xref: /linux/arch/arm64/Kconfig (revision ca6c080eef42e4149110f79cf73a48a6ec4e965d)
1# SPDX-License-Identifier: GPL-2.0-only
2config ARM64
3	def_bool y
4	select ACPI_APMT if ACPI
5	select ACPI_CCA_REQUIRED if ACPI
6	select ACPI_GENERIC_GSI if ACPI
7	select ACPI_GTDT if ACPI
8	select ACPI_IORT if ACPI
9	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
10	select ACPI_MCFG if (ACPI && PCI)
11	select ACPI_SPCR_TABLE if ACPI
12	select ACPI_PPTT if ACPI
13	select ARCH_HAS_DEBUG_WX
14	select ARCH_BINFMT_ELF_EXTRA_PHDRS
15	select ARCH_BINFMT_ELF_STATE
16	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
17	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
18	select ARCH_ENABLE_MEMORY_HOTPLUG
19	select ARCH_ENABLE_MEMORY_HOTREMOVE
20	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
21	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
22	select ARCH_HAS_CACHE_LINE_SIZE
23	select ARCH_HAS_CURRENT_STACK_POINTER
24	select ARCH_HAS_DEBUG_VIRTUAL
25	select ARCH_HAS_DEBUG_VM_PGTABLE
26	select ARCH_HAS_DMA_PREP_COHERENT
27	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
28	select ARCH_HAS_FAST_MULTIPLIER
29	select ARCH_HAS_FORTIFY_SOURCE
30	select ARCH_HAS_GCOV_PROFILE_ALL
31	select ARCH_HAS_GIGANTIC_PAGE
32	select ARCH_HAS_KCOV
33	select ARCH_HAS_KEEPINITRD
34	select ARCH_HAS_MEMBARRIER_SYNC_CORE
35	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
36	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
37	select ARCH_HAS_PTE_DEVMAP
38	select ARCH_HAS_PTE_SPECIAL
39	select ARCH_HAS_HW_PTE_YOUNG
40	select ARCH_HAS_SETUP_DMA_OPS
41	select ARCH_HAS_SET_DIRECT_MAP
42	select ARCH_HAS_SET_MEMORY
43	select ARCH_STACKWALK
44	select ARCH_HAS_STRICT_KERNEL_RWX
45	select ARCH_HAS_STRICT_MODULE_RWX
46	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
47	select ARCH_HAS_SYNC_DMA_FOR_CPU
48	select ARCH_HAS_SYSCALL_WRAPPER
49	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
50	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
51	select ARCH_HAS_ZONE_DMA_SET if EXPERT
52	select ARCH_HAVE_ELF_PROT
53	select ARCH_HAVE_NMI_SAFE_CMPXCHG
54	select ARCH_HAVE_TRACE_MMIO_ACCESS
55	select ARCH_INLINE_READ_LOCK if !PREEMPTION
56	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
57	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
58	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
59	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
60	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
61	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
62	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
63	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
64	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
65	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
66	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
67	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
68	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
69	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
70	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
71	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
72	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
73	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
74	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
75	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
76	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
77	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
78	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
79	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
80	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
81	select ARCH_KEEP_MEMBLOCK
82	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
83	select ARCH_USE_CMPXCHG_LOCKREF
84	select ARCH_USE_GNU_PROPERTY
85	select ARCH_USE_MEMTEST
86	select ARCH_USE_QUEUED_RWLOCKS
87	select ARCH_USE_QUEUED_SPINLOCKS
88	select ARCH_USE_SYM_ANNOTATIONS
89	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
90	select ARCH_SUPPORTS_HUGETLBFS
91	select ARCH_SUPPORTS_MEMORY_FAILURE
92	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
93	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
94	select ARCH_SUPPORTS_LTO_CLANG_THIN
95	select ARCH_SUPPORTS_CFI_CLANG
96	select ARCH_SUPPORTS_ATOMIC_RMW
97	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
98	select ARCH_SUPPORTS_NUMA_BALANCING
99	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
100	select ARCH_SUPPORTS_PER_VMA_LOCK
101	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
102	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
103	select ARCH_WANT_DEFAULT_BPF_JIT
104	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
105	select ARCH_WANT_FRAME_POINTERS
106	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
107	select ARCH_WANT_LD_ORPHAN_WARN
108	select ARCH_WANTS_NO_INSTR
109	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
110	select ARCH_HAS_UBSAN_SANITIZE_ALL
111	select ARM_AMBA
112	select ARM_ARCH_TIMER
113	select ARM_GIC
114	select AUDIT_ARCH_COMPAT_GENERIC
115	select ARM_GIC_V2M if PCI
116	select ARM_GIC_V3
117	select ARM_GIC_V3_ITS if PCI
118	select ARM_PSCI_FW
119	select BUILDTIME_TABLE_SORT
120	select CLONE_BACKWARDS
121	select COMMON_CLK
122	select CPU_PM if (SUSPEND || CPU_IDLE)
123	select CRC32
124	select DCACHE_WORD_ACCESS
125	select DYNAMIC_FTRACE if FUNCTION_TRACER
126	select DMA_BOUNCE_UNALIGNED_KMALLOC
127	select DMA_DIRECT_REMAP
128	select EDAC_SUPPORT
129	select FRAME_POINTER
130	select FUNCTION_ALIGNMENT_4B
131	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
132	select GENERIC_ALLOCATOR
133	select GENERIC_ARCH_TOPOLOGY
134	select GENERIC_CLOCKEVENTS_BROADCAST
135	select GENERIC_CPU_AUTOPROBE
136	select GENERIC_CPU_VULNERABILITIES
137	select GENERIC_EARLY_IOREMAP
138	select GENERIC_IDLE_POLL_SETUP
139	select GENERIC_IOREMAP
140	select GENERIC_IRQ_IPI
141	select GENERIC_IRQ_PROBE
142	select GENERIC_IRQ_SHOW
143	select GENERIC_IRQ_SHOW_LEVEL
144	select GENERIC_LIB_DEVMEM_IS_ALLOWED
145	select GENERIC_PCI_IOMAP
146	select GENERIC_PTDUMP
147	select GENERIC_SCHED_CLOCK
148	select GENERIC_SMP_IDLE_THREAD
149	select GENERIC_TIME_VSYSCALL
150	select GENERIC_GETTIMEOFDAY
151	select GENERIC_VDSO_TIME_NS
152	select HARDIRQS_SW_RESEND
153	select HAS_IOPORT
154	select HAVE_MOVE_PMD
155	select HAVE_MOVE_PUD
156	select HAVE_PCI
157	select HAVE_ACPI_APEI if (ACPI && EFI)
158	select HAVE_ALIGNED_STRUCT_PAGE
159	select HAVE_ARCH_AUDITSYSCALL
160	select HAVE_ARCH_BITREVERSE
161	select HAVE_ARCH_COMPILER_H
162	select HAVE_ARCH_HUGE_VMALLOC
163	select HAVE_ARCH_HUGE_VMAP
164	select HAVE_ARCH_JUMP_LABEL
165	select HAVE_ARCH_JUMP_LABEL_RELATIVE
166	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
167	select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
168	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
169	select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
170	# Some instrumentation may be unsound, hence EXPERT
171	select HAVE_ARCH_KCSAN if EXPERT
172	select HAVE_ARCH_KFENCE
173	select HAVE_ARCH_KGDB
174	select HAVE_ARCH_MMAP_RND_BITS
175	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
176	select HAVE_ARCH_PREL32_RELOCATIONS
177	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
178	select HAVE_ARCH_SECCOMP_FILTER
179	select HAVE_ARCH_STACKLEAK
180	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
181	select HAVE_ARCH_TRACEHOOK
182	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
183	select HAVE_ARCH_VMAP_STACK
184	select HAVE_ARM_SMCCC
185	select HAVE_ASM_MODVERSIONS
186	select HAVE_EBPF_JIT
187	select HAVE_C_RECORDMCOUNT
188	select HAVE_CMPXCHG_DOUBLE
189	select HAVE_CMPXCHG_LOCAL
190	select HAVE_CONTEXT_TRACKING_USER
191	select HAVE_DEBUG_KMEMLEAK
192	select HAVE_DMA_CONTIGUOUS
193	select HAVE_DYNAMIC_FTRACE
194	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
195		if $(cc-option,-fpatchable-function-entry=2)
196	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
197		if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
198	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
199		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
200		    !CC_OPTIMIZE_FOR_SIZE)
201	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
202		if DYNAMIC_FTRACE_WITH_ARGS
203	select HAVE_SAMPLE_FTRACE_DIRECT
204	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
205	select HAVE_EFFICIENT_UNALIGNED_ACCESS
206	select HAVE_FAST_GUP
207	select HAVE_FTRACE_MCOUNT_RECORD
208	select HAVE_FUNCTION_TRACER
209	select HAVE_FUNCTION_ERROR_INJECTION
210	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
211	select HAVE_FUNCTION_GRAPH_TRACER
212	select HAVE_GCC_PLUGINS
213	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
214		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
215	select HAVE_HW_BREAKPOINT if PERF_EVENTS
216	select HAVE_IOREMAP_PROT
217	select HAVE_IRQ_TIME_ACCOUNTING
218	select HAVE_KVM
219	select HAVE_MOD_ARCH_SPECIFIC
220	select HAVE_NMI
221	select HAVE_PERF_EVENTS
222	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
223	select HAVE_PERF_REGS
224	select HAVE_PERF_USER_STACK_DUMP
225	select HAVE_PREEMPT_DYNAMIC_KEY
226	select HAVE_REGS_AND_STACK_ACCESS_API
227	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
228	select HAVE_FUNCTION_ARG_ACCESS_API
229	select MMU_GATHER_RCU_TABLE_FREE
230	select HAVE_RSEQ
231	select HAVE_STACKPROTECTOR
232	select HAVE_SYSCALL_TRACEPOINTS
233	select HAVE_KPROBES
234	select HAVE_KRETPROBES
235	select HAVE_GENERIC_VDSO
236	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
237	select IRQ_DOMAIN
238	select IRQ_FORCED_THREADING
239	select KASAN_VMALLOC if KASAN
240	select LOCK_MM_AND_FIND_VMA
241	select MODULES_USE_ELF_RELA
242	select NEED_DMA_MAP_STATE
243	select NEED_SG_DMA_LENGTH
244	select OF
245	select OF_EARLY_FLATTREE
246	select PCI_DOMAINS_GENERIC if PCI
247	select PCI_ECAM if (ACPI && PCI)
