xref: /openbmc/linux/arch/arm64/Kconfig (revision b830f94f)
1# SPDX-License-Identifier: GPL-2.0-only
2config ARM64
3	def_bool y
4	select ACPI_CCA_REQUIRED if ACPI
5	select ACPI_GENERIC_GSI if ACPI
6	select ACPI_GTDT if ACPI
7	select ACPI_IORT if ACPI
8	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
9	select ACPI_MCFG if (ACPI && PCI)
10	select ACPI_SPCR_TABLE if ACPI
11	select ACPI_PPTT if ACPI
12	select ARCH_CLOCKSOURCE_DATA
13	select ARCH_HAS_DEBUG_VIRTUAL
14	select ARCH_HAS_DEVMEM_IS_ALLOWED
15	select ARCH_HAS_DMA_COHERENT_TO_PFN
16	select ARCH_HAS_DMA_MMAP_PGPROT
17	select ARCH_HAS_DMA_PREP_COHERENT
18	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
19	select ARCH_HAS_ELF_RANDOMIZE
20	select ARCH_HAS_FAST_MULTIPLIER
21	select ARCH_HAS_FORTIFY_SOURCE
22	select ARCH_HAS_GCOV_PROFILE_ALL
23	select ARCH_HAS_GIGANTIC_PAGE
24	select ARCH_HAS_KCOV
25	select ARCH_HAS_KEEPINITRD
26	select ARCH_HAS_MEMBARRIER_SYNC_CORE
27	select ARCH_HAS_PTE_DEVMAP
28	select ARCH_HAS_PTE_SPECIAL
29	select ARCH_HAS_SETUP_DMA_OPS
30	select ARCH_HAS_SET_DIRECT_MAP
31	select ARCH_HAS_SET_MEMORY
32	select ARCH_HAS_STRICT_KERNEL_RWX
33	select ARCH_HAS_STRICT_MODULE_RWX
34	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
35	select ARCH_HAS_SYNC_DMA_FOR_CPU
36	select ARCH_HAS_SYSCALL_WRAPPER
37	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
38	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
39	select ARCH_HAVE_NMI_SAFE_CMPXCHG
40	select ARCH_INLINE_READ_LOCK if !PREEMPT
41	select ARCH_INLINE_READ_LOCK_BH if !PREEMPT
42	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT
43	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT
44	select ARCH_INLINE_READ_UNLOCK if !PREEMPT
45	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT
46	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT
47	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT
48	select ARCH_INLINE_WRITE_LOCK if !PREEMPT
49	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT
50	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT
51	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT
52	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT
53	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT
54	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT
55	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT
56	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPT
57	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPT
58	select ARCH_INLINE_SPIN_LOCK if !PREEMPT
59	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPT
60	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPT
61	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPT
62	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPT
63	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT
64	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT
65	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT
66	select ARCH_KEEP_MEMBLOCK
67	select ARCH_USE_CMPXCHG_LOCKREF
68	select ARCH_USE_QUEUED_RWLOCKS
69	select ARCH_USE_QUEUED_SPINLOCKS
70	select ARCH_SUPPORTS_MEMORY_FAILURE
71	select ARCH_SUPPORTS_ATOMIC_RMW
72	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG
73	select ARCH_SUPPORTS_NUMA_BALANCING
74	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
75	select ARCH_WANT_FRAME_POINTERS
76	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
77	select ARCH_HAS_UBSAN_SANITIZE_ALL
78	select ARM_AMBA
79	select ARM_ARCH_TIMER
80	select ARM_GIC
81	select AUDIT_ARCH_COMPAT_GENERIC
82	select ARM_GIC_V2M if PCI
83	select ARM_GIC_V3
84	select ARM_GIC_V3_ITS if PCI
85	select ARM_PSCI_FW
86	select BUILDTIME_EXTABLE_SORT
87	select CLONE_BACKWARDS
88	select COMMON_CLK
89	select CPU_PM if (SUSPEND || CPU_IDLE)
90	select CRC32
91	select DCACHE_WORD_ACCESS
92	select DMA_DIRECT_REMAP
93	select EDAC_SUPPORT
94	select FRAME_POINTER
95	select GENERIC_ALLOCATOR
96	select GENERIC_ARCH_TOPOLOGY
97	select GENERIC_CLOCKEVENTS
98	select GENERIC_CLOCKEVENTS_BROADCAST
99	select GENERIC_CPU_AUTOPROBE
100	select GENERIC_CPU_VULNERABILITIES
101	select GENERIC_EARLY_IOREMAP
102	select GENERIC_IDLE_POLL_SETUP
103	select GENERIC_IRQ_MULTI_HANDLER
104	select GENERIC_IRQ_PROBE
105	select GENERIC_IRQ_SHOW
106	select GENERIC_IRQ_SHOW_LEVEL
107	select GENERIC_PCI_IOMAP
108	select GENERIC_SCHED_CLOCK
109	select GENERIC_SMP_IDLE_THREAD
110	select GENERIC_STRNCPY_FROM_USER
111	select GENERIC_STRNLEN_USER
112	select GENERIC_TIME_VSYSCALL
113	select GENERIC_GETTIMEOFDAY
114	select GENERIC_COMPAT_VDSO if (!CPU_BIG_ENDIAN && COMPAT)
115	select HANDLE_DOMAIN_IRQ
116	select HARDIRQS_SW_RESEND
117	select HAVE_PCI
118	select HAVE_ACPI_APEI if (ACPI && EFI)
119	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
120	select HAVE_ARCH_AUDITSYSCALL
121	select HAVE_ARCH_BITREVERSE
122	select HAVE_ARCH_HUGE_VMAP
123	select HAVE_ARCH_JUMP_LABEL
124	select HAVE_ARCH_JUMP_LABEL_RELATIVE
125	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
126	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
127	select HAVE_ARCH_KGDB
128	select HAVE_ARCH_MMAP_RND_BITS
129	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
130	select HAVE_ARCH_PREL32_RELOCATIONS
131	select HAVE_ARCH_SECCOMP_FILTER
132	select HAVE_ARCH_STACKLEAK
133	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
134	select HAVE_ARCH_TRACEHOOK
135	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
136	select HAVE_ARCH_VMAP_STACK
137	select HAVE_ARM_SMCCC
138	select HAVE_EBPF_JIT
139	select HAVE_C_RECORDMCOUNT
140	select HAVE_CMPXCHG_DOUBLE
141	select HAVE_CMPXCHG_LOCAL
142	select HAVE_CONTEXT_TRACKING
143	select HAVE_DEBUG_BUGVERBOSE
144	select HAVE_DEBUG_KMEMLEAK
145	select HAVE_DMA_CONTIGUOUS
146	select HAVE_DYNAMIC_FTRACE
147	select HAVE_EFFICIENT_UNALIGNED_ACCESS
148	select HAVE_FAST_GUP
149	select HAVE_FTRACE_MCOUNT_RECORD
150	select HAVE_FUNCTION_TRACER
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_USER_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
300source "arch/arm64/Kconfig.platforms"
301
302menu "Kernel Features"
303
304menu "ARM errata workarounds via the alternatives framework"
