xref: /linux/arch/arm64/Kconfig (revision a1c3be890440a1769ed6f822376a3e3ab0d42994)
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_HAS_DEBUG_WX
13	select ARCH_BINFMT_ELF_STATE
14	select ARCH_HAS_DEBUG_VIRTUAL
15	select ARCH_HAS_DEBUG_VM_PGTABLE
16	select ARCH_HAS_DMA_PREP_COHERENT
17	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
18	select ARCH_HAS_FAST_MULTIPLIER
19	select ARCH_HAS_FORTIFY_SOURCE
20	select ARCH_HAS_GCOV_PROFILE_ALL
21	select ARCH_HAS_GIGANTIC_PAGE
22	select ARCH_HAS_KCOV
23	select ARCH_HAS_KEEPINITRD
24	select ARCH_HAS_MEMBARRIER_SYNC_CORE
25	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
26	select ARCH_HAS_PTE_DEVMAP
27	select ARCH_HAS_PTE_SPECIAL
28	select ARCH_HAS_SETUP_DMA_OPS
29	select ARCH_HAS_SET_DIRECT_MAP
30	select ARCH_HAS_SET_MEMORY
31	select ARCH_STACKWALK
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_ELF_PROT
40	select ARCH_HAVE_NMI_SAFE_CMPXCHG
41	select ARCH_INLINE_READ_LOCK if !PREEMPTION
42	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
43	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
44	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
45	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
46	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
47	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
48	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
49	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
50	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
51	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
52	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
53	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
54	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
55	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
56	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
57	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
58	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
59	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
60	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
61	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
62	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
63	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
64	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
65	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
66	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
67	select ARCH_KEEP_MEMBLOCK
68	select ARCH_USE_CMPXCHG_LOCKREF
69	select ARCH_USE_GNU_PROPERTY
70	select ARCH_USE_QUEUED_RWLOCKS
71	select ARCH_USE_QUEUED_SPINLOCKS
72	select ARCH_USE_SYM_ANNOTATIONS
73	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
74	select ARCH_SUPPORTS_MEMORY_FAILURE
75	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
76	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
77	select ARCH_SUPPORTS_LTO_CLANG_THIN
78	select ARCH_SUPPORTS_ATOMIC_RMW
79	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG)
80	select ARCH_SUPPORTS_NUMA_BALANCING
81	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
82	select ARCH_WANT_DEFAULT_BPF_JIT
83	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
84	select ARCH_WANT_FRAME_POINTERS
85	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
86	select ARCH_WANT_LD_ORPHAN_WARN
87	select ARCH_HAS_UBSAN_SANITIZE_ALL
88	select ARM_AMBA
89	select ARM_ARCH_TIMER
90	select ARM_GIC
91	select AUDIT_ARCH_COMPAT_GENERIC
92	select ARM_GIC_V2M if PCI
93	select ARM_GIC_V3
94	select ARM_GIC_V3_ITS if PCI
95	select ARM_PSCI_FW
96	select BUILDTIME_TABLE_SORT
97	select CLONE_BACKWARDS
98	select COMMON_CLK
99	select CPU_PM if (SUSPEND || CPU_IDLE)
100	select CRC32
101	select DCACHE_WORD_ACCESS
102	select DMA_DIRECT_REMAP
103	select EDAC_SUPPORT
104	select FRAME_POINTER
105	select GENERIC_ALLOCATOR
106	select GENERIC_ARCH_TOPOLOGY
107	select GENERIC_CLOCKEVENTS_BROADCAST
108	select GENERIC_CPU_AUTOPROBE
109	select GENERIC_CPU_VULNERABILITIES
110	select GENERIC_EARLY_IOREMAP
111	select GENERIC_IDLE_POLL_SETUP
112	select GENERIC_IRQ_IPI
113	select GENERIC_IRQ_MULTI_HANDLER
114	select GENERIC_IRQ_PROBE
115	select GENERIC_IRQ_SHOW
116	select GENERIC_IRQ_SHOW_LEVEL
117	select GENERIC_LIB_DEVMEM_IS_ALLOWED
118	select GENERIC_PCI_IOMAP
119	select GENERIC_PTDUMP
120	select GENERIC_SCHED_CLOCK
121	select GENERIC_SMP_IDLE_THREAD
122	select GENERIC_STRNCPY_FROM_USER
123	select GENERIC_STRNLEN_USER
124	select GENERIC_TIME_VSYSCALL
125	select GENERIC_GETTIMEOFDAY
126	select GENERIC_VDSO_TIME_NS
127	select HANDLE_DOMAIN_IRQ
128	select HARDIRQS_SW_RESEND
129	select HAVE_MOVE_PMD
130	select HAVE_MOVE_PUD
131	select HAVE_PCI
132	select HAVE_ACPI_APEI if (ACPI && EFI)
133	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
134	select HAVE_ARCH_AUDITSYSCALL
135	select HAVE_ARCH_BITREVERSE
136	select HAVE_ARCH_COMPILER_H
137	select HAVE_ARCH_HUGE_VMAP
138	select HAVE_ARCH_JUMP_LABEL
139	select HAVE_ARCH_JUMP_LABEL_RELATIVE
140	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
141	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
142	select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
143	select HAVE_ARCH_KFENCE
144	select HAVE_ARCH_KGDB
145	select HAVE_ARCH_MMAP_RND_BITS
146	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
147	select HAVE_ARCH_PFN_VALID
148	select HAVE_ARCH_PREL32_RELOCATIONS
149	select HAVE_ARCH_SECCOMP_FILTER
150	select HAVE_ARCH_STACKLEAK
151	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
152	select HAVE_ARCH_TRACEHOOK
153	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
154	select HAVE_ARCH_VMAP_STACK
155	select HAVE_ARM_SMCCC
156	select HAVE_ASM_MODVERSIONS
157	select HAVE_EBPF_JIT
158	select HAVE_C_RECORDMCOUNT
159	select HAVE_CMPXCHG_DOUBLE
160	select HAVE_CMPXCHG_LOCAL
161	select HAVE_CONTEXT_TRACKING
162	select HAVE_DEBUG_BUGVERBOSE
163	select HAVE_DEBUG_KMEMLEAK
164	select HAVE_DMA_CONTIGUOUS
165	select HAVE_DYNAMIC_FTRACE
166	select HAVE_DYNAMIC_FTRACE_WITH_REGS \
167		if $(cc-option,-fpatchable-function-entry=2)
168	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
169		if DYNAMIC_FTRACE_WITH_REGS
170	select HAVE_EFFICIENT_UNALIGNED_ACCESS
171	select HAVE_FAST_GUP
172	select HAVE_FTRACE_MCOUNT_RECORD
173	select HAVE_FUNCTION_TRACER
174	select HAVE_FUNCTION_ERROR_INJECTION
175	select HAVE_FUNCTION_GRAPH_TRACER
176	select HAVE_GCC_PLUGINS
177	select HAVE_HW_BREAKPOINT if PERF_EVENTS
178	select HAVE_IRQ_TIME_ACCOUNTING
179	select HAVE_NMI
180	select HAVE_PATA_PLATFORM
181	select HAVE_PERF_EVENTS
182	select HAVE_PERF_REGS
183	select HAVE_PERF_USER_STACK_DUMP
184	select HAVE_REGS_AND_STACK_ACCESS_API
185	select HAVE_FUNCTION_ARG_ACCESS_API
186	select HAVE_FUTEX_CMPXCHG if FUTEX
187	select MMU_GATHER_RCU_TABLE_FREE
188	select HAVE_RSEQ
189	select HAVE_STACKPROTECTOR
190	select HAVE_SYSCALL_TRACEPOINTS
191	select HAVE_KPROBES
192	select HAVE_KRETPROBES
193	select HAVE_GENERIC_VDSO
194	select IOMMU_DMA if IOMMU_SUPPORT
195	select IRQ_DOMAIN
196	select IRQ_FORCED_THREADING
197	select MODULES_USE_ELF_RELA
198	select NEED_DMA_MAP_STATE
199	select NEED_SG_DMA_LENGTH
200	select OF
201	select OF_EARLY_FLATTREE
202	select PCI_DOMAINS_GENERIC if PCI
203	select PCI_ECAM if (ACPI && PCI)