248	select PCI_SYSCALL if PCI
249	select POWER_RESET
250	select POWER_SUPPLY
251	select SPARSE_IRQ
252	select SWIOTLB
253	select SYSCTL_EXCEPTION_TRACE
254	select THREAD_INFO_IN_TASK
255	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
256	select TRACE_IRQFLAGS_SUPPORT
257	select TRACE_IRQFLAGS_NMI_SUPPORT
258	select HAVE_SOFTIRQ_ON_OWN_STACK
259	help
260	  ARM 64-bit (AArch64) Linux support.
261
262config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
263	def_bool CC_IS_CLANG
264	# https://github.com/ClangBuiltLinux/linux/issues/1507
265	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
266	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
267
268config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
269	def_bool CC_IS_GCC
270	depends on $(cc-option,-fpatchable-function-entry=2)
271	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
272
273config 64BIT
274	def_bool y
275
276config MMU
277	def_bool y
278
279config ARM64_PAGE_SHIFT
280	int
281	default 16 if ARM64_64K_PAGES
282	default 14 if ARM64_16K_PAGES
283	default 12
284
285config ARM64_CONT_PTE_SHIFT
286	int
287	default 5 if ARM64_64K_PAGES
288	default 7 if ARM64_16K_PAGES
289	default 4
290
291config ARM64_CONT_PMD_SHIFT
292	int
293	default 5 if ARM64_64K_PAGES
294	default 5 if ARM64_16K_PAGES
295	default 4
296
297config ARCH_MMAP_RND_BITS_MIN
298	default 14 if ARM64_64K_PAGES
299	default 16 if ARM64_16K_PAGES
300	default 18
301
302# max bits determined by the following formula:
303#  VA_BITS - PAGE_SHIFT - 3
304config ARCH_MMAP_RND_BITS_MAX
305	default 19 if ARM64_VA_BITS=36
306	default 24 if ARM64_VA_BITS=39
307	default 27 if ARM64_VA_BITS=42
308	default 30 if ARM64_VA_BITS=47
309	default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
310	default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
311	default 33 if ARM64_VA_BITS=48
312	default 14 if ARM64_64K_PAGES
313	default 16 if ARM64_16K_PAGES
314	default 18
315
316config ARCH_MMAP_RND_COMPAT_BITS_MIN
317	default 7 if ARM64_64K_PAGES
318	default 9 if ARM64_16K_PAGES
319	default 11
320
321config ARCH_MMAP_RND_COMPAT_BITS_MAX
322	default 16
323
324config NO_IOPORT_MAP
325	def_bool y if !PCI
326
327config STACKTRACE_SUPPORT
328	def_bool y
329
330config ILLEGAL_POINTER_VALUE
331	hex
332	default 0xdead000000000000
333
334config LOCKDEP_SUPPORT
335	def_bool y
336
337config GENERIC_BUG
338	def_bool y
339	depends on BUG
340
341config GENERIC_BUG_RELATIVE_POINTERS
342	def_bool y
343	depends on GENERIC_BUG
344
345config GENERIC_HWEIGHT
346	def_bool y
347
348config GENERIC_CSUM
349	def_bool y
350
351config GENERIC_CALIBRATE_DELAY
352	def_bool y
353
354config SMP
355	def_bool y
356
357config KERNEL_MODE_NEON
358	def_bool y
359
360config FIX_EARLYCON_MEM
361	def_bool y
362
363config PGTABLE_LEVELS
364	int
365	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
366	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
367	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
368	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
369	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
370	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
371
372config ARCH_SUPPORTS_UPROBES
373	def_bool y
374
375config ARCH_PROC_KCORE_TEXT
376	def_bool y
377
378config BROKEN_GAS_INST
379	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
380
381config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
382	bool
383	# Clang's __builtin_return_adddress() strips the PAC since 12.0.0
384	# https://reviews.llvm.org/D75044
385	default y if CC_IS_CLANG && (CLANG_VERSION >= 120000)
386	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
387	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
388	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
389	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
390	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
391	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
392	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
393	default n
394
395config KASAN_SHADOW_OFFSET
396	hex
397	depends on KASAN_GENERIC || KASAN_SW_TAGS
398	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
399	default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
400	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
401	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
402	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
403	default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
404	default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
405	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
406	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
407	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
408	default 0xffffffffffffffff
409
410config UNWIND_TABLES
411	bool
412
413source "arch/arm64/Kconfig.platforms"
414
415menu "Kernel Features"
416
417menu "ARM errata workarounds via the alternatives framework"
418
419config AMPERE_ERRATUM_AC03_CPU_38
420        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
421	default y
422	help
423	  This option adds an alternative code sequence to work around Ampere
424	  erratum AC03_CPU_38 on AmpereOne.
425
426	  The affected design reports FEAT_HAFDBS as not implemented in
427	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
428	  as required by the architecture. The unadvertised HAFDBS
429	  implementation suffers from an additional erratum where hardware
430	  A/D updates can occur after a PTE has been marked invalid.
431
432	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
433	  which avoids enabling unadvertised hardware Access Flag management
434	  at stage-2.
435
436	  If unsure, say Y.
437
438config ARM64_WORKAROUND_CLEAN_CACHE
439	bool
440
441config ARM64_ERRATUM_826319
442	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
443	default y
444	select ARM64_WORKAROUND_CLEAN_CACHE
445	help
446	  This option adds an alternative code sequence to work around ARM
447	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
448	  AXI master interface and an L2 cache.
449
450	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
451	  and is unable to accept a certain write via this interface, it will
452	  not progress on read data presented on the read data channel and the
453	  system can deadlock.
454
455	  The workaround promotes data cache clean instructions to
456	  data cache clean-and-invalidate.
457	  Please note that this does not necessarily enable the workaround,
458	  as it depends on the alternative framework, which will only patch
459	  the kernel if an affected CPU is detected.
460
461	  If unsure, say Y.
462
463config ARM64_ERRATUM_827319
464	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
465	default y
466	select ARM64_WORKAROUND_CLEAN_CACHE
467	help
468	  This option adds an alternative code sequence to work around ARM
469	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
470	  master interface and an L2 cache.
471
472	  Under certain conditions this erratum can cause a clean line eviction
473	  to occur at the same time as another transaction to the same address
474	  on the AMBA 5 CHI interface, which can cause data corruption if the
475	  interconnect reorders the two transactions.
476
477	  The workaround promotes data cache clean instructions to
478	  data cache clean-and-invalidate.
479	  Please note that this does not necessarily enable the workaround,
480	  as it depends on the alternative framework, which will only patch
481	  the kernel if an affected CPU is detected.
482
483	  If unsure, say Y.
484
485config ARM64_ERRATUM_824069
486	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
487	default y
488	select ARM64_WORKAROUND_CLEAN_CACHE
489	help
490	  This option adds an alternative code sequence to work around ARM
491	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
492	  to a coherent interconnect.
493
494	  If a Cortex-A53 processor is executing a store or prefetch for
495	  write instruction at the same time as a processor in another
496	  cluster is executing a cache maintenance operation to the same
497	  address, then this erratum might cause a clean cache line to be
498	  incorrectly marked as dirty.
499
500	  The workaround promotes data cache clean instructions to
501	  data cache clean-and-invalidate.
502	  Please note that this option does not necessarily enable the
503	  workaround, as it depends on the alternative framework, which will
504	  only patch the kernel if an affected CPU is detected.
505
506	  If unsure, say Y.
507
508config ARM64_ERRATUM_819472
509	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
510	default y
511	select ARM64_WORKAROUND_CLEAN_CACHE
512	help
513	  This option adds an alternative code sequence to work around ARM
514	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
515	  present when it is connected to a coherent interconnect.
516
517	  If the processor is executing a load and store exclusive sequence at
518	  the same time as a processor in another cluster is executing a cache
519	  maintenance operation to the same address, then this erratum might
520	  cause data corruption.
521
522	  The workaround promotes data cache clean instructions to
523	  data cache clean-and-invalidate.
524	  Please note that this does not necessarily enable the workaround,
525	  as it depends on the alternative framework, which will only patch
526	  the kernel if an affected CPU is detected.
527
528	  If unsure, say Y.
529
530config ARM64_ERRATUM_832075
531	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
532	default y
533	help
534	  This option adds an alternative code sequence to work around ARM
535	  erratum 832075 on Cortex-A57 parts up to r1p2.
536
537	  Affected Cortex-A57 parts might deadlock when exclusive load/store
538	  instructions to Write-Back memory are mixed with Device loads.
539
540	  The workaround is to promote device loads to use Load-Acquire
541	  semantics.
542	  Please note that this does not necessarily enable the workaround,
543	  as it depends on the alternative framework, which will only patch
544	  the kernel if an affected CPU is detected.
