xref: /openbmc/linux/arch/arm64/Kconfig (revision 8e4a28f9)
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_SETUP_DMA_OPS
40	select ARCH_HAS_SET_DIRECT_MAP
41	select ARCH_HAS_SET_MEMORY
42	select ARCH_STACKWALK
43	select ARCH_HAS_STRICT_KERNEL_RWX
44	select ARCH_HAS_STRICT_MODULE_RWX
45	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
46	select ARCH_HAS_SYNC_DMA_FOR_CPU
47	select ARCH_HAS_SYSCALL_WRAPPER
48	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
49	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
50	select ARCH_HAS_ZONE_DMA_SET if EXPERT
51	select ARCH_HAVE_ELF_PROT
52	select ARCH_HAVE_NMI_SAFE_CMPXCHG
53	select ARCH_HAVE_TRACE_MMIO_ACCESS
54	select ARCH_INLINE_READ_LOCK if !PREEMPTION
55	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
56	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
57	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
58	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
59	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
60	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
61	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
62	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
63	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
64	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
65	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
66	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
67	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
68	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
69	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
70	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
71	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
72	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
73	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
74	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
75	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
76	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
77	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
78	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
79	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
80	select ARCH_KEEP_MEMBLOCK
81	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
82	select ARCH_USE_CMPXCHG_LOCKREF
83	select ARCH_USE_GNU_PROPERTY
84	select ARCH_USE_MEMTEST
85	select ARCH_USE_QUEUED_RWLOCKS
86	select ARCH_USE_QUEUED_SPINLOCKS
87	select ARCH_USE_SYM_ANNOTATIONS
88	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
89	select ARCH_SUPPORTS_HUGETLBFS
90	select ARCH_SUPPORTS_MEMORY_FAILURE
91	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
92	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
93	select ARCH_SUPPORTS_LTO_CLANG_THIN
94	select ARCH_SUPPORTS_CFI_CLANG
95	select ARCH_SUPPORTS_ATOMIC_RMW
96	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
97	select ARCH_SUPPORTS_NUMA_BALANCING
98	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
99	select ARCH_SUPPORTS_PER_VMA_LOCK
100	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
101	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
102	select ARCH_WANT_DEFAULT_BPF_JIT
103	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
104	select ARCH_WANT_FRAME_POINTERS
105	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
106	select ARCH_WANT_LD_ORPHAN_WARN
107	select ARCH_WANTS_NO_INSTR
108	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
109	select ARCH_HAS_UBSAN_SANITIZE_ALL
110	select ARM_AMBA
111	select ARM_ARCH_TIMER
112	select ARM_GIC
113	select AUDIT_ARCH_COMPAT_GENERIC
114	select ARM_GIC_V2M if PCI
115	select ARM_GIC_V3
116	select ARM_GIC_V3_ITS if PCI
117	select ARM_PSCI_FW
118	select BUILDTIME_TABLE_SORT
119	select CLONE_BACKWARDS
120	select COMMON_CLK
121	select CPU_PM if (SUSPEND || CPU_IDLE)
122	select CRC32
123	select DCACHE_WORD_ACCESS
124	select DYNAMIC_FTRACE if FUNCTION_TRACER
125	select DMA_BOUNCE_UNALIGNED_KMALLOC
126	select DMA_DIRECT_REMAP
127	select EDAC_SUPPORT
128	select FRAME_POINTER
129	select FUNCTION_ALIGNMENT_4B
130	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
131	select GENERIC_ALLOCATOR
132	select GENERIC_ARCH_TOPOLOGY
133	select GENERIC_CLOCKEVENTS_BROADCAST
134	select GENERIC_CPU_AUTOPROBE
