operation.
540
541	  If unsure, say Y.
542
543config ARM64_ERRATUM_1463225
544	bool "Cortex-A76: Software Step might prevent interrupt recognition"
545	default y
546	help
547	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
548
549	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
550	  of a system call instruction (SVC) can prevent recognition of
551	  subsequent interrupts when software stepping is disabled in the
552	  exception handler of the system call and either kernel debugging
553	  is enabled or VHE is in use.
554
555	  Work around the erratum by triggering a dummy step exception
556	  when handling a system call from a task that is being stepped
557	  in a VHE configuration of the kernel.
558
559	  If unsure, say Y.
560
561config CAVIUM_ERRATUM_22375
562	bool "Cavium erratum 22375, 24313"
563	default y
564	help
565	  Enable workaround for errata 22375 and 24313.
566
567	  This implements two gicv3-its errata workarounds for ThunderX. Both
568	  with a small impact affecting only ITS table allocation.
569
570	    erratum 22375: only alloc 8MB table size
571	    erratum 24313: ignore memory access type
572
573	  The fixes are in ITS initialization and basically ignore memory access
574	  type and table size provided by the TYPER and BASER registers.
575
576	  If unsure, say Y.
577
578config CAVIUM_ERRATUM_23144
579	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
580	depends on NUMA
581	default y
582	help
583	  ITS SYNC command hang for cross node io and collections/cpu mapping.
584
585	  If unsure, say Y.
586
587config CAVIUM_ERRATUM_23154
588	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
589	default y
590	help
591	  The gicv3 of ThunderX requires a modified version for
592	  reading the IAR status to ensure data synchronization
593	  (access to icc_iar1_el1 is not sync'ed before and after).
594
595	  If unsure, say Y.
596
597config CAVIUM_ERRATUM_27456
598	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
599	default y
600	help
601	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
602	  instructions may cause the icache to become corrupted if it
603	  contains data for a non-current ASID.  The fix is to
604	  invalidate the icache when changing the mm context.
605
606	  If unsure, say Y.
607
608config CAVIUM_ERRATUM_30115
609	bool "Cavium erratum 30115: Guest may disable interrupts in host"
610	default y
611	help
612	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
613	  1.2, and T83 Pass 1.0, KVM guest execution may disable
614	  interrupts in host. Trapping both GICv3 group-0 and group-1
615	  accesses sidesteps the issue.
616
617	  If unsure, say Y.
618
619config QCOM_FALKOR_ERRATUM_1003
620	bool "Falkor E1003: Incorrect translation due to ASID change"
621	default y
622	help
623	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
624	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
625	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
626	  then only for entries in the walk cache, since the leaf translation
627	  is unchanged. Work around the erratum by invalidating the walk cache
628	  entries for the trampoline before entering the kernel proper.
629
630config ARM64_WORKAROUND_REPEAT_TLBI
631	bool
632
633config QCOM_FALKOR_ERRATUM_1009
634	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
635	default y
636	select ARM64_WORKAROUND_REPEAT_TLBI
637	help
638	  On Falkor v1, the CPU may prematurely complete a DSB following a
639	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
640	  one more time to fix the issue.
641
642	  If unsure, say Y.
643
644config QCOM_QDF2400_ERRATUM_0065
645	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
646	default y
647	help
648	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
649	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
650	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
651
652	  If unsure, say Y.
653
654config SOCIONEXT_SYNQUACER_PREITS
655	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
656	default y
657	help
658	  Socionext Synquacer SoCs implement a separate h/w block to generate
659	  MSI doorbell writes with non-zero values for the device ID.
660
661	  If unsure, say Y.
662
663config HISILICON_ERRATUM_161600802
664	bool "Hip07 161600802: Erroneous redistributor VLPI base"
665	default y
666	help
667	  The HiSilicon Hip07 SoC uses the wrong redistributor base
668	  when issued ITS commands such as VMOVP and VMAPP, and requires
669	  a 128kB offset to be applied to the target address in this commands.
670
671	  If unsure, say Y.
672
673config QCOM_FALKOR_ERRATUM_E1041
674	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
675	default y
676	help
677	  Falkor CPU may speculatively fetch instructions from an improper
678	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
679	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
680
681	  If unsure, say Y.
682
683config FUJITSU_ERRATUM_010001
684	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
685	default y
686	help
687	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
688	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
689	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
690	  This fault occurs under a specific hardware condition when a
691	  load/store instruction performs an address translation using:
692	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
693	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
694	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
695	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
696
697	  The workaround is to ensure these bits are clear in TCR_ELx.
698	  The workaround only affects the Fujitsu-A64FX.
699
700	  If unsure, say Y.
701
702endmenu
703
704
705choice
706	prompt "Page size"
707	default ARM64_4K_PAGES
708	help
709	  Page size (translation granule) configuration.
710
711config ARM64_4K_PAGES
712	bool "4KB"
713	help
714	  This feature enables 4KB pages support.
715
716config ARM64_16K_PAGES
717	bool "16KB"
718	help
719	  The system will use 16KB pages support. AArch32 emulation
720	  requires applications compiled with 16K (or a multiple of 16K)
721	  aligned segments.