545
546	  If unsure, say Y.
547
548config ARM64_ERRATUM_834220
549	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
550	depends on KVM
551	default y
552	help
553	  This option adds an alternative code sequence to work around ARM
554	  erratum 834220 on Cortex-A57 parts up to r1p2.
555
556	  Affected Cortex-A57 parts might report a Stage 2 translation
557	  fault as the result of a Stage 1 fault for load crossing a
558	  page boundary when there is a permission or device memory
559	  alignment fault at Stage 1 and a translation fault at Stage 2.
560
561	  The workaround is to verify that the Stage 1 translation
562	  doesn't generate a fault before handling the Stage 2 fault.
563	  Please note that this does not necessarily enable the workaround,
564	  as it depends on the alternative framework, which will only patch
565	  the kernel if an affected CPU is detected.
566
567	  If unsure, say Y.
568
569config ARM64_ERRATUM_1742098
570	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
571	depends on COMPAT
572	default y
573	help
574	  This option removes the AES hwcap for aarch32 user-space to
575	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
576
577	  Affected parts may corrupt the AES state if an interrupt is
578	  taken between a pair of AES instructions. These instructions
579	  are only present if the cryptography extensions are present.
580	  All software should have a fallback implementation for CPUs
581	  that don't implement the cryptography extensions.
582
583	  If unsure, say Y.
584
585config ARM64_ERRATUM_845719
586	bool "Cortex-A53: 845719: a load might read incorrect data"
587	depends on COMPAT
588	default y
589	help
590	  This option adds an alternative code sequence to work around ARM
591	  erratum 845719 on Cortex-A53 parts up to r0p4.
592
593	  When running a compat (AArch32) userspace on an affected Cortex-A53
594	  part, a load at EL0 from a virtual address that matches the bottom 32
595	  bits of the virtual address used by a recent load at (AArch64) EL1
596	  might return incorrect data.
597
598	  The workaround is to write the contextidr_el1 register on exception
599	  return to a 32-bit task.
600	  Please note that this does not necessarily enable the workaround,
601	  as it depends on the alternative framework, which will only patch
602	  the kernel if an affected CPU is detected.
603
604	  If unsure, say Y.
605
606config ARM64_ERRATUM_843419
607	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
608	default y
609	help
610	  This option links the kernel with '--fix-cortex-a53-843419' and
611	  enables PLT support to replace certain ADRP instructions, which can
612	  cause subsequent memory accesses to use an incorrect address on
613	  Cortex-A53 parts up to r0p4.
614
615	  If unsure, say Y.
616
617config ARM64_LD_HAS_FIX_ERRATUM_843419
618	def_bool $(ld-option,--fix-cortex-a53-843419)
619
620config ARM64_ERRATUM_1024718
621	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
622	default y
623	help
624	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
625
626	  Affected Cortex-A55 cores (all revisions) could cause incorrect
627	  update of the hardware dirty bit when the DBM/AP bits are updated
628	  without a break-before-make. The workaround is to disable the usage
629	  of hardware DBM locally on the affected cores. CPUs not affected by
630	  this erratum will continue to use the feature.
631
632	  If unsure, say Y.
633
634config ARM64_ERRATUM_1418040
635	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
636	default y
637	depends on COMPAT
638	help
639	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
640	  errata 1188873 and 1418040.
641
642	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
643	  cause register corruption when accessing the timer registers
644	  from AArch32 userspace.
645
646	  If unsure, say Y.
647
648config ARM64_WORKAROUND_SPECULATIVE_AT
649	bool
650
651config ARM64_ERRATUM_1165522
652	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
653	default y
654	select ARM64_WORKAROUND_SPECULATIVE_AT
655	help
656	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
657
658	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
659	  corrupted TLBs by speculating an AT instruction during a guest
660	  context switch.
661
662	  If unsure, say Y.
663
664config ARM64_ERRATUM_1319367
665	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
666	default y
667	select ARM64_WORKAROUND_SPECULATIVE_AT
668	help
669	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
670	  and A72 erratum 1319367
671
672	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
673	  speculating an AT instruction during a guest context switch.
674
675	  If unsure, say Y.
676
677config ARM64_ERRATUM_1530923
678	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
679	default y
680	select ARM64_WORKAROUND_SPECULATIVE_AT
681	help
682	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
683
684	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
685	  corrupted TLBs by speculating an AT instruction during a guest
686	  context switch.
687
688	  If unsure, say Y.
689
690config ARM64_WORKAROUND_REPEAT_TLBI
691	bool
692
693config ARM64_ERRATUM_2441007
694	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
695	default y
696	select ARM64_WORKAROUND_REPEAT_TLBI
697	help
698	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
699
700	  Under very rare circumstances, affected Cortex-A55 CPUs
701	  may not handle a race between a break-before-make sequence on one
702	  CPU, and another CPU accessing the same page. This could allow a
703	  store to a page that has been unmapped.
704
705	  Work around this by adding the affected CPUs to the list that needs
706	  TLB sequences to be done twice.
707
708	  If unsure, say Y.
709
710config ARM64_ERRATUM_1286807
711	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
712	default y
713	select ARM64_WORKAROUND_REPEAT_TLBI
714	help
715	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
716
717	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
718	  address for a cacheable mapping of a location is being
719	  accessed by a core while another core is remapping the virtual
720	  address to a new physical page using the recommended
721	  break-before-make sequence, then under very rare circumstances
722	  TLBI+DSB completes before a read using the translation being
723	  invalidated has been observed by other observers. The
724	  workaround repeats the TLBI+DSB operation.
725
726config ARM64_ERRATUM_1463225
727	bool "Cortex-A76: Software Step might prevent interrupt recognition"
728	default y
729	help
730	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
731
732	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
733	  of a system call instruction (SVC) can prevent recognition of
734	  subsequent interrupts when software stepping is disabled in the
735	  exception handler of the system call and either kernel debugging
736	  is enabled or VHE is in use.
737
738	  Work around the erratum by triggering a dummy step exception
739	  when handling a system call from a task that is being stepped
740	  in a VHE configuration of the kernel.
741
742	  If unsure, say Y.
743
744config ARM64_ERRATUM_1542419
745	bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
746	default y
747	help
748	  This option adds a workaround for ARM Neoverse-N1 erratum
749	  1542419.
750
751	  Affected Neoverse-N1 cores could execute a stale instruction when
752	  modified by another CPU. The workaround depends on a firmware
753	  counterpart.
754
755	  Workaround the issue by hiding the DIC feature from EL0. This
756	  forces user-space to perform cache maintenance.
757
758	  If unsure, say Y.
759
760config ARM64_ERRATUM_1508412
761	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
762	default y
763	help
764	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
765
766	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
767	  of a store-exclusive or read of PAR_EL1 and a load with device or
768	  non-cacheable memory attributes. The workaround depends on a firmware
769	  counterpart.
770
771	  KVM guests must also have the workaround implemented or they can
772	  deadlock the system.
773
774	  Work around the issue by inserting DMB SY barriers around PAR_EL1
775	  register reads and warning KVM users. The DMB barrier is sufficient
776	  to prevent a speculative PAR_EL1 read.
777
778	  If unsure, say Y.
779
780config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
781	bool
782
783config ARM64_ERRATUM_2051678
784	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
785	default y
786	help
787	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
788	  Affected Cortex-A510 might not respect the ordering rules for
789	  hardware update of the page table's dirty bit. The workaround
790	  is to not enable the feature on affected CPUs.
791
792	  If unsure, say Y.
793
794config ARM64_ERRATUM_2077057
795	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
796	default y
797	help
798	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
799	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
800	  expected, but a Pointer Authentication trap is taken instead. The
801	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
802	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
803
804	  This can only happen when EL2 is stepping EL1.
805
806	  When these conditions occur, the SPSR_EL2 value is unchanged from the
807	  previous guest entry, and can be restored from the in-memory copy.
808
809	  If unsure, say Y.
810
811config ARM64_ERRATUM_2658417
812	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
813	default y
814	help
815	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
816	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
817	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
818	  A510 CPUs are using shared neon hardware. As the sharing is not
819	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
820	  user-space should not be using these instructions.
821
822	  If unsure, say Y.
823
824config ARM64_ERRATUM_2119858
825	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
826	default y
827	depends on CORESIGHT_TRBE
828	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
829	help
830	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
831
832	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
833	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
834	  the event of a WRAP event.
835
836	  Work around the issue by always making sure we move the TRBPTR_EL1 by
837	  256 bytes before enabling the buffer and filling the first 256 bytes of
838	  the buffer with ETM ignore packets upon disabling.
839
840	  If unsure, say Y.
841
842config ARM64_ERRATUM_2139208
843	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
844	default y
845	depends on CORESIGHT_TRBE
846	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
847	help
848	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
849
850	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
851	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
852	  the event of a WRAP event.
853
854	  Work around the issue by always making sure we move the TRBPTR_EL1 by
855	  256 bytes before enabling the buffer and filling the first 256 bytes of
856	  the buffer with ETM ignore packets upon disabling.
857
858	  If unsure, say Y.
859
860config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
861	bool
862
863config ARM64_ERRATUM_2054223
864	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
865	default y
866	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
867	help
868	  Enable workaround for ARM Cortex-A710 erratum 2054223
869
870	  Affected cores may fail to flush the trace data on a TSB instruction, when
871	  the PE is in trace prohibited state. This will cause losing a few bytes
872	  of the trace cached.
873
874	  Workaround is to issue two TSB consecutively on affected cores.
875
876	  If unsure, say Y.
877
878config ARM64_ERRATUM_2067961
879	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
880	default y
881	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
882	help
883	  Enable workaround for ARM Neoverse-N2 erratum 2067961
884
885	  Affected cores may fail to flush the trace data on a TSB instruction, when
886	  the PE is in trace prohibited state. This will cause losing a few bytes
887	  of the trace cached.