135	select GENERIC_CPU_VULNERABILITIES
136	select GENERIC_EARLY_IOREMAP
137	select GENERIC_IDLE_POLL_SETUP
138	select GENERIC_IOREMAP
139	select GENERIC_IRQ_IPI
140	select GENERIC_IRQ_PROBE
141	select GENERIC_IRQ_SHOW
142	select GENERIC_IRQ_SHOW_LEVEL
143	select GENERIC_LIB_DEVMEM_IS_ALLOWED
144	select GENERIC_PCI_IOMAP
145	select GENERIC_PTDUMP
146	select GENERIC_SCHED_CLOCK
147	select GENERIC_SMP_IDLE_THREAD
148	select GENERIC_TIME_VSYSCALL
149	select GENERIC_GETTIMEOFDAY
150	select GENERIC_VDSO_TIME_NS
151	select HARDIRQS_SW_RESEND
152	select HAS_IOPORT
153	select HAVE_MOVE_PMD
154	select HAVE_MOVE_PUD
155	select HAVE_PCI
156	select HAVE_ACPI_APEI if (ACPI && EFI)
157	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
158	select HAVE_ARCH_AUDITSYSCALL
159	select HAVE_ARCH_BITREVERSE
160	select HAVE_ARCH_COMPILER_H
161	select HAVE_ARCH_HUGE_VMALLOC
162	select HAVE_ARCH_HUGE_VMAP
163	select HAVE_ARCH_JUMP_LABEL
164	select HAVE_ARCH_JUMP_LABEL_RELATIVE
165	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
166	select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
167	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
168	select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
169	# Some instrumentation may be unsound, hence EXPERT
170	select HAVE_ARCH_KCSAN if EXPERT
171	select HAVE_ARCH_KFENCE
172	select HAVE_ARCH_KGDB
173	select HAVE_ARCH_MMAP_RND_BITS
174	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
175	select HAVE_ARCH_PREL32_RELOCATIONS
176	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
177	select HAVE_ARCH_SECCOMP_FILTER
178	select HAVE_ARCH_STACKLEAK
179	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
180	select HAVE_ARCH_TRACEHOOK
181	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
182	select HAVE_ARCH_VMAP_STACK
183	select HAVE_ARM_SMCCC
184	select HAVE_ASM_MODVERSIONS
185	select HAVE_EBPF_JIT
186	select HAVE_C_RECORDMCOUNT
187	select HAVE_CMPXCHG_DOUBLE
188	select HAVE_CMPXCHG_LOCAL
189	select HAVE_CONTEXT_TRACKING_USER
190	select HAVE_DEBUG_KMEMLEAK
191	select HAVE_DMA_CONTIGUOUS
192	select HAVE_DYNAMIC_FTRACE
193	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
194		if $(cc-option,-fpatchable-function-entry=2)
195	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
196		if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
197	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
198		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
199		    !CC_OPTIMIZE_FOR_SIZE)
200	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
201		if DYNAMIC_FTRACE_WITH_ARGS
202	select HAVE_SAMPLE_FTRACE_DIRECT
203	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
204	select HAVE_EFFICIENT_UNALIGNED_ACCESS
205	select HAVE_FAST_GUP
206	select HAVE_FTRACE_MCOUNT_RECORD
207	select HAVE_FUNCTION_TRACER
208	select HAVE_FUNCTION_ERROR_INJECTION
209	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
210	select HAVE_FUNCTION_GRAPH_TRACER
211	select HAVE_GCC_PLUGINS
212	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
213		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
214	select HAVE_HW_BREAKPOINT if PERF_EVENTS
215	select HAVE_IOREMAP_PROT
216	select HAVE_IRQ_TIME_ACCOUNTING
217	select HAVE_KVM
218	select HAVE_MOD_ARCH_SPECIFIC
219	select HAVE_NMI
220	select HAVE_PERF_EVENTS
221	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
222	select HAVE_PERF_REGS
223	select HAVE_PERF_USER_STACK_DUMP
224	select HAVE_PREEMPT_DYNAMIC_KEY
225	select HAVE_REGS_AND_STACK_ACCESS_API
226	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
227	select HAVE_FUNCTION_ARG_ACCESS_API
228	select MMU_GATHER_RCU_TABLE_FREE
229	select HAVE_RSEQ
230	select HAVE_STACKPROTECTOR
231	select HAVE_SYSCALL_TRACEPOINTS
232	select HAVE_KPROBES
233	select HAVE_KRETPROBES
234	select HAVE_GENERIC_VDSO
235	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
236	select IRQ_DOMAIN
237	select IRQ_FORCED_THREADING
238	select KASAN_VMALLOC if KASAN
239	select LOCK_MM_AND_FIND_VMA
240	select MODULES_USE_ELF_RELA
241	select NEED_DMA_MAP_STATE
242	select NEED_SG_DMA_LENGTH
243	select OF
244	select OF_EARLY_FLATTREE
245	select PCI_DOMAINS_GENERIC if PCI
246	select PCI_ECAM if (ACPI && PCI)
