xref: /linux/arch/arm64/Kconfig (revision 302df34c4e64b9e83ee31cbf508b38b62b428bd6)
1config ARM64
2	def_bool y
3	select ACPI_CCA_REQUIRED if ACPI
4	select ACPI_GENERIC_GSI if ACPI
5	select ACPI_GTDT if ACPI
6	select ACPI_IORT if ACPI
7	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
8	select ACPI_MCFG if (ACPI && PCI)
9	select ACPI_SPCR_TABLE if ACPI
10	select ACPI_PPTT if ACPI
11	select ARCH_CLOCKSOURCE_DATA
12	select ARCH_HAS_DEBUG_VIRTUAL
13	select ARCH_HAS_DEVMEM_IS_ALLOWED
14	select ARCH_HAS_DMA_COHERENT_TO_PFN
15	select ARCH_HAS_DMA_MMAP_PGPROT
16	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
17	select ARCH_HAS_ELF_RANDOMIZE
18	select ARCH_HAS_FAST_MULTIPLIER
19	select ARCH_HAS_FORTIFY_SOURCE
20	select ARCH_HAS_GCOV_PROFILE_ALL
21	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
22	select ARCH_HAS_KCOV
23	select ARCH_HAS_MEMBARRIER_SYNC_CORE
24	select ARCH_HAS_PTE_SPECIAL
25	select ARCH_HAS_SET_MEMORY
26	select ARCH_HAS_SG_CHAIN
27	select ARCH_HAS_STRICT_KERNEL_RWX
28	select ARCH_HAS_STRICT_MODULE_RWX
29	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
30	select ARCH_HAS_SYNC_DMA_FOR_CPU
31	select ARCH_HAS_SYSCALL_WRAPPER
32	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
33	select ARCH_HAVE_NMI_SAFE_CMPXCHG
34	select ARCH_INLINE_READ_LOCK if !PREEMPT
35	select ARCH_INLINE_READ_LOCK_BH if !PREEMPT
36	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT
37	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT
38	select ARCH_INLINE_READ_UNLOCK if !PREEMPT
39	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT
40	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT
41	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT
42	select ARCH_INLINE_WRITE_LOCK if !PREEMPT
43	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT
44	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT
45	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT
46	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT
47	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT
48	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT
49	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT
50	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPT
51	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPT
52	select ARCH_INLINE_SPIN_LOCK if !PREEMPT
53	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPT
54	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPT
55	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPT
56	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPT
57	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT
58	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT
59	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT
60	select ARCH_USE_CMPXCHG_LOCKREF
61	select ARCH_USE_QUEUED_RWLOCKS
62	select ARCH_USE_QUEUED_SPINLOCKS
63	select ARCH_SUPPORTS_MEMORY_FAILURE
64	select ARCH_SUPPORTS_ATOMIC_RMW
65	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG
66	select ARCH_SUPPORTS_NUMA_BALANCING
67	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
68	select ARCH_WANT_FRAME_POINTERS
69	select ARCH_HAS_UBSAN_SANITIZE_ALL
70	select ARM_AMBA
71	select ARM_ARCH_TIMER
72	select ARM_GIC
73	select AUDIT_ARCH_COMPAT_GENERIC
74	select ARM_GIC_V2M if PCI
75	select ARM_GIC_V3
76	select ARM_GIC_V3_ITS if PCI
77	select ARM_PSCI_FW
78	select BUILDTIME_EXTABLE_SORT
79	select CLONE_BACKWARDS
80	select COMMON_CLK
81	select CPU_PM if (SUSPEND || CPU_IDLE)
82	select CRC32
83	select DCACHE_WORD_ACCESS
84	select DMA_DIRECT_OPS
85	select EDAC_SUPPORT
86	select FRAME_POINTER
87	select GENERIC_ALLOCATOR
88	select GENERIC_ARCH_TOPOLOGY
89	select GENERIC_CLOCKEVENTS
90	select GENERIC_CLOCKEVENTS_BROADCAST
91	select GENERIC_CPU_AUTOPROBE
92	select GENERIC_EARLY_IOREMAP
93	select GENERIC_IDLE_POLL_SETUP
94	select GENERIC_IRQ_MULTI_HANDLER
95	select GENERIC_IRQ_PROBE
96	select GENERIC_IRQ_SHOW
97	select GENERIC_IRQ_SHOW_LEVEL
98	select GENERIC_PCI_IOMAP
99	select GENERIC_SCHED_CLOCK
100	select GENERIC_SMP_IDLE_THREAD
101	select GENERIC_STRNCPY_FROM_USER
102	select GENERIC_STRNLEN_USER
103	select GENERIC_TIME_VSYSCALL
104	select HANDLE_DOMAIN_IRQ
105	select HARDIRQS_SW_RESEND
106	select HAVE_ACPI_APEI if (ACPI && EFI)
107	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
108	select HAVE_ARCH_AUDITSYSCALL
109	select HAVE_ARCH_BITREVERSE
110	select HAVE_ARCH_HUGE_VMAP
111	select HAVE_ARCH_JUMP_LABEL
112	select HAVE_ARCH_JUMP_LABEL_RELATIVE
113	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
114	select HAVE_ARCH_KGDB
115	select HAVE_ARCH_MMAP_RND_BITS
116	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
117	select HAVE_ARCH_PREL32_RELOCATIONS
118	select HAVE_ARCH_SECCOMP_FILTER
119	select HAVE_ARCH_STACKLEAK
120	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
121	select HAVE_ARCH_TRACEHOOK
122	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
123	select HAVE_ARCH_VMAP_STACK
124	select HAVE_ARM_SMCCC
125	select HAVE_EBPF_JIT
126	select HAVE_C_RECORDMCOUNT
127	select HAVE_CMPXCHG_DOUBLE
128	select HAVE_CMPXCHG_LOCAL
129	select HAVE_CONTEXT_TRACKING
130	select HAVE_DEBUG_BUGVERBOSE
131	select HAVE_DEBUG_KMEMLEAK
132	select HAVE_DMA_CONTIGUOUS
133	select HAVE_DYNAMIC_FTRACE
134	select HAVE_EFFICIENT_UNALIGNED_ACCESS
135	select HAVE_FTRACE_MCOUNT_RECORD
136	select HAVE_FUNCTION_TRACER
137	select HAVE_FUNCTION_GRAPH_TRACER
138	select HAVE_GCC_PLUGINS
139	select HAVE_GENERIC_DMA_COHERENT
140	select HAVE_HW_BREAKPOINT if PERF_EVENTS
141	select HAVE_IRQ_TIME_ACCOUNTING
142	select HAVE_MEMBLOCK_NODE_MAP if NUMA
143	select HAVE_NMI
144	select HAVE_PATA_PLATFORM
145	select HAVE_PERF_EVENTS
146	select HAVE_PERF_REGS
147	select HAVE_PERF_USER_STACK_DUMP
148	select HAVE_REGS_AND_STACK_ACCESS_API
149	select HAVE_RCU_TABLE_FREE
150	select HAVE_RCU_TABLE_INVALIDATE
151	select HAVE_RSEQ
152	select HAVE_STACKPROTECTOR
153	select HAVE_SYSCALL_TRACEPOINTS
154	select HAVE_KPROBES
155	select HAVE_KRETPROBES
156	select IOMMU_DMA if IOMMU_SUPPORT
157	select IRQ_DOMAIN
158	select IRQ_FORCED_THREADING
159	select MODULES_USE_ELF_RELA
160	select MULTI_IRQ_HANDLER
161	select NEED_DMA_MAP_STATE
162	select NEED_SG_DMA_LENGTH
163	select OF
164	select OF_EARLY_FLATTREE
165	select OF_RESERVED_MEM
166	select PCI_ECAM if (ACPI && PCI)