305
306config ARM64_WORKAROUND_CLEAN_CACHE
307	bool
308
309config ARM64_ERRATUM_826319
310	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
311	default y
312	select ARM64_WORKAROUND_CLEAN_CACHE
313	help
314	  This option adds an alternative code sequence to work around ARM
315	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
316	  AXI master interface and an L2 cache.
317
318	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
319	  and is unable to accept a certain write via this interface, it will
320	  not progress on read data presented on the read data channel and the
321	  system can deadlock.
322
323	  The workaround promotes data cache clean instructions to
324	  data cache clean-and-invalidate.
325	  Please note that this does not necessarily enable the workaround,
326	  as it depends on the alternative framework, which will only patch
327	  the kernel if an affected CPU is detected.
328
329	  If unsure, say Y.
330
331config ARM64_ERRATUM_827319
332	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
333	default y
334	select ARM64_WORKAROUND_CLEAN_CACHE
335	help
336	  This option adds an alternative code sequence to work around ARM
337	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
338	  master interface and an L2 cache.
339
340	  Under certain conditions this erratum can cause a clean line eviction
341	  to occur at the same time as another transaction to the same address
342	  on the AMBA 5 CHI interface, which can cause data corruption if the
343	  interconnect reorders the two transactions.
344
345	  The workaround promotes data cache clean instructions to
346	  data cache clean-and-invalidate.
347	  Please note that this does not necessarily enable the workaround,
348	  as it depends on the alternative framework, which will only patch
349	  the kernel if an affected CPU is detected.
350
351	  If unsure, say Y.
352
353config ARM64_ERRATUM_824069
354	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
355	default y
356	select ARM64_WORKAROUND_CLEAN_CACHE
357	help
358	  This option adds an alternative code sequence to work around ARM
359	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
360	  to a coherent interconnect.
361
362	  If a Cortex-A53 processor is executing a store or prefetch for
363	  write instruction at the same time as a processor in another
364	  cluster is executing a cache maintenance operation to the same
365	  address, then this erratum might cause a clean cache line to be
366	  incorrectly marked as dirty.
367
368	  The workaround promotes data cache clean instructions to
369	  data cache clean-and-invalidate.
370	  Please note that this option does not necessarily enable the
371	  workaround, as it depends on the alternative framework, which will
372	  only patch the kernel if an affected CPU is detected.
373
374	  If unsure, say Y.
375
376config ARM64_ERRATUM_819472
377	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
378	default y
379	select ARM64_WORKAROUND_CLEAN_CACHE
380	help
381	  This option adds an alternative code sequence to work around ARM
382	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
383	  present when it is connected to a coherent interconnect.
384
385	  If the processor is executing a load and store exclusive sequence at
386	  the same time as a processor in another cluster is executing a cache
387	  maintenance operation to the same address, then this erratum might
388	  cause data corruption.
389
390	  The workaround promotes data cache clean instructions to
391	  data cache clean-and-invalidate.
392	  Please note that this does not necessarily enable the workaround,
393	  as it depends on the alternative framework, which will only patch
394	  the kernel if an affected CPU is detected.
395
396	  If unsure, say Y.
397
398config ARM64_ERRATUM_832075
399	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
400	default y
401	help
402	  This option adds an alternative code sequence to work around ARM
403	  erratum 832075 on Cortex-A57 parts up to r1p2.
404
405	  Affected Cortex-A57 parts might deadlock when exclusive load/store
406	  instructions to Write-Back memory are mixed with Device loads.
407
408	  The workaround is to promote device loads to use Load-Acquire
409	  semantics.
410	  Please note that this does not necessarily enable the workaround,
411	  as it depends on the alternative framework, which will only patch
412	  the kernel if an affected CPU is detected.
413
414	  If unsure, say Y.
415
416config ARM64_ERRATUM_834220
417	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
418	depends on KVM
419	default y
420	help
421	  This option adds an alternative code sequence to work around ARM
422	  erratum 834220 on Cortex-A57 parts up to r1p2.
423
424	  Affected Cortex-A57 parts might report a Stage 2 translation
425	  fault as the result of a Stage 1 fault for load crossing a
426	  page boundary when there is a permission or device memory
427	  alignment fault at Stage 1 and a translation fault at Stage 2.
428
429	  The workaround is to verify that the Stage 1 translation
430	  doesn't generate a fault before handling the Stage 2 fault.
431	  Please note that this does not necessarily enable the workaround,
432	  as it depends on the alternative framework, which will only patch
433	  the kernel if an affected CPU is detected.
434
435	  If unsure, say Y.
436
437config ARM64_ERRATUM_845719
438	bool "Cortex-A53: 845719: a load might read incorrect data"
439	depends on COMPAT
440	default y
441	help
442	  This option adds an alternative code sequence to work around ARM
443	  erratum 845719 on Cortex-A53 parts up to r0p4.
444
445	  When running a compat (AArch32) userspace on an affected Cortex-A53
446	  part, a load at EL0 from a virtual address that matches the bottom 32
447	  bits of the virtual address used by a recent load at (AArch64) EL1
448	  might return incorrect data.
449
450	  The workaround is to write the contextidr_el1 register on exception
451	  return to a 32-bit task.
452	  Please note that this does not necessarily enable the workaround,
453	  as it depends on the alternative framework, which will only patch
454	  the kernel if an affected CPU is detected.
455
456	  If unsure, say Y.
457
458config ARM64_ERRATUM_843419
459	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
460	default y
461	select ARM64_MODULE_PLTS if MODULES
462	help
463	  This option links the kernel with '--fix-cortex-a53-843419' and
464	  enables PLT support to replace certain ADRP instructions, which can
465	  cause subsequent memory accesses to use an incorrect address on
466	  Cortex-A53 parts up to r0p4.
467
468	  If unsure, say Y.
469
470config ARM64_ERRATUM_1024718
471	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
472	default y
473	help
474	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
475
476	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
477	  update of the hardware dirty bit when the DBM/AP bits are updated
478	  without a break-before-make. The workaround is to disable the usage
479	  of hardware DBM locally on the affected cores. CPUs not affected by
480	  this erratum will continue to use the feature.