247	select PCI_SYSCALL if PCI
248	select POWER_RESET
249	select POWER_SUPPLY
250	select SPARSE_IRQ
251	select SWIOTLB
252	select SYSCTL_EXCEPTION_TRACE
253	select THREAD_INFO_IN_TASK
254	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
255	select TRACE_IRQFLAGS_SUPPORT
256	select TRACE_IRQFLAGS_NMI_SUPPORT
257	select HAVE_SOFTIRQ_ON_OWN_STACK
258	help
259	  ARM 64-bit (AArch64) Linux support.
260
261config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
262	def_bool CC_IS_CLANG
263	# https://github.com/ClangBuiltLinux/linux/issues/1507
264	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
265	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
266
267config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
268	def_bool CC_IS_GCC
269	depends on $(cc-option,-fpatchable-function-entry=2)
270	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
271
272config 64BIT
273	def_bool y
274
275config MMU
276	def_bool y
277
278config ARM64_PAGE_SHIFT
279	int
280	default 16 if ARM64_64K_PAGES
281	default 14 if ARM64_16K_PAGES
282	default 12
283
284config ARM64_CONT_PTE_SHIFT
285	int
286	default 5 if ARM64_64K_PAGES
287	default 7 if ARM64_16K_PAGES
288	default 4
289
290config ARM64_CONT_PMD_SHIFT
291	int
292	default 5 if ARM64_64K_PAGES
293	default 5 if ARM64_16K_PAGES
294	default 4
295
296config ARCH_MMAP_RND_BITS_MIN
297	default 14 if ARM64_64K_PAGES
298	default 16 if ARM64_16K_PAGES
299	default 18
300
301# max bits determined by the following formula:
302#  VA_BITS - PAGE_SHIFT - 3
303config ARCH_MMAP_RND_BITS_MAX
304	default 19 if ARM64_VA_BITS=36
305	default 24 if ARM64_VA_BITS=39
306	default 27 if ARM64_VA_BITS=42
307	default 30 if ARM64_VA_BITS=47
308	default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
309	default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
310	default 33 if ARM64_VA_BITS=48
311	default 14 if ARM64_64K_PAGES
312	default 16 if ARM64_16K_PAGES
313	default 18
314
315config ARCH_MMAP_RND_COMPAT_BITS_MIN
316	default 7 if ARM64_64K_PAGES
317	default 9 if ARM64_16K_PAGES
318	default 11
319
320config ARCH_MMAP_RND_COMPAT_BITS_MAX
321	default 16
322
323config NO_IOPORT_MAP
324	def_bool y if !PCI
325
326config STACKTRACE_SUPPORT
327	def_bool y
328
329config ILLEGAL_POINTER_VALUE
330	hex
331	default 0xdead000000000000
332
333config LOCKDEP_SUPPORT
334	def_bool y
335
336config GENERIC_BUG
337	def_bool y
338	depends on BUG
339
340config GENERIC_BUG_RELATIVE_POINTERS
341	def_bool y
342	depends on GENERIC_BUG
343
344config GENERIC_HWEIGHT
345	def_bool y
346
347config GENERIC_CSUM
348	def_bool y
349
350config GENERIC_CALIBRATE_DELAY
351	def_bool y
352
353config SMP
354	def_bool y
355
356config KERNEL_MODE_NEON
357	def_bool y
358
359config FIX_EARLYCON_MEM
360	def_bool y
361
362config PGTABLE_LEVELS
363	int
364	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
365	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
366	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
367	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
368	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
369	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
370
371config ARCH_SUPPORTS_UPROBES
372	def_bool y
373
374config ARCH_PROC_KCORE_TEXT
375	def_bool y
376
377config BROKEN_GAS_INST
378	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
379
380config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
381	bool
382	# Clang's __builtin_return_adddress() strips the PAC since 12.0.0
383	# https://reviews.llvm.org/D75044
384	default y if CC_IS_CLANG && (CLANG_VERSION >= 120000)
385	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
386	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
387	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
388	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
389	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
390	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
391	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
392	default n
393
394config KASAN_SHADOW_OFFSET
395	hex
396	depends on KASAN_GENERIC || KASAN_SW_TAGS
397	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
398	default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
399	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
400	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
401	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
402	default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
403	default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
404	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
405	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
406	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
407	default 0xffffffffffffffff
408
409config UNWIND_TABLES
410	bool
411
412source "arch/arm64/Kconfig.platforms"
413
414menu "Kernel Features"
415
416menu "ARM errata workarounds via the alternatives framework"
417
418config AMPERE_ERRATUM_AC03_CPU_38
419        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
420	default y
421	help
422	  This option adds an alternative code sequence to work around Ampere
423	  erratum AC03_CPU_38 on AmpereOne.
424
425	  The affected design reports FEAT_HAFDBS as not implemented in
426	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
427	  as required by the architecture. The unadvertised HAFDBS
428	  implementation suffers from an additional erratum where hardware
429	  A/D updates can occur after a PTE has been marked invalid.
430
431	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
432	  which avoids enabling unadvertised hardware Access Flag management
433	  at stage-2.
434
435	  If unsure, say Y.
436
437config ARM64_WORKAROUND_CLEAN_CACHE
438	bool
439
440config ARM64_ERRATUM_826319
441	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
442	default y
443	select ARM64_WORKAROUND_CLEAN_CACHE
444	help
445	  This option adds an alternative code sequence to work around ARM
446	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
447	  AXI master interface and an L2 cache.
448
449	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
450	  and is unable to accept a certain write via this interface, it will
451	  not progress on read data presented on the read data channel and the
452	  system can deadlock.