167	select POWER_RESET
168	select POWER_SUPPLY
169	select REFCOUNT_FULL
170	select SPARSE_IRQ
171	select SWIOTLB
172	select SYSCTL_EXCEPTION_TRACE
173	select THREAD_INFO_IN_TASK
174	help
175	  ARM 64-bit (AArch64) Linux support.
176
177config 64BIT
178	def_bool y
179
180config MMU
181	def_bool y
182
183config ARM64_PAGE_SHIFT
184	int
185	default 16 if ARM64_64K_PAGES
186	default 14 if ARM64_16K_PAGES
187	default 12
188
189config ARM64_CONT_SHIFT
190	int
191	default 5 if ARM64_64K_PAGES
192	default 7 if ARM64_16K_PAGES
193	default 4
194
195config ARCH_MMAP_RND_BITS_MIN
196       default 14 if ARM64_64K_PAGES
197       default 16 if ARM64_16K_PAGES
198       default 18
199
200# max bits determined by the following formula:
201#  VA_BITS - PAGE_SHIFT - 3
202config ARCH_MMAP_RND_BITS_MAX
203       default 19 if ARM64_VA_BITS=36
204       default 24 if ARM64_VA_BITS=39
205       default 27 if ARM64_VA_BITS=42
206       default 30 if ARM64_VA_BITS=47
207       default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
208       default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
209       default 33 if ARM64_VA_BITS=48
210       default 14 if ARM64_64K_PAGES
211       default 16 if ARM64_16K_PAGES
212       default 18
213
214config ARCH_MMAP_RND_COMPAT_BITS_MIN
215       default 7 if ARM64_64K_PAGES
216       default 9 if ARM64_16K_PAGES
217       default 11
218
219config ARCH_MMAP_RND_COMPAT_BITS_MAX
220       default 16
221
222config NO_IOPORT_MAP
223	def_bool y if !PCI
224
225config STACKTRACE_SUPPORT
226	def_bool y
227
228config ILLEGAL_POINTER_VALUE
229	hex
230	default 0xdead000000000000
231
232config LOCKDEP_SUPPORT
233	def_bool y
234
235config TRACE_IRQFLAGS_SUPPORT
236	def_bool y
237
238config RWSEM_XCHGADD_ALGORITHM
239	def_bool y
240
241config GENERIC_BUG
242	def_bool y
243	depends on BUG
244
245config GENERIC_BUG_RELATIVE_POINTERS
246	def_bool y
247	depends on GENERIC_BUG
248
249config GENERIC_HWEIGHT
250	def_bool y
251
252config GENERIC_CSUM
253        def_bool y
254
255config GENERIC_CALIBRATE_DELAY
256	def_bool y
257
258config ZONE_DMA32
259	def_bool y
260
261config HAVE_GENERIC_GUP
262	def_bool y
263
264config ARCH_ENABLE_MEMORY_HOTPLUG
265	def_bool y
266
267config SMP
268	def_bool y
269
270config KERNEL_MODE_NEON
271	def_bool y
272
273config FIX_EARLYCON_MEM
274	def_bool y
275
276config PGTABLE_LEVELS
277	int
278	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
279	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
280	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52)
281	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
282	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
283	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
284
285config ARCH_SUPPORTS_UPROBES
286	def_bool y
287
288config ARCH_PROC_KCORE_TEXT
289	def_bool y
290
291source "arch/arm64/Kconfig.platforms"
292
293menu "Bus support"
294
295config PCI
296	bool "PCI support"
297	help
298	  This feature enables support for PCI bus system. If you say Y
299	  here, the kernel will include drivers and infrastructure code
300	  to support PCI bus devices.
301
302config PCI_DOMAINS
303	def_bool PCI
304
305config PCI_DOMAINS_GENERIC
306	def_bool PCI
307
308config PCI_SYSCALL
309	def_bool PCI
310
311source "drivers/pci/Kconfig"
312
313endmenu
314
315menu "Kernel Features"
316
317menu "ARM errata workarounds via the alternatives framework"
318
319config ARM64_WORKAROUND_CLEAN_CACHE
320	def_bool n
321
322config ARM64_ERRATUM_826319
323	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
324	default y
325	select ARM64_WORKAROUND_CLEAN_CACHE
326	help
327	  This option adds an alternative code sequence to work around ARM
328	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
329	  AXI master interface and an L2 cache.
330
331	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
332	  and is unable to accept a certain write via this interface, it will
333	  not progress on read data presented on the read data channel and the
334	  system can deadlock.
335
336	  The workaround promotes data cache clean instructions to
337	  data cache clean-and-invalidate.
338	  Please note that this does not necessarily enable the workaround,
339	  as it depends on the alternative framework, which will only patch
340	  the kernel if an affected CPU is detected.
341
342	  If unsure, say Y.
343
344config ARM64_ERRATUM_827319
345	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
346	default y
347	select ARM64_WORKAROUND_CLEAN_CACHE
348	help
349	  This option adds an alternative code sequence to work around ARM
350	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
351	  master interface and an L2 cache.
352
353	  Under certain conditions this erratum can cause a clean line eviction
354	  to occur at the same time as another transaction to the same address
355	  on the AMBA 5 CHI interface, which can cause data corruption if the
356	  interconnect reorders the two transactions.
357
358	  The workaround promotes data cache clean instructions to
359	  data cache clean-and-invalidate.