722
723config ARM64_64K_PAGES
724	bool "64KB"
725	help
726	  This feature enables 64KB pages support (4KB by default)
727	  allowing only two levels of page tables and faster TLB
728	  look-up. AArch32 emulation requires applications compiled
729	  with 64K aligned segments.
730
731endchoice
732
733choice
734	prompt "Virtual address space size"
735	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
736	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
737	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
738	help
739	  Allows choosing one of multiple possible virtual address
740	  space sizes. The level of translation table is determined by
741	  a combination of page size and virtual address space size.
742
743config ARM64_VA_BITS_36
744	bool "36-bit" if EXPERT
745	depends on ARM64_16K_PAGES
746
747config ARM64_VA_BITS_39
748	bool "39-bit"
749	depends on ARM64_4K_PAGES
750
751config ARM64_VA_BITS_42
752	bool "42-bit"
753	depends on ARM64_64K_PAGES
754
755config ARM64_VA_BITS_47
756	bool "47-bit"
757	depends on ARM64_16K_PAGES
758
759config ARM64_VA_BITS_48
760	bool "48-bit"
761
762config ARM64_VA_BITS_52
763	bool "52-bit"
764	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
765	help
766	  Enable 52-bit virtual addressing for userspace when explicitly
767	  requested via a hint to mmap(). The kernel will also use 52-bit
768	  virtual addresses for its own mappings (provided HW support for
769	  this feature is available, otherwise it reverts to 48-bit).
770
771	  NOTE: Enabling 52-bit virtual addressing in conjunction with
772	  ARMv8.3 Pointer Authentication will result in the PAC being
773	  reduced from 7 bits to 3 bits, which may have a significant
774	  impact on its susceptibility to brute-force attacks.
775
776	  If unsure, select 48-bit virtual addressing instead.
777
778endchoice
779
780config ARM64_FORCE_52BIT
781	bool "Force 52-bit virtual addresses for userspace"
782	depends on ARM64_VA_BITS_52 && EXPERT
783	help
784	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
785	  to maintain compatibility with older software by providing 48-bit VAs
786	  unless a hint is supplied to mmap.
787
788	  This configuration option disables the 48-bit compatibility logic, and
789	  forces all userspace addresses to be 52-bit on HW that supports it. One
790	  should only enable this configuration option for stress testing userspace
791	  memory management code. If unsure say N here.
792
793config ARM64_VA_BITS
794	int
795	default 36 if ARM64_VA_BITS_36
796	default 39 if ARM64_VA_BITS_39
797	default 42 if ARM64_VA_BITS_42
798	default 47 if ARM64_VA_BITS_47
799	default 48 if ARM64_VA_BITS_48
800	default 52 if ARM64_VA_BITS_52
801
802choice
803	prompt "Physical address space size"
804	default ARM64_PA_BITS_48
805	help
806	  Choose the maximum physical address range that the kernel will
807	  support.
808
809config ARM64_PA_BITS_48
810	bool "48-bit"
811
812config ARM64_PA_BITS_52
813	bool "52-bit (ARMv8.2)"
814	depends on ARM64_64K_PAGES
815	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
816	help
817	  Enable support for a 52-bit physical address space, introduced as
818	  part of the ARMv8.2-LPA extension.
819
820	  With this enabled, the kernel will also continue to work on CPUs that
821	  do not support ARMv8.2-LPA, but with some added memory overhead (and
822	  minor performance overhead).
823
824endchoice
825
826config ARM64_PA_BITS
827	int
828	default 48 if ARM64_PA_BITS_48
829	default 52 if ARM64_PA_BITS_52
830
831config CPU_BIG_ENDIAN
832       bool "Build big-endian kernel"
833       help
834         Say Y if you plan on running a kernel in big-endian mode.
835
836config SCHED_MC
837	bool "Multi-core scheduler support"
838	help
839	  Multi-core scheduler support improves the CPU scheduler's decision
840	  making when dealing with multi-core CPU chips at a cost of slightly
841	  increased overhead in some places. If unsure say N here.
842
843config SCHED_SMT
844	bool "SMT scheduler support"
845	help
846	  Improves the CPU scheduler's decision making when dealing with
847	  MultiThreading at a cost of slightly increased overhead in some
848	  places. If unsure say N here.
849
850config NR_CPUS
851	int "Maximum number of CPUs (2-4096)"
852	range 2 4096
853	default "256"
854
855config HOTPLUG_CPU
856	bool "Support for hot-pluggable CPUs"
857	select GENERIC_IRQ_MIGRATION
858	help
859	  Say Y here to experiment with turning CPUs off and on.  CPUs
860	  can be controlled through /sys/devices/system/cpu.