481
482	  If unsure, say Y.
483
484config ARM64_ERRATUM_1418040
485	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
486	default y
487	depends on COMPAT
488	help
489	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
490	  errata 1188873 and 1418040.
491
492	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
493	  cause register corruption when accessing the timer registers
494	  from AArch32 userspace.
495
496	  If unsure, say Y.
497
498config ARM64_ERRATUM_1165522
499	bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
500	default y
501	help
502	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
503
504	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
505	  corrupted TLBs by speculating an AT instruction during a guest
506	  context switch.
507
508	  If unsure, say Y.
509
510config ARM64_ERRATUM_1286807
511	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
512	default y
513	select ARM64_WORKAROUND_REPEAT_TLBI
514	help
515	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
516
517	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
518	  address for a cacheable mapping of a location is being
519	  accessed by a core while another core is remapping the virtual
520	  address to a new physical page using the recommended
521	  break-before-make sequence, then under very rare circumstances
522	  TLBI+DSB completes before a read using the translation being
523	  invalidated has been observed by other observers. The
524	  workaround repeats the TLBI+DSB operation.
525
526	  If unsure, say Y.
527
528config ARM64_ERRATUM_1463225
529	bool "Cortex-A76: Software Step might prevent interrupt recognition"
530	default y
531	help
532	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
533
534	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
535	  of a system call instruction (SVC) can prevent recognition of
536	  subsequent interrupts when software stepping is disabled in the
537	  exception handler of the system call and either kernel debugging
538	  is enabled or VHE is in use.
539
540	  Work around the erratum by triggering a dummy step exception
541	  when handling a system call from a task that is being stepped
542	  in a VHE configuration of the kernel.
543
544	  If unsure, say Y.
545
546config CAVIUM_ERRATUM_22375
547	bool "Cavium erratum 22375, 24313"
548	default y
549	help
550	  Enable workaround for errata 22375 and 24313.
551
552	  This implements two gicv3-its errata workarounds for ThunderX. Both
553	  with a small impact affecting only ITS table allocation.
554
555	    erratum 22375: only alloc 8MB table size
556	    erratum 24313: ignore memory access type
557
558	  The fixes are in ITS initialization and basically ignore memory access
559	  type and table size provided by the TYPER and BASER registers.
560
561	  If unsure, say Y.
562
563config CAVIUM_ERRATUM_23144
564	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
565	depends on NUMA
566	default y
567	help
568	  ITS SYNC command hang for cross node io and collections/cpu mapping.
569
570	  If unsure, say Y.
571
572config CAVIUM_ERRATUM_23154
573	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
574	default y
575	help
576	  The gicv3 of ThunderX requires a modified version for
577	  reading the IAR status to ensure data synchronization
578	  (access to icc_iar1_el1 is not sync'ed before and after).
579
580	  If unsure, say Y.
581
582config CAVIUM_ERRATUM_27456
583	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
584	default y
585	help
586	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
587	  instructions may cause the icache to become corrupted if it
588	  contains data for a non-current ASID.  The fix is to
589	  invalidate the icache when changing the mm context.
590
591	  If unsure, say Y.
592
593config CAVIUM_ERRATUM_30115
594	bool "Cavium erratum 30115: Guest may disable interrupts in host"
595	default y
596	help
597	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
598	  1.2, and T83 Pass 1.0, KVM guest execution may disable
599	  interrupts in host. Trapping both GICv3 group-0 and group-1
600	  accesses sidesteps the issue.
601
602	  If unsure, say Y.
603
604config QCOM_FALKOR_ERRATUM_1003
605	bool "Falkor E1003: Incorrect translation due to ASID change"
606	default y
607	help
608	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
609	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
610	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
611	  then only for entries in the walk cache, since the leaf translation
612	  is unchanged. Work around the erratum by invalidating the walk cache
613	  entries for the trampoline before entering the kernel proper.
614
615config ARM64_WORKAROUND_REPEAT_TLBI
616	bool
617
618config QCOM_FALKOR_ERRATUM_1009
619	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
620	default y
621	select ARM64_WORKAROUND_REPEAT_TLBI
622	help
623	  On Falkor v1, the CPU may prematurely complete a DSB following a
624	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
625	  one more time to fix the issue.
626
627	  If unsure, say Y.
628
629config QCOM_QDF2400_ERRATUM_0065
630	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
631	default y
632	help
633	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
634	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
635	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
636
637	  If unsure, say Y.
638
639config SOCIONEXT_SYNQUACER_PREITS
640	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
641	default y
642	help
643	  Socionext Synquacer SoCs implement a separate h/w block to generate
644	  MSI doorbell writes with non-zero values for the device ID.
645
646	  If unsure, say Y.
647
648config HISILICON_ERRATUM_161600802
649	bool "Hip07 161600802: Erroneous redistributor VLPI base"
650	default y
651	help
652	  The HiSilicon Hip07 SoC uses the wrong redistributor base
653	  when issued ITS commands such as VMOVP and VMAPP, and requires
654	  a 128kB offset to be applied to the target address in this commands.
655
656	  If unsure, say Y.
657
658config QCOM_FALKOR_ERRATUM_E1041
659	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
660	default y
661	help
662	  Falkor CPU may speculatively fetch instructions from an improper
663	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
664	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
665
666	  If unsure, say Y.
667
668config FUJITSU_ERRATUM_010001
669	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
670	default y
671	help
672	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
673	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
674	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
675	  This fault occurs under a specific hardware condition when a
676	  load/store instruction performs an address translation using:
677	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
678	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
679	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
680	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
681
682	  The workaround is to ensure these bits are clear in TCR_ELx.
683	  The workaround only affects the Fujitsu-A64FX.
684
685	  If unsure, say Y.
686
687endmenu
688
689
690choice
691	prompt "Page size"
692	default ARM64_4K_PAGES
693	help
694	  Page size (translation granule) configuration.
695
696config ARM64_4K_PAGES
697	bool "4KB"
698	help
699	  This feature enables 4KB pages support.
700
701config ARM64_16K_PAGES
702	bool "16KB"
703	help
704	  The system will use 16KB pages support. AArch32 emulation
705	  requires applications compiled with 16K (or a multiple of 16K)
706	  aligned segments.