360	  Please note that this does not necessarily enable the workaround,
361	  as it depends on the alternative framework, which will only patch
362	  the kernel if an affected CPU is detected.
363
364	  If unsure, say Y.
365
366config ARM64_ERRATUM_824069
367	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
368	default y
369	select ARM64_WORKAROUND_CLEAN_CACHE
370	help
371	  This option adds an alternative code sequence to work around ARM
372	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
373	  to a coherent interconnect.
374
375	  If a Cortex-A53 processor is executing a store or prefetch for
376	  write instruction at the same time as a processor in another
377	  cluster is executing a cache maintenance operation to the same
378	  address, then this erratum might cause a clean cache line to be
379	  incorrectly marked as dirty.
380
381	  The workaround promotes data cache clean instructions to
382	  data cache clean-and-invalidate.
383	  Please note that this option does not necessarily enable the
384	  workaround, as it depends on the alternative framework, which will
385	  only patch the kernel if an affected CPU is detected.
386
387	  If unsure, say Y.
388
389config ARM64_ERRATUM_819472
390	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
391	default y
392	select ARM64_WORKAROUND_CLEAN_CACHE
393	help
394	  This option adds an alternative code sequence to work around ARM
395	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
396	  present when it is connected to a coherent interconnect.
397
398	  If the processor is executing a load and store exclusive sequence at
399	  the same time as a processor in another cluster is executing a cache
400	  maintenance operation to the same address, then this erratum might
401	  cause data corruption.
402
403	  The workaround promotes data cache clean instructions to
404	  data cache clean-and-invalidate.
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_832075
412	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
413	default y
414	help
415	  This option adds an alternative code sequence to work around ARM
416	  erratum 832075 on Cortex-A57 parts up to r1p2.
417
418	  Affected Cortex-A57 parts might deadlock when exclusive load/store
419	  instructions to Write-Back memory are mixed with Device loads.
420
421	  The workaround is to promote device loads to use Load-Acquire
422	  semantics.
423	  Please note that this does not necessarily enable the workaround,
424	  as it depends on the alternative framework, which will only patch
425	  the kernel if an affected CPU is detected.
426
427	  If unsure, say Y.
428
429config ARM64_ERRATUM_834220
430	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
431	depends on KVM
432	default y
433	help
434	  This option adds an alternative code sequence to work around ARM
435	  erratum 834220 on Cortex-A57 parts up to r1p2.
436
437	  Affected Cortex-A57 parts might report a Stage 2 translation
438	  fault as the result of a Stage 1 fault for load crossing a
439	  page boundary when there is a permission or device memory
440	  alignment fault at Stage 1 and a translation fault at Stage 2.
441
442	  The workaround is to verify that the Stage 1 translation
443	  doesn't generate a fault before handling the Stage 2 fault.
444	  Please note that this does not necessarily enable the workaround,
445	  as it depends on the alternative framework, which will only patch
446	  the kernel if an affected CPU is detected.
447
448	  If unsure, say Y.
449
450config ARM64_ERRATUM_845719
451	bool "Cortex-A53: 845719: a load might read incorrect data"
452	depends on COMPAT
453	default y
454	help
455	  This option adds an alternative code sequence to work around ARM
456	  erratum 845719 on Cortex-A53 parts up to r0p4.
457
458	  When running a compat (AArch32) userspace on an affected Cortex-A53
459	  part, a load at EL0 from a virtual address that matches the bottom 32
460	  bits of the virtual address used by a recent load at (AArch64) EL1
461	  might return incorrect data.
462
463	  The workaround is to write the contextidr_el1 register on exception
464	  return to a 32-bit task.
465	  Please note that this does not necessarily enable the workaround,
466	  as it depends on the alternative framework, which will only patch
467	  the kernel if an affected CPU is detected.
468
469	  If unsure, say Y.
470
471config ARM64_ERRATUM_843419
472	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
473	default y
474	select ARM64_MODULE_PLTS if MODULES
475	help
476	  This option links the kernel with '--fix-cortex-a53-843419' and
477	  enables PLT support to replace certain ADRP instructions, which can
478	  cause subsequent memory accesses to use an incorrect address on
479	  Cortex-A53 parts up to r0p4.
480
481	  If unsure, say Y.
482
483config ARM64_ERRATUM_1024718
484	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
485	default y
486	help
487	  This option adds work around for Arm Cortex-A55 Erratum 1024718.
488
489	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
490	  update of the hardware dirty bit when the DBM/AP bits are updated
491	  without a break-before-make. The work around is to disable the usage
492	  of hardware DBM locally on the affected cores. CPUs not affected by
493	  erratum will continue to use the feature.
494
495	  If unsure, say Y.
496
497config ARM64_ERRATUM_1188873
498	bool "Cortex-A76: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
499	default y
500	select ARM_ARCH_TIMER_OOL_WORKAROUND
501	help
502	  This option adds work arounds for ARM Cortex-A76 erratum 1188873
503
504	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could cause
505	  register corruption when accessing the timer registers from
506	  AArch32 userspace.
507
508	  If unsure, say Y.
509
510config ARM64_ERRATUM_1165522
511	bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
512	default y
513	help
514	  This option adds work arounds for ARM Cortex-A76 erratum 1165522
515
516	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
517	  corrupted TLBs by speculating an AT instruction during a guest
518	  context switch.
519
520	  If unsure, say Y.
521
522config ARM64_ERRATUM_1286807
523	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
524	default y
525	select ARM64_WORKAROUND_REPEAT_TLBI
526	help
527	  This option adds workaround for ARM Cortex-A76 erratum 1286807
528
529	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
530	  address for a cacheable mapping of a location is being
531	  accessed by a core while another core is remapping the virtual
532	  address to a new physical page using the recommended
533	  break-before-make sequence, then under very rare circumstances
534	  TLBI+DSB completes before a read using the translation being
535	  invalidated has been observed by other observers. The
536	  workaround repeats the TLBI+DSB operation.
537
538	  If unsure, say Y.
539
540config CAVIUM_ERRATUM_22375
541	bool "Cavium erratum 22375, 24313"
542	default y
543	help
544	  Enable workaround for erratum 22375, 24313.
545
546	  This implements two gicv3-its errata workarounds for ThunderX. Both
547	  with small impact affecting only ITS table allocation.
548
549	    erratum 22375: only alloc 8MB table size
550	    erratum 24313: ignore memory access type
551
552	  The fixes are in ITS initialization and basically ignore memory access
553	  type and table size provided by the TYPER and BASER registers.