204	select PCI_SYSCALL if PCI
205	select POWER_RESET
206	select POWER_SUPPLY
207	select SPARSE_IRQ
208	select SWIOTLB
209	select SYSCTL_EXCEPTION_TRACE
210	select THREAD_INFO_IN_TASK
211	help
212	  ARM 64-bit (AArch64) Linux support.
213
214config 64BIT
215	def_bool y
216
217config MMU
218	def_bool y
219
220config ARM64_PAGE_SHIFT
221	int
222	default 16 if ARM64_64K_PAGES
223	default 14 if ARM64_16K_PAGES
224	default 12
225
226config ARM64_CONT_PTE_SHIFT
227	int
228	default 5 if ARM64_64K_PAGES
229	default 7 if ARM64_16K_PAGES
230	default 4
231
232config ARM64_CONT_PMD_SHIFT
233	int
234	default 5 if ARM64_64K_PAGES
235	default 5 if ARM64_16K_PAGES
236	default 4
237
238config ARCH_MMAP_RND_BITS_MIN
239       default 14 if ARM64_64K_PAGES
240       default 16 if ARM64_16K_PAGES
241       default 18
242
243# max bits determined by the following formula:
244#  VA_BITS - PAGE_SHIFT - 3
245config ARCH_MMAP_RND_BITS_MAX
246       default 19 if ARM64_VA_BITS=36
247       default 24 if ARM64_VA_BITS=39
248       default 27 if ARM64_VA_BITS=42
249       default 30 if ARM64_VA_BITS=47
250       default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
251       default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
252       default 33 if ARM64_VA_BITS=48
253       default 14 if ARM64_64K_PAGES
254       default 16 if ARM64_16K_PAGES
255       default 18
256
257config ARCH_MMAP_RND_COMPAT_BITS_MIN
258       default 7 if ARM64_64K_PAGES
259       default 9 if ARM64_16K_PAGES
260       default 11
261
262config ARCH_MMAP_RND_COMPAT_BITS_MAX
263       default 16
264
265config NO_IOPORT_MAP
266	def_bool y if !PCI
267
268config STACKTRACE_SUPPORT
269	def_bool y
270
271config ILLEGAL_POINTER_VALUE
272	hex
273	default 0xdead000000000000
274
275config LOCKDEP_SUPPORT
276	def_bool y
277
278config TRACE_IRQFLAGS_SUPPORT
279	def_bool y
280
281config GENERIC_BUG
282	def_bool y
283	depends on BUG
284
285config GENERIC_BUG_RELATIVE_POINTERS
286	def_bool y
287	depends on GENERIC_BUG
288
289config GENERIC_HWEIGHT
290	def_bool y
291
292config GENERIC_CSUM
293        def_bool y
294
295config GENERIC_CALIBRATE_DELAY
296	def_bool y
297
298config ZONE_DMA
299	bool "Support DMA zone" if EXPERT
300	default y
301
302config ZONE_DMA32
303	bool "Support DMA32 zone" if EXPERT
304	default y
305
306config ARCH_ENABLE_MEMORY_HOTPLUG
307	def_bool y
308
309config ARCH_ENABLE_MEMORY_HOTREMOVE
310	def_bool y
311
312config SMP
313	def_bool y
314
315config KERNEL_MODE_NEON
316	def_bool y
317
318config FIX_EARLYCON_MEM
319	def_bool y
320
321config PGTABLE_LEVELS
322	int
323	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
324	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
325	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
326	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
327	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
328	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
329
330config ARCH_SUPPORTS_UPROBES
331	def_bool y
332
333config ARCH_PROC_KCORE_TEXT
334	def_bool y
335
336config BROKEN_GAS_INST
337	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
338
339config KASAN_SHADOW_OFFSET
340	hex
341	depends on KASAN_GENERIC || KASAN_SW_TAGS
342	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
343	default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
344	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
345	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
346	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
347	default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
348	default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
349	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
350	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
351	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
352	default 0xffffffffffffffff
353
354source "arch/arm64/Kconfig.platforms"
355
356menu "Kernel Features"
357
358menu "ARM errata workarounds via the alternatives framework"
359
360config ARM64_WORKAROUND_CLEAN_CACHE
361	bool
362
363config ARM64_ERRATUM_826319
364	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
365	default y
366	select ARM64_WORKAROUND_CLEAN_CACHE
367	help
368	  This option adds an alternative code sequence to work around ARM
369	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
370	  AXI master interface and an L2 cache.
371
372	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
373	  and is unable to accept a certain write via this interface, it will
374	  not progress on read data presented on the read data channel and the
375	  system can deadlock.
376
377	  The workaround promotes data cache clean instructions to
378	  data cache clean-and-invalidate.
379	  Please note that this does not necessarily enable the workaround,
380	  as it depends on the alternative framework, which will only patch
381	  the kernel if an affected CPU is detected.
382
383	  If unsure, say Y.
384
385config ARM64_ERRATUM_827319
386	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
387	default y
388	select ARM64_WORKAROUND_CLEAN_CACHE
389	help
390	  This option adds an alternative code sequence to work around ARM
391	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
392	  master interface and an L2 cache.
393
394	  Under certain conditions this erratum can cause a clean line eviction
395	  to occur at the same time as another transaction to the same address
396	  on the AMBA 5 CHI interface, which can cause data corruption if the
397	  interconnect reorders the two transactions.
398
399	  The workaround promotes data cache clean instructions to
400	  data cache clean-and-invalidate.
401	  Please note that this does not necessarily enable the workaround,
402	  as it depends on the alternative framework, which will only patch
403	  the kernel if an affected CPU is detected.
404
405	  If unsure, say Y.
406
407config ARM64_ERRATUM_824069
408	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
409	default y
410	select ARM64_WORKAROUND_CLEAN_CACHE
411	help
412	  This option adds an alternative code sequence to work around ARM
413	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
414	  to a coherent interconnect.
415
416	  If a Cortex-A53 processor is executing a store or prefetch for
417	  write instruction at the same time as a processor in another
418	  cluster is executing a cache maintenance operation to the same
419	  address, then this erratum might cause a clean cache line to be
420	  incorrectly marked as dirty.
421
422	  The workaround promotes data cache clean instructions to
423	  data cache clean-and-invalidate.
424	  Please note that this option does not necessarily enable the
425	  workaround, as it depends on the alternative framework, which will
426	  only patch the kernel if an affected CPU is detected.
427
428	  If unsure, say Y.
429
430config ARM64_ERRATUM_819472
431	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
432	default y
433	select ARM64_WORKAROUND_CLEAN_CACHE
434	help
435	  This option adds an alternative code sequence to work around ARM
436	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
437	  present when it is connected to a coherent interconnect.
438
439	  If the processor is executing a load and store exclusive sequence at
440	  the same time as a processor in another cluster is executing a cache
441	  maintenance operation to the same address, then this erratum might
442	  cause data corruption.
443
444	  The workaround promotes data cache clean instructions to
445	  data cache clean-and-invalidate.
446	  Please note that this does not necessarily enable the workaround,
447	  as it depends on the alternative framework, which will only patch
448	  the kernel if an affected CPU is detected.
449
450	  If unsure, say Y.
451
452config ARM64_ERRATUM_832075
453	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
454	default y
455	help
456	  This option adds an alternative code sequence to work around ARM
457	  erratum 832075 on Cortex-A57 parts up to r1p2.
458
459	  Affected Cortex-A57 parts might deadlock when exclusive load/store
460	  instructions to Write-Back memory are mixed with Device loads.
461
462	  The workaround is to promote device loads to use Load-Acquire
463	  semantics.
464	  Please note that this does not necessarily enable the workaround,
465	  as it depends on the alternative framework, which will only patch
466	  the kernel if an affected CPU is detected.
467
468	  If unsure, say Y.
469
470config ARM64_ERRATUM_834220
471	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
472	depends on KVM
473	default y
474	help
475	  This option adds an alternative code sequence to work around ARM
476	  erratum 834220 on Cortex-A57 parts up to r1p2.
477
478	  Affected Cortex-A57 parts might report a Stage 2 translation
479	  fault as the result of a Stage 1 fault for load crossing a
480	  page boundary when there is a permission or device memory
481	  alignment fault at Stage 1 and a translation fault at Stage 2.
482
483	  The workaround is to verify that the Stage 1 translation
484	  doesn't generate a fault before handling the Stage 2 fault.
485	  Please note that this does not necessarily enable the workaround,
486	  as it depends on the alternative framework, which will only patch
487	  the kernel if an affected CPU is detected.