453
454	  The workaround promotes data cache clean instructions to
455	  data cache clean-and-invalidate.
456	  Please note that this does not necessarily enable the workaround,
457	  as it depends on the alternative framework, which will only patch
458	  the kernel if an affected CPU is detected.
459
460	  If unsure, say Y.
461
462config ARM64_ERRATUM_827319
463	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
464	default y
465	select ARM64_WORKAROUND_CLEAN_CACHE
466	help
467	  This option adds an alternative code sequence to work around ARM
468	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
469	  master interface and an L2 cache.
470
471	  Under certain conditions this erratum can cause a clean line eviction
472	  to occur at the same time as another transaction to the same address
473	  on the AMBA 5 CHI interface, which can cause data corruption if the
474	  interconnect reorders the two transactions.
475
476	  The workaround promotes data cache clean instructions to
477	  data cache clean-and-invalidate.
478	  Please note that this does not necessarily enable the workaround,
479	  as it depends on the alternative framework, which will only patch
480	  the kernel if an affected CPU is detected.
481
482	  If unsure, say Y.
483
484config ARM64_ERRATUM_824069
485	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
486	default y
487	select ARM64_WORKAROUND_CLEAN_CACHE
488	help
489	  This option adds an alternative code sequence to work around ARM
490	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
491	  to a coherent interconnect.
492
493	  If a Cortex-A53 processor is executing a store or prefetch for
494	  write instruction at the same time as a processor in another
495	  cluster is executing a cache maintenance operation to the same
496	  address, then this erratum might cause a clean cache line to be
497	  incorrectly marked as dirty.
498
499	  The workaround promotes data cache clean instructions to
500	  data cache clean-and-invalidate.
501	  Please note that this option does not necessarily enable the
502	  workaround, as it depends on the alternative framework, which will
503	  only patch the kernel if an affected CPU is detected.
504
505	  If unsure, say Y.
506
507config ARM64_ERRATUM_819472
508	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
509	default y
510	select ARM64_WORKAROUND_CLEAN_CACHE
511	help
512	  This option adds an alternative code sequence to work around ARM
513	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
514	  present when it is connected to a coherent interconnect.
515
516	  If the processor is executing a load and store exclusive sequence at
517	  the same time as a processor in another cluster is executing a cache
518	  maintenance operation to the same address, then this erratum might
519	  cause data corruption.
520
521	  The workaround promotes data cache clean instructions to
522	  data cache clean-and-invalidate.
523	  Please note that this does not necessarily enable the workaround,
524	  as it depends on the alternative framework, which will only patch
525	  the kernel if an affected CPU is detected.
526
527	  If unsure, say Y.
528
529config ARM64_ERRATUM_832075
530	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
531	default y
532	help
533	  This option adds an alternative code sequence to work around ARM
534	  erratum 832075 on Cortex-A57 parts up to r1p2.
535
536	  Affected Cortex-A57 parts might deadlock when exclusive load/store
537	  instructions to Write-Back memory are mixed with Device loads.
538
539	  The workaround is to promote device loads to use Load-Acquire
540	  semantics.
541	  Please note that this does not necessarily enable the workaround,
542	  as it depends on the alternative framework, which will only patch
543	  the kernel if an affected CPU is detected.
544
545	  If unsure, say Y.
546
547config ARM64_ERRATUM_834220
548	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
549	depends on KVM
550	default y
551	help
552	  This option adds an alternative code sequence to work around ARM
553	  erratum 834220 on Cortex-A57 parts up to r1p2.
554
555	  Affected Cortex-A57 parts might report a Stage 2 translation
556	  fault as the result of a Stage 1 fault for load crossing a
557	  page boundary when there is a permission or device memory
558	  alignment fault at Stage 1 and a translation fault at Stage 2.
559
560	  The workaround is to verify that the Stage 1 translation
561	  doesn't generate a fault before handling the Stage 2 fault.
562	  Please note that this does not necessarily enable the workaround,
563	  as it depends on the alternative framework, which will only patch
564	  the kernel if an affected CPU is detected.
565
566	  If unsure, say Y.
567
568config ARM64_ERRATUM_1742098
569	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
570	depends on COMPAT
571	default y
572	help
573	  This option removes the AES hwcap for aarch32 user-space to
574	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
575
576	  Affected parts may corrupt the AES state if an interrupt is
577	  taken between a pair of AES instructions. These instructions
578	  are only present if the cryptography extensions are present.
579	  All software should have a fallback implementation for CPUs
580	  that don't implement the cryptography extensions.
581
582	  If unsure, say Y.
583
584config ARM64_ERRATUM_845719
585	bool "Cortex-A53: 845719: a load might read incorrect data"
586	depends on COMPAT
587	default y
588	help
589	  This option adds an alternative code sequence to work around ARM
590	  erratum 845719 on Cortex-A53 parts up to r0p4.