554
555	  If unsure, say Y.
556
557config CAVIUM_ERRATUM_23144
558	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
559	depends on NUMA
560	default y
561	help
562	  ITS SYNC command hang for cross node io and collections/cpu mapping.
563
564	  If unsure, say Y.
565
566config CAVIUM_ERRATUM_23154
567	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
568	default y
569	help
570	  The gicv3 of ThunderX requires a modified version for
571	  reading the IAR status to ensure data synchronization
572	  (access to icc_iar1_el1 is not sync'ed before and after).
573
574	  If unsure, say Y.
575
576config CAVIUM_ERRATUM_27456
577	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
578	default y
579	help
580	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
581	  instructions may cause the icache to become corrupted if it
582	  contains data for a non-current ASID.  The fix is to
583	  invalidate the icache when changing the mm context.
584
585	  If unsure, say Y.
586
587config CAVIUM_ERRATUM_30115
588	bool "Cavium erratum 30115: Guest may disable interrupts in host"
589	default y
590	help
591	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
592	  1.2, and T83 Pass 1.0, KVM guest execution may disable
593	  interrupts in host. Trapping both GICv3 group-0 and group-1
594	  accesses sidesteps the issue.
595
596	  If unsure, say Y.
597
598config QCOM_FALKOR_ERRATUM_1003
599	bool "Falkor E1003: Incorrect translation due to ASID change"
600	default y
601	help
602	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
603	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
604	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
605	  then only for entries in the walk cache, since the leaf translation
606	  is unchanged. Work around the erratum by invalidating the walk cache
607	  entries for the trampoline before entering the kernel proper.
608
609config ARM64_WORKAROUND_REPEAT_TLBI
610	bool
611	help
612	  Enable the repeat TLBI workaround for Falkor erratum 1009 and
613	  Cortex-A76 erratum 1286807.
614
615config QCOM_FALKOR_ERRATUM_1009
616	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
617	default y
618	select ARM64_WORKAROUND_REPEAT_TLBI
619	help
620	  On Falkor v1, the CPU may prematurely complete a DSB following a
621	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
622	  one more time to fix the issue.
623
624	  If unsure, say Y.
625
626config QCOM_QDF2400_ERRATUM_0065
627	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
628	default y
629	help
630	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
631	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
632	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
633
634	  If unsure, say Y.
635
636config SOCIONEXT_SYNQUACER_PREITS
637	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
638	default y
639	help
640	  Socionext Synquacer SoCs implement a separate h/w block to generate
641	  MSI doorbell writes with non-zero values for the device ID.
642
643	  If unsure, say Y.
644
645config HISILICON_ERRATUM_161600802
646	bool "Hip07 161600802: Erroneous redistributor VLPI base"
647	default y
648	help
649	  The HiSilicon Hip07 SoC usees the wrong redistributor base
650	  when issued ITS commands such as VMOVP and VMAPP, and requires
651	  a 128kB offset to be applied to the target address in this commands.
652
653	  If unsure, say Y.
654
655config QCOM_FALKOR_ERRATUM_E1041
656	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
657	default y
658	help
659	  Falkor CPU may speculatively fetch instructions from an improper
660	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
661	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
662
663	  If unsure, say Y.
664
665endmenu
666
667
668choice
669	prompt "Page size"
670	default ARM64_4K_PAGES
671	help
672	  Page size (translation granule) configuration.
673
674config ARM64_4K_PAGES
675	bool "4KB"
676	help
677	  This feature enables 4KB pages support.
678
679config ARM64_16K_PAGES
680	bool "16KB"
681	help
682	  The system will use 16KB pages support. AArch32 emulation
683	  requires applications compiled with 16K (or a multiple of 16K)
684	  aligned segments.
685
686config ARM64_64K_PAGES
687	bool "64KB"
688	help
689	  This feature enables 64KB pages support (4KB by default)
690	  allowing only two levels of page tables and faster TLB
691	  look-up. AArch32 emulation requires applications compiled
692	  with 64K aligned segments.
693
694endchoice
695
696choice
697	prompt "Virtual address space size"
698	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
699	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
700	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
701	help
702	  Allows choosing one of multiple possible virtual address
703	  space sizes. The level of translation table is determined by
704	  a combination of page size and virtual address space size.
705
706config ARM64_VA_BITS_36
707	bool "36-bit" if EXPERT
708	depends on ARM64_16K_PAGES
709
710config ARM64_VA_BITS_39
711	bool "39-bit"
712	depends on ARM64_4K_PAGES
713
714config ARM64_VA_BITS_42
715	bool "42-bit"
716	depends on ARM64_64K_PAGES
717
718config ARM64_VA_BITS_47
719	bool "47-bit"
720	depends on ARM64_16K_PAGES
721
722config ARM64_VA_BITS_48
723	bool "48-bit"
724
725config ARM64_USER_VA_BITS_52
726	bool "52-bit (user)"
727	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
728	help
729	  Enable 52-bit virtual addressing for userspace when explicitly
730	  requested via a hint to mmap(). The kernel will continue to
731	  use 48-bit virtual addresses for its own mappings.
732
733	  NOTE: Enabling 52-bit virtual addressing in conjunction with
734	  ARMv8.3 Pointer Authentication will result in the PAC being
735	  reduced from 7 bits to 3 bits, which may have a significant
736	  impact on its susceptibility to brute-force attacks.
737
738	  If unsure, select 48-bit virtual addressing instead.
739
740endchoice
741
742config ARM64_FORCE_52BIT
743	bool "Force 52-bit virtual addresses for userspace"
744	depends on ARM64_USER_VA_BITS_52 && EXPERT
745	help
746	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
747	  to maintain compatibility with older software by providing 48-bit VAs
748	  unless a hint is supplied to mmap.
749
750	  This configuration option disables the 48-bit compatibility logic, and
751	  forces all userspace addresses to be 52-bit on HW that supports it. One
752	  should only enable this configuration option for stress testing userspace
753	  memory management code. If unsure say N here.
754
755config ARM64_VA_BITS
756	int
757	default 36 if ARM64_VA_BITS_36
758	default 39 if ARM64_VA_BITS_39
759	default 42 if ARM64_VA_BITS_42
760	default 47 if ARM64_VA_BITS_47
761	default 48 if ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52
762
763choice
764	prompt "Physical address space size"
765	default ARM64_PA_BITS_48
766	help
767	  Choose the maximum physical address range that the kernel will
768	  support.
769
770config ARM64_PA_BITS_48
771	bool "48-bit"
772
773config ARM64_PA_BITS_52
774	bool "52-bit (ARMv8.2)"
775	depends on ARM64_64K_PAGES
776	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
777	help
778	  Enable support for a 52-bit physical address space, introduced as
779	  part of the ARMv8.2-LPA extension.