488
489	  If unsure, say Y.
490
491config ARM64_ERRATUM_845719
492	bool "Cortex-A53: 845719: a load might read incorrect data"
493	depends on COMPAT
494	default y
495	help
496	  This option adds an alternative code sequence to work around ARM
497	  erratum 845719 on Cortex-A53 parts up to r0p4.
498
499	  When running a compat (AArch32) userspace on an affected Cortex-A53
500	  part, a load at EL0 from a virtual address that matches the bottom 32
501	  bits of the virtual address used by a recent load at (AArch64) EL1
502	  might return incorrect data.
503
504	  The workaround is to write the contextidr_el1 register on exception
505	  return to a 32-bit task.
506	  Please note that this does not necessarily enable the workaround,
507	  as it depends on the alternative framework, which will only patch
508	  the kernel if an affected CPU is detected.
509
510	  If unsure, say Y.
511
512config ARM64_ERRATUM_843419
513	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
514	default y
515	select ARM64_MODULE_PLTS if MODULES
516	help
517	  This option links the kernel with '--fix-cortex-a53-843419' and
518	  enables PLT support to replace certain ADRP instructions, which can
519	  cause subsequent memory accesses to use an incorrect address on
520	  Cortex-A53 parts up to r0p4.
521
522	  If unsure, say Y.
523
524config ARM64_ERRATUM_1024718
525	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
526	default y
527	help
528	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
529
530	  Affected Cortex-A55 cores (all revisions) could cause incorrect
531	  update of the hardware dirty bit when the DBM/AP bits are updated
532	  without a break-before-make. The workaround is to disable the usage
533	  of hardware DBM locally on the affected cores. CPUs not affected by
534	  this erratum will continue to use the feature.
535
536	  If unsure, say Y.
537
538config ARM64_ERRATUM_1418040
539	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
540	default y
541	depends on COMPAT
542	help
543	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
544	  errata 1188873 and 1418040.
545
546	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
547	  cause register corruption when accessing the timer registers
548	  from AArch32 userspace.
549
550	  If unsure, say Y.
551
552config ARM64_WORKAROUND_SPECULATIVE_AT
553	bool
554
555config ARM64_ERRATUM_1165522
556	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
557	default y
558	select ARM64_WORKAROUND_SPECULATIVE_AT
559	help
560	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
561
562	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
563	  corrupted TLBs by speculating an AT instruction during a guest
564	  context switch.
565
566	  If unsure, say Y.
567
568config ARM64_ERRATUM_1319367
569	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
570	default y
571	select ARM64_WORKAROUND_SPECULATIVE_AT
572	help
573	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
574	  and A72 erratum 1319367
575
576	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
577	  speculating an AT instruction during a guest context switch.
578
579	  If unsure, say Y.
580
581config ARM64_ERRATUM_1530923
582	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
583	default y
584	select ARM64_WORKAROUND_SPECULATIVE_AT
585	help
586	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
587
588	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
589	  corrupted TLBs by speculating an AT instruction during a guest
590	  context switch.
591
592	  If unsure, say Y.
593
594config ARM64_WORKAROUND_REPEAT_TLBI
595	bool
596
597config ARM64_ERRATUM_1286807
598	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
599	default y
600	select ARM64_WORKAROUND_REPEAT_TLBI
601	help
602	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
603
604	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
605	  address for a cacheable mapping of a location is being
606	  accessed by a core while another core is remapping the virtual
607	  address to a new physical page using the recommended
608	  break-before-make sequence, then under very rare circumstances
609	  TLBI+DSB completes before a read using the translation being
610	  invalidated has been observed by other observers. The
611	  workaround repeats the TLBI+DSB operation.
612
613config ARM64_ERRATUM_1463225
614	bool "Cortex-A76: Software Step might prevent interrupt recognition"
615	default y
616	help
617	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
618
619	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
620	  of a system call instruction (SVC) can prevent recognition of
621	  subsequent interrupts when software stepping is disabled in the
622	  exception handler of the system call and either kernel debugging
623	  is enabled or VHE is in use.
624
625	  Work around the erratum by triggering a dummy step exception
626	  when handling a system call from a task that is being stepped
627	  in a VHE configuration of the kernel.
628
629	  If unsure, say Y.
630
631config ARM64_ERRATUM_1542419
632	bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
633	default y
634	help
635	  This option adds a workaround for ARM Neoverse-N1 erratum
636	  1542419.
637
638	  Affected Neoverse-N1 cores could execute a stale instruction when
639	  modified by another CPU. The workaround depends on a firmware
640	  counterpart.
641
642	  Workaround the issue by hiding the DIC feature from EL0. This
643	  forces user-space to perform cache maintenance.
644
645	  If unsure, say Y.
646
647config ARM64_ERRATUM_1508412
648	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
649	default y
650	help
651	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
652
653	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
654	  of a store-exclusive or read of PAR_EL1 and a load with device or
655	  non-cacheable memory attributes. The workaround depends on a firmware
656	  counterpart.
657
658	  KVM guests must also have the workaround implemented or they can
659	  deadlock the system.
660
661	  Work around the issue by inserting DMB SY barriers around PAR_EL1
662	  register reads and warning KVM users. The DMB barrier is sufficient
663	  to prevent a speculative PAR_EL1 read.
664
665	  If unsure, say Y.
666
667config CAVIUM_ERRATUM_22375
668	bool "Cavium erratum 22375, 24313"
669	default y
670	help
671	  Enable workaround for errata 22375 and 24313.
672
673	  This implements two gicv3-its errata workarounds for ThunderX. Both
674	  with a small impact affecting only ITS table allocation.
675
676	    erratum 22375: only alloc 8MB table size
677	    erratum 24313: ignore memory access type
678
679	  The fixes are in ITS initialization and basically ignore memory access
680	  type and table size provided by the TYPER and BASER registers.
681
682	  If unsure, say Y.
683
684config CAVIUM_ERRATUM_23144
685	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
686	depends on NUMA
687	default y
688	help
689	  ITS SYNC command hang for cross node io and collections/cpu mapping.
690
691	  If unsure, say Y.
692
693config CAVIUM_ERRATUM_23154
694	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
695	default y
696	help
697	  The gicv3 of ThunderX requires a modified version for
698	  reading the IAR status to ensure data synchronization
699	  (access to icc_iar1_el1 is not sync'ed before and after).
700
701	  If unsure, say Y.
702
703config CAVIUM_ERRATUM_27456
704	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
705	default y
706	help
707	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
708	  instructions may cause the icache to become corrupted if it
709	  contains data for a non-current ASID.  The fix is to
710	  invalidate the icache when changing the mm context.
711
712	  If unsure, say Y.
713
714config CAVIUM_ERRATUM_30115
715	bool "Cavium erratum 30115: Guest may disable interrupts in host"
716	default y
717	help
718	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
719	  1.2, and T83 Pass 1.0, KVM guest execution may disable
720	  interrupts in host. Trapping both GICv3 group-0 and group-1
721	  accesses sidesteps the issue.
722
723	  If unsure, say Y.
724
725config CAVIUM_TX2_ERRATUM_219
726	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
727	default y
728	help
729	  On Cavium ThunderX2, a load, store or prefetch instruction between a
730	  TTBR update and the corresponding context synchronizing operation can
731	  cause a spurious Data Abort to be delivered to any hardware thread in
732	  the CPU core.
733
734	  Work around the issue by avoiding the problematic code sequence and
735	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
736	  trap handler performs the corresponding register access, skips the
737	  instruction and ensures context synchronization by virtue of the
738	  exception return.
739
740	  If unsure, say Y.
741
742config FUJITSU_ERRATUM_010001
743	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
744	default y
745	help
746	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
747	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
748	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
749	  This fault occurs under a specific hardware condition when a
750	  load/store instruction performs an address translation using:
751	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
752	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
753	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
754	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
755
756	  The workaround is to ensure these bits are clear in TCR_ELx.
757	  The workaround only affects the Fujitsu-A64FX.
758
759	  If unsure, say Y.
760
761config HISILICON_ERRATUM_161600802
762	bool "Hip07 161600802: Erroneous redistributor VLPI base"
763	default y
764	help
765	  The HiSilicon Hip07 SoC uses the wrong redistributor base
766	  when issued ITS commands such as VMOVP and VMAPP, and requires
767	  a 128kB offset to be applied to the target address in this commands.