591
592	  When running a compat (AArch32) userspace on an affected Cortex-A53
593	  part, a load at EL0 from a virtual address that matches the bottom 32
594	  bits of the virtual address used by a recent load at (AArch64) EL1
595	  might return incorrect data.
596
597	  The workaround is to write the contextidr_el1 register on exception
598	  return to a 32-bit task.
599	  Please note that this does not necessarily enable the workaround,
600	  as it depends on the alternative framework, which will only patch
601	  the kernel if an affected CPU is detected.
602
603	  If unsure, say Y.
604
605config ARM64_ERRATUM_843419
606	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
607	default y
608	help
609	  This option links the kernel with '--fix-cortex-a53-843419' and
610	  enables PLT support to replace certain ADRP instructions, which can
611	  cause subsequent memory accesses to use an incorrect address on
612	  Cortex-A53 parts up to r0p4.
613
614	  If unsure, say Y.
615
616config ARM64_LD_HAS_FIX_ERRATUM_843419
617	def_bool $(ld-option,--fix-cortex-a53-843419)
618
619config ARM64_ERRATUM_1024718
620	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
621	default y
622	help
623	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
624
625	  Affected Cortex-A55 cores (all revisions) could cause incorrect
626	  update of the hardware dirty bit when the DBM/AP bits are updated
627	  without a break-before-make. The workaround is to disable the usage
628	  of hardware DBM locally on the affected cores. CPUs not affected by
629	  this erratum will continue to use the feature.
630
631	  If unsure, say Y.
632
633config ARM64_ERRATUM_1418040
634	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
635	default y
636	depends on COMPAT
637	help
638	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
639	  errata 1188873 and 1418040.
640
641	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
642	  cause register corruption when accessing the timer registers
643	  from AArch32 userspace.
644
645	  If unsure, say Y.
646
647config ARM64_WORKAROUND_SPECULATIVE_AT
648	bool
649
650config ARM64_ERRATUM_1165522
651	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
652	default y
653	select ARM64_WORKAROUND_SPECULATIVE_AT
654	help
655	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
656
657	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
658	  corrupted TLBs by speculating an AT instruction during a guest
659	  context switch.
660
661	  If unsure, say Y.
662
663config ARM64_ERRATUM_1319367
664	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
665	default y
666	select ARM64_WORKAROUND_SPECULATIVE_AT
667	help
668	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
669	  and A72 erratum 1319367
670
671	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
672	  speculating an AT instruction during a guest context switch.
673
674	  If unsure, say Y.
675
676config ARM64_ERRATUM_1530923
677	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
678	default y
679	select ARM64_WORKAROUND_SPECULATIVE_AT
680	help
681	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
682
683	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
684	  corrupted TLBs by speculating an AT instruction during a guest
685	  context switch.
686
687	  If unsure, say Y.
688
689config ARM64_WORKAROUND_REPEAT_TLBI
690	bool
691
692config ARM64_ERRATUM_2441007
693	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
694	default y
695	select ARM64_WORKAROUND_REPEAT_TLBI
696	help
697	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
698
699	  Under very rare circumstances, affected Cortex-A55 CPUs
700	  may not handle a race between a break-before-make sequence on one
701	  CPU, and another CPU accessing the same page. This could allow a
702	  store to a page that has been unmapped.
703
704	  Work around this by adding the affected CPUs to the list that needs
705	  TLB sequences to be done twice.
706
707	  If unsure, say Y.
708
709config ARM64_ERRATUM_1286807
710	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
711	default y
712	select ARM64_WORKAROUND_REPEAT_TLBI
713	help
714	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
715
716	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
717	  address for a cacheable mapping of a location is being
718	  accessed by a core while another core is remapping the virtual
719	  address to a new physical page using the recommended
720	  break-before-make sequence, then under very rare circumstances
721	  TLBI+DSB completes before a read using the translation being
722	  invalidated has been observed by other observers. The
723	  workaround repeats the TLBI+DSB operation.
724
725config ARM64_ERRATUM_1463225
726	bool "Cortex-A76: Software Step might prevent interrupt recognition"
727	default y
728	help
729	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
730
731	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
732	  of a system call instruction (SVC) can prevent recognition of
733	  subsequent interrupts when software stepping is disabled in the
734	  exception handler of the system call and either kernel debugging
735	  is enabled or VHE is in use.
736
737	  Work around the erratum by triggering a dummy step exception
738	  when handling a system call from a task that is being stepped
739	  in a VHE configuration of the kernel.
740
741	  If unsure, say Y.
742
743config ARM64_ERRATUM_1542419
744	bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
745	default y
746	help
747	  This option adds a workaround for ARM Neoverse-N1 erratum
748	  1542419.