888
889	  Workaround is to issue two TSB consecutively on affected cores.
890
891	  If unsure, say Y.
892
893config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
894	bool
895
896config ARM64_ERRATUM_2253138
897	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
898	depends on CORESIGHT_TRBE
899	default y
900	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
901	help
902	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
903
904	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
905	  for TRBE. Under some conditions, the TRBE might generate a write to the next
906	  virtually addressed page following the last page of the TRBE address space
907	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
908
909	  Work around this in the driver by always making sure that there is a
910	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
911
912	  If unsure, say Y.
913
914config ARM64_ERRATUM_2224489
915	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
916	depends on CORESIGHT_TRBE
917	default y
918	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
919	help
920	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
921
922	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
923	  for TRBE. Under some conditions, the TRBE might generate a write to the next
924	  virtually addressed page following the last page of the TRBE address space
925	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
926
927	  Work around this in the driver by always making sure that there is a
928	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
929
930	  If unsure, say Y.
931
932config ARM64_ERRATUM_2441009
933	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
934	default y
935	select ARM64_WORKAROUND_REPEAT_TLBI
936	help
937	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
938
939	  Under very rare circumstances, affected Cortex-A510 CPUs
940	  may not handle a race between a break-before-make sequence on one
941	  CPU, and another CPU accessing the same page. This could allow a
942	  store to a page that has been unmapped.
943
944	  Work around this by adding the affected CPUs to the list that needs
945	  TLB sequences to be done twice.
946
947	  If unsure, say Y.
948
949config ARM64_ERRATUM_2064142
950	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
951	depends on CORESIGHT_TRBE
952	default y
953	help
954	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
955
956	  Affected Cortex-A510 core might fail to write into system registers after the
957	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
958	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
959	  and TRBTRG_EL1 will be ignored and will not be effected.
960
961	  Work around this in the driver by executing TSB CSYNC and DSB after collection
962	  is stopped and before performing a system register write to one of the affected
963	  registers.
964
965	  If unsure, say Y.
966
967config ARM64_ERRATUM_2038923
968	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
969	depends on CORESIGHT_TRBE
970	default y
971	help
972	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
973
974	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
975	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
976	  might be corrupted. This happens after TRBE buffer has been enabled by setting
977	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
978	  execution changes from a context, in which trace is prohibited to one where it
979	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
980	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
981	  the trace buffer state might be corrupted.
982
983	  Work around this in the driver by preventing an inconsistent view of whether the
984	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
985	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
986	  two ISB instructions if no ERET is to take place.
987
988	  If unsure, say Y.
989
990config ARM64_ERRATUM_1902691
991	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
992	depends on CORESIGHT_TRBE
993	default y
994	help
995	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
996
997	  Affected Cortex-A510 core might cause trace data corruption, when being written
998	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
999	  trace data.
1000
1001	  Work around this problem in the driver by just preventing TRBE initialization on
1002	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1003	  on such implementations. This will cover the kernel for any firmware that doesn't
1004	  do this already.
1005
1006	  If unsure, say Y.
1007
1008config ARM64_ERRATUM_2457168
1009	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1010	depends on ARM64_AMU_EXTN
1011	default y
1012	help
1013	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1014
1015	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1016	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1017	  incorrectly giving a significantly higher output value.
1018
1019	  Work around this problem by returning 0 when reading the affected counter in
1020	  key locations that results in disabling all users of this counter. This effect
1021	  is the same to firmware disabling affected counters.
1022
1023	  If unsure, say Y.
1024
1025config ARM64_ERRATUM_2645198
1026	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1027	default y
1028	help
1029	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1030
1031	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1032	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1033	  next instruction abort caused by permission fault.
1034
1035	  Only user-space does executable to non-executable permission transition via
1036	  mprotect() system call. Workaround the problem by doing a break-before-make
1037	  TLB invalidation, for all changes to executable user space mappings.
1038
1039	  If unsure, say Y.
1040
1041config ARM64_ERRATUM_2966298
1042	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1043	default y
1044	help
1045	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1046
1047	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1048	  load might leak data from a privileged level via a cache side channel.
1049
1050	  Work around this problem by executing a TLBI before returning to EL0.
1051
1052	  If unsure, say Y.
1053
1054config CAVIUM_ERRATUM_22375
1055	bool "Cavium erratum 22375, 24313"
1056	default y
1057	help
1058	  Enable workaround for errata 22375 and 24313.
1059
1060	  This implements two gicv3-its errata workarounds for ThunderX. Both
1061	  with a small impact affecting only ITS table allocation.
1062
1063	    erratum 22375: only alloc 8MB table size
1064	    erratum 24313: ignore memory access type
1065
1066	  The fixes are in ITS initialization and basically ignore memory access
1067	  type and table size provided by the TYPER and BASER registers.
1068
1069	  If unsure, say Y.
1070
1071config CAVIUM_ERRATUM_23144
1072	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1073	depends on NUMA
1074	default y
1075	help
1076	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1077
1078	  If unsure, say Y.
1079
1080config CAVIUM_ERRATUM_23154
1081	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1082	default y
1083	help
1084	  The ThunderX GICv3 implementation requires a modified version for
1085	  reading the IAR status to ensure data synchronization
1086	  (access to icc_iar1_el1 is not sync'ed before and after).
1087
1088	  It also suffers from erratum 38545 (also present on Marvell's
1089	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1090	  spuriously presented to the CPU interface.
1091
1092	  If unsure, say Y.
1093
1094config CAVIUM_ERRATUM_27456
1095	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1096	default y
1097	help
1098	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1099	  instructions may cause the icache to become corrupted if it
1100	  contains data for a non-current ASID.  The fix is to
1101	  invalidate the icache when changing the mm context.
1102
1103	  If unsure, say Y.
1104
1105config CAVIUM_ERRATUM_30115
1106	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1107	default y
1108	help
1109	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1110	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1111	  interrupts in host. Trapping both GICv3 group-0 and group-1
1112	  accesses sidesteps the issue.
1113
1114	  If unsure, say Y.
1115
1116config CAVIUM_TX2_ERRATUM_219
1117	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1118	default y
1119	help
1120	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1121	  TTBR update and the corresponding context synchronizing operation can
1122	  cause a spurious Data Abort to be delivered to any hardware thread in
1123	  the CPU core.
1124
1125	  Work around the issue by avoiding the problematic code sequence and
1126	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1127	  trap handler performs the corresponding register access, skips the
1128	  instruction and ensures context synchronization by virtue of the
1129	  exception return.
1130
1131	  If unsure, say Y.
1132
1133config FUJITSU_ERRATUM_010001
1134	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1135	default y
1136	help
1137	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1138	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1139	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1140	  This fault occurs under a specific hardware condition when a
1141	  load/store instruction performs an address translation using:
1142	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1143	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1144	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1145	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1146
1147	  The workaround is to ensure these bits are clear in TCR_ELx.
1148	  The workaround only affects the Fujitsu-A64FX.
1149
1150	  If unsure, say Y.
1151
1152config HISILICON_ERRATUM_161600802
1153	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1154	default y
1155	help
1156	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1157	  when issued ITS commands such as VMOVP and VMAPP, and requires
1158	  a 128kB offset to be applied to the target address in this commands.
1159
1160	  If unsure, say Y.
1161
1162config QCOM_FALKOR_ERRATUM_1003
1163	bool "Falkor E1003: Incorrect translation due to ASID change"
1164	default y
1165	help
1166	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1167	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1168	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1169	  then only for entries in the walk cache, since the leaf translation
1170	  is unchanged. Work around the erratum by invalidating the walk cache
1171	  entries for the trampoline before entering the kernel proper.
1172
1173config QCOM_FALKOR_ERRATUM_1009
1174	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1175	default y
1176	select ARM64_WORKAROUND_REPEAT_TLBI
1177	help
1178	  On Falkor v1, the CPU may prematurely complete a DSB following a
1179	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1180	  one more time to fix the issue.
1181
1182	  If unsure, say Y.
1183
1184config QCOM_QDF2400_ERRATUM_0065
1185	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1186	default y
1187	help
1188	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1189	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1190	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1191
1192	  If unsure, say Y.
1193
1194config QCOM_FALKOR_ERRATUM_E1041
1195	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1196	default y
1197	help
1198	  Falkor CPU may speculatively fetch instructions from an improper
1199	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1200	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1201
1202	  If unsure, say Y.
1203
1204config NVIDIA_CARMEL_CNP_ERRATUM
1205	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1206	default y
1207	help
1208	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1209	  invalidate shared TLB entries installed by a different core, as it would
1210	  on standard ARM cores.
1211
1212	  If unsure, say Y.
1213
1214config ROCKCHIP_ERRATUM_3588001
1215	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1216	default y
1217	help
1218	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1219	  This means, that its sharability feature may not be used, even though it
1220	  is supported by the IP itself.
1221
1222	  If unsure, say Y.
1223
1224config SOCIONEXT_SYNQUACER_PREITS
1225	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1226	default y
1227	help
1228	  Socionext Synquacer SoCs implement a separate h/w block to generate
1229	  MSI doorbell writes with non-zero values for the device ID.
1230
1231	  If unsure, say Y.
1232
1233endmenu # "ARM errata workarounds via the alternatives framework"
1234
1235choice
1236	prompt "Page size"
1237	default ARM64_4K_PAGES
1238	help
1239	  Page size (translation granule) configuration.
1240
1241config ARM64_4K_PAGES
1242	bool "4KB"
1243	help
1244	  This feature enables 4KB pages support.
1245
1246config ARM64_16K_PAGES
1247	bool "16KB"
1248	help
1249	  The system will use 16KB pages support. AArch32 emulation
1250	  requires applications compiled with 16K (or a multiple of 16K)
1251	  aligned segments.