780
781	  With this enabled, the kernel will also continue to work on CPUs that
782	  do not support ARMv8.2-LPA, but with some added memory overhead (and
783	  minor performance overhead).
784
785endchoice
786
787config ARM64_PA_BITS
788	int
789	default 48 if ARM64_PA_BITS_48
790	default 52 if ARM64_PA_BITS_52
791
792config CPU_BIG_ENDIAN
793       bool "Build big-endian kernel"
794       help
795         Say Y if you plan on running a kernel in big-endian mode.
796
797config SCHED_MC
798	bool "Multi-core scheduler support"
799	help
800	  Multi-core scheduler support improves the CPU scheduler's decision
801	  making when dealing with multi-core CPU chips at a cost of slightly
802	  increased overhead in some places. If unsure say N here.
803
804config SCHED_SMT
805	bool "SMT scheduler support"
806	help
807	  Improves the CPU scheduler's decision making when dealing with
808	  MultiThreading at a cost of slightly increased overhead in some
809	  places. If unsure say N here.
810
811config NR_CPUS
812	int "Maximum number of CPUs (2-4096)"
813	range 2 4096
814	# These have to remain sorted largest to smallest
815	default "64"
816
817config HOTPLUG_CPU
818	bool "Support for hot-pluggable CPUs"
819	select GENERIC_IRQ_MIGRATION
820	help
821	  Say Y here to experiment with turning CPUs off and on.  CPUs
822	  can be controlled through /sys/devices/system/cpu.
823
824# Common NUMA Features
825config NUMA
826	bool "Numa Memory Allocation and Scheduler Support"
827	select ACPI_NUMA if ACPI
828	select OF_NUMA
829	help
830	  Enable NUMA (Non Uniform Memory Access) support.
831
832	  The kernel will try to allocate memory used by a CPU on the
833	  local memory of the CPU and add some more
834	  NUMA awareness to the kernel.
835
836config NODES_SHIFT
837	int "Maximum NUMA Nodes (as a power of 2)"
838	range 1 10
839	default "2"
840	depends on NEED_MULTIPLE_NODES
841	help
842	  Specify the maximum number of NUMA Nodes available on the target
843	  system.  Increases memory reserved to accommodate various tables.
844
845config USE_PERCPU_NUMA_NODE_ID
846	def_bool y
847	depends on NUMA
848
849config HAVE_SETUP_PER_CPU_AREA
850	def_bool y
851	depends on NUMA
852
853config NEED_PER_CPU_EMBED_FIRST_CHUNK
854	def_bool y
855	depends on NUMA
856
857config HOLES_IN_ZONE
858	def_bool y
859
860source kernel/Kconfig.hz
861
862config ARCH_SUPPORTS_DEBUG_PAGEALLOC
863	def_bool y
864
865config ARCH_SPARSEMEM_ENABLE
866	def_bool y
867	select SPARSEMEM_VMEMMAP_ENABLE
868
869config ARCH_SPARSEMEM_DEFAULT
870	def_bool ARCH_SPARSEMEM_ENABLE
871
872config ARCH_SELECT_MEMORY_MODEL
873	def_bool ARCH_SPARSEMEM_ENABLE
874
875config ARCH_FLATMEM_ENABLE
876	def_bool !NUMA
877
878config HAVE_ARCH_PFN_VALID
879	def_bool y
880
881config HW_PERF_EVENTS
882	def_bool y
883	depends on ARM_PMU
884
885config SYS_SUPPORTS_HUGETLBFS
886	def_bool y
887
888config ARCH_WANT_HUGE_PMD_SHARE
889	def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
890
891config ARCH_HAS_CACHE_LINE_SIZE
892	def_bool y
893
894config SECCOMP
895	bool "Enable seccomp to safely compute untrusted bytecode"
896	---help---
897	  This kernel feature is useful for number crunching applications
898	  that may need to compute untrusted bytecode during their
899	  execution. By using pipes or other transports made available to
900	  the process as file descriptors supporting the read/write
901	  syscalls, it's possible to isolate those applications in
902	  their own address space using seccomp. Once seccomp is
903	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
904	  and the task is only allowed to execute a few safe syscalls
905	  defined by each seccomp mode.
906
907config PARAVIRT
908	bool "Enable paravirtualization code"
909	help
910	  This changes the kernel so it can modify itself when it is run
911	  under a hypervisor, potentially improving performance significantly
912	  over full virtualization.
913
914config PARAVIRT_TIME_ACCOUNTING
915	bool "Paravirtual steal time accounting"
916	select PARAVIRT
917	default n
918	help
919	  Select this option to enable fine granularity task steal time
920	  accounting. Time spent executing other tasks in parallel with
921	  the current vCPU is discounted from the vCPU power. To account for
922	  that, there can be a small performance impact.
923
924	  If in doubt, say N here.
925
926config KEXEC
927	depends on PM_SLEEP_SMP
928	select KEXEC_CORE
929	bool "kexec system call"
930	---help---
931	  kexec is a system call that implements the ability to shutdown your
932	  current kernel, and to start another kernel.  It is like a reboot
933	  but it is independent of the system firmware.   And like a reboot
934	  you can start any kernel with it, not just Linux.
935
936config KEXEC_FILE
937	bool "kexec file based system call"
938	select KEXEC_CORE
939	help
940	  This is new version of kexec system call. This system call is
941	  file based and takes file descriptors as system call argument
942	  for kernel and initramfs as opposed to list of segments as
943	  accepted by previous system call.
944
945config KEXEC_VERIFY_SIG
946	bool "Verify kernel signature during kexec_file_load() syscall"
947	depends on KEXEC_FILE
948	help
949	  Select this option to verify a signature with loaded kernel
950	  image. If configured, any attempt of loading a image without
951	  valid signature will fail.
952
953	  In addition to that option, you need to enable signature
954	  verification for the corresponding kernel image type being
955	  loaded in order for this to work.
956
957config KEXEC_IMAGE_VERIFY_SIG
958	bool "Enable Image signature verification support"
959	default y
960	depends on KEXEC_VERIFY_SIG
961	depends on EFI && SIGNED_PE_FILE_VERIFICATION
962	help
963	  Enable Image signature verification support.
964
965comment "Support for PE file signature verification disabled"
966	depends on KEXEC_VERIFY_SIG
967	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
968
969config CRASH_DUMP
970	bool "Build kdump crash kernel"
971	help
972	  Generate crash dump after being started by kexec. This should
973	  be normally only set in special crash dump kernels which are
974	  loaded in the main kernel with kexec-tools into a specially
975	  reserved region and then later executed after a crash by
976	  kdump/kexec.