749
750	  Affected Neoverse-N1 cores could execute a stale instruction when
751	  modified by another CPU. The workaround depends on a firmware
752	  counterpart.
753
754	  Workaround the issue by hiding the DIC feature from EL0. This
755	  forces user-space to perform cache maintenance.
756
757	  If unsure, say Y.
758
759config ARM64_ERRATUM_1508412
760	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
761	default y
762	help
763	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
764
765	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
766	  of a store-exclusive or read of PAR_EL1 and a load with device or
767	  non-cacheable memory attributes. The workaround depends on a firmware
768	  counterpart.
769
770	  KVM guests must also have the workaround implemented or they can
771	  deadlock the system.
772
773	  Work around the issue by inserting DMB SY barriers around PAR_EL1
774	  register reads and warning KVM users. The DMB barrier is sufficient
775	  to prevent a speculative PAR_EL1 read.
776
777	  If unsure, say Y.
778
779config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
780	bool
781
782config ARM64_ERRATUM_2051678
783	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
784	default y
785	help
786	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
787	  Affected Cortex-A510 might not respect the ordering rules for
788	  hardware update of the page table's dirty bit. The workaround
789	  is to not enable the feature on affected CPUs.
790
791	  If unsure, say Y.
792
793config ARM64_ERRATUM_2077057
794	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
795	default y
796	help
797	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
798	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
799	  expected, but a Pointer Authentication trap is taken instead. The
800	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
801	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
802
803	  This can only happen when EL2 is stepping EL1.
804
805	  When these conditions occur, the SPSR_EL2 value is unchanged from the
806	  previous guest entry, and can be restored from the in-memory copy.
807
808	  If unsure, say Y.
809
810config ARM64_ERRATUM_2658417
811	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
812	default y
813	help
814	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
815	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
816	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
817	  A510 CPUs are using shared neon hardware. As the sharing is not
818	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
819	  user-space should not be using these instructions.
820
821	  If unsure, say Y.
822
823config ARM64_ERRATUM_2119858
824	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
825	default y
826	depends on CORESIGHT_TRBE
827	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
828	help
829	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
830
831	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
832	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
833	  the event of a WRAP event.
834
835	  Work around the issue by always making sure we move the TRBPTR_EL1 by
836	  256 bytes before enabling the buffer and filling the first 256 bytes of
837	  the buffer with ETM ignore packets upon disabling.
838
839	  If unsure, say Y.
840
841config ARM64_ERRATUM_2139208
842	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
843	default y
844	depends on CORESIGHT_TRBE
845	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
846	help
847	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
848
849	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
850	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
851	  the event of a WRAP event.
852
853	  Work around the issue by always making sure we move the TRBPTR_EL1 by
854	  256 bytes before enabling the buffer and filling the first 256 bytes of
855	  the buffer with ETM ignore packets upon disabling.
856
857	  If unsure, say Y.
858
859config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
860	bool
861
862config ARM64_ERRATUM_2054223
863	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
864	default y
865	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
866	help
867	  Enable workaround for ARM Cortex-A710 erratum 2054223
868
869	  Affected cores may fail to flush the trace data on a TSB instruction, when
870	  the PE is in trace prohibited state. This will cause losing a few bytes
871	  of the trace cached.
872
873	  Workaround is to issue two TSB consecutively on affected cores.
874
875	  If unsure, say Y.
876
877config ARM64_ERRATUM_2067961
878	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
879	default y
880	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
881	help
882	  Enable workaround for ARM Neoverse-N2 erratum 2067961
883
884	  Affected cores may fail to flush the trace data on a TSB instruction, when
885	  the PE is in trace prohibited state. This will cause losing a few bytes
886	  of the trace cached.
887
888	  Workaround is to issue two TSB consecutively on affected cores.
889
890	  If unsure, say Y.
891
892config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
893	bool
894
895config ARM64_ERRATUM_2253138
896	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
897	depends on CORESIGHT_TRBE
898	default y
899	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
900	help
901	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
902
903	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
904	  for TRBE. Under some conditions, the TRBE might generate a write to the next
905	  virtually addressed page following the last page of the TRBE address space
906	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
907
908	  Work around this in the driver by always making sure that there is a
909	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
910
911	  If unsure, say Y.
912
913config ARM64_ERRATUM_2224489
914	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
915	depends on CORESIGHT_TRBE
916	default y
917	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
918	help
919	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
920
921	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
922	  for TRBE. Under some conditions, the TRBE might generate a write to the next
923	  virtually addressed page following the last page of the TRBE address space
924	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
925
926	  Work around this in the driver by always making sure that there is a
927	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
928
929	  If unsure, say Y.
930
931config ARM64_ERRATUM_2441009
932	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
933	default y
934	select ARM64_WORKAROUND_REPEAT_TLBI
935	help
936	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
937
938	  Under very rare circumstances, affected Cortex-A510 CPUs
939	  may not handle a race between a break-before-make sequence on one
940	  CPU, and another CPU accessing the same page. This could allow a
941	  store to a page that has been unmapped.