861
862# Common NUMA Features
863config NUMA
864	bool "Numa Memory Allocation and Scheduler Support"
865	select ACPI_NUMA if ACPI
866	select OF_NUMA
867	help
868	  Enable NUMA (Non Uniform Memory Access) support.
869
870	  The kernel will try to allocate memory used by a CPU on the
871	  local memory of the CPU and add some more
872	  NUMA awareness to the kernel.
873
874config NODES_SHIFT
875	int "Maximum NUMA Nodes (as a power of 2)"
876	range 1 10
877	default "2"
878	depends on NEED_MULTIPLE_NODES
879	help
880	  Specify the maximum number of NUMA Nodes available on the target
881	  system.  Increases memory reserved to accommodate various tables.
882
883config USE_PERCPU_NUMA_NODE_ID
884	def_bool y
885	depends on NUMA
886
887config HAVE_SETUP_PER_CPU_AREA
888	def_bool y
889	depends on NUMA
890
891config NEED_PER_CPU_EMBED_FIRST_CHUNK
892	def_bool y
893	depends on NUMA
894
895config HOLES_IN_ZONE
896	def_bool y
897
898source "kernel/Kconfig.hz"
899
900config ARCH_SUPPORTS_DEBUG_PAGEALLOC
901	def_bool y
902
903config ARCH_SPARSEMEM_ENABLE
904	def_bool y
905	select SPARSEMEM_VMEMMAP_ENABLE
906
907config ARCH_SPARSEMEM_DEFAULT
908	def_bool ARCH_SPARSEMEM_ENABLE
909
910config ARCH_SELECT_MEMORY_MODEL
911	def_bool ARCH_SPARSEMEM_ENABLE
912
913config ARCH_FLATMEM_ENABLE
914	def_bool !NUMA
915
916config HAVE_ARCH_PFN_VALID
917	def_bool y
918
919config HW_PERF_EVENTS
920	def_bool y
921	depends on ARM_PMU
922
923config SYS_SUPPORTS_HUGETLBFS
924	def_bool y
925
926config ARCH_WANT_HUGE_PMD_SHARE
927
928config ARCH_HAS_CACHE_LINE_SIZE
929	def_bool y
930
931config ARCH_ENABLE_SPLIT_PMD_PTLOCK
932	def_bool y if PGTABLE_LEVELS > 2
933
934config SECCOMP
935	bool "Enable seccomp to safely compute untrusted bytecode"
936	---help---
937	  This kernel feature is useful for number crunching applications
938	  that may need to compute untrusted bytecode during their
939	  execution. By using pipes or other transports made available to
940	  the process as file descriptors supporting the read/write
941	  syscalls, it's possible to isolate those applications in
942	  their own address space using seccomp. Once seccomp is
943	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
944	  and the task is only allowed to execute a few safe syscalls
945	  defined by each seccomp mode.
946
947config PARAVIRT
948	bool "Enable paravirtualization code"
949	help
950	  This changes the kernel so it can modify itself when it is run
951	  under a hypervisor, potentially improving performance significantly
952	  over full virtualization.
953
954config PARAVIRT_TIME_ACCOUNTING
955	bool "Paravirtual steal time accounting"
956	select PARAVIRT
957	help
958	  Select this option to enable fine granularity task steal time
959	  accounting. Time spent executing other tasks in parallel with
960	  the current vCPU is discounted from the vCPU power. To account for
961	  that, there can be a small performance impact.
962
963	  If in doubt, say N here.
964
965config KEXEC
966	depends on PM_SLEEP_SMP
967	select KEXEC_CORE
968	bool "kexec system call"
969	---help---
970	  kexec is a system call that implements the ability to shutdown your
971	  current kernel, and to start another kernel.  It is like a reboot
972	  but it is independent of the system firmware.   And like a reboot
973	  you can start any kernel with it, not just Linux.
974
975config KEXEC_FILE
976	bool "kexec file based system call"
977	select KEXEC_CORE
978	help
979	  This is new version of kexec system call. This system call is
980	  file based and takes file descriptors as system call argument
981	  for kernel and initramfs as opposed to list of segments as
982	  accepted by previous system call.
983
984config KEXEC_SIG
985	bool "Verify kernel signature during kexec_file_load() syscall"
986	depends on KEXEC_FILE
987	help
988	  Select this option to verify a signature with loaded kernel
989	  image. If configured, any attempt of loading a image without
990	  valid signature will fail.
991
992	  In addition to that option, you need to enable signature
993	  verification for the corresponding kernel image type being
994	  loaded in order for this to work.
995
996config KEXEC_IMAGE_VERIFY_SIG
997	bool "Enable Image signature verification support"
998	default y
999	depends on KEXEC_SIG
1000	depends on EFI && SIGNED_PE_FILE_VERIFICATION
1001	help
1002	  Enable Image signature verification support.
1003
1004comment "Support for PE file signature verification disabled"
1005	depends on KEXEC_SIG
1006	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
1007
1008config CRASH_DUMP
1009	bool "Build kdump crash kernel"
1010	help
1011	  Generate crash dump after being started by kexec. This should
1012	  be normally only set in special crash dump kernels which are
1013	  loaded in the main kernel with kexec-tools into a specially
1014	  reserved region and then later executed after a crash by
1015	  kdump/kexec.