1252
1253config ARM64_64K_PAGES
1254	bool "64KB"
1255	help
1256	  This feature enables 64KB pages support (4KB by default)
1257	  allowing only two levels of page tables and faster TLB
1258	  look-up. AArch32 emulation requires applications compiled
1259	  with 64K aligned segments.
1260
1261endchoice
1262
1263choice
1264	prompt "Virtual address space size"
1265	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1266	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1267	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1268	help
1269	  Allows choosing one of multiple possible virtual address
1270	  space sizes. The level of translation table is determined by
1271	  a combination of page size and virtual address space size.
1272
1273config ARM64_VA_BITS_36
1274	bool "36-bit" if EXPERT
1275	depends on ARM64_16K_PAGES
1276
1277config ARM64_VA_BITS_39
1278	bool "39-bit"
1279	depends on ARM64_4K_PAGES
1280
1281config ARM64_VA_BITS_42
1282	bool "42-bit"
1283	depends on ARM64_64K_PAGES
1284
1285config ARM64_VA_BITS_47
1286	bool "47-bit"
1287	depends on ARM64_16K_PAGES
1288
1289config ARM64_VA_BITS_48
1290	bool "48-bit"
1291
1292config ARM64_VA_BITS_52
1293	bool "52-bit"
1294	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1295	help
1296	  Enable 52-bit virtual addressing for userspace when explicitly
1297	  requested via a hint to mmap(). The kernel will also use 52-bit
1298	  virtual addresses for its own mappings (provided HW support for
1299	  this feature is available, otherwise it reverts to 48-bit).
1300
1301	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1302	  ARMv8.3 Pointer Authentication will result in the PAC being
1303	  reduced from 7 bits to 3 bits, which may have a significant
1304	  impact on its susceptibility to brute-force attacks.
1305
1306	  If unsure, select 48-bit virtual addressing instead.
1307
1308endchoice
1309
1310config ARM64_FORCE_52BIT
1311	bool "Force 52-bit virtual addresses for userspace"
1312	depends on ARM64_VA_BITS_52 && EXPERT
1313	help
1314	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1315	  to maintain compatibility with older software by providing 48-bit VAs
1316	  unless a hint is supplied to mmap.
1317
1318	  This configuration option disables the 48-bit compatibility logic, and
1319	  forces all userspace addresses to be 52-bit on HW that supports it. One
1320	  should only enable this configuration option for stress testing userspace
1321	  memory management code. If unsure say N here.
1322
1323config ARM64_VA_BITS
1324	int
1325	default 36 if ARM64_VA_BITS_36
1326	default 39 if ARM64_VA_BITS_39
1327	default 42 if ARM64_VA_BITS_42
1328	default 47 if ARM64_VA_BITS_47
1329	default 48 if ARM64_VA_BITS_48
1330	default 52 if ARM64_VA_BITS_52
1331
1332choice
1333	prompt "Physical address space size"
1334	default ARM64_PA_BITS_48
1335	help
1336	  Choose the maximum physical address range that the kernel will
1337	  support.
1338
1339config ARM64_PA_BITS_48
1340	bool "48-bit"
1341
1342config ARM64_PA_BITS_52
1343	bool "52-bit (ARMv8.2)"
1344	depends on ARM64_64K_PAGES
1345	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1346	help
1347	  Enable support for a 52-bit physical address space, introduced as
1348	  part of the ARMv8.2-LPA extension.
1349
1350	  With this enabled, the kernel will also continue to work on CPUs that
1351	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1352	  minor performance overhead).
1353
1354endchoice
1355
1356config ARM64_PA_BITS
1357	int
1358	default 48 if ARM64_PA_BITS_48
1359	default 52 if ARM64_PA_BITS_52
1360
1361choice
1362	prompt "Endianness"
1363	default CPU_LITTLE_ENDIAN
1364	help
1365	  Select the endianness of data accesses performed by the CPU. Userspace
1366	  applications will need to be compiled and linked for the endianness
1367	  that is selected here.
1368
1369config CPU_BIG_ENDIAN
1370	bool "Build big-endian kernel"
1371	depends on !LD_IS_LLD || LLD_VERSION >= 130000
1372	# https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1373	depends on AS_IS_GNU || AS_VERSION >= 150000
1374	help
1375	  Say Y if you plan on running a kernel with a big-endian userspace.
1376
1377config CPU_LITTLE_ENDIAN
1378	bool "Build little-endian kernel"
1379	help
1380	  Say Y if you plan on running a kernel with a little-endian userspace.
1381	  This is usually the case for distributions targeting arm64.
1382
1383endchoice
1384
1385config SCHED_MC
1386	bool "Multi-core scheduler support"
1387	help
1388	  Multi-core scheduler support improves the CPU scheduler's decision
1389	  making when dealing with multi-core CPU chips at a cost of slightly
1390	  increased overhead in some places. If unsure say N here.
1391
1392config SCHED_CLUSTER
1393	bool "Cluster scheduler support"
1394	help
1395	  Cluster scheduler support improves the CPU scheduler's decision
1396	  making when dealing with machines that have clusters of CPUs.
1397	  Cluster usually means a couple of CPUs which are placed closely
1398	  by sharing mid-level caches, last-level cache tags or internal
1399	  busses.
1400
1401config SCHED_SMT
1402	bool "SMT scheduler support"
1403	help
1404	  Improves the CPU scheduler's decision making when dealing with
1405	  MultiThreading at a cost of slightly increased overhead in some
1406	  places. If unsure say N here.
1407
1408config NR_CPUS
1409	int "Maximum number of CPUs (2-4096)"
1410	range 2 4096
1411	default "256"
1412
1413config HOTPLUG_CPU
1414	bool "Support for hot-pluggable CPUs"
1415	select GENERIC_IRQ_MIGRATION
1416	help
1417	  Say Y here to experiment with turning CPUs off and on.  CPUs
1418	  can be controlled through /sys/devices/system/cpu.
1419
1420# Common NUMA Features
1421config NUMA
1422	bool "NUMA Memory Allocation and Scheduler Support"
1423	select GENERIC_ARCH_NUMA
1424	select ACPI_NUMA if ACPI
1425	select OF_NUMA
1426	select HAVE_SETUP_PER_CPU_AREA
1427	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1428	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1429	select USE_PERCPU_NUMA_NODE_ID
1430	help
1431	  Enable NUMA (Non-Uniform Memory Access) support.
1432
1433	  The kernel will try to allocate memory used by a CPU on the
1434	  local memory of the CPU and add some more
1435	  NUMA awareness to the kernel.
1436
1437config NODES_SHIFT
1438	int "Maximum NUMA Nodes (as a power of 2)"
1439	range 1 10
1440	default "4"
1441	depends on NUMA
1442	help
1443	  Specify the maximum number of NUMA Nodes available on the target
1444	  system.  Increases memory reserved to accommodate various tables.
1445
1446source "kernel/Kconfig.hz"
1447
1448config ARCH_SPARSEMEM_ENABLE
1449	def_bool y
1450	select SPARSEMEM_VMEMMAP_ENABLE
1451	select SPARSEMEM_VMEMMAP
1452
1453config HW_PERF_EVENTS
1454	def_bool y
1455	depends on ARM_PMU
1456
1457# Supported by clang >= 7.0 or GCC >= 12.0.0
1458config CC_HAVE_SHADOW_CALL_STACK
1459	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1460
1461config PARAVIRT
1462	bool "Enable paravirtualization code"
1463	help
1464	  This changes the kernel so it can modify itself when it is run
1465	  under a hypervisor, potentially improving performance significantly
1466	  over full virtualization.
1467
1468config PARAVIRT_TIME_ACCOUNTING
1469	bool "Paravirtual steal time accounting"
1470	select PARAVIRT
1471	help
1472	  Select this option to enable fine granularity task steal time
1473	  accounting. Time spent executing other tasks in parallel with
1474	  the current vCPU is discounted from the vCPU power. To account for
1475	  that, there can be a small performance impact.
1476
1477	  If in doubt, say N here.
1478
1479config ARCH_SUPPORTS_KEXEC
1480	def_bool PM_SLEEP_SMP
1481
1482config ARCH_SUPPORTS_KEXEC_FILE
1483	def_bool y
1484
1485config ARCH_SELECTS_KEXEC_FILE
1486	def_bool y
1487	depends on KEXEC_FILE
1488	select HAVE_IMA_KEXEC if IMA
1489
1490config ARCH_SUPPORTS_KEXEC_SIG
1491	def_bool y
1492
1493config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1494	def_bool y
1495
1496config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1497	def_bool y
1498
1499config ARCH_SUPPORTS_CRASH_DUMP
1500	def_bool y
1501
1502config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1503	def_bool CRASH_CORE
1504
1505config TRANS_TABLE
1506	def_bool y
1507	depends on HIBERNATION || KEXEC_CORE
1508
1509config XEN_DOM0
1510	def_bool y
1511	depends on XEN
1512
1513config XEN
1514	bool "Xen guest support on ARM64"
1515	depends on ARM64 && OF
1516	select SWIOTLB_XEN
1517	select PARAVIRT
1518	help
1519	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1520
1521# include/linux/mmzone.h requires the following to be true:
1522#
1523#   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1524#
1525# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1526#
1527#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1528# ----+-------------------+--------------+----------------------+-------------------------+
1529# 4K  |       27          |      12      |       15             |         10              |
1530# 16K |       27          |      14      |       13             |         11              |
1531# 64K |       29          |      16      |       13             |         13              |
1532config ARCH_FORCE_MAX_ORDER
1533	int
1534	default "13" if ARM64_64K_PAGES
1535	default "11" if ARM64_16K_PAGES
1536	default "10"
1537	help
1538	  The kernel page allocator limits the size of maximal physically
1539	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1540	  defines the maximal power of two of number of pages that can be
1541	  allocated as a single contiguous block. This option allows
1542	  overriding the default setting when ability to allocate very
1543	  large blocks of physically contiguous memory is required.