768
769	  If unsure, say Y.
770
771config QCOM_FALKOR_ERRATUM_1003
772	bool "Falkor E1003: Incorrect translation due to ASID change"
773	default y
774	help
775	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
776	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
777	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
778	  then only for entries in the walk cache, since the leaf translation
779	  is unchanged. Work around the erratum by invalidating the walk cache
780	  entries for the trampoline before entering the kernel proper.
781
782config QCOM_FALKOR_ERRATUM_1009
783	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
784	default y
785	select ARM64_WORKAROUND_REPEAT_TLBI
786	help
787	  On Falkor v1, the CPU may prematurely complete a DSB following a
788	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
789	  one more time to fix the issue.
790
791	  If unsure, say Y.
792
793config QCOM_QDF2400_ERRATUM_0065
794	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
795	default y
796	help
797	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
798	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
799	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
800
801	  If unsure, say Y.
802
803config QCOM_FALKOR_ERRATUM_E1041
804	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
805	default y
806	help
807	  Falkor CPU may speculatively fetch instructions from an improper
808	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
809	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
810
811	  If unsure, say Y.
812
813config SOCIONEXT_SYNQUACER_PREITS
814	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
815	default y
816	help
817	  Socionext Synquacer SoCs implement a separate h/w block to generate
818	  MSI doorbell writes with non-zero values for the device ID.
819
820	  If unsure, say Y.
821
822endmenu
823
824
825choice
826	prompt "Page size"
827	default ARM64_4K_PAGES
828	help
829	  Page size (translation granule) configuration.
830
831config ARM64_4K_PAGES
832	bool "4KB"
833	help
834	  This feature enables 4KB pages support.
835
836config ARM64_16K_PAGES
837	bool "16KB"
838	help
839	  The system will use 16KB pages support. AArch32 emulation
840	  requires applications compiled with 16K (or a multiple of 16K)
841	  aligned segments.
842
843config ARM64_64K_PAGES
844	bool "64KB"
845	help
846	  This feature enables 64KB pages support (4KB by default)
847	  allowing only two levels of page tables and faster TLB
848	  look-up. AArch32 emulation requires applications compiled
849	  with 64K aligned segments.
850
851endchoice
852
853choice
854	prompt "Virtual address space size"
855	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
856	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
857	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
858	help
859	  Allows choosing one of multiple possible virtual address
860	  space sizes. The level of translation table is determined by
861	  a combination of page size and virtual address space size.
862
863config ARM64_VA_BITS_36
864	bool "36-bit" if EXPERT
865	depends on ARM64_16K_PAGES
866
867config ARM64_VA_BITS_39
868	bool "39-bit"
869	depends on ARM64_4K_PAGES
870
871config ARM64_VA_BITS_42
872	bool "42-bit"
873	depends on ARM64_64K_PAGES
874
875config ARM64_VA_BITS_47
876	bool "47-bit"
877	depends on ARM64_16K_PAGES
878
879config ARM64_VA_BITS_48
880	bool "48-bit"
881
882config ARM64_VA_BITS_52
883	bool "52-bit"
884	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
885	help
886	  Enable 52-bit virtual addressing for userspace when explicitly
887	  requested via a hint to mmap(). The kernel will also use 52-bit
888	  virtual addresses for its own mappings (provided HW support for
889	  this feature is available, otherwise it reverts to 48-bit).
890
891	  NOTE: Enabling 52-bit virtual addressing in conjunction with
892	  ARMv8.3 Pointer Authentication will result in the PAC being
893	  reduced from 7 bits to 3 bits, which may have a significant
894	  impact on its susceptibility to brute-force attacks.
895
896	  If unsure, select 48-bit virtual addressing instead.
897
898endchoice
899
900config ARM64_FORCE_52BIT
901	bool "Force 52-bit virtual addresses for userspace"
902	depends on ARM64_VA_BITS_52 && EXPERT
903	help
904	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
905	  to maintain compatibility with older software by providing 48-bit VAs
906	  unless a hint is supplied to mmap.
907
908	  This configuration option disables the 48-bit compatibility logic, and
909	  forces all userspace addresses to be 52-bit on HW that supports it. One
910	  should only enable this configuration option for stress testing userspace
911	  memory management code. If unsure say N here.
912
913config ARM64_VA_BITS
914	int
915	default 36 if ARM64_VA_BITS_36
916	default 39 if ARM64_VA_BITS_39
917	default 42 if ARM64_VA_BITS_42
918	default 47 if ARM64_VA_BITS_47
919	default 48 if ARM64_VA_BITS_48
920	default 52 if ARM64_VA_BITS_52
921
922choice
923	prompt "Physical address space size"
924	default ARM64_PA_BITS_48
925	help
926	  Choose the maximum physical address range that the kernel will
927	  support.
928
929config ARM64_PA_BITS_48
930	bool "48-bit"
931
932config ARM64_PA_BITS_52
933	bool "52-bit (ARMv8.2)"
934	depends on ARM64_64K_PAGES
935	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
936	help
937	  Enable support for a 52-bit physical address space, introduced as
938	  part of the ARMv8.2-LPA extension.
939
940	  With this enabled, the kernel will also continue to work on CPUs that
941	  do not support ARMv8.2-LPA, but with some added memory overhead (and
942	  minor performance overhead).
943
944endchoice
945
946config ARM64_PA_BITS
947	int
948	default 48 if ARM64_PA_BITS_48
949	default 52 if ARM64_PA_BITS_52
950
951choice
952	prompt "Endianness"
953	default CPU_LITTLE_ENDIAN
954	help
955	  Select the endianness of data accesses performed by the CPU. Userspace
956	  applications will need to be compiled and linked for the endianness
957	  that is selected here.
958
959config CPU_BIG_ENDIAN
960	bool "Build big-endian kernel"
961	depends on !LD_IS_LLD || LLD_VERSION >= 130000
962	help
963	  Say Y if you plan on running a kernel with a big-endian userspace.
964
965config CPU_LITTLE_ENDIAN
966	bool "Build little-endian kernel"
967	help
968	  Say Y if you plan on running a kernel with a little-endian userspace.
969	  This is usually the case for distributions targeting arm64.
970
971endchoice
972
973config SCHED_MC
974	bool "Multi-core scheduler support"
975	help
976	  Multi-core scheduler support improves the CPU scheduler's decision
977	  making when dealing with multi-core CPU chips at a cost of slightly
978	  increased overhead in some places. If unsure say N here.
979
980config SCHED_SMT
981	bool "SMT scheduler support"
982	help
983	  Improves the CPU scheduler's decision making when dealing with
984	  MultiThreading at a cost of slightly increased overhead in some
985	  places. If unsure say N here.
986
987config NR_CPUS
988	int "Maximum number of CPUs (2-4096)"
989	range 2 4096
990	default "256"
991
992config HOTPLUG_CPU
993	bool "Support for hot-pluggable CPUs"
994	select GENERIC_IRQ_MIGRATION
995	help
996	  Say Y here to experiment with turning CPUs off and on.  CPUs
997	  can be controlled through /sys/devices/system/cpu.
998
999# Common NUMA Features
1000config NUMA
1001	bool "NUMA Memory Allocation and Scheduler Support"
1002	select GENERIC_ARCH_NUMA
1003	select ACPI_NUMA if ACPI
1004	select OF_NUMA
1005	help
1006	  Enable NUMA (Non-Uniform Memory Access) support.
1007
1008	  The kernel will try to allocate memory used by a CPU on the
1009	  local memory of the CPU and add some more
1010	  NUMA awareness to the kernel.
1011
1012config NODES_SHIFT
1013	int "Maximum NUMA Nodes (as a power of 2)"
1014	range 1 10
1015	default "4"
1016	depends on NEED_MULTIPLE_NODES
1017	help
1018	  Specify the maximum number of NUMA Nodes available on the target
1019	  system.  Increases memory reserved to accommodate various tables.