1016
1017	  For more details see Documentation/admin-guide/kdump/kdump.rst
1018
1019config XEN_DOM0
1020	def_bool y
1021	depends on XEN
1022
1023config XEN
1024	bool "Xen guest support on ARM64"
1025	depends on ARM64 && OF
1026	select SWIOTLB_XEN
1027	select PARAVIRT
1028	help
1029	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1030
1031config FORCE_MAX_ZONEORDER
1032	int
1033	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
1034	default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
1035	default "11"
1036	help
1037	  The kernel memory allocator divides physically contiguous memory
1038	  blocks into "zones", where each zone is a power of two number of
1039	  pages.  This option selects the largest power of two that the kernel
1040	  keeps in the memory allocator.  If you need to allocate very large
1041	  blocks of physically contiguous memory, then you may need to
1042	  increase this value.
1043
1044	  This config option is actually maximum order plus one. For example,
1045	  a value of 11 means that the largest free memory block is 2^10 pages.
1046
1047	  We make sure that we can allocate upto a HugePage size for each configuration.
1048	  Hence we have :
1049		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1050
1051	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1052	  4M allocations matching the default size used by generic code.
1053
1054config UNMAP_KERNEL_AT_EL0
1055	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1056	default y
1057	help
1058	  Speculation attacks against some high-performance processors can
1059	  be used to bypass MMU permission checks and leak kernel data to
1060	  userspace. This can be defended against by unmapping the kernel
1061	  when running in userspace, mapping it back in on exception entry
1062	  via a trampoline page in the vector table.
1063
1064	  If unsure, say Y.
1065
1066config HARDEN_BRANCH_PREDICTOR
1067	bool "Harden the branch predictor against aliasing attacks" if EXPERT
1068	default y
1069	help
1070	  Speculation attacks against some high-performance processors rely on
1071	  being able to manipulate the branch predictor for a victim context by
1072	  executing aliasing branches in the attacker context.  Such attacks
1073	  can be partially mitigated against by clearing internal branch
1074	  predictor state and limiting the prediction logic in some situations.
1075
1076	  This config option will take CPU-specific actions to harden the
1077	  branch predictor against aliasing attacks and may rely on specific
1078	  instruction sequences or control bits being set by the system
1079	  firmware.
1080
1081	  If unsure, say Y.
1082
1083config HARDEN_EL2_VECTORS
1084	bool "Harden EL2 vector mapping against system register leak" if EXPERT
1085	default y
1086	help
1087	  Speculation attacks against some high-performance processors can
1088	  be used to leak privileged information such as the vector base
1089	  register, resulting in a potential defeat of the EL2 layout
1090	  randomization.
1091
1092	  This config option will map the vectors to a fixed location,
1093	  independent of the EL2 code mapping, so that revealing VBAR_EL2
1094	  to an attacker does not give away any extra information. This
1095	  only gets enabled on affected CPUs.
1096
1097	  If unsure, say Y.
1098
1099config ARM64_SSBD
1100	bool "Speculative Store Bypass Disable" if EXPERT
1101	default y
1102	help
1103	  This enables mitigation of the bypassing of previous stores
1104	  by speculative loads.
1105
1106	  If unsure, say Y.
1107
1108config RODATA_FULL_DEFAULT_ENABLED
1109	bool "Apply r/o permissions of VM areas also to their linear aliases"
1110	default y
1111	help
1112	  Apply read-only attributes of VM areas to the linear alias of
1113	  the backing pages as well. This prevents code or read-only data
1114	  from being modified (inadvertently or intentionally) via another
1115	  mapping of the same memory page. This additional enhancement can
1116	  be turned off at runtime by passing rodata=[off|on] (and turned on
1117	  with rodata=full if this option is set to 'n')
1118
1119	  This requires the linear region to be mapped down to pages,
1120	  which may adversely affect performance in some cases.
1121
1122config ARM64_SW_TTBR0_PAN
1123	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1124	help
1125	  Enabling this option prevents the kernel from accessing
1126	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1127	  zeroed area and reserved ASID. The user access routines
1128	  restore the valid TTBR0_EL1 temporarily.