1544
1545	  The maximal size of allocation cannot exceed the size of the
1546	  section, so the value of MAX_PAGE_ORDER should satisfy
1547
1548	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1549
1550	  Don't change if unsure.
1551
1552config UNMAP_KERNEL_AT_EL0
1553	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1554	default y
1555	help
1556	  Speculation attacks against some high-performance processors can
1557	  be used to bypass MMU permission checks and leak kernel data to
1558	  userspace. This can be defended against by unmapping the kernel
1559	  when running in userspace, mapping it back in on exception entry
1560	  via a trampoline page in the vector table.
1561
1562	  If unsure, say Y.
1563
1564config MITIGATE_SPECTRE_BRANCH_HISTORY
1565	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1566	default y
1567	help
1568	  Speculation attacks against some high-performance processors can
1569	  make use of branch history to influence future speculation.
1570	  When taking an exception from user-space, a sequence of branches
1571	  or a firmware call overwrites the branch history.
1572
1573config RODATA_FULL_DEFAULT_ENABLED
1574	bool "Apply r/o permissions of VM areas also to their linear aliases"
1575	default y
1576	help
1577	  Apply read-only attributes of VM areas to the linear alias of
1578	  the backing pages as well. This prevents code or read-only data
1579	  from being modified (inadvertently or intentionally) via another
1580	  mapping of the same memory page. This additional enhancement can
1581	  be turned off at runtime by passing rodata=[off|on] (and turned on
1582	  with rodata=full if this option is set to 'n')
1583
1584	  This requires the linear region to be mapped down to pages,
1585	  which may adversely affect performance in some cases.
1586
1587config ARM64_SW_TTBR0_PAN
1588	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1589	help
1590	  Enabling this option prevents the kernel from accessing
1591	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1592	  zeroed area and reserved ASID. The user access routines
1593	  restore the valid TTBR0_EL1 temporarily.
1594
1595config ARM64_TAGGED_ADDR_ABI
1596	bool "Enable the tagged user addresses syscall ABI"
1597	default y
1598	help
1599	  When this option is enabled, user applications can opt in to a
1600	  relaxed ABI via prctl() allowing tagged addresses to be passed
1601	  to system calls as pointer arguments. For details, see
1602	  Documentation/arch/arm64/tagged-address-abi.rst.
1603
1604menuconfig COMPAT
1605	bool "Kernel support for 32-bit EL0"
1606	depends on ARM64_4K_PAGES || EXPERT
1607	select HAVE_UID16
1608	select OLD_SIGSUSPEND3
1609	select COMPAT_OLD_SIGACTION
1610	help
1611	  This option enables support for a 32-bit EL0 running under a 64-bit
1612	  kernel at EL1. AArch32-specific components such as system calls,
1613	  the user helper functions, VFP support and the ptrace interface are
1614	  handled appropriately by the kernel.
1615
1616	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1617	  that you will only be able to execute AArch32 binaries that were compiled
1618	  with page size aligned segments.
1619
1620	  If you want to execute 32-bit userspace applications, say Y.
1621
1622if COMPAT
1623
1624config KUSER_HELPERS
1625	bool "Enable kuser helpers page for 32-bit applications"
1626	default y
1627	help
1628	  Warning: disabling this option may break 32-bit user programs.
1629
1630	  Provide kuser helpers to compat tasks. The kernel provides
1631	  helper code to userspace in read only form at a fixed location
1632	  to allow userspace to be independent of the CPU type fitted to
1633	  the system. This permits binaries to be run on ARMv4 through
1634	  to ARMv8 without modification.
1635
1636	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1637
1638	  However, the fixed address nature of these helpers can be used
1639	  by ROP (return orientated programming) authors when creating
1640	  exploits.
1641
1642	  If all of the binaries and libraries which run on your platform
1643	  are built specifically for your platform, and make no use of
1644	  these helpers, then you can turn this option off to hinder
1645	  such exploits. However, in that case, if a binary or library
1646	  relying on those helpers is run, it will not function correctly.
1647
1648	  Say N here only if you are absolutely certain that you do not
1649	  need these helpers; otherwise, the safe option is to say Y.
1650
1651config COMPAT_VDSO
1652	bool "Enable vDSO for 32-bit applications"
1653	depends on !CPU_BIG_ENDIAN
1654	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1655	select GENERIC_COMPAT_VDSO
1656	default y
1657	help
1658	  Place in the process address space of 32-bit applications an
1659	  ELF shared object providing fast implementations of gettimeofday
1660	  and clock_gettime.
1661
1662	  You must have a 32-bit build of glibc 2.22 or later for programs
1663	  to seamlessly take advantage of this.
1664
1665config THUMB2_COMPAT_VDSO
1666	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1667	depends on COMPAT_VDSO
1668	default y
1669	help
1670	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1671	  otherwise with '-marm'.
1672
1673config COMPAT_ALIGNMENT_FIXUPS
1674	bool "Fix up misaligned multi-word loads and stores in user space"
1675
1676menuconfig ARMV8_DEPRECATED
1677	bool "Emulate deprecated/obsolete ARMv8 instructions"
1678	depends on SYSCTL
1679	help
1680	  Legacy software support may require certain instructions
1681	  that have been deprecated or obsoleted in the architecture.
1682
1683	  Enable this config to enable selective emulation of these
1684	  features.
1685
1686	  If unsure, say Y
1687
1688if ARMV8_DEPRECATED
1689
1690config SWP_EMULATION
1691	bool "Emulate SWP/SWPB instructions"
1692	help
1693	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1694	  they are always undefined. Say Y here to enable software
1695	  emulation of these instructions for userspace using LDXR/STXR.
1696	  This feature can be controlled at runtime with the abi.swp
1697	  sysctl which is disabled by default.
1698
1699	  In some older versions of glibc [<=2.8] SWP is used during futex
1700	  trylock() operations with the assumption that the code will not
1701	  be preempted. This invalid assumption may be more likely to fail
1702	  with SWP emulation enabled, leading to deadlock of the user
1703	  application.
1704
1705	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1706	  on an external transaction monitoring block called a global
1707	  monitor to maintain update atomicity. If your system does not
1708	  implement a global monitor, this option can cause programs that
1709	  perform SWP operations to uncached memory to deadlock.
1710
1711	  If unsure, say Y
1712
1713config CP15_BARRIER_EMULATION
1714	bool "Emulate CP15 Barrier instructions"
1715	help
1716	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1717	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1718	  strongly recommended to use the ISB, DSB, and DMB
1719	  instructions instead.
1720
1721	  Say Y here to enable software emulation of these
1722	  instructions for AArch32 userspace code. When this option is
1723	  enabled, CP15 barrier usage is traced which can help
1724	  identify software that needs updating. This feature can be
1725	  controlled at runtime with the abi.cp15_barrier sysctl.
1726
1727	  If unsure, say Y
1728
1729config SETEND_EMULATION
1730	bool "Emulate SETEND instruction"
1731	help
1732	  The SETEND instruction alters the data-endianness of the
1733	  AArch32 EL0, and is deprecated in ARMv8.
1734
1735	  Say Y here to enable software emulation of the instruction
1736	  for AArch32 userspace code. This feature can be controlled
1737	  at runtime with the abi.setend sysctl.
1738
1739	  Note: All the cpus on the system must have mixed endian support at EL0
1740	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1741	  endian - is hotplugged in after this feature has been enabled, there could
1742	  be unexpected results in the applications.
1743
1744	  If unsure, say Y
1745endif # ARMV8_DEPRECATED
1746
1747endif # COMPAT
1748
1749menu "ARMv8.1 architectural features"
1750
1751config ARM64_HW_AFDBM
1752	bool "Support for hardware updates of the Access and Dirty page flags"
1753	default y
1754	help
1755	  The ARMv8.1 architecture extensions introduce support for
1756	  hardware updates of the access and dirty information in page
1757	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1758	  capable processors, accesses to pages with PTE_AF cleared will
1759	  set this bit instead of raising an access flag fault.
1760	  Similarly, writes to read-only pages with the DBM bit set will
1761	  clear the read-only bit (AP[2]) instead of raising a
1762	  permission fault.
1763
1764	  Kernels built with this configuration option enabled continue
1765	  to work on pre-ARMv8.1 hardware and the performance impact is
1766	  minimal. If unsure, say Y.
1767
1768config ARM64_PAN
1769	bool "Enable support for Privileged Access Never (PAN)"
1770	default y
1771	help
1772	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1773	  prevents the kernel or hypervisor from accessing user-space (EL0)
1774	  memory directly.
1775
1776	  Choosing this option will cause any unprotected (not using
1777	  copy_to_user et al) memory access to fail with a permission fault.
1778
1779	  The feature is detected at runtime, and will remain as a 'nop'
1780	  instruction if the cpu does not implement the feature.
1781
1782config AS_HAS_LSE_ATOMICS
1783	def_bool $(as-instr,.arch_extension lse)
1784
1785config ARM64_LSE_ATOMICS
1786	bool
1787	default ARM64_USE_LSE_ATOMICS
1788	depends on AS_HAS_LSE_ATOMICS
1789
1790config ARM64_USE_LSE_ATOMICS
1791	bool "Atomic instructions"
1792	default y
1793	help
1794	  As part of the Large System Extensions, ARMv8.1 introduces new
1795	  atomic instructions that are designed specifically to scale in
1796	  very large systems.