1020
1021config USE_PERCPU_NUMA_NODE_ID
1022	def_bool y
1023	depends on NUMA
1024
1025config HAVE_SETUP_PER_CPU_AREA
1026	def_bool y
1027	depends on NUMA
1028
1029config NEED_PER_CPU_EMBED_FIRST_CHUNK
1030	def_bool y
1031	depends on NUMA
1032
1033config HOLES_IN_ZONE
1034	def_bool y
1035
1036source "kernel/Kconfig.hz"
1037
1038config ARCH_SPARSEMEM_ENABLE
1039	def_bool y
1040	select SPARSEMEM_VMEMMAP_ENABLE
1041
1042config ARCH_SPARSEMEM_DEFAULT
1043	def_bool ARCH_SPARSEMEM_ENABLE
1044
1045config ARCH_SELECT_MEMORY_MODEL
1046	def_bool ARCH_SPARSEMEM_ENABLE
1047
1048config ARCH_FLATMEM_ENABLE
1049	def_bool !NUMA
1050
1051config HW_PERF_EVENTS
1052	def_bool y
1053	depends on ARM_PMU
1054
1055config SYS_SUPPORTS_HUGETLBFS
1056	def_bool y
1057
1058config ARCH_HAS_CACHE_LINE_SIZE
1059	def_bool y
1060
1061config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1062	def_bool y if PGTABLE_LEVELS > 2
1063
1064# Supported by clang >= 7.0
1065config CC_HAVE_SHADOW_CALL_STACK
1066	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1067
1068config PARAVIRT
1069	bool "Enable paravirtualization code"
1070	help
1071	  This changes the kernel so it can modify itself when it is run
1072	  under a hypervisor, potentially improving performance significantly
1073	  over full virtualization.
1074
1075config PARAVIRT_TIME_ACCOUNTING
1076	bool "Paravirtual steal time accounting"
1077	select PARAVIRT
1078	help
1079	  Select this option to enable fine granularity task steal time
1080	  accounting. Time spent executing other tasks in parallel with
1081	  the current vCPU is discounted from the vCPU power. To account for
1082	  that, there can be a small performance impact.
1083
1084	  If in doubt, say N here.
1085
1086config KEXEC
1087	depends on PM_SLEEP_SMP
1088	select KEXEC_CORE
1089	bool "kexec system call"
1090	help
1091	  kexec is a system call that implements the ability to shutdown your
1092	  current kernel, and to start another kernel.  It is like a reboot
1093	  but it is independent of the system firmware.   And like a reboot
1094	  you can start any kernel with it, not just Linux.
1095
1096config KEXEC_FILE
1097	bool "kexec file based system call"
1098	select KEXEC_CORE
1099	help
1100	  This is new version of kexec system call. This system call is
1101	  file based and takes file descriptors as system call argument
1102	  for kernel and initramfs as opposed to list of segments as
1103	  accepted by previous system call.
1104
1105config KEXEC_SIG
1106	bool "Verify kernel signature during kexec_file_load() syscall"
1107	depends on KEXEC_FILE
1108	help
1109	  Select this option to verify a signature with loaded kernel
1110	  image. If configured, any attempt of loading a image without
1111	  valid signature will fail.
1112
1113	  In addition to that option, you need to enable signature
1114	  verification for the corresponding kernel image type being
1115	  loaded in order for this to work.
1116
1117config KEXEC_IMAGE_VERIFY_SIG
1118	bool "Enable Image signature verification support"
1119	default y
1120	depends on KEXEC_SIG
1121	depends on EFI && SIGNED_PE_FILE_VERIFICATION
1122	help
1123	  Enable Image signature verification support.
1124
1125comment "Support for PE file signature verification disabled"
1126	depends on KEXEC_SIG
1127	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
1128
1129config CRASH_DUMP
1130	bool "Build kdump crash kernel"
1131	help
1132	  Generate crash dump after being started by kexec. This should
1133	  be normally only set in special crash dump kernels which are
1134	  loaded in the main kernel with kexec-tools into a specially
1135	  reserved region and then later executed after a crash by
1136	  kdump/kexec.
1137
1138	  For more details see Documentation/admin-guide/kdump/kdump.rst
1139
1140config TRANS_TABLE
1141	def_bool y
1142	depends on HIBERNATION
1143
1144config XEN_DOM0
1145	def_bool y
1146	depends on XEN
1147
1148config XEN
1149	bool "Xen guest support on ARM64"
1150	depends on ARM64 && OF
1151	select SWIOTLB_XEN
1152	select PARAVIRT
1153	help
1154	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1155
1156config FORCE_MAX_ZONEORDER
1157	int
1158	default "14" if ARM64_64K_PAGES
1159	default "12" if ARM64_16K_PAGES
1160	default "11"
1161	help
1162	  The kernel memory allocator divides physically contiguous memory
1163	  blocks into "zones", where each zone is a power of two number of
1164	  pages.  This option selects the largest power of two that the kernel
1165	  keeps in the memory allocator.  If you need to allocate very large
1166	  blocks of physically contiguous memory, then you may need to
1167	  increase this value.
1168
1169	  This config option is actually maximum order plus one. For example,
1170	  a value of 11 means that the largest free memory block is 2^10 pages.
1171
1172	  We make sure that we can allocate upto a HugePage size for each configuration.
1173	  Hence we have :
1174		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1175
1176	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1177	  4M allocations matching the default size used by generic code.
1178
1179config UNMAP_KERNEL_AT_EL0
1180	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1181	default y
1182	help
1183	  Speculation attacks against some high-performance processors can
1184	  be used to bypass MMU permission checks and leak kernel data to
1185	  userspace. This can be defended against by unmapping the kernel
1186	  when running in userspace, mapping it back in on exception entry
1187	  via a trampoline page in the vector table.
1188
1189	  If unsure, say Y.
1190
1191config RODATA_FULL_DEFAULT_ENABLED
1192	bool "Apply r/o permissions of VM areas also to their linear aliases"
1193	default y
1194	help
1195	  Apply read-only attributes of VM areas to the linear alias of
1196	  the backing pages as well. This prevents code or read-only data
1197	  from being modified (inadvertently or intentionally) via another
1198	  mapping of the same memory page. This additional enhancement can
1199	  be turned off at runtime by passing rodata=[off|on] (and turned on
1200	  with rodata=full if this option is set to 'n')
1201
1202	  This requires the linear region to be mapped down to pages,
1203	  which may adversely affect performance in some cases.
1204
1205config ARM64_SW_TTBR0_PAN
1206	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1207	help
1208	  Enabling this option prevents the kernel from accessing
1209	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1210	  zeroed area and reserved ASID. The user access routines
1211	  restore the valid TTBR0_EL1 temporarily.
1212
1213config ARM64_TAGGED_ADDR_ABI
1214	bool "Enable the tagged user addresses syscall ABI"
1215	default y
1216	help
1217	  When this option is enabled, user applications can opt in to a
1218	  relaxed ABI via prctl() allowing tagged addresses to be passed
1219	  to system calls as pointer arguments. For details, see
1220	  Documentation/arm64/tagged-address-abi.rst.
1221
1222menuconfig COMPAT
1223	bool "Kernel support for 32-bit EL0"
1224	depends on ARM64_4K_PAGES || EXPERT
1225	select HAVE_UID16
1226	select OLD_SIGSUSPEND3
1227	select COMPAT_OLD_SIGACTION
1228	help
1229	  This option enables support for a 32-bit EL0 running under a 64-bit
1230	  kernel at EL1. AArch32-specific components such as system calls,
1231	  the user helper functions, VFP support and the ptrace interface are
1232	  handled appropriately by the kernel.
1233
1234	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1235	  that you will only be able to execute AArch32 binaries that were compiled
1236	  with page size aligned segments.
1237
1238	  If you want to execute 32-bit userspace applications, say Y.
1239
1240if COMPAT
1241
1242config KUSER_HELPERS
1243	bool "Enable kuser helpers page for 32-bit applications"
1244	default y
1245	help
1246	  Warning: disabling this option may break 32-bit user programs.
1247
1248	  Provide kuser helpers to compat tasks. The kernel provides
1249	  helper code to userspace in read only form at a fixed location
1250	  to allow userspace to be independent of the CPU type fitted to
1251	  the system. This permits binaries to be run on ARMv4 through
1252	  to ARMv8 without modification.
1253
1254	  See Documentation/arm/kernel_user_helpers.rst for details.
1255
1256	  However, the fixed address nature of these helpers can be used
1257	  by ROP (return orientated programming) authors when creating
1258	  exploits.
1259
1260	  If all of the binaries and libraries which run on your platform
1261	  are built specifically for your platform, and make no use of
1262	  these helpers, then you can turn this option off to hinder
1263	  such exploits. However, in that case, if a binary or library
1264	  relying on those helpers is run, it will not function correctly.