942
943	  Work around this by adding the affected CPUs to the list that needs
944	  TLB sequences to be done twice.
945
946	  If unsure, say Y.
947
948config ARM64_ERRATUM_2064142
949	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
950	depends on CORESIGHT_TRBE
951	default y
952	help
953	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
954
955	  Affected Cortex-A510 core might fail to write into system registers after the
956	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
957	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
958	  and TRBTRG_EL1 will be ignored and will not be effected.
959
960	  Work around this in the driver by executing TSB CSYNC and DSB after collection
961	  is stopped and before performing a system register write to one of the affected
962	  registers.
963
964	  If unsure, say Y.
965
966config ARM64_ERRATUM_2038923
967	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
968	depends on CORESIGHT_TRBE
969	default y
970	help
971	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
972
973	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
974	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
975	  might be corrupted. This happens after TRBE buffer has been enabled by setting
976	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
977	  execution changes from a context, in which trace is prohibited to one where it
978	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
979	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
980	  the trace buffer state might be corrupted.
981
982	  Work around this in the driver by preventing an inconsistent view of whether the
983	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
984	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
985	  two ISB instructions if no ERET is to take place.
986
987	  If unsure, say Y.
988
989config ARM64_ERRATUM_1902691
990	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
991	depends on CORESIGHT_TRBE
992	default y
993	help
994	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
995
996	  Affected Cortex-A510 core might cause trace data corruption, when being written
997	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
998	  trace data.
999
1000	  Work around this problem in the driver by just preventing TRBE initialization on
1001	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1002	  on such implementations. This will cover the kernel for any firmware that doesn't
1003	  do this already.
1004
1005	  If unsure, say Y.
1006
1007config ARM64_ERRATUM_2457168
1008	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1009	depends on ARM64_AMU_EXTN
1010	default y
1011	help
1012	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1013
1014	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1015	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1016	  incorrectly giving a significantly higher output value.
1017
1018	  Work around this problem by returning 0 when reading the affected counter in
1019	  key locations that results in disabling all users of this counter. This effect
1020	  is the same to firmware disabling affected counters.
1021
1022	  If unsure, say Y.
1023
1024config ARM64_ERRATUM_2645198
1025	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1026	default y
1027	help
1028	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1029
1030	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1031	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1032	  next instruction abort caused by permission fault.
1033
1034	  Only user-space does executable to non-executable permission transition via
1035	  mprotect() system call. Workaround the problem by doing a break-before-make
1036	  TLB invalidation, for all changes to executable user space mappings.
1037
1038	  If unsure, say Y.
1039
1040config CAVIUM_ERRATUM_22375
1041	bool "Cavium erratum 22375, 24313"
1042	default y
1043	help
1044	  Enable workaround for errata 22375 and 24313.
1045
1046	  This implements two gicv3-its errata workarounds for ThunderX. Both
1047	  with a small impact affecting only ITS table allocation.
1048
1049	    erratum 22375: only alloc 8MB table size
1050	    erratum 24313: ignore memory access type
1051
1052	  The fixes are in ITS initialization and basically ignore memory access
1053	  type and table size provided by the TYPER and BASER registers.
1054
1055	  If unsure, say Y.
1056
1057config CAVIUM_ERRATUM_23144
1058	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1059	depends on NUMA
1060	default y
1061	help
1062	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1063
1064	  If unsure, say Y.
1065
1066config CAVIUM_ERRATUM_23154
1067	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1068	default y
1069	help
1070	  The ThunderX GICv3 implementation requires a modified version for
1071	  reading the IAR status to ensure data synchronization
1072	  (access to icc_iar1_el1 is not sync'ed before and after).
1073
1074	  It also suffers from erratum 38545 (also present on Marvell's
1075	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1076	  spuriously presented to the CPU interface.
1077
1078	  If unsure, say Y.
1079
1080config CAVIUM_ERRATUM_27456
1081	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1082	default y
1083	help
1084	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1085	  instructions may cause the icache to become corrupted if it
1086	  contains data for a non-current ASID.  The fix is to
1087	  invalidate the icache when changing the mm context.
1088
1089	  If unsure, say Y.
1090
1091config CAVIUM_ERRATUM_30115
1092	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1093	default y
1094	help
1095	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1096	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1097	  interrupts in host. Trapping both GICv3 group-0 and group-1
1098	  accesses sidesteps the issue.
1099
1100	  If unsure, say Y.
1101
1102config CAVIUM_TX2_ERRATUM_219
1103	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1104	default y
1105	help
1106	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1107	  TTBR update and the corresponding context synchronizing operation can
1108	  cause a spurious Data Abort to be delivered to any hardware thread in
1109	  the CPU core.