707
708config ARM64_64K_PAGES
709	bool "64KB"
710	help
711	  This feature enables 64KB pages support (4KB by default)
712	  allowing only two levels of page tables and faster TLB
713	  look-up. AArch32 emulation requires applications compiled
714	  with 64K aligned segments.
715
716endchoice
717
718choice
719	prompt "Virtual address space size"
720	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
721	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
722	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
723	help
724	  Allows choosing one of multiple possible virtual address
725	  space sizes. The level of translation table is determined by
726	  a combination of page size and virtual address space size.
727
728config ARM64_VA_BITS_36
729	bool "36-bit" if EXPERT
730	depends on ARM64_16K_PAGES
731
732config ARM64_VA_BITS_39
733	bool "39-bit"
734	depends on ARM64_4K_PAGES
735
736config ARM64_VA_BITS_42
737	bool "42-bit"
738	depends on ARM64_64K_PAGES
739
740config ARM64_VA_BITS_47
741	bool "47-bit"
742	depends on ARM64_16K_PAGES
743
744config ARM64_VA_BITS_48
745	bool "48-bit"
746
747config ARM64_USER_VA_BITS_52
748	bool "52-bit (user)"
749	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
750	help
751	  Enable 52-bit virtual addressing for userspace when explicitly
752	  requested via a hint to mmap(). The kernel will continue to
753	  use 48-bit virtual addresses for its own mappings.
754
755	  NOTE: Enabling 52-bit virtual addressing in conjunction with
756	  ARMv8.3 Pointer Authentication will result in the PAC being
757	  reduced from 7 bits to 3 bits, which may have a significant
758	  impact on its susceptibility to brute-force attacks.
759
760	  If unsure, select 48-bit virtual addressing instead.
761
762endchoice
763
764config ARM64_FORCE_52BIT
765	bool "Force 52-bit virtual addresses for userspace"
766	depends on ARM64_USER_VA_BITS_52 && EXPERT
767	help
768	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
769	  to maintain compatibility with older software by providing 48-bit VAs
770	  unless a hint is supplied to mmap.
771
772	  This configuration option disables the 48-bit compatibility logic, and
773	  forces all userspace addresses to be 52-bit on HW that supports it. One
774	  should only enable this configuration option for stress testing userspace
775	  memory management code. If unsure say N here.
776
777config ARM64_VA_BITS
778	int
779	default 36 if ARM64_VA_BITS_36
780	default 39 if ARM64_VA_BITS_39
781	default 42 if ARM64_VA_BITS_42
782	default 47 if ARM64_VA_BITS_47
783	default 48 if ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52
784
785choice
786	prompt "Physical address space size"
787	default ARM64_PA_BITS_48
788	help
789	  Choose the maximum physical address range that the kernel will
790	  support.
791
792config ARM64_PA_BITS_48
793	bool "48-bit"
794
795config ARM64_PA_BITS_52
796	bool "52-bit (ARMv8.2)"
797	depends on ARM64_64K_PAGES
798	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
799	help
800	  Enable support for a 52-bit physical address space, introduced as
801	  part of the ARMv8.2-LPA extension.
802
803	  With this enabled, the kernel will also continue to work on CPUs that
804	  do not support ARMv8.2-LPA, but with some added memory overhead (and
805	  minor performance overhead).
806
807endchoice
808
809config ARM64_PA_BITS
810	int
811	default 48 if ARM64_PA_BITS_48
812	default 52 if ARM64_PA_BITS_52
813
814config CPU_BIG_ENDIAN
815       bool "Build big-endian kernel"
816       help
817         Say Y if you plan on running a kernel in big-endian mode.
818
819config SCHED_MC
820	bool "Multi-core scheduler support"
821	help
822	  Multi-core scheduler support improves the CPU scheduler's decision
823	  making when dealing with multi-core CPU chips at a cost of slightly
824	  increased overhead in some places. If unsure say N here.
825
826config SCHED_SMT
827	bool "SMT scheduler support"
828	help
829	  Improves the CPU scheduler's decision making when dealing with
830	  MultiThreading at a cost of slightly increased overhead in some
831	  places. If unsure say N here.
832
833config NR_CPUS
834	int "Maximum number of CPUs (2-4096)"
835	range 2 4096
836	default "256"
837
838config HOTPLUG_CPU
839	bool "Support for hot-pluggable CPUs"
840	select GENERIC_IRQ_MIGRATION
841	help
842	  Say Y here to experiment with turning CPUs off and on.  CPUs
843	  can be controlled through /sys/devices/system/cpu.
844
845# Common NUMA Features
846config NUMA
847	bool "Numa Memory Allocation and Scheduler Support"
848	select ACPI_NUMA if ACPI
849	select OF_NUMA
850	help
851	  Enable NUMA (Non Uniform Memory Access) support.
852
853	  The kernel will try to allocate memory used by a CPU on the
854	  local memory of the CPU and add some more
855	  NUMA awareness to the kernel.
856
857config NODES_SHIFT
858	int "Maximum NUMA Nodes (as a power of 2)"
859	range 1 10
860	default "2"
861	depends on NEED_MULTIPLE_NODES
862	help
863	  Specify the maximum number of NUMA Nodes available on the target
864	  system.  Increases memory reserved to accommodate various tables.
865
866config USE_PERCPU_NUMA_NODE_ID
867	def_bool y
868	depends on NUMA
869
870config HAVE_SETUP_PER_CPU_AREA
871	def_bool y
872	depends on NUMA
873
874config NEED_PER_CPU_EMBED_FIRST_CHUNK
875	def_bool y
876	depends on NUMA
877
878config HOLES_IN_ZONE
879	def_bool y
880
881source "kernel/Kconfig.hz"
882
883config ARCH_SUPPORTS_DEBUG_PAGEALLOC
884	def_bool y
885
886config ARCH_SPARSEMEM_ENABLE
887	def_bool y
888	select SPARSEMEM_VMEMMAP_ENABLE
889
890config ARCH_SPARSEMEM_DEFAULT
891	def_bool ARCH_SPARSEMEM_ENABLE
892
893config ARCH_SELECT_MEMORY_MODEL
894	def_bool ARCH_SPARSEMEM_ENABLE
895
896config ARCH_FLATMEM_ENABLE
897	def_bool !NUMA
898
899config HAVE_ARCH_PFN_VALID
900	def_bool y
901
902config HW_PERF_EVENTS
903	def_bool y
904	depends on ARM_PMU
905
906config SYS_SUPPORTS_HUGETLBFS
907	def_bool y
908
909config ARCH_WANT_HUGE_PMD_SHARE
910
911config ARCH_HAS_CACHE_LINE_SIZE
912	def_bool y
913
914config ARCH_ENABLE_SPLIT_PMD_PTLOCK
915	def_bool y if PGTABLE_LEVELS > 2
916
917config SECCOMP
918	bool "Enable seccomp to safely compute untrusted bytecode"
919	---help---
920	  This kernel feature is useful for number crunching applications
921	  that may need to compute untrusted bytecode during their
922	  execution. By using pipes or other transports made available to
923	  the process as file descriptors supporting the read/write
924	  syscalls, it's possible to isolate those applications in
925	  their own address space using seccomp. Once seccomp is
926	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
927	  and the task is only allowed to execute a few safe syscalls
928	  defined by each seccomp mode.