1265
1266	  Say N here only if you are absolutely certain that you do not
1267	  need these helpers; otherwise, the safe option is to say Y.
1268
1269config COMPAT_VDSO
1270	bool "Enable vDSO for 32-bit applications"
1271	depends on !CPU_BIG_ENDIAN && "$(CROSS_COMPILE_COMPAT)" != ""
1272	select GENERIC_COMPAT_VDSO
1273	default y
1274	help
1275	  Place in the process address space of 32-bit applications an
1276	  ELF shared object providing fast implementations of gettimeofday
1277	  and clock_gettime.
1278
1279	  You must have a 32-bit build of glibc 2.22 or later for programs
1280	  to seamlessly take advantage of this.
1281
1282config THUMB2_COMPAT_VDSO
1283	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1284	depends on COMPAT_VDSO
1285	default y
1286	help
1287	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1288	  otherwise with '-marm'.
1289
1290menuconfig ARMV8_DEPRECATED
1291	bool "Emulate deprecated/obsolete ARMv8 instructions"
1292	depends on SYSCTL
1293	help
1294	  Legacy software support may require certain instructions
1295	  that have been deprecated or obsoleted in the architecture.
1296
1297	  Enable this config to enable selective emulation of these
1298	  features.
1299
1300	  If unsure, say Y
1301
1302if ARMV8_DEPRECATED
1303
1304config SWP_EMULATION
1305	bool "Emulate SWP/SWPB instructions"
1306	help
1307	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1308	  they are always undefined. Say Y here to enable software
1309	  emulation of these instructions for userspace using LDXR/STXR.
1310	  This feature can be controlled at runtime with the abi.swp
1311	  sysctl which is disabled by default.
1312
1313	  In some older versions of glibc [<=2.8] SWP is used during futex
1314	  trylock() operations with the assumption that the code will not
1315	  be preempted. This invalid assumption may be more likely to fail
1316	  with SWP emulation enabled, leading to deadlock of the user
1317	  application.
1318
1319	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1320	  on an external transaction monitoring block called a global
1321	  monitor to maintain update atomicity. If your system does not
1322	  implement a global monitor, this option can cause programs that
1323	  perform SWP operations to uncached memory to deadlock.
1324
1325	  If unsure, say Y
1326
1327config CP15_BARRIER_EMULATION
1328	bool "Emulate CP15 Barrier instructions"
1329	help
1330	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1331	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1332	  strongly recommended to use the ISB, DSB, and DMB
1333	  instructions instead.
1334
1335	  Say Y here to enable software emulation of these
1336	  instructions for AArch32 userspace code. When this option is
1337	  enabled, CP15 barrier usage is traced which can help
1338	  identify software that needs updating. This feature can be
1339	  controlled at runtime with the abi.cp15_barrier sysctl.
1340
1341	  If unsure, say Y
1342
1343config SETEND_EMULATION
1344	bool "Emulate SETEND instruction"
1345	help
1346	  The SETEND instruction alters the data-endianness of the
1347	  AArch32 EL0, and is deprecated in ARMv8.
1348
1349	  Say Y here to enable software emulation of the instruction
1350	  for AArch32 userspace code. This feature can be controlled
1351	  at runtime with the abi.setend sysctl.
1352
1353	  Note: All the cpus on the system must have mixed endian support at EL0
1354	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1355	  endian - is hotplugged in after this feature has been enabled, there could
1356	  be unexpected results in the applications.
1357
1358	  If unsure, say Y
1359endif
1360
1361endif
1362
1363menu "ARMv8.1 architectural features"
1364
1365config ARM64_HW_AFDBM
1366	bool "Support for hardware updates of the Access and Dirty page flags"
1367	default y
1368	help
1369	  The ARMv8.1 architecture extensions introduce support for
1370	  hardware updates of the access and dirty information in page
1371	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1372	  capable processors, accesses to pages with PTE_AF cleared will
1373	  set this bit instead of raising an access flag fault.
1374	  Similarly, writes to read-only pages with the DBM bit set will
1375	  clear the read-only bit (AP[2]) instead of raising a
1376	  permission fault.
1377
1378	  Kernels built with this configuration option enabled continue
1379	  to work on pre-ARMv8.1 hardware and the performance impact is
1380	  minimal. If unsure, say Y.
1381
1382config ARM64_PAN
1383	bool "Enable support for Privileged Access Never (PAN)"
1384	default y
1385	help
1386	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1387	 prevents the kernel or hypervisor from accessing user-space (EL0)
1388	 memory directly.
1389
1390	 Choosing this option will cause any unprotected (not using
1391	 copy_to_user et al) memory access to fail with a permission fault.
1392
1393	 The feature is detected at runtime, and will remain as a 'nop'
1394	 instruction if the cpu does not implement the feature.
1395
1396config AS_HAS_LDAPR
1397	def_bool $(as-instr,.arch_extension rcpc)
1398
1399config ARM64_LSE_ATOMICS
1400	bool
1401	default ARM64_USE_LSE_ATOMICS
1402	depends on $(as-instr,.arch_extension lse)
1403
1404config ARM64_USE_LSE_ATOMICS
1405	bool "Atomic instructions"
1406	depends on JUMP_LABEL
1407	default y
1408	help
1409	  As part of the Large System Extensions, ARMv8.1 introduces new
1410	  atomic instructions that are designed specifically to scale in
1411	  very large systems.
1412
1413	  Say Y here to make use of these instructions for the in-kernel
1414	  atomic routines. This incurs a small overhead on CPUs that do
1415	  not support these instructions and requires the kernel to be
1416	  built with binutils >= 2.25 in order for the new instructions
1417	  to be used.
1418
1419config ARM64_VHE
1420	bool "Enable support for Virtualization Host Extensions (VHE)"
1421	default y
1422	help
1423	  Virtualization Host Extensions (VHE) allow the kernel to run
1424	  directly at EL2 (instead of EL1) on processors that support
1425	  it. This leads to better performance for KVM, as they reduce
1426	  the cost of the world switch.
1427
1428	  Selecting this option allows the VHE feature to be detected
1429	  at runtime, and does not affect processors that do not
1430	  implement this feature.
1431
1432endmenu
1433
1434menu "ARMv8.2 architectural features"
1435
1436config ARM64_PMEM
1437	bool "Enable support for persistent memory"
1438	select ARCH_HAS_PMEM_API
1439	select ARCH_HAS_UACCESS_FLUSHCACHE
1440	help
1441	  Say Y to enable support for the persistent memory API based on the
1442	  ARMv8.2 DCPoP feature.
1443
1444	  The feature is detected at runtime, and the kernel will use DC CVAC
1445	  operations if DC CVAP is not supported (following the behaviour of
1446	  DC CVAP itself if the system does not define a point of persistence).
1447
1448config ARM64_RAS_EXTN
1449	bool "Enable support for RAS CPU Extensions"
1450	default y
1451	help
1452	  CPUs that support the Reliability, Availability and Serviceability
1453	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1454	  errors, classify them and report them to software.
1455
1456	  On CPUs with these extensions system software can use additional
1457	  barriers to determine if faults are pending and read the
1458	  classification from a new set of registers.
1459
1460	  Selecting this feature will allow the kernel to use these barriers
1461	  and access the new registers if the system supports the extension.
1462	  Platform RAS features may additionally depend on firmware support.
1463
1464config ARM64_CNP
1465	bool "Enable support for Common Not Private (CNP) translations"
1466	default y
1467	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1468	help
1469	  Common Not Private (CNP) allows translation table entries to
1470	  be shared between different PEs in the same inner shareable
1471	  domain, so the hardware can use this fact to optimise the
1472	  caching of such entries in the TLB.
1473
1474	  Selecting this option allows the CNP feature to be detected
1475	  at runtime, and does not affect PEs that do not implement
1476	  this feature.
1477
1478endmenu
1479
1480menu "ARMv8.3 architectural features"
1481
1482config ARM64_PTR_AUTH
1483	bool "Enable support for pointer authentication"
1484	default y
1485	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC
1486	# Modern compilers insert a .note.gnu.property section note for PAC
1487	# which is only understood by binutils starting with version 2.33.1.
1488	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1489	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1490	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
1491	help
1492	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1493	  instructions for signing and authenticating pointers against secret
1494	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1495	  and other attacks.