1129
1130config ARM64_TAGGED_ADDR_ABI
1131	bool "Enable the tagged user addresses syscall ABI"
1132	default y
1133	help
1134	  When this option is enabled, user applications can opt in to a
1135	  relaxed ABI via prctl() allowing tagged addresses to be passed
1136	  to system calls as pointer arguments. For details, see
1137	  Documentation/arm64/tagged-address-abi.rst.
1138
1139menuconfig COMPAT
1140	bool "Kernel support for 32-bit EL0"
1141	depends on ARM64_4K_PAGES || EXPERT
1142	select COMPAT_BINFMT_ELF if BINFMT_ELF
1143	select HAVE_UID16
1144	select OLD_SIGSUSPEND3
1145	select COMPAT_OLD_SIGACTION
1146	help
1147	  This option enables support for a 32-bit EL0 running under a 64-bit
1148	  kernel at EL1. AArch32-specific components such as system calls,
1149	  the user helper functions, VFP support and the ptrace interface are
1150	  handled appropriately by the kernel.
1151
1152	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1153	  that you will only be able to execute AArch32 binaries that were compiled
1154	  with page size aligned segments.
1155
1156	  If you want to execute 32-bit userspace applications, say Y.
1157
1158if COMPAT
1159
1160config KUSER_HELPERS
1161	bool "Enable kuser helpers page for 32-bit applications"
1162	default y
1163	help
1164	  Warning: disabling this option may break 32-bit user programs.
1165
1166	  Provide kuser helpers to compat tasks. The kernel provides
1167	  helper code to userspace in read only form at a fixed location
1168	  to allow userspace to be independent of the CPU type fitted to
1169	  the system. This permits binaries to be run on ARMv4 through
1170	  to ARMv8 without modification.
1171
1172	  See Documentation/arm/kernel_user_helpers.rst for details.
1173
1174	  However, the fixed address nature of these helpers can be used
1175	  by ROP (return orientated programming) authors when creating
1176	  exploits.
1177
1178	  If all of the binaries and libraries which run on your platform
1179	  are built specifically for your platform, and make no use of
1180	  these helpers, then you can turn this option off to hinder
1181	  such exploits. However, in that case, if a binary or library
1182	  relying on those helpers is run, it will not function correctly.
1183
1184	  Say N here only if you are absolutely certain that you do not
1185	  need these helpers; otherwise, the safe option is to say Y.
1186
1187config COMPAT_VDSO
1188	bool "Enable vDSO for 32-bit applications"
1189	depends on !CPU_BIG_ENDIAN && "$(CROSS_COMPILE_COMPAT)" != ""
1190	select GENERIC_COMPAT_VDSO
1191	default y
1192	help
1193	  Place in the process address space of 32-bit applications an
1194	  ELF shared object providing fast implementations of gettimeofday
1195	  and clock_gettime.
1196
1197	  You must have a 32-bit build of glibc 2.22 or later for programs
1198	  to seamlessly take advantage of this.
1199
1200menuconfig ARMV8_DEPRECATED
1201	bool "Emulate deprecated/obsolete ARMv8 instructions"
1202	depends on SYSCTL
1203	help
1204	  Legacy software support may require certain instructions
1205	  that have been deprecated or obsoleted in the architecture.
1206
1207	  Enable this config to enable selective emulation of these
1208	  features.
1209
1210	  If unsure, say Y
1211
1212if ARMV8_DEPRECATED
1213
1214config SWP_EMULATION
1215	bool "Emulate SWP/SWPB instructions"
1216	help
1217	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1218	  they are always undefined. Say Y here to enable software
1219	  emulation of these instructions for userspace using LDXR/STXR.
1220
1221	  In some older versions of glibc [<=2.8] SWP is used during futex
1222	  trylock() operations with the assumption that the code will not
1223	  be preempted. This invalid assumption may be more likely to fail
1224	  with SWP emulation enabled, leading to deadlock of the user
1225	  application.
1226
1227	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1228	  on an external transaction monitoring block called a global
1229	  monitor to maintain update atomicity. If your system does not
1230	  implement a global monitor, this option can cause programs that
1231	  perform SWP operations to uncached memory to deadlock.
1232
1233	  If unsure, say Y
1234
1235config CP15_BARRIER_EMULATION
1236	bool "Emulate CP15 Barrier instructions"
1237	help
1238	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1239	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1240	  strongly recommended to use the ISB, DSB, and DMB
1241	  instructions instead.
1242
1243	  Say Y here to enable software emulation of these
1244	  instructions for AArch32 userspace code. When this option is
1245	  enabled, CP15 barrier usage is traced which can help
1246	  identify software that needs updating.
1247
1248	  If unsure, say Y
1249
1250config SETEND_EMULATION
1251	bool "Emulate SETEND instruction"
1252	help
1253	  The SETEND instruction alters the data-endianness of the
1254	  AArch32 EL0, and is deprecated in ARMv8.
1255
1256	  Say Y here to enable software emulation of the instruction
1257	  for AArch32 userspace code.
1258
1259	  Note: All the cpus on the system must have mixed endian support at EL0
1260	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1261	  endian - is hotplugged in after this feature has been enabled, there could
1262	  be unexpected results in the applications.