929
930config PARAVIRT
931	bool "Enable paravirtualization code"
932	help
933	  This changes the kernel so it can modify itself when it is run
934	  under a hypervisor, potentially improving performance significantly
935	  over full virtualization.
936
937config PARAVIRT_TIME_ACCOUNTING
938	bool "Paravirtual steal time accounting"
939	select PARAVIRT
940	help
941	  Select this option to enable fine granularity task steal time
942	  accounting. Time spent executing other tasks in parallel with
943	  the current vCPU is discounted from the vCPU power. To account for
944	  that, there can be a small performance impact.
945
946	  If in doubt, say N here.
947
948config KEXEC
949	depends on PM_SLEEP_SMP
950	select KEXEC_CORE
951	bool "kexec system call"
952	---help---
953	  kexec is a system call that implements the ability to shutdown your
954	  current kernel, and to start another kernel.  It is like a reboot
955	  but it is independent of the system firmware.   And like a reboot
956	  you can start any kernel with it, not just Linux.
957
958config KEXEC_FILE
959	bool "kexec file based system call"
960	select KEXEC_CORE
961	help
962	  This is new version of kexec system call. This system call is
963	  file based and takes file descriptors as system call argument
964	  for kernel and initramfs as opposed to list of segments as
965	  accepted by previous system call.
966
967config KEXEC_VERIFY_SIG
968	bool "Verify kernel signature during kexec_file_load() syscall"
969	depends on KEXEC_FILE
970	help
971	  Select this option to verify a signature with loaded kernel
972	  image. If configured, any attempt of loading a image without
973	  valid signature will fail.
974
975	  In addition to that option, you need to enable signature
976	  verification for the corresponding kernel image type being
977	  loaded in order for this to work.
978
979config KEXEC_IMAGE_VERIFY_SIG
980	bool "Enable Image signature verification support"
981	default y
982	depends on KEXEC_VERIFY_SIG
983	depends on EFI && SIGNED_PE_FILE_VERIFICATION
984	help
985	  Enable Image signature verification support.
986
987comment "Support for PE file signature verification disabled"
988	depends on KEXEC_VERIFY_SIG
989	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
990
991config CRASH_DUMP
992	bool "Build kdump crash kernel"
993	help
994	  Generate crash dump after being started by kexec. This should
995	  be normally only set in special crash dump kernels which are
996	  loaded in the main kernel with kexec-tools into a specially
997	  reserved region and then later executed after a crash by
998	  kdump/kexec.
999
1000	  For more details see Documentation/admin-guide/kdump/kdump.rst
1001
1002config XEN_DOM0
1003	def_bool y
1004	depends on XEN
1005
1006config XEN
1007	bool "Xen guest support on ARM64"
1008	depends on ARM64 && OF
1009	select SWIOTLB_XEN
1010	select PARAVIRT
1011	help
1012	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1013
1014config FORCE_MAX_ZONEORDER
1015	int
1016	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
1017	default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
1018	default "11"
1019	help
1020	  The kernel memory allocator divides physically contiguous memory
1021	  blocks into "zones", where each zone is a power of two number of
1022	  pages.  This option selects the largest power of two that the kernel
1023	  keeps in the memory allocator.  If you need to allocate very large
1024	  blocks of physically contiguous memory, then you may need to
1025	  increase this value.
1026
1027	  This config option is actually maximum order plus one. For example,
1028	  a value of 11 means that the largest free memory block is 2^10 pages.
1029
1030	  We make sure that we can allocate upto a HugePage size for each configuration.
1031	  Hence we have :
1032		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1033
1034	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1035	  4M allocations matching the default size used by generic code.
1036
1037config UNMAP_KERNEL_AT_EL0
1038	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1039	default y
1040	help
1041	  Speculation attacks against some high-performance processors can
1042	  be used to bypass MMU permission checks and leak kernel data to
1043	  userspace. This can be defended against by unmapping the kernel
1044	  when running in userspace, mapping it back in on exception entry
1045	  via a trampoline page in the vector table.
1046
1047	  If unsure, say Y.
1048
1049config HARDEN_BRANCH_PREDICTOR
1050	bool "Harden the branch predictor against aliasing attacks" if EXPERT
1051	default y
1052	help
1053	  Speculation attacks against some high-performance processors rely on
1054	  being able to manipulate the branch predictor for a victim context by
1055	  executing aliasing branches in the attacker context.  Such attacks
1056	  can be partially mitigated against by clearing internal branch
1057	  predictor state and limiting the prediction logic in some situations.
1058
1059	  This config option will take CPU-specific actions to harden the
1060	  branch predictor against aliasing attacks and may rely on specific
1061	  instruction sequences or control bits being set by the system
1062	  firmware.
1063
1064	  If unsure, say Y.
1065
1066config HARDEN_EL2_VECTORS
1067	bool "Harden EL2 vector mapping against system register leak" if EXPERT
1068	default y
1069	help
1070	  Speculation attacks against some high-performance processors can
1071	  be used to leak privileged information such as the vector base
1072	  register, resulting in a potential defeat of the EL2 layout
1073	  randomization.
1074
1075	  This config option will map the vectors to a fixed location,
1076	  independent of the EL2 code mapping, so that revealing VBAR_EL2
1077	  to an attacker does not give away any extra information. This
1078	  only gets enabled on affected CPUs.
1079
1080	  If unsure, say Y.
1081
1082config ARM64_SSBD
1083	bool "Speculative Store Bypass Disable" if EXPERT
1084	default y
1085	help
1086	  This enables mitigation of the bypassing of previous stores
1087	  by speculative loads.