1110
1111	  Work around the issue by avoiding the problematic code sequence and
1112	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1113	  trap handler performs the corresponding register access, skips the
1114	  instruction and ensures context synchronization by virtue of the
1115	  exception return.
1116
1117	  If unsure, say Y.
1118
1119config FUJITSU_ERRATUM_010001
1120	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1121	default y
1122	help
1123	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1124	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1125	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1126	  This fault occurs under a specific hardware condition when a
1127	  load/store instruction performs an address translation using:
1128	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1129	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1130	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1131	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1132
1133	  The workaround is to ensure these bits are clear in TCR_ELx.
1134	  The workaround only affects the Fujitsu-A64FX.
1135
1136	  If unsure, say Y.
1137
1138config HISILICON_ERRATUM_161600802
1139	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1140	default y
1141	help
1142	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1143	  when issued ITS commands such as VMOVP and VMAPP, and requires
1144	  a 128kB offset to be applied to the target address in this commands.
1145
1146	  If unsure, say Y.
1147
1148config QCOM_FALKOR_ERRATUM_1003
1149	bool "Falkor E1003: Incorrect translation due to ASID change"
1150	default y
1151	help
1152	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1153	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1154	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1155	  then only for entries in the walk cache, since the leaf translation
1156	  is unchanged. Work around the erratum by invalidating the walk cache
1157	  entries for the trampoline before entering the kernel proper.
1158
1159config QCOM_FALKOR_ERRATUM_1009
1160	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1161	default y
1162	select ARM64_WORKAROUND_REPEAT_TLBI
1163	help
1164	  On Falkor v1, the CPU may prematurely complete a DSB following a
1165	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1166	  one more time to fix the issue.
1167
1168	  If unsure, say Y.
1169
1170config QCOM_QDF2400_ERRATUM_0065
1171	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1172	default y
1173	help
1174	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1175	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1176	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1177
1178	  If unsure, say Y.
1179
1180config QCOM_FALKOR_ERRATUM_E1041
1181	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1182	default y
1183	help
1184	  Falkor CPU may speculatively fetch instructions from an improper
1185	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1186	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1187
1188	  If unsure, say Y.
1189
1190config NVIDIA_CARMEL_CNP_ERRATUM
1191	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1192	default y
1193	help
1194	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1195	  invalidate shared TLB entries installed by a different core, as it would
1196	  on standard ARM cores.
1197
1198	  If unsure, say Y.
1199
1200config ROCKCHIP_ERRATUM_3588001
1201	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1202	default y
1203	help
1204	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1205	  This means, that its sharability feature may not be used, even though it
1206	  is supported by the IP itself.
1207
1208	  If unsure, say Y.
1209
1210config SOCIONEXT_SYNQUACER_PREITS
1211	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1212	default y
1213	help
1214	  Socionext Synquacer SoCs implement a separate h/w block to generate
1215	  MSI doorbell writes with non-zero values for the device ID.
1216
1217	  If unsure, say Y.
1218
1219endmenu # "ARM errata workarounds via the alternatives framework"
1220
1221choice
1222	prompt "Page size"
1223	default ARM64_4K_PAGES
1224	help
1225	  Page size (translation granule) configuration.
1226
1227config ARM64_4K_PAGES
1228	bool "4KB"
1229	help
1230	  This feature enables 4KB pages support.
1231
1232config ARM64_16K_PAGES
1233	bool "16KB"
1234	help
1235	  The system will use 16KB pages support. AArch32 emulation
1236	  requires applications compiled with 16K (or a multiple of 16K)
1237	  aligned segments.
1238
1239config ARM64_64K_PAGES
1240	bool "64KB"
1241	help
1242	  This feature enables 64KB pages support (4KB by default)
1243	  allowing only two levels of page tables and faster TLB
1244	  look-up. AArch32 emulation requires applications compiled
1245	  with 64K aligned segments.
1246
1247endchoice
1248
1249choice
1250	prompt "Virtual address space size"
1251	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1252	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1253	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1254	help
1255	  Allows choosing one of multiple possible virtual address
1256	  space sizes. The level of translation table is determined by
1257	  a combination of page size and virtual address space size.
1258
1259config ARM64_VA_BITS_36
1260	bool "36-bit" if EXPERT
1261	depends on ARM64_16K_PAGES
1262
1263config ARM64_VA_BITS_39
1264	bool "39-bit"
1265	depends on ARM64_4K_PAGES
1266
1267config ARM64_VA_BITS_42
1268	bool "42-bit"
1269	depends on ARM64_64K_PAGES
1270
1271config ARM64_VA_BITS_47
1272	bool "47-bit"
1273	depends on ARM64_16K_PAGES
1274
1275config ARM64_VA_BITS_48
1