1496
1497	  This option enables these instructions at EL0 (i.e. for userspace).
1498	  Choosing this option will cause the kernel to initialise secret keys
1499	  for each process at exec() time, with these keys being
1500	  context-switched along with the process.
1501
1502	  If the compiler supports the -mbranch-protection or
1503	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1504	  will also cause the kernel itself to be compiled with return address
1505	  protection. In this case, and if the target hardware is known to
1506	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1507	  disabled with minimal loss of protection.
1508
1509	  The feature is detected at runtime. If the feature is not present in
1510	  hardware it will not be advertised to userspace/KVM guest nor will it
1511	  be enabled.
1512
1513	  If the feature is present on the boot CPU but not on a late CPU, then
1514	  the late CPU will be parked. Also, if the boot CPU does not have
1515	  address auth and the late CPU has then the late CPU will still boot
1516	  but with the feature disabled. On such a system, this option should
1517	  not be selected.
1518
1519	  This feature works with FUNCTION_GRAPH_TRACER option only if
1520	  DYNAMIC_FTRACE_WITH_REGS is enabled.
1521
1522config CC_HAS_BRANCH_PROT_PAC_RET
1523	# GCC 9 or later, clang 8 or later
1524	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1525
1526config CC_HAS_SIGN_RETURN_ADDRESS
1527	# GCC 7, 8
1528	def_bool $(cc-option,-msign-return-address=all)
1529
1530config AS_HAS_PAC
1531	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1532
1533config AS_HAS_CFI_NEGATE_RA_STATE
1534	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1535
1536endmenu
1537
1538menu "ARMv8.4 architectural features"
1539
1540config ARM64_AMU_EXTN
1541	bool "Enable support for the Activity Monitors Unit CPU extension"
1542	default y
1543	help
1544	  The activity monitors extension is an optional extension introduced
1545	  by the ARMv8.4 CPU architecture. This enables support for version 1
1546	  of the activity monitors architecture, AMUv1.
1547
1548	  To enable the use of this extension on CPUs that implement it, say Y.
1549
1550	  Note that for architectural reasons, firmware _must_ implement AMU
1551	  support when running on CPUs that present the activity monitors
1552	  extension. The required support is present in:
1553	    * Version 1.5 and later of the ARM Trusted Firmware
1554
1555	  For kernels that have this configuration enabled but boot with broken
1556	  firmware, you may need to say N here until the firmware is fixed.
1557	  Otherwise you may experience firmware panics or lockups when
1558	  accessing the counter registers. Even if you are not observing these
1559	  symptoms, the values returned by the register reads might not
1560	  correctly reflect reality. Most commonly, the value read will be 0,
1561	  indicating that the counter is not enabled.
1562
1563config AS_HAS_ARMV8_4
1564	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1565
1566config ARM64_TLB_RANGE
1567	bool "Enable support for tlbi range feature"
1568	default y
1569	depends on AS_HAS_ARMV8_4
1570	help
1571	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1572	  range of input addresses.
1573
1574	  The feature introduces new assembly instructions, and they were
1575	  support when binutils >= 2.30.
1576
1577endmenu
1578
1579menu "ARMv8.5 architectural features"
1580
1581config AS_HAS_ARMV8_5
1582	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1583
1584config ARM64_BTI
1585	bool "Branch Target Identification support"
1586	default y
1587	help
1588	  Branch Target Identification (part of the ARMv8.5 Extensions)
1589	  provides a mechanism to limit the set of locations to which computed
1590	  branch instructions such as BR or BLR can jump.
1591
1592	  To make use of BTI on CPUs that support it, say Y.
1593
1594	  BTI is intended to provide complementary protection to other control
1595	  flow integrity protection mechanisms, such as the Pointer
1596	  authentication mechanism provided as part of the ARMv8.3 Extensions.
1597	  For this reason, it does not make sense to enable this option without
1598	  also enabling support for pointer authentication.  Thus, when
1599	  enabling this option you should also select ARM64_PTR_AUTH=y.
1600
1601	  Userspace binaries must also be specifically compiled to make use of
1602	  this mechanism.  If you say N here or the hardware does not support
1603	  BTI, such binaries can still run, but you get no additional
1604	  enforcement of branch destinations.
1605
1606config ARM64_BTI_KERNEL
1607	bool "Use Branch Target Identification for kernel"
1608	default y
1609	depends on ARM64_BTI
1610	depends on ARM64_PTR_AUTH
1611	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1612	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1613	depends on !CC_IS_GCC || GCC_VERSION >= 100100
1614	depends on !(CC_IS_CLANG && GCOV_KERNEL)
1615	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
1616	help
1617	  Build the kernel with Branch Target Identification annotations
1618	  and enable enforcement of this for kernel code. When this option
1619	  is enabled and the system supports BTI all kernel code including
1620	  modular code must have BTI enabled.
1621
1622config CC_HAS_BRANCH_PROT_PAC_RET_BTI
1623	# GCC 9 or later, clang 8 or later
1624	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
1625
1626config ARM64_E0PD
1627	bool "Enable support for E0PD"
1628	default y
1629	help
1630	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
1631	  that EL0 accesses made via TTBR1 always fault in constant time,
1632	  providing similar benefits to KASLR as those provided by KPTI, but
1633	  with lower overhead and without disrupting legitimate access to
1634	  kernel memory such as SPE.
1635
1636	  This option enables E0PD for TTBR1 where available.
1637
1638config ARCH_RANDOM
1639	bool "Enable support for random number generation"
1640	default y
1641	help
1642	  Random number generation (part of the ARMv8.5 Extensions)
1643	  provides a high bandwidth, cryptographically secure
1644	  hardware random number generator.
1645
1646config ARM64_AS_HAS_MTE
1647	# Initial support for MTE went in binutils 2.32.0, checked with
1648	# ".arch armv8.5-a+memtag" below. However, this was incomplete
1649	# as a late addition to the final architecture spec (LDGM/STGM)
1650	# is only supported in the newer 2.32.x and 2.33 binutils
1651	# versions, hence the extra "stgm" instruction check below.
1652	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
1653
1654config ARM64_MTE
1655	bool "Memory Tagging Extension support"
1656	default y
1657	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
1658	depends on AS_HAS_ARMV8_5
1659	# Required for tag checking in the uaccess routines
1660	depends on ARM64_PAN
1661	select ARCH_USES_HIGH_VMA_FLAGS
1662	help
1663	  Memory Tagging (part of the ARMv8.5 Extensions) provides
1664	  architectural support for run-time, always-on detection of
1665	  various classes of memory error to aid with software debugging
1666	  to eliminate vulnerabilities arising from memory-unsafe
1667	  languages.
1668
1669	  This option enables the support for the Memory Tagging
1670	  Extension at EL0 (i.e. for userspace).
1671
1672	  Selecting this option allows the feature to be detected at
1673	  runtime. Any secondary CPU not implementing this feature will
1674	  not be allowed a late bring-up.
1675
1676	  Userspace binaries that want to use this feature must
1677	  explicitly opt in. The mechanism for the userspace is
1678	  described in:
1679
1680	  Documentation/arm64/memory-tagging-extension.rst.
1681
1682endmenu
1683
1684config ARM64_SVE
1685	bool "ARM Scalable Vector Extension support"
1686	default y
1687	depends on !KVM || ARM64_VHE
1688	help
1689	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1690	  execution state which complements and extends the SIMD functionality
1691	  of the base architecture to support much larger vectors and to enable
1692	  additional vectorisation opportunities.
1693
1694	  To enable use of this extension on CPUs that implement it, say Y.
1695
1696	  On CPUs that support the SVE2 extensions, this option will enable
1697	  those too.
1698
1699	  Note that for architectural reasons, firmware _must_ implement SVE
1700	  support when running on SVE capable hardware.  The required support
1701	  is present in:
1702
1703	    * version 1.5 and later of the ARM Trusted Firmware
1704	    * the AArch64 boot wrapper since commit 5e1261e08abf
1705	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1706
1707	  For other firmware implementations, consult the firmware documentation
1708	  or vendor.
1709
1710	  If you need the kernel to boot on SVE-capable hardware with broken
1711	  firmware, you may need to say N here until you get your firmware
1712	  fixed.  Otherwise, you may experience firmware panics or lockups when
1713	  booting the kernel.  If unsure and you are not observing these
1714	  symptoms, you should assume that it is safe to say Y.