977
978	  For more details see Documentation/kdump/kdump.txt
979
980config XEN_DOM0
981	def_bool y
982	depends on XEN
983
984config XEN
985	bool "Xen guest support on ARM64"
986	depends on ARM64 && OF
987	select SWIOTLB_XEN
988	select PARAVIRT
989	help
990	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
991
992config FORCE_MAX_ZONEORDER
993	int
994	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
995	default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
996	default "11"
997	help
998	  The kernel memory allocator divides physically contiguous memory
999	  blocks into "zones", where each zone is a power of two number of
1000	  pages.  This option selects the largest power of two that the kernel
1001	  keeps in the memory allocator.  If you need to allocate very large
1002	  blocks of physically contiguous memory, then you may need to
1003	  increase this value.
1004
1005	  This config option is actually maximum order plus one. For example,
1006	  a value of 11 means that the largest free memory block is 2^10 pages.
1007
1008	  We make sure that we can allocate upto a HugePage size for each configuration.
1009	  Hence we have :
1010		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1011
1012	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1013	  4M allocations matching the default size used by generic code.
1014
1015config UNMAP_KERNEL_AT_EL0
1016	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1017	default y
1018	help
1019	  Speculation attacks against some high-performance processors can
1020	  be used to bypass MMU permission checks and leak kernel data to
1021	  userspace. This can be defended against by unmapping the kernel
1022	  when running in userspace, mapping it back in on exception entry
1023	  via a trampoline page in the vector table.
1024
1025	  If unsure, say Y.
1026
1027config HARDEN_BRANCH_PREDICTOR
1028	bool "Harden the branch predictor against aliasing attacks" if EXPERT
1029	default y
1030	help
1031	  Speculation attacks against some high-performance processors rely on
1032	  being able to manipulate the branch predictor for a victim context by
1033	  executing aliasing branches in the attacker context.  Such attacks
1034	  can be partially mitigated against by clearing internal branch
1035	  predictor state and limiting the prediction logic in some situations.
1036
1037	  This config option will take CPU-specific actions to harden the
1038	  branch predictor against aliasing attacks and may rely on specific
1039	  instruction sequences or control bits being set by the system
1040	  firmware.
1041
1042	  If unsure, say Y.
1043
1044config HARDEN_EL2_VECTORS
1045	bool "Harden EL2 vector mapping against system register leak" if EXPERT
1046	default y
1047	help
1048	  Speculation attacks against some high-performance processors can
1049	  be used to leak privileged information such as the vector base
1050	  register, resulting in a potential defeat of the EL2 layout
1051	  randomization.
1052
1053	  This config option will map the vectors to a fixed location,
1054	  independent of the EL2 code mapping, so that revealing VBAR_EL2
1055	  to an attacker does not give away any extra information. This
1056	  only gets enabled on affected CPUs.
1057
1058	  If unsure, say Y.
1059
1060config ARM64_SSBD
1061	bool "Speculative Store Bypass Disable" if EXPERT
1062	default y
1063	help
1064	  This enables mitigation of the bypassing of previous stores
1065	  by speculative loads.
1066
1067	  If unsure, say Y.
1068
1069config RODATA_FULL_DEFAULT_ENABLED
1070	bool "Apply r/o permissions of VM areas also to their linear aliases"
1071	default y
1072	help
1073	  Apply read-only attributes of VM areas to the linear alias of
1074	  the backing pages as well. This prevents code or read-only data
1075	  from being modified (inadvertently or intentionally) via another
1076	  mapping of the same memory page. This additional enhancement can
1077	  be turned off at runtime by passing rodata=[off|on] (and turned on
1078	  with rodata=full if this option is set to 'n')
1079
1080	  This requires the linear region to be mapped down to pages,
1081	  which may adversely affect performance in some cases.
1082
1083menuconfig ARMV8_DEPRECATED
1084	bool "Emulate deprecated/obsolete ARMv8 instructions"
1085	depends on COMPAT
1086	depends on SYSCTL
1087	help
1088	  Legacy software support may require certain instructions
1089	  that have been deprecated or obsoleted in the architecture.
1090
1091	  Enable this config to enable selective emulation of these
1092	  features.
1093
1094	  If unsure, say Y
1095
1096if ARMV8_DEPRECATED
1097
1098config SWP_EMULATION
1099	bool "Emulate SWP/SWPB instructions"
1100	help
1101	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1102	  they are always undefined. Say Y here to enable software
1103	  emulation of these instructions for userspace using LDXR/STXR.
1104
1105	  In some older versions of glibc [<=2.8] SWP is used during futex
1106	  trylock() operations with the assumption that the code will not
1107	  be preempted. This invalid assumption may be more likely to fail
1108	  with SWP emulation enabled, leading to deadlock of the user
1109	  application.
1110
1111	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1112	  on an external transaction monitoring block called a global
1113	  monitor to maintain update atomicity. If your system does not
1114	  implement a global monitor, this option can cause programs that
1115	  perform SWP operations to uncached memory to deadlock.
1116
1117	  If unsure, say Y
1118
1119config CP15_BARRIER_EMULATION
1120	bool "Emulate CP15 Barrier instructions"
1121	help
1122	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1123	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1124	  strongly recommended to use the ISB, DSB, and DMB
1125	  instructions instead.
1126
1127	  Say Y here to enable software emulation of these
1128	  instructions for AArch32 userspace code. When this option is
1129	  enabled, CP15 barrier usage is traced which can help
1130	  identify software that needs updating.
1131
1132	  If unsure, say Y
1133
1134config SETEND_EMULATION
1135	bool "Emulate SETEND instruction"
1136	help
1137	  The SETEND instruction alters the data-endianness of the
1138	  AArch32 EL0, and is deprecated in ARMv8.
1139
1140	  Say Y here to enable software emulation of the instruction
1141	  for AArch32 userspace code.
1142
1143	  Note: All the cpus on the system must have mixed endian support at EL0
1144	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1145	  endian - is hotplugged in after this feature has been enabled, there could
1146	  be unexpected results in the applications.
1147
1148	  If unsure, say Y
1149endif
1150
1151config ARM64_SW_TTBR0_PAN
1152	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1153	help
1154	  Enabling this option prevents the kernel from accessing
1155	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1156	  zeroed area and reserved ASID. The user access routines
1157	  restore the valid TTBR0_EL1 temporarily.