1263
1264	  If unsure, say Y
1265endif
1266
1267endif
1268
1269menu "ARMv8.1 architectural features"
1270
1271config ARM64_HW_AFDBM
1272	bool "Support for hardware updates of the Access and Dirty page flags"
1273	default y
1274	help
1275	  The ARMv8.1 architecture extensions introduce support for
1276	  hardware updates of the access and dirty information in page
1277	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1278	  capable processors, accesses to pages with PTE_AF cleared will
1279	  set this bit instead of raising an access flag fault.
1280	  Similarly, writes to read-only pages with the DBM bit set will
1281	  clear the read-only bit (AP[2]) instead of raising a
1282	  permission fault.
1283
1284	  Kernels built with this configuration option enabled continue
1285	  to work on pre-ARMv8.1 hardware and the performance impact is
1286	  minimal. If unsure, say Y.
1287
1288config ARM64_PAN
1289	bool "Enable support for Privileged Access Never (PAN)"
1290	default y
1291	help
1292	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1293	 prevents the kernel or hypervisor from accessing user-space (EL0)
1294	 memory directly.
1295
1296	 Choosing this option will cause any unprotected (not using
1297	 copy_to_user et al) memory access to fail with a permission fault.
1298
1299	 The feature is detected at runtime, and will remain as a 'nop'
1300	 instruction if the cpu does not implement the feature.
1301
1302config ARM64_LSE_ATOMICS
1303	bool "Atomic instructions"
1304	depends on JUMP_LABEL
1305	default y
1306	help
1307	  As part of the Large System Extensions, ARMv8.1 introduces new
1308	  atomic instructions that are designed specifically to scale in
1309	  very large systems.
1310
1311	  Say Y here to make use of these instructions for the in-kernel
1312	  atomic routines. This incurs a small overhead on CPUs that do
1313	  not support these instructions and requires the kernel to be
1314	  built with binutils >= 2.25 in order for the new instructions
1315	  to be used.
1316
1317config ARM64_VHE
1318	bool "Enable support for Virtualization Host Extensions (VHE)"
1319	default y
1320	help
1321	  Virtualization Host Extensions (VHE) allow the kernel to run
1322	  directly at EL2 (instead of EL1) on processors that support
1323	  it. This leads to better performance for KVM, as they reduce
1324	  the cost of the world switch.
1325
1326	  Selecting this option allows the VHE feature to be detected
1327	  at runtime, and does not affect processors that do not
1328	  implement this feature.
1329
1330endmenu
1331
1332menu "ARMv8.2 architectural features"
1333
1334config ARM64_UAO
1335	bool "Enable support for User Access Override (UAO)"
1336	default y
1337	help
1338	  User Access Override (UAO; part of the ARMv8.2 Extensions)
1339	  causes the 'unprivileged' variant of the load/store instructions to
1340	  be overridden to be privileged.
1341
1342	  This option changes get_user() and friends to use the 'unprivileged'
1343	  variant of the load/store instructions. This ensures that user-space
1344	  really did have access to the supplied memory. When addr_limit is
1345	  set to kernel memory the UAO bit will be set, allowing privileged
1346	  access to kernel memory.
1347
1348	  Choosing this option will cause copy_to_user() et al to use user-space
1349	  memory permissions.
1350
1351	  The feature is detected at runtime, the kernel will use the
1352	  regular load/store instructions if the cpu does not implement the
1353	  feature.
1354
1355config ARM64_PMEM
1356	bool "Enable support for persistent memory"
1357	select ARCH_HAS_PMEM_API
1358	select ARCH_HAS_UACCESS_FLUSHCACHE
1359	help
1360	  Say Y to enable support for the persistent memory API based on the
1361	  ARMv8.2 DCPoP feature.
1362
1363	  The feature is detected at runtime, and the kernel will use DC CVAC
1364	  operations if DC CVAP is not supported (following the behaviour of
1365	  DC CVAP itself if the system does not define a point of persistence).
1366
1367config ARM64_RAS_EXTN
1368	bool "Enable support for RAS CPU Extensions"
1369	default y
1370	help
1371	  CPUs that support the Reliability, Availability and Serviceability
1372	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1373	  errors, classify them and report them to software.
1374
1375	  On CPUs with these extensions system software can use additional
1376	  barriers to determine if faults are pending and read the
1377	  classification from a new set of registers.
1378
1379	  Selecting this feature will allow the kernel to use these barriers
1380	  and access the new registers if the system supports the extension.
1381	  Platform RAS features may additionally depend on firmware support.
1382
1383config ARM64_CNP
1384	bool "Enable support for Common Not Private (CNP) translations"
1385	default y
1386	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1387	help
1388	  Common Not Private (CNP) allows translation table entries to
1389	  be shared between different PEs in the same inner shareable
1390	  domain, so the hardware can use this fact to optimise the
1391	  caching of such entries in the TLB.
1392
1393	  Selecting this option allows the CNP feature to be detected
1394	  at runtime, and does not affect PEs that do not implement
1395	  this feature.