1797
1798	  Say Y here to make use of these instructions for the in-kernel
1799	  atomic routines. This incurs a small overhead on CPUs that do
1800	  not support these instructions and requires the kernel to be
1801	  built with binutils >= 2.25 in order for the new instructions
1802	  to be used.
1803
1804endmenu # "ARMv8.1 architectural features"
1805
1806menu "ARMv8.2 architectural features"
1807
1808config AS_HAS_ARMV8_2
1809	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1810
1811config AS_HAS_SHA3
1812	def_bool $(as-instr,.arch armv8.2-a+sha3)
1813
1814config ARM64_PMEM
1815	bool "Enable support for persistent memory"
1816	select ARCH_HAS_PMEM_API
1817	select ARCH_HAS_UACCESS_FLUSHCACHE
1818	help
1819	  Say Y to enable support for the persistent memory API based on the
1820	  ARMv8.2 DCPoP feature.
1821
1822	  The feature is detected at runtime, and the kernel will use DC CVAC
1823	  operations if DC CVAP is not supported (following the behaviour of
1824	  DC CVAP itself if the system does not define a point of persistence).
1825
1826config ARM64_RAS_EXTN
1827	bool "Enable support for RAS CPU Extensions"
1828	default y
1829	help
1830	  CPUs that support the Reliability, Availability and Serviceability
1831	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1832	  errors, classify them and report them to software.
1833
1834	  On CPUs with these extensions system software can use additional
1835	  barriers to determine if faults are pending and read the
1836	  classification from a new set of registers.
1837
1838	  Selecting this feature will allow the kernel to use these barriers
1839	  and access the new registers if the system supports the extension.
1840	  Platform RAS features may additionally depend on firmware support.
1841
1842config ARM64_CNP
1843	bool "Enable support for Common Not Private (CNP) translations"
1844	default y
1845	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1846	help
1847	  Common Not Private (CNP) allows translation table entries to
1848	  be shared between different PEs in the same inner shareable
1849	  domain, so the hardware can use this fact to optimise the
1850	  caching of such entries in the TLB.
1851
1852	  Selecting this option allows the CNP feature to be detected
1853	  at runtime, and does not affect PEs that do not implement
1854	  this feature.
1855
1856endmenu # "ARMv8.2 architectural features"
1857
1858menu "ARMv8.3 architectural features"
1859
1860config ARM64_PTR_AUTH
1861	bool "Enable support for pointer authentication"
1862	default y
1863	help
1864	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1865	  instructions for signing and authenticating pointers against secret
1866	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1867	  and other attacks.
1868
1869	  This option enables these instructions at EL0 (i.e. for userspace).
1870	  Choosing this option will cause the kernel to initialise secret keys
1871	  for each process at exec() time, with these keys being
1872	  context-switched along with the process.
1873
1874	  The feature is detected at runtime. If the feature is not present in
1875	  hardware it will not be advertised to userspace/KVM guest nor will it
1876	  be enabled.
1877
1878	  If the feature is present on the boot CPU but not on a late CPU, then
1879	  the late CPU will be parked. Also, if the boot CPU does not have
1880	  address auth and the late CPU has then the late CPU will still boot
1881	  but with the feature disabled. On such a system, this option should
1882	  not be selected.
1883
1884config ARM64_PTR_AUTH_KERNEL
1885	bool "Use pointer authentication for kernel"
1886	default y
1887	depends on ARM64_PTR_AUTH
1888	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1889	# Modern compilers insert a .note.gnu.property section note for PAC
1890	# which is only understood by binutils starting with version 2.33.1.
1891	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1892	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1893	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1894	help
1895	  If the compiler supports the -mbranch-protection or
1896	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1897	  will cause the kernel itself to be compiled with return address
1898	  protection. In this case, and if the target hardware is known to
1899	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1900	  disabled with minimal loss of protection.
1901
1902	  This feature works with FUNCTION_GRAPH_TRACER option only if
1903	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
1904
1905config CC_HAS_BRANCH_PROT_PAC_RET
1906	# GCC 9 or later, clang 8 or later
1907	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1908
1909config CC_HAS_SIGN_RETURN_ADDRESS
1910	# GCC 7, 8
1911	def_bool $(cc-option,-msign-return-address=all)
1912
1913config AS_HAS_ARMV8_3
1914	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1915
1916config AS_HAS_CFI_NEGATE_RA_STATE
1917	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1918
1919config AS_HAS_LDAPR
1920	def_bool $(as-instr,.arch_extension rcpc)
1921
1922endmenu # "ARMv8.3 architectural features"
1923
1924menu "ARMv8.4 architectural features"
1925
1926config ARM64_AMU_EXTN
1927	bool "Enable support for the Activity Monitors Unit CPU extension"
1928	default y
1929	help
1930	  The activity monitors extension is an optional extension introduced
1931	  by the ARMv8.4 CPU architecture. This enables support for version 1
1932	  of the activity monitors architecture, AMUv1.
1933
1934	  To enable the use of this extension on CPUs that implement it, say Y.
1935
1936	  Note that for architectural reasons, firmware _must_ implement AMU
1937	  support when running on CPUs that present the activity monitors
1938	  extension. The required support is present in:
1939	    * Version 1.5 and later of the ARM Trusted Firmware
1940
1941	  For kernels that have this configuration enabled but boot with broken
1942	  firmware, you may need to say N here until the firmware is fixed.
1943	  Otherwise you may experience firmware panics or lockups when
1944	  accessing the counter registers. Even if you are not observing these
1945	  symptoms, the values returned by the register reads might not
1946	  correctly reflect reality. Most commonly, the value read will be 0,
1947	  indicating that the counter is not enabled.
1948
1949config AS_HAS_ARMV8_4
1950	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1951
1952config ARM64_TLB_RANGE
1953	bool "Enable support for tlbi range feature"
1954	default y
1955	depends on AS_HAS_ARMV8_4
1956	help
1957	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1958	  range of input addresses.
1959
1960	  The feature introduces new assembly instructions, and they were
1961	  support when binutils >= 2.30.
1962
1963endmenu # "ARMv8.4 architectural features"
1964
1965menu "ARMv8.5 architectural features"
1966
1967config AS_HAS_ARMV8_5
1968	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1969
1970config ARM64_BTI
1971	bool "Branch Target Identification support"
1972	default y
1973	help
1974	  Branch Target Identification (part of the ARMv8.5 Extensions)
1975	  provides a mechanism to limit the set of locations to which computed
1976	  branch instructions such as BR or BLR can jump.
1977
1978	  To make use of BTI on CPUs that support it, say Y.
1979
1980	  BTI is intended to provide complementary protection to other control
1981	  flow integrity protection mechanisms, such as the Pointer
1982	  authentication mechanism provided as part of the ARMv8.3 Extensions.
1983	  For this reason, it does not make sense to enable this option without
1984	  also enabling support for pointer authentication.  Thus, when
1985	  enabling this option you should also select ARM64_PTR_AUTH=y.
1986
1987	  Userspace binaries must also be specifically compiled to make use of
1988	  this mechanism.  If you say N here or the hardware does not support
1989	  BTI, such binaries can still run, but you get no additional
1990	  enforcement of branch destinations.
1991
1992config ARM64_BTI_KERNEL
1993	bool "Use Branch Target Identification for kernel"
1994	default y
1995	depends on ARM64_BTI
1996	depends on ARM64_PTR_AUTH_KERNEL
1997	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1998	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1999	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2000	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2001	depends on !CC_IS_GCC
2002	# https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
2003	depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
2004	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2005	help
2006	  Build the kernel with Branch Target Identification annotations
2007	  and enable enforcement of this for kernel code. When this option
2008	  is enabled and the system supports BTI all kernel code including
2009	  modular code must have BTI enabled.
2010
2011config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2012	# GCC 9 or later, clang 8 or later
2013	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2014
2015config ARM64_E0PD
2016	bool "Enable support for E0PD"
2017	default y
2018	help
2019	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2020	  that EL0 accesses made via TTBR1 always fault in constant time,
2021	  providing similar benefits to KASLR as those provided by KPTI, but
2022	  with lower overhead and without disrupting legitimate access to
2023	  kernel memory such as SPE.
2024
2025	  This option enables E0PD for TTBR1 where available.
2026
2027config ARM64_AS_HAS_MTE
2028	# Initial support for MTE went in binutils 2.32.0, checked with
2029	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2030	# as a late addition to the final architecture spec (LDGM/STGM)
2031	# is only supported in the newer 2.32.x and 2.33 binutils
2032	# versions, hence the extra "stgm" instruction check below.
2033	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2034
2035config ARM64_MTE
2036	bool "Memory Tagging Extension support"
2037	default y
2038	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2039	depends on AS_HAS_ARMV8_5
2040	depends on AS_HAS_LSE_ATOMICS
2041	# Required for tag checking in the uaccess routines
2042	depends on ARM64_PAN
2043	select ARCH_HAS_SUBPAGE_FAULTS
2044	select ARCH_USES_HIGH_VMA_FLAGS
2045	select ARCH_USES_PG_ARCH_X
2046	help
2047	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2048	  architectural support for run-time, always-on detection of
2049	  various classes of memory error to aid with software debugging
2050	  to eliminate vulnerabilities arising from memory-unsafe
2051	  languages.