1088
1089	  If unsure, say Y.
1090
1091config RODATA_FULL_DEFAULT_ENABLED
1092	bool "Apply r/o permissions of VM areas also to their linear aliases"
1093	default y
1094	help
1095	  Apply read-only attributes of VM areas to the linear alias of
1096	  the backing pages as well. This prevents code or read-only data
1097	  from being modified (inadvertently or intentionally) via another
1098	  mapping of the same memory page. This additional enhancement can
1099	  be turned off at runtime by passing rodata=[off|on] (and turned on
1100	  with rodata=full if this option is set to 'n')
1101
1102	  This requires the linear region to be mapped down to pages,
1103	  which may adversely affect performance in some cases.
1104
1105config ARM64_SW_TTBR0_PAN
1106	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1107	help
1108	  Enabling this option prevents the kernel from accessing
1109	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1110	  zeroed area and reserved ASID. The user access routines
1111	  restore the valid TTBR0_EL1 temporarily.
1112
1113menuconfig COMPAT
1114	bool "Kernel support for 32-bit EL0"
1115	depends on ARM64_4K_PAGES || EXPERT
1116	select COMPAT_BINFMT_ELF if BINFMT_ELF
1117	select HAVE_UID16
1118	select OLD_SIGSUSPEND3
1119	select COMPAT_OLD_SIGACTION
1120	help
1121	  This option enables support for a 32-bit EL0 running under a 64-bit
1122	  kernel at EL1. AArch32-specific components such as system calls,
1123	  the user helper functions, VFP support and the ptrace interface are
1124	  handled appropriately by the kernel.
1125
1126	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1127	  that you will only be able to execute AArch32 binaries that were compiled
1128	  with page size aligned segments.
1129
1130	  If you want to execute 32-bit userspace applications, say Y.
1131
1132if COMPAT
1133
1134config KUSER_HELPERS
1135	bool "Enable kuser helpers page for 32 bit applications"
1136	default y
1137	help
1138	  Warning: disabling this option may break 32-bit user programs.
1139
1140	  Provide kuser helpers to compat tasks. The kernel provides
1141	  helper code to userspace in read only form at a fixed location
1142	  to allow userspace to be independent of the CPU type fitted to
1143	  the system. This permits binaries to be run on ARMv4 through
1144	  to ARMv8 without modification.
1145
1146	  See Documentation/arm/kernel_user_helpers.rst for details.
1147
1148	  However, the fixed address nature of these helpers can be used
1149	  by ROP (return orientated programming) authors when creating
1150	  exploits.
1151
1152	  If all of the binaries and libraries which run on your platform
1153	  are built specifically for your platform, and make no use of
1154	  these helpers, then you can turn this option off to hinder
1155	  such exploits. However, in that case, if a binary or library
1156	  relying on those helpers is run, it will not function correctly.
1157
1158	  Say N here only if you are absolutely certain that you do not
1159	  need these helpers; otherwise, the safe option is to say Y.
1160
1161
1162menuconfig ARMV8_DEPRECATED
1163	bool "Emulate deprecated/obsolete ARMv8 instructions"
1164	depends on SYSCTL
1165	help
1166	  Legacy software support may require certain instructions
1167	  that have been deprecated or obsoleted in the architecture.
1168
1169	  Enable this config to enable selective emulation of these
1170	  features.
1171
1172	  If unsure, say Y
1173
1174if ARMV8_DEPRECATED
1175
1176config SWP_EMULATION
1177	bool "Emulate SWP/SWPB instructions"
1178	help
1179	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1180	  they are always undefined. Say Y here to enable software
1181	  emulation of these instructions for userspace using LDXR/STXR.
1182
1183	  In some older versions of glibc [<=2.8] SWP is used during futex
1184	  trylock() operations with the assumption that the code will not
1185	  be preempted. This invalid assumption may be more likely to fail
1186	  with SWP emulation enabled, leading to deadlock of the user
1187	  application.
1188
1189	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1190	  on an external transaction monitoring block called a global
1191	  monitor to maintain update atomicity. If your system does not
1192	  implement a global monitor, this option can cause programs that
1193	  perform SWP operations to uncached memory to deadlock.
1194
1195	  If unsure, say Y
1196
1197config CP15_BARRIER_EMULATION
1198	bool "Emulate CP15 Barrier instructions"
1199	help
1200	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1201	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1202	  strongly recommended to use the ISB, DSB, and DMB
1203	  instructions instead.
1204
1205	  Say Y here to enable software emulation of these
1206	  instructions for AArch32 userspace code. When this option is
1207	  enabled, CP15 barrier usage is traced which can help
1208	  identify software that needs updating.
1209
1210	  If unsure, say Y
1211
1212config SETEND_EMULATION
1213	bool "Emulate SETEND instruction"
1214	help
1215	  The SETEND instruction alters the data-endianness of the
1216	  AArch32 EL0, and is deprecated in ARMv8.
1217
1218	  Say Y here to enable software emulation of the instruction
1219	  for AArch32 userspace code.
1220
1221	  Note: All the cpus on the system must have mixed endian support at EL0
1222	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1223	  endian - is hotplugged in after this feature has been enabled, there could
1224	  be unexpected results in the applications.
1225
1226	  If unsure, say Y
1227endif
1228
1229endif
1230
1231menu "ARMv8.1 architectural features"
1232
1233config ARM64_HW_AFDBM
1234	bool "Support for hardware updates of the Access and Dirty page flags"
1235	default y
1236	help
1237	  The ARMv8.1 architecture extensions introduce support for
1238	  hardware updates of the access and dirty information in page
1239	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1240	  capable processors, accesses to pages with PTE_AF cleared will
1241	  set this bit instead of raising an access flag fault.
1242	  Similarly, writes to read-only pages with the DBM bit set will
1243	  clear the read-only bit (AP[2]) instead of raising a
1244	  permission fault.
1245
1246	  Kernels built with this configuration option enabled continue
1247	  to work on pre-ARMv8.1 hardware and the performance impact is
1248	  minimal. If unsure, say Y.
1249
1250config ARM64_PAN
1251	bool "Enable support for Privileged Access Never (PAN)"
1252	default y
1253	help
1254	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1255	 prevents the kernel or hypervisor from accessing user-space (EL0)
1256	 memory directly.
1257
1258	 Choosing this option will cause any unprotected (not using
1259	 copy_to_user et al) memory access to fail with a permission fault.
1260
1261	 The feature is detected at runtime, and will remain as a 'nop'
1262	 instruction if the cpu does not implement the feature.
1263
1264config ARM64_LSE_ATOMICS
1265	bool "Atomic instructions"
1266	default y
1267	help
1268	  As part of the Large System Extensions, ARMv8.1 introduces new
1269	  atomic instructions that are designed specifically to scale in
1270	  very large systems.