1396
1397endmenu
1398
1399menu "ARMv8.3 architectural features"
1400
1401config ARM64_PTR_AUTH
1402	bool "Enable support for pointer authentication"
1403	default y
1404	depends on !KVM || ARM64_VHE
1405	help
1406	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1407	  instructions for signing and authenticating pointers against secret
1408	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1409	  and other attacks.
1410
1411	  This option enables these instructions at EL0 (i.e. for userspace).
1412
1413	  Choosing this option will cause the kernel to initialise secret keys
1414	  for each process at exec() time, with these keys being
1415	  context-switched along with the process.
1416
1417	  The feature is detected at runtime. If the feature is not present in
1418	  hardware it will not be advertised to userspace/KVM guest nor will it
1419	  be enabled. However, KVM guest also require VHE mode and hence
1420	  CONFIG_ARM64_VHE=y option to use this feature.
1421
1422endmenu
1423
1424config ARM64_SVE
1425	bool "ARM Scalable Vector Extension support"
1426	default y
1427	depends on !KVM || ARM64_VHE
1428	help
1429	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1430	  execution state which complements and extends the SIMD functionality
1431	  of the base architecture to support much larger vectors and to enable
1432	  additional vectorisation opportunities.
1433
1434	  To enable use of this extension on CPUs that implement it, say Y.
1435
1436	  On CPUs that support the SVE2 extensions, this option will enable
1437	  those too.
1438
1439	  Note that for architectural reasons, firmware _must_ implement SVE
1440	  support when running on SVE capable hardware.  The required support
1441	  is present in:
1442
1443	    * version 1.5 and later of the ARM Trusted Firmware
1444	    * the AArch64 boot wrapper since commit 5e1261e08abf
1445	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1446
1447	  For other firmware implementations, consult the firmware documentation
1448	  or vendor.
1449
1450	  If you need the kernel to boot on SVE-capable hardware with broken
1451	  firmware, you may need to say N here until you get your firmware
1452	  fixed.  Otherwise, you may experience firmware panics or lockups when
1453	  booting the kernel.  If unsure and you are not observing these
1454	  symptoms, you should assume that it is safe to say Y.
1455
1456	  CPUs that support SVE are architecturally required to support the
1457	  Virtualization Host Extensions (VHE), so the kernel makes no
1458	  provision for supporting SVE alongside KVM without VHE enabled.
1459	  Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
1460	  KVM in the same kernel image.
1461
1462config ARM64_MODULE_PLTS
1463	bool "Use PLTs to allow module memory to spill over into vmalloc area"
1464	depends on MODULES
1465	select HAVE_MOD_ARCH_SPECIFIC
1466	help
1467	  Allocate PLTs when loading modules so that jumps and calls whose
1468	  targets are too far away for their relative offsets to be encoded
1469	  in the instructions themselves can be bounced via veneers in the
1470	  module's PLT. This allows modules to be allocated in the generic
1471	  vmalloc area after the dedicated module memory area has been
1472	  exhausted.
1473
1474	  When running with address space randomization (KASLR), the module
1475	  region itself may be too far away for ordinary relative jumps and
1476	  calls, and so in that case, module PLTs are required and cannot be
1477	  disabled.
1478
1479	  Specific errata workaround(s) might also force module PLTs to be
1480	  enabled (ARM64_ERRATUM_843419).
1481
1482config ARM64_PSEUDO_NMI
1483	bool "Support for NMI-like interrupts"
1484	select CONFIG_ARM_GIC_V3
1485	help
1486	  Adds support for mimicking Non-Maskable Interrupts through the use of
1487	  GIC interrupt priority. This support requires version 3 or later of
1488	  ARM GIC.
1489
1490	  This high priority configuration for interrupts needs to be
1491	  explicitly enabled by setting the kernel parameter
1492	  "irqchip.gicv3_pseudo_nmi" to 1.
1493
1494	  If unsure, say N
1495
1496if ARM64_PSEUDO_NMI
1497config ARM64_DEBUG_PRIORITY_MASKING
1498	bool "Debug interrupt priority masking"
1499	help
1500	  This adds runtime checks to functions enabling/disabling
1501	  interrupts when using priority masking. The additional checks verify
1502	  the validity of ICC_PMR_EL1 when calling concerned functions.
1503
1504	  If unsure, say N
1505endif
1506
1507config RELOCATABLE
1508	bool
1509	select ARCH_HAS_RELR
1510	help
1511	  This builds the kernel as a Position Independent Executable (PIE),
1512	  which retains all relocation metadata required to relocate the
1513	  kernel binary at runtime to a different virtual address than the
1514	  address it was linked at.
1515	  Since AArch64 uses the RELA relocation format, this requires a
1516	  relocation pass at runtime even if the kernel is loaded at the
1517	  same address it was linked at.