2052
2053	  This option enables the support for the Memory Tagging
2054	  Extension at EL0 (i.e. for userspace).
2055
2056	  Selecting this option allows the feature to be detected at
2057	  runtime. Any secondary CPU not implementing this feature will
2058	  not be allowed a late bring-up.
2059
2060	  Userspace binaries that want to use this feature must
2061	  explicitly opt in. The mechanism for the userspace is
2062	  described in:
2063
2064	  Documentation/arch/arm64/memory-tagging-extension.rst.
2065
2066endmenu # "ARMv8.5 architectural features"
2067
2068menu "ARMv8.7 architectural features"
2069
2070config ARM64_EPAN
2071	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2072	default y
2073	depends on ARM64_PAN
2074	help
2075	  Enhanced Privileged Access Never (EPAN) allows Privileged
2076	  Access Never to be used with Execute-only mappings.
2077
2078	  The feature is detected at runtime, and will remain disabled
2079	  if the cpu does not implement the feature.
2080endmenu # "ARMv8.7 architectural features"
2081
2082config ARM64_SVE
2083	bool "ARM Scalable Vector Extension support"
2084	default y
2085	help
2086	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2087	  execution state which complements and extends the SIMD functionality
2088	  of the base architecture to support much larger vectors and to enable
2089	  additional vectorisation opportunities.
2090
2091	  To enable use of this extension on CPUs that implement it, say Y.
2092
2093	  On CPUs that support the SVE2 extensions, this option will enable
2094	  those too.
2095
2096	  Note that for architectural reasons, firmware _must_ implement SVE
2097	  support when running on SVE capable hardware.  The required support
2098	  is present in:
2099
2100	    * version 1.5 and later of the ARM Trusted Firmware
2101	    * the AArch64 boot wrapper since commit 5e1261e08abf
2102	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2103
2104	  For other firmware implementations, consult the firmware documentation
2105	  or vendor.
2106
2107	  If you need the kernel to boot on SVE-capable hardware with broken
2108	  firmware, you may need to say N here until you get your firmware
2109	  fixed.  Otherwise, you may experience firmware panics or lockups when
2110	  booting the kernel.  If unsure and you are not observing these
2111	  symptoms, you should assume that it is safe to say Y.
2112
2113config ARM64_SME
2114	bool "ARM Scalable Matrix Extension support"
2115	default y
2116	depends on ARM64_SVE
2117	help
2118	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2119	  execution state which utilises a substantial subset of the SVE
2120	  instruction set, together with the addition of new architectural
2121	  register state capable of holding two dimensional matrix tiles to
2122	  enable various matrix operations.
2123
2124config ARM64_PSEUDO_NMI
2125	bool "Support for NMI-like interrupts"
2126	select ARM_GIC_V3
2127	help
2128	  Adds support for mimicking Non-Maskable Interrupts through the use of
2129	  GIC interrupt priority. This support requires version 3 or later of
2130	  ARM GIC.
2131
2132	  This high priority configuration for interrupts needs to be
2133	  explicitly enabled by setting the kernel parameter
2134	  "irqchip.gicv3_pseudo_nmi" to 1.
2135
2136	  If unsure, say N
2137
2138if ARM64_PSEUDO_NMI
2139config ARM64_DEBUG_PRIORITY_MASKING
2140	bool "Debug interrupt priority masking"
2141	help
2142	  This adds runtime checks to functions enabling/disabling
2143	  interrupts when using priority masking. The additional checks verify
2144	  the validity of ICC_PMR_EL1 when calling concerned functions.
2145
2146	  If unsure, say N
2147endif # ARM64_PSEUDO_NMI
2148
2149config RELOCATABLE
2150	bool "Build a relocatable kernel image" if EXPERT
2151	select ARCH_HAS_RELR
2152	default y
2153	help
2154	  This builds the kernel as a Position Independent Executable (PIE),
2155	  which retains all relocation metadata required to relocate the
2156	  kernel binary at runtime to a different virtual address than the
2157	  address it was linked at.
2158	  Since AArch64 uses the RELA relocation format, this requires a
2159	  relocation pass at runtime even if the kernel is loaded at the
2160	  same address it was linked at.
2161
2162config RANDOMIZE_BASE
2163	bool "Randomize the address of the kernel image"
2164	select RELOCATABLE
2165	help
2166	  Randomizes the virtual address at which the kernel image is
2167	  loaded, as a security feature that deters exploit attempts
2168	  relying on knowledge of the location of kernel internals.
2169
2170	  It is the bootloader's job to provide entropy, by passing a
2171	  random u64 value in /chosen/kaslr-seed at kernel entry.
2172
2173	  When booting via the UEFI stub, it will invoke the firmware's
2174	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2175	  to the kernel proper. In addition, it will randomise the physical
2176	  location of the kernel Image as well.
2177
2178	  If unsure, say N.
2179
2180config RANDOMIZE_MODULE_REGION_FULL
2181	bool "Randomize the module region over a 2 GB range"
2182	depends on RANDOMIZE_BASE
2183	default y
2184	help
2185	  Randomizes the location of the module region inside a 2 GB window
2186	  covering the core kernel. This way, it is less likely for modules
2187	  to leak information about the location of core kernel data structures
2188	  but it does imply that function calls between modules and the core
2189	  kernel will need to be resolved via veneers in the module PLT.
2190
2191	  When this option is not set, the module region will be randomized over
2192	  a limited range that contains the [_stext, _etext] interval of the
2193	  core kernel, so branch relocations are almost always in range unless
2194	  the region is exhausted. In this particular case of region
2195	  exhaustion, modules might be able to fall back to a larger 2GB area.
2196
2197config CC_HAVE_STACKPROTECTOR_SYSREG
2198	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2199
2200config STACKPROTECTOR_PER_TASK
2201	def_bool y
2202	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2203
2204config UNWIND_PATCH_PAC_INTO_SCS
2205	bool "Enable shadow call stack dynamically using code patching"
2206	# needs Clang with https://reviews.llvm.org/D111780 incorporated
2207	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2208	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2209	depends on SHADOW_CALL_STACK
2210	select UNWIND_TABLES
2211	select DYNAMIC_SCS
2212
2213endmenu # "Kernel Features"
2214
2215menu "Boot options"
2216
2217config ARM64_ACPI_PARKING_PROTOCOL
2218	bool "Enable support for the ARM64 ACPI parking protocol"
2219	depends on ACPI
2220	help
2221	  Enable support for the ARM64 ACPI parking protocol. If disabled
2222	  the kernel will not allow booting through the ARM64 ACPI parking
2223	  protocol even if the corresponding data is present in the ACPI
2224	  MADT table.
2225
2226config CMDLINE
2227	string "Default kernel command string"
2228	default ""
2229	help
2230	  Provide a set of default command-line options at build time by
2231	  entering them here. As a minimum, you should specify the the
2232	  root device (e.g. root=/dev/nfs).
2233
2234choice
2235	prompt "Kernel command line type" if CMDLINE != ""
2236	default CMDLINE_FROM_BOOTLOADER
2237	help
2238	  Choose how the kernel will handle the provided default kernel
2239	  command line string.
2240
2241config CMDLINE_FROM_BOOTLOADER
2242	bool "Use bootloader kernel arguments if available"
2243	help
2244	  Uses the command-line options passed by the boot loader. If
2245	  the boot loader doesn't provide any, the default kernel command
2246	  string provided in CMDLINE will be used.
2247
2248config CMDLINE_FORCE
2249	bool "Always use the default kernel command string"
2250	help
2251	  Always use the default kernel command string, even if the boot
2252	  loader passes other arguments to the kernel.
2253	  This is useful if you cannot or don't want to change the
2254	  command-line options your boot loader passes to the kernel.
2255
2256endchoice
2257
2258config EFI_STUB
2259	bool
2260
2261config EFI
2262	bool "UEFI runtime support"
2263	depends on OF && !CPU_BIG_ENDIAN
2264	depends on KERNEL_MODE_NEON
2265	select ARCH_SUPPORTS_ACPI
2266	select LIBFDT
2267	select UCS2_STRING
2268	select EFI_PARAMS_FROM_FDT
2269	select EFI_RUNTIME_WRAPPERS
2270	select EFI_STUB
2271	select EFI_GENERIC_STUB
2272	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2273	default y
2274	help
2275	  This option provides support for runtime services provided
2276	  by UEFI firmware (such as non-volatile variables, realtime
2277	  clock, and platform reset). A UEFI stub is also provided to
2278	  allow the kernel to be booted as an EFI application. This
2279	  is only useful on systems that have UEFI firmware.
2280
2281config DMI
2282	bool "Enable support for SMBIOS (DMI) tables"
2283	depends on EFI
2284	default y
2285	help
2286	  This enables SMBIOS/DMI feature for systems.
2287
2288	  This option is only useful on systems that have UEFI firmware.
2289	  However, even with this option, the resultant kernel should
2290	  continue to boot on existing non-UEFI platforms.
2291
2292endmenu # "Boot options"
2293
2294menu "Power management options"
2295
2296source "kernel/power/Kconfig"
2297
2298config ARCH_HIBERNATION_POSSIBLE
2299	def_bool y
2300	depends on CPU_PM
2301
2302config ARCH_HIBERNATION_HEADER
2303	def_bool y
2304	depends on HIBERNATION
2305
2306config ARCH_SUSPEND_POSSIBLE
2307	def_bool y
2308
2309endmenu # "Power management options"
2310
2311menu "CPU Power Management"
2312
2313source "drivers/cpuidle/Kconfig"
2314
2315source "drivers/cpufreq/Kconfig"
2316
2317endmenu # "CPU Power Management"
2318
2319source "drivers/acpi/Kconfig"
2320
2321source "arch/arm64/kvm/Kconfig"
2322
2323