1271
1272	  Say Y here to make use of these instructions for the in-kernel
1273	  atomic routines. This incurs a small overhead on CPUs that do
1274	  not support these instructions and requires the kernel to be
1275	  built with binutils >= 2.25 in order for the new instructions
1276	  to be used.
1277
1278config ARM64_VHE
1279	bool "Enable support for Virtualization Host Extensions (VHE)"
1280	default y
1281	help
1282	  Virtualization Host Extensions (VHE) allow the kernel to run
1283	  directly at EL2 (instead of EL1) on processors that support
1284	  it. This leads to better performance for KVM, as they reduce
1285	  the cost of the world switch.
1286
1287	  Selecting this option allows the VHE feature to be detected
1288	  at runtime, and does not affect processors that do not
1289	  implement this feature.
1290
1291endmenu
1292
1293menu "ARMv8.2 architectural features"
1294
1295config ARM64_UAO
1296	bool "Enable support for User Access Override (UAO)"
1297	default y
1298	help
1299	  User Access Override (UAO; part of the ARMv8.2 Extensions)
1300	  causes the 'unprivileged' variant of the load/store instructions to
1301	  be overridden to be privileged.
1302
1303	  This option changes get_user() and friends to use the 'unprivileged'
1304	  variant of the load/store instructions. This ensures that user-space
1305	  really did have access to the supplied memory. When addr_limit is
1306	  set to kernel memory the UAO bit will be set, allowing privileged
1307	  access to kernel memory.
1308
1309	  Choosing this option will cause copy_to_user() et al to use user-space
1310	  memory permissions.
1311
1312	  The feature is detected at runtime, the kernel will use the
1313	  regular load/store instructions if the cpu does not implement the
1314	  feature.
1315
1316config ARM64_PMEM
1317	bool "Enable support for persistent memory"
1318	select ARCH_HAS_PMEM_API
1319	select ARCH_HAS_UACCESS_FLUSHCACHE
1320	help
1321	  Say Y to enable support for the persistent memory API based on the
1322	  ARMv8.2 DCPoP feature.
1323
1324	  The feature is detected at runtime, and the kernel will use DC CVAC
1325	  operations if DC CVAP is not supported (following the behaviour of
1326	  DC CVAP itself if the system does not define a point of persistence).
1327
1328config ARM64_RAS_EXTN
1329	bool "Enable support for RAS CPU Extensions"
1330	default y
1331	help
1332	  CPUs that support the Reliability, Availability and Serviceability
1333	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1334	  errors, classify them and report them to software.
1335
1336	  On CPUs with these extensions system software can use additional
1337	  barriers to determine if faults are pending and read the
1338	  classification from a new set of registers.
1339
1340	  Selecting this feature will allow the kernel to use these barriers
1341	  and access the new registers if the system supports the extension.
1342	  Platform RAS features may additionally depend on firmware support.
1343
1344config ARM64_CNP
1345	bool "Enable support for Common Not Private (CNP) translations"
1346	default y
1347	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1348	help
1349	  Common Not Private (CNP) allows translation table entries to
1350	  be shared between different PEs in the same inner shareable
1351	  domain, so the hardware can use this fact to optimise the
1352	  caching of such entries in the TLB.
1353
1354	  Selecting this option allows the CNP feature to be detected
1355	  at runtime, and does not affect PEs that do not implement
1356	  this feature.
1357
1358endmenu
1359
1360menu "ARMv8.3 architectural features"
1361
1362config ARM64_PTR_AUTH
1363	bool "Enable support for pointer authentication"
1364	default y
1365	depends on !KVM || ARM64_VHE
1366	help
1367	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1368	  instructions for signing and authenticating pointers against secret
1369	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1370	  and other attacks.
1371
1372	  This option enables these instructions at EL0 (i.e. for userspace).
1373
1374	  Choosing this option will cause the kernel to initialise secret keys
1375	  for each process at exec() time, with these keys being
1376	  context-switched along with the process.
1377
1378	  The feature is detected at runtime. If the feature is not present in
1379	  hardware it will not be advertised to userspace/KVM guest nor will it
1380	  be enabled. However, KVM guest also require VHE mode and hence
1381	  CONFIG_ARM64_VHE=y option to use this feature.
1382
1383endmenu
1384
1385config ARM64_SVE
1386	bool "ARM Scalable Vector Extension support"
1387	default y
1388	depends on !KVM || ARM64_VHE
1389	help
1390	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1391	  execution state which complements and extends the SIMD functionality
1392	  of the base architecture to support much larger vectors and to enable
1393	  additional vectorisation opportunities.
1394
1395	  To enable use of this extension on CPUs that implement it, say Y.
1396
1397	  On CPUs that support the SVE2 extensions, this option will enable
1398	  those too.
1399
1400	  Note that for architectural reasons, firmware _must_ implement SVE
1401	  support when running on SVE capable hardware.  The required support
1402	  is present in:
1403
1404	    * version 1.5 and later of the ARM Trusted Firmware
1405	    * the AArch64 boot wrapper since commit 5e1261e08abf
1406	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1407
1408	  For other firmware implementations, consult the firmware documentation
1409	  or vendor.
1410
1411	  If you need the kernel to boot on SVE-capable hardware with broken
1412	  firmware, you may need to say N here until you get your firmware
1413	  fixed.  Otherwise, you may experience firmware panics or lockups when
1414	  booting the kernel.  If unsure and you are not observing these
1415	  symptoms, you should assume that it is safe to say Y.
1416
1417	  CPUs that support SVE are architecturally required to support the
1418	  Virtualization Host Extensions (VHE), so the kernel makes no
1419	  provision for supporting SVE alongside KVM without VHE enabled.
1420	  Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
1421	  KVM in the same kernel image.
1422
1423config ARM64_MODULE_PLTS
1424	bool "Use PLTs to allow module memory to spill over into vmalloc area"
1425	depends on MODULES
1426	select HAVE_MOD_ARCH_SPECIFIC
1427	help
1428	  Allocate PLTs when loading modules so that jumps and calls whose
1429	  targets are too far away for their relative offsets to be encoded
1430	  in the instructions themselves can be bounced via veneers in the
1431	  module's PLT. This allows modules to be allocated in the generic
1432	  vmalloc area after the dedicated module memory area has been
1433	  exhausted.
1434
1435	  When running with address space randomization (KASLR), the module
1436	  region itself may be too far away for ordinary relative jumps and
1437	  calls, and so in that case, module PLTs are required and cannot be
1438	  disabled.
1439
1440	  Specific errata workaround(s) might also force module PLTs to be
1441	  enabled (ARM64_ERRATUM_843419).