1518
1519config RANDOMIZE_BASE
1520	bool "Randomize the address of the kernel image"
1521	select ARM64_MODULE_PLTS if MODULES
1522	select RELOCATABLE
1523	help
1524	  Randomizes the virtual address at which the kernel image is
1525	  loaded, as a security feature that deters exploit attempts
1526	  relying on knowledge of the location of kernel internals.
1527
1528	  It is the bootloader's job to provide entropy, by passing a
1529	  random u64 value in /chosen/kaslr-seed at kernel entry.
1530
1531	  When booting via the UEFI stub, it will invoke the firmware's
1532	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1533	  to the kernel proper. In addition, it will randomise the physical
1534	  location of the kernel Image as well.
1535
1536	  If unsure, say N.
1537
1538config RANDOMIZE_MODULE_REGION_FULL
1539	bool "Randomize the module region over a 4 GB range"
1540	depends on RANDOMIZE_BASE
1541	default y
1542	help
1543	  Randomizes the location of the module region inside a 4 GB window
1544	  covering the core kernel. This way, it is less likely for modules
1545	  to leak information about the location of core kernel data structures
1546	  but it does imply that function calls between modules and the core
1547	  kernel will need to be resolved via veneers in the module PLT.
1548
1549	  When this option is not set, the module region will be randomized over
1550	  a limited range that contains the [_stext, _etext] interval of the
1551	  core kernel, so branch relocations are always in range.
1552
1553config CC_HAVE_STACKPROTECTOR_SYSREG
1554	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1555
1556config STACKPROTECTOR_PER_TASK
1557	def_bool y
1558	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1559
1560endmenu
1561
1562menu "Boot options"
1563
1564config ARM64_ACPI_PARKING_PROTOCOL
1565	bool "Enable support for the ARM64 ACPI parking protocol"
1566	depends on ACPI
1567	help
1568	  Enable support for the ARM64 ACPI parking protocol. If disabled
1569	  the kernel will not allow booting through the ARM64 ACPI parking
1570	  protocol even if the corresponding data is present in the ACPI
1571	  MADT table.
1572
1573config CMDLINE
1574	string "Default kernel command string"
1575	default ""
1576	help
1577	  Provide a set of default command-line options at build time by
1578	  entering them here. As a minimum, you should specify the the
1579	  root device (e.g. root=/dev/nfs).
1580
1581config CMDLINE_FORCE
1582	bool "Always use the default kernel command string"
1583	help
1584	  Always use the default kernel command string, even if the boot
1585	  loader passes other arguments to the kernel.
1586	  This is useful if you cannot or don't want to change the
1587	  command-line options your boot loader passes to the kernel.
1588
1589config EFI_STUB
1590	bool
1591
1592config EFI
1593	bool "UEFI runtime support"
1594	depends on OF && !CPU_BIG_ENDIAN
1595	depends on KERNEL_MODE_NEON
1596	select ARCH_SUPPORTS_ACPI
1597	select LIBFDT
1598	select UCS2_STRING
1599	select EFI_PARAMS_FROM_FDT
1600	select EFI_RUNTIME_WRAPPERS
1601	select EFI_STUB
1602	select EFI_ARMSTUB
1603	default y
1604	help
1605	  This option provides support for runtime services provided
1606	  by UEFI firmware (such as non-volatile variables, realtime
1607          clock, and platform reset). A UEFI stub is also provided to
1608	  allow the kernel to be booted as an EFI application. This
1609	  is only useful on systems that have UEFI firmware.
1610
1611config DMI
1612	bool "Enable support for SMBIOS (DMI) tables"
1613	depends on EFI
1614	default y
1615	help
1616	  This enables SMBIOS/DMI feature for systems.
1617
1618	  This option is only useful on systems that have UEFI firmware.
1619	  However, even with this option, the resultant kernel should
1620	  continue to boot on existing non-UEFI platforms.
1621
1622endmenu
1623
1624config SYSVIPC_COMPAT
1625	def_bool y
1626	depends on COMPAT && SYSVIPC
1627
1628config ARCH_ENABLE_HUGEPAGE_MIGRATION
1629	def_bool y
1630	depends on HUGETLB_PAGE && MIGRATION
1631
1632menu "Power management options"
1633
1634source "kernel/power/Kconfig"
1635
1636config ARCH_HIBERNATION_POSSIBLE
1637	def_bool y
1638	depends on CPU_PM
1639
1640config ARCH_HIBERNATION_HEADER
1641	def_bool y
1642	depends on HIBERNATION
1643
1644config ARCH_SUSPEND_POSSIBLE
1645	def_bool y
1646
1647endmenu
1648
1649menu "CPU Power Management"
1650
1651source "drivers/cpuidle/Kconfig"
1652
1653source "drivers/cpufreq/Kconfig"
1654
1655endmenu
1656
1657source "drivers/firmware/Kconfig"
1658
1659source "drivers/acpi/Kconfig"
1660
1661source "arch/arm64/kvm/Kconfig"
1662
1663if CRYPTO
1664source "arch/arm64/crypto/Kconfig"
1665endif
1666