1158
1159menu "ARMv8.1 architectural features"
1160
1161config ARM64_HW_AFDBM
1162	bool "Support for hardware updates of the Access and Dirty page flags"
1163	default y
1164	help
1165	  The ARMv8.1 architecture extensions introduce support for
1166	  hardware updates of the access and dirty information in page
1167	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1168	  capable processors, accesses to pages with PTE_AF cleared will
1169	  set this bit instead of raising an access flag fault.
1170	  Similarly, writes to read-only pages with the DBM bit set will
1171	  clear the read-only bit (AP[2]) instead of raising a
1172	  permission fault.
1173
1174	  Kernels built with this configuration option enabled continue
1175	  to work on pre-ARMv8.1 hardware and the performance impact is
1176	  minimal. If unsure, say Y.
1177
1178config ARM64_PAN
1179	bool "Enable support for Privileged Access Never (PAN)"
1180	default y
1181	help
1182	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1183	 prevents the kernel or hypervisor from accessing user-space (EL0)
1184	 memory directly.
1185
1186	 Choosing this option will cause any unprotected (not using
1187	 copy_to_user et al) memory access to fail with a permission fault.
1188
1189	 The feature is detected at runtime, and will remain as a 'nop'
1190	 instruction if the cpu does not implement the feature.
1191
1192config ARM64_LSE_ATOMICS
1193	bool "Atomic instructions"
1194	default y
1195	help
1196	  As part of the Large System Extensions, ARMv8.1 introduces new
1197	  atomic instructions that are designed specifically to scale in
1198	  very large systems.
1199
1200	  Say Y here to make use of these instructions for the in-kernel
1201	  atomic routines. This incurs a small overhead on CPUs that do
1202	  not support these instructions and requires the kernel to be
1203	  built with binutils >= 2.25 in order for the new instructions
1204	  to be used.
1205
1206config ARM64_VHE
1207	bool "Enable support for Virtualization Host Extensions (VHE)"
1208	default y
1209	help
1210	  Virtualization Host Extensions (VHE) allow the kernel to run
1211	  directly at EL2 (instead of EL1) on processors that support
1212	  it. This leads to better performance for KVM, as they reduce
1213	  the cost of the world switch.
1214
1215	  Selecting this option allows the VHE feature to be detected
1216	  at runtime, and does not affect processors that do not
1217	  implement this feature.
1218
1219endmenu
1220
1221menu "ARMv8.2 architectural features"
1222
1223config ARM64_UAO
1224	bool "Enable support for User Access Override (UAO)"
1225	default y
1226	help
1227	  User Access Override (UAO; part of the ARMv8.2 Extensions)
1228	  causes the 'unprivileged' variant of the load/store instructions to
1229	  be overridden to be privileged.
1230
1231	  This option changes get_user() and friends to use the 'unprivileged'
1232	  variant of the load/store instructions. This ensures that user-space
1233	  really did have access to the supplied memory. When addr_limit is
1234	  set to kernel memory the UAO bit will be set, allowing privileged
1235	  access to kernel memory.
1236
1237	  Choosing this option will cause copy_to_user() et al to use user-space
1238	  memory permissions.
1239
1240	  The feature is detected at runtime, the kernel will use the
1241	  regular load/store instructions if the cpu does not implement the
1242	  feature.
1243
1244config ARM64_PMEM
1245	bool "Enable support for persistent memory"
1246	select ARCH_HAS_PMEM_API
1247	select ARCH_HAS_UACCESS_FLUSHCACHE
1248	help
1249	  Say Y to enable support for the persistent memory API based on the
1250	  ARMv8.2 DCPoP feature.
1251
1252	  The feature is detected at runtime, and the kernel will use DC CVAC
1253	  operations if DC CVAP is not supported (following the behaviour of
1254	  DC CVAP itself if the system does not define a point of persistence).
1255
1256config ARM64_RAS_EXTN
1257	bool "Enable support for RAS CPU Extensions"
1258	default y
1259	help
1260	  CPUs that support the Reliability, Availability and Serviceability
1261	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1262	  errors, classify them and report them to software.
1263
1264	  On CPUs with these extensions system software can use additional
1265	  barriers to determine if faults are pending and read the
1266	  classification from a new set of registers.
1267
1268	  Selecting this feature will allow the kernel to use these barriers
1269	  and access the new registers if the system supports the extension.
1270	  Platform RAS features may additionally depend on firmware support.
1271
1272config ARM64_CNP
1273	bool "Enable support for Common Not Private (CNP) translations"
1274	default y
1275	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1276	help
1277	  Common Not Private (CNP) allows translation table entries to
1278	  be shared between different PEs in the same inner shareable
1279	  domain, so the hardware can use this fact to optimise the
1280	  caching of such entries in the TLB.
1281
1282	  Selecting this option allows the CNP feature to be detected
1283	  at runtime, and does not affect PEs that do not implement
1284	  this feature.
1285
1286endmenu
1287
1288menu "ARMv8.3 architectural features"
1289
1290config ARM64_PTR_AUTH
1291	bool "Enable support for pointer authentication"
1292	default y
1293	help
1294	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1295	  instructions for signing and authenticating pointers against secret
1296	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1297	  and other attacks.
1298
1299	  This option enables these instructions at EL0 (i.e. for userspace).
1300
1301	  Choosing this option will cause the kernel to initialise secret keys
1302	  for each process at exec() time, with these keys being
1303	  context-switched along with the process.
1304
1305	  The feature is detected at runtime. If the feature is not present in
1306	  hardware it will not be advertised to userspace nor will it be
1307	  enabled.
1308
1309endmenu
1310
1311config ARM64_SVE
1312	bool "ARM Scalable Vector Extension support"
1313	default y
1314	depends on !KVM || ARM64_VHE
1315	help
1316	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1317	  execution state which complements and extends the SIMD functionality
1318	  of the base architecture to support much larger vectors and to enable
1319	  additional vectorisation opportunities.
1320
1321	  To enable use of this extension on CPUs that implement it, say Y.
1322
1323	  Note that for architectural reasons, firmware _must_ implement SVE
1324	  support when running on SVE capable hardware.  The required support
1325	  is present in:
1326
1327	    * version 1.5 and later of the ARM Trusted Firmware
1328	    * the AArch64 boot wrapper since commit 5e1261e08abf
1329	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1330
1331	  For other firmware implementations, consult the firmware documentation
1332	  or vendor.
1333
1334	  If you need the kernel to boot on SVE-capable hardware with broken
1335	  firmware, you may need to say N here until you get your firmware
1336	  fixed.  Otherwise, you may experience firmware panics or lockups when
1337	  booting the kernel.  If unsure and you are not observing these
1338	  symptoms, you should assume that it is safe to say Y.