1442
1443config ARM64_PSEUDO_NMI
1444	bool "Support for NMI-like interrupts"
1445	select CONFIG_ARM_GIC_V3
1446	help
1447	  Adds support for mimicking Non-Maskable Interrupts through the use of
1448	  GIC interrupt priority. This support requires version 3 or later of
1449	  ARM GIC.
1450
1451	  This high priority configuration for interrupts needs to be
1452	  explicitly enabled by setting the kernel parameter
1453	  "irqchip.gicv3_pseudo_nmi" to 1.
1454
1455	  If unsure, say N
1456
1457if ARM64_PSEUDO_NMI
1458config ARM64_DEBUG_PRIORITY_MASKING
1459	bool "Debug interrupt priority masking"
1460	help
1461	  This adds runtime checks to functions enabling/disabling
1462	  interrupts when using priority masking. The additional checks verify
1463	  the validity of ICC_PMR_EL1 when calling concerned functions.
1464
1465	  If unsure, say N
1466endif
1467
1468config RELOCATABLE
1469	bool
1470	help
1471	  This builds the kernel as a Position Independent Executable (PIE),
1472	  which retains all relocation metadata required to relocate the
1473	  kernel binary at runtime to a different virtual address than the
1474	  address it was linked at.
1475	  Since AArch64 uses the RELA relocation format, this requires a
1476	  relocation pass at runtime even if the kernel is loaded at the
1477	  same address it was linked at.
1478
1479config RANDOMIZE_BASE
1480	bool "Randomize the address of the kernel image"
1481	select ARM64_MODULE_PLTS if MODULES
1482	select RELOCATABLE
1483	help
1484	  Randomizes the virtual address at which the kernel image is
1485	  loaded, as a security feature that deters exploit attempts
1486	  relying on knowledge of the location of kernel internals.
1487
1488	  It is the bootloader's job to provide entropy, by passing a
1489	  random u64 value in /chosen/kaslr-seed at kernel entry.
1490
1491	  When booting via the UEFI stub, it will invoke the firmware's
1492	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1493	  to the kernel proper. In addition, it will randomise the physical
1494	  location of the kernel Image as well.
1495
1496	  If unsure, say N.
1497
1498config RANDOMIZE_MODULE_REGION_FULL
1499	bool "Randomize the module region over a 4 GB range"
1500	depends on RANDOMIZE_BASE
1501	default y
1502	help
1503	  Randomizes the location of the module region inside a 4 GB window
1504	  covering the core kernel. This way, it is less likely for modules
1505	  to leak information about the location of core kernel data structures
1506	  but it does imply that function calls between modules and the core
1507	  kernel will need to be resolved via veneers in the module PLT.
1508
1509	  When this option is not set, the module region will be randomized over
1510	  a limited range that contains the [_stext, _etext] interval of the
1511	  core kernel, so branch relocations are always in range.
1512
1513config CC_HAVE_STACKPROTECTOR_SYSREG
1514	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1515
1516config STACKPROTECTOR_PER_TASK
1517	def_bool y
1518	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1519
1520endmenu
1521
1522menu "Boot options"
1523
1524config ARM64_ACPI_PARKING_PROTOCOL
1525	bool "Enable support for the ARM64 ACPI parking protocol"
1526	depends on ACPI
1527	help
1528	  Enable support for the ARM64 ACPI parking protocol. If disabled
1529	  the kernel will not allow booting through the ARM64 ACPI parking
1530	  protocol even if the corresponding data is present in the ACPI
1531	  MADT table.
1532
1533config CMDLINE
1534	string "Default kernel command string"
1535	default ""
1536	help
1537	  Provide a set of default command-line options at build time by
1538	  entering them here. As a minimum, you should specify the the
1539	  root device (e.g. root=/dev/nfs).
1540
1541config CMDLINE_FORCE
1542	bool "Always use the default kernel command string"
1543	help
1544	  Always use the default kernel command string, even if the boot
1545	  loader passes other arguments to the kernel.
1546	  This is useful if you cannot or don't want to change the
1547	  command-line options your boot loader passes to the kernel.
1548
1549config EFI_STUB
1550	bool
1551
1552config EFI
1553	bool "UEFI runtime support"
1554	depends on OF && !CPU_BIG_ENDIAN
1555	depends on KERNEL_MODE_NEON
1556	select ARCH_SUPPORTS_ACPI
1557	select LIBFDT
1558	select UCS2_STRING
1559	select EFI_PARAMS_FROM_FDT
1560	select EFI_RUNTIME_WRAPPERS
1561	select EFI_STUB
1562	select EFI_ARMSTUB
1563	default y
1564	help
1565	  This option provides support for runtime services provided
1566	  by UEFI firmware (such as non-volatile variables, realtime
1567          clock, and platform reset). A UEFI stub is also provided to
1568	  allow the kernel to be booted as an EFI application. This
1569	  is only useful on systems that have UEFI firmware.
1570
1571config DMI
1572	bool "Enable support for SMBIOS (DMI) tables"
1573	depends on EFI
1574	default y
1575	help
1576	  This enables SMBIOS/DMI feature for systems.
1577
1578	  This option is only useful on systems that have UEFI firmware.
1579	  However, even with this option, the resultant kernel should
1580	  continue to boot on existing non-UEFI platforms.
1581
1582endmenu
1583
1584config SYSVIPC_COMPAT
1585	def_bool y
1586	depends on COMPAT && SYSVIPC
1587
1588config ARCH_ENABLE_HUGEPAGE_MIGRATION
1589	def_bool y
1590	depends on HUGETLB_PAGE && MIGRATION
1591
1592menu "Power management options"
1593
1594source "kernel/power/Kconfig"
1595
1596config ARCH_HIBERNATION_POSSIBLE
1597	def_bool y
1598	depends on CPU_PM
1599
1600config ARCH_HIBERNATION_HEADER
1601	def_bool y
1602	depends on HIBERNATION
1603
1604config ARCH_SUSPEND_POSSIBLE
1605	def_bool y
1606
1607endmenu
1608
1609menu "CPU Power Management"
1610
1611source "drivers/cpuidle/Kconfig"
1612
1613source "drivers/cpufreq/Kconfig"
1614
1615endmenu
1616
1617source "drivers/firmware/Kconfig"
1618
1619source "drivers/acpi/Kconfig"
1620
1621source "arch/arm64/kvm/Kconfig"
1622
1623if CRYPTO
1624source "arch/arm64/crypto/Kconfig"
1625endif
1626