1715
1716	  CPUs that support SVE are architecturally required to support the
1717	  Virtualization Host Extensions (VHE), so the kernel makes no
1718	  provision for supporting SVE alongside KVM without VHE enabled.
1719	  Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
1720	  KVM in the same kernel image.
1721
1722config ARM64_MODULE_PLTS
1723	bool "Use PLTs to allow module memory to spill over into vmalloc area"
1724	depends on MODULES
1725	select HAVE_MOD_ARCH_SPECIFIC
1726	help
1727	  Allocate PLTs when loading modules so that jumps and calls whose
1728	  targets are too far away for their relative offsets to be encoded
1729	  in the instructions themselves can be bounced via veneers in the
1730	  module's PLT. This allows modules to be allocated in the generic
1731	  vmalloc area after the dedicated module memory area has been
1732	  exhausted.
1733
1734	  When running with address space randomization (KASLR), the module
1735	  region itself may be too far away for ordinary relative jumps and
1736	  calls, and so in that case, module PLTs are required and cannot be
1737	  disabled.
1738
1739	  Specific errata workaround(s) might also force module PLTs to be
1740	  enabled (ARM64_ERRATUM_843419).
1741
1742config ARM64_PSEUDO_NMI
1743	bool "Support for NMI-like interrupts"
1744	select ARM_GIC_V3
1745	help
1746	  Adds support for mimicking Non-Maskable Interrupts through the use of
1747	  GIC interrupt priority. This support requires version 3 or later of
1748	  ARM GIC.
1749
1750	  This high priority configuration for interrupts needs to be
1751	  explicitly enabled by setting the kernel parameter
1752	  "irqchip.gicv3_pseudo_nmi" to 1.
1753
1754	  If unsure, say N
1755
1756if ARM64_PSEUDO_NMI
1757config ARM64_DEBUG_PRIORITY_MASKING
1758	bool "Debug interrupt priority masking"
1759	help
1760	  This adds runtime checks to functions enabling/disabling
1761	  interrupts when using priority masking. The additional checks verify
1762	  the validity of ICC_PMR_EL1 when calling concerned functions.
1763
1764	  If unsure, say N
1765endif
1766
1767config RELOCATABLE
1768	bool "Build a relocatable kernel image" if EXPERT
1769	select ARCH_HAS_RELR
1770	default y
1771	help
1772	  This builds the kernel as a Position Independent Executable (PIE),
1773	  which retains all relocation metadata required to relocate the
1774	  kernel binary at runtime to a different virtual address than the
1775	  address it was linked at.
1776	  Since AArch64 uses the RELA relocation format, this requires a
1777	  relocation pass at runtime even if the kernel is loaded at the
1778	  same address it was linked at.
1779
1780config RANDOMIZE_BASE
1781	bool "Randomize the address of the kernel image"
1782	select ARM64_MODULE_PLTS if MODULES
1783	select RELOCATABLE
1784	help
1785	  Randomizes the virtual address at which the kernel image is
1786	  loaded, as a security feature that deters exploit attempts
1787	  relying on knowledge of the location of kernel internals.
1788
1789	  It is the bootloader's job to provide entropy, by passing a
1790	  random u64 value in /chosen/kaslr-seed at kernel entry.
1791
1792	  When booting via the UEFI stub, it will invoke the firmware's
1793	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1794	  to the kernel proper. In addition, it will randomise the physical
1795	  location of the kernel Image as well.
1796
1797	  If unsure, say N.
1798
1799config RANDOMIZE_MODULE_REGION_FULL
1800	bool "Randomize the module region over a 4 GB range"
1801	depends on RANDOMIZE_BASE
1802	default y
1803	help
1804	  Randomizes the location of the module region inside a 4 GB window
1805	  covering the core kernel. This way, it is less likely for modules
1806	  to leak information about the location of core kernel data structures
1807	  but it does imply that function calls between modules and the core
1808	  kernel will need to be resolved via veneers in the module PLT.
1809
1810	  When this option is not set, the module region will be randomized over
1811	  a limited range that contains the [_stext, _etext] interval of the
1812	  core kernel, so branch relocations are always in range.
1813
1814config CC_HAVE_STACKPROTECTOR_SYSREG
1815	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1816
1817config STACKPROTECTOR_PER_TASK
1818	def_bool y
1819	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1820
1821endmenu
1822
1823menu "Boot options"
1824
1825config ARM64_ACPI_PARKING_PROTOCOL
1826	bool "Enable support for the ARM64 ACPI parking protocol"
1827	depends on ACPI
1828	help
1829	  Enable support for the ARM64 ACPI parking protocol. If disabled
1830	  the kernel will not allow booting through the ARM64 ACPI parking
1831	  protocol even if the corresponding data is present in the ACPI
1832	  MADT table.
1833
1834config CMDLINE
1835	string "Default kernel command string"
1836	default ""
1837	help
1838	  Provide a set of default command-line options at build time by
1839	  entering them here. As a minimum, you should specify the the
1840	  root device (e.g. root=/dev/nfs).
1841
1842choice
1843	prompt "Kernel command line type" if CMDLINE != ""
1844	default CMDLINE_FROM_BOOTLOADER
1845	help
1846	  Choose how the kernel will handle the provided default kernel
1847	  command line string.
1848
1849config CMDLINE_FROM_BOOTLOADER
1850	bool "Use bootloader kernel arguments if available"
1851	help
1852	  Uses the command-line options passed by the boot loader. If
1853	  the boot loader doesn't provide any, the default kernel command
1854	  string provided in CMDLINE will be used.
1855
1856config CMDLINE_FORCE
1857	bool "Always use the default kernel command string"
1858	help
1859	  Always use the default kernel command string, even if the boot
1860	  loader passes other arguments to the kernel.
1861	  This is useful if you cannot or don't want to change the
1862	  command-line options your boot loader passes to the kernel.
1863
1864endchoice
1865
1866config EFI_STUB
1867	bool
1868
1869config EFI
1870	bool "UEFI runtime support"
1871	depends on OF && !CPU_BIG_ENDIAN
1872	depends on KERNEL_MODE_NEON
1873	select ARCH_SUPPORTS_ACPI
1874	select LIBFDT
1875	select UCS2_STRING
1876	select EFI_PARAMS_FROM_FDT
1877	select EFI_RUNTIME_WRAPPERS
1878	select EFI_STUB
1879	select EFI_GENERIC_STUB
1880	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
1881	default y
1882	help
1883	  This option provides support for runtime services provided
1884	  by UEFI firmware (such as non-volatile variables, realtime
1885          clock, and platform reset). A UEFI stub is also provided to
1886	  allow the kernel to be booted as an EFI application. This
1887	  is only useful on systems that have UEFI firmware.
1888
1889config DMI
1890	bool "Enable support for SMBIOS (DMI) tables"
1891	depends on EFI
1892	default y
1893	help
1894	  This enables SMBIOS/DMI feature for systems.
1895
1896	  This option is only useful on systems that have UEFI firmware.
1897	  However, even with this option, the resultant kernel should
1898	  continue to boot on existing non-UEFI platforms.
1899
1900endmenu
1901
1902config SYSVIPC_COMPAT
1903	def_bool y
1904	depends on COMPAT && SYSVIPC
1905
1906config ARCH_ENABLE_HUGEPAGE_MIGRATION
1907	def_bool y
1908	depends on HUGETLB_PAGE && MIGRATION
1909
1910config ARCH_ENABLE_THP_MIGRATION
1911	def_bool y
1912	depends on TRANSPARENT_HUGEPAGE
1913
1914menu "Power management options"
1915
1916source "kernel/power/Kconfig"
1917
1918config ARCH_HIBERNATION_POSSIBLE
1919	def_bool y
1920	depends on CPU_PM
1921
1922config ARCH_HIBERNATION_HEADER
1923	def_bool y
1924	depends on HIBERNATION
1925
1926config ARCH_SUSPEND_POSSIBLE
1927	def_bool y
1928
1929endmenu
1930
1931menu "CPU Power Management"
1932
1933source "drivers/cpuidle/Kconfig"
1934
1935source "drivers/cpufreq/Kconfig"
1936
1937endmenu
1938
1939source "drivers/firmware/Kconfig"
1940
1941source "drivers/acpi/Kconfig"
1942
1943source "arch/arm64/kvm/Kconfig"
1944
1945if CRYPTO
1946source "arch/arm64/crypto/Kconfig"
1947endif
1948