1339
1340	  CPUs that support SVE are architecturally required to support the
1341	  Virtualization Host Extensions (VHE), so the kernel makes no
1342	  provision for supporting SVE alongside KVM without VHE enabled.
1343	  Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
1344	  KVM in the same kernel image.
1345
1346config ARM64_MODULE_PLTS
1347	bool
1348	select HAVE_MOD_ARCH_SPECIFIC
1349
1350config RELOCATABLE
1351	bool
1352	help
1353	  This builds the kernel as a Position Independent Executable (PIE),
1354	  which retains all relocation metadata required to relocate the
1355	  kernel binary at runtime to a different virtual address than the
1356	  address it was linked at.
1357	  Since AArch64 uses the RELA relocation format, this requires a
1358	  relocation pass at runtime even if the kernel is loaded at the
1359	  same address it was linked at.
1360
1361config RANDOMIZE_BASE
1362	bool "Randomize the address of the kernel image"
1363	select ARM64_MODULE_PLTS if MODULES
1364	select RELOCATABLE
1365	help
1366	  Randomizes the virtual address at which the kernel image is
1367	  loaded, as a security feature that deters exploit attempts
1368	  relying on knowledge of the location of kernel internals.
1369
1370	  It is the bootloader's job to provide entropy, by passing a
1371	  random u64 value in /chosen/kaslr-seed at kernel entry.
1372
1373	  When booting via the UEFI stub, it will invoke the firmware's
1374	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1375	  to the kernel proper. In addition, it will randomise the physical
1376	  location of the kernel Image as well.
1377
1378	  If unsure, say N.
1379
1380config RANDOMIZE_MODULE_REGION_FULL
1381	bool "Randomize the module region over a 4 GB range"
1382	depends on RANDOMIZE_BASE
1383	default y
1384	help
1385	  Randomizes the location of the module region inside a 4 GB window
1386	  covering the core kernel. This way, it is less likely for modules
1387	  to leak information about the location of core kernel data structures
1388	  but it does imply that function calls between modules and the core
1389	  kernel will need to be resolved via veneers in the module PLT.
1390
1391	  When this option is not set, the module region will be randomized over
1392	  a limited range that contains the [_stext, _etext] interval of the
1393	  core kernel, so branch relocations are always in range.
1394
1395config CC_HAVE_STACKPROTECTOR_SYSREG
1396	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1397
1398config STACKPROTECTOR_PER_TASK
1399	def_bool y
1400	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1401
1402endmenu
1403
1404menu "Boot options"
1405
1406config ARM64_ACPI_PARKING_PROTOCOL
1407	bool "Enable support for the ARM64 ACPI parking protocol"
1408	depends on ACPI
1409	help
1410	  Enable support for the ARM64 ACPI parking protocol. If disabled
1411	  the kernel will not allow booting through the ARM64 ACPI parking
1412	  protocol even if the corresponding data is present in the ACPI
1413	  MADT table.
1414
1415config CMDLINE
1416	string "Default kernel command string"
1417	default ""
1418	help
1419	  Provide a set of default command-line options at build time by
1420	  entering them here. As a minimum, you should specify the the
1421	  root device (e.g. root=/dev/nfs).
1422
1423config CMDLINE_FORCE
1424	bool "Always use the default kernel command string"
1425	help
1426	  Always use the default kernel command string, even if the boot
1427	  loader passes other arguments to the kernel.
1428	  This is useful if you cannot or don't want to change the
1429	  command-line options your boot loader passes to the kernel.
1430
1431config EFI_STUB
1432	bool
1433
1434config EFI
1435	bool "UEFI runtime support"
1436	depends on OF && !CPU_BIG_ENDIAN
1437	depends on KERNEL_MODE_NEON
1438	select ARCH_SUPPORTS_ACPI
1439	select LIBFDT
1440	select UCS2_STRING
1441	select EFI_PARAMS_FROM_FDT
1442	select EFI_RUNTIME_WRAPPERS
1443	select EFI_STUB
1444	select EFI_ARMSTUB
1445	default y
1446	help
1447	  This option provides support for runtime services provided
1448	  by UEFI firmware (such as non-volatile variables, realtime
1449          clock, and platform reset). A UEFI stub is also provided to
1450	  allow the kernel to be booted as an EFI application. This
1451	  is only useful on systems that have UEFI firmware.
1452
1453config DMI
1454	bool "Enable support for SMBIOS (DMI) tables"
1455	depends on EFI
1456	default y
1457	help
1458	  This enables SMBIOS/DMI feature for systems.
1459
1460	  This option is only useful on systems that have UEFI firmware.
1461	  However, even with this option, the resultant kernel should
1462	  continue to boot on existing non-UEFI platforms.
1463
1464endmenu
1465
1466config COMPAT
1467	bool "Kernel support for 32-bit EL0"
1468	depends on ARM64_4K_PAGES || EXPERT
1469	select COMPAT_BINFMT_ELF if BINFMT_ELF
1470	select HAVE_UID16
1471	select OLD_SIGSUSPEND3
1472	select COMPAT_OLD_SIGACTION
1473	help
1474	  This option enables support for a 32-bit EL0 running under a 64-bit
1475	  kernel at EL1. AArch32-specific components such as system calls,
1476	  the user helper functions, VFP support and the ptrace interface are
1477	  handled appropriately by the kernel.
1478
1479	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1480	  that you will only be able to execute AArch32 binaries that were compiled
1481	  with page size aligned segments.
1482
1483	  If you want to execute 32-bit userspace applications, say Y.
1484
1485config SYSVIPC_COMPAT
1486	def_bool y
1487	depends on COMPAT && SYSVIPC
1488
1489menu "Power management options"
1490
1491source "kernel/power/Kconfig"
1492
1493config ARCH_HIBERNATION_POSSIBLE
1494	def_bool y
1495	depends on CPU_PM
1496
1497config ARCH_HIBERNATION_HEADER
1498	def_bool y
1499	depends on HIBERNATION
1500
1501config ARCH_SUSPEND_POSSIBLE
1502	def_bool y
1503
1504endmenu
1505
1506menu "CPU Power Management"
1507
1508source "drivers/cpuidle/Kconfig"
1509
1510source "drivers/cpufreq/Kconfig"
1511
1512endmenu
1513
1514source "drivers/firmware/Kconfig"
1515
1516source "drivers/acpi/Kconfig"
1517
1518source "arch/arm64/kvm/Kconfig"
1519
1520if CRYPTO
1521source "arch/arm64/crypto/Kconfig"
1522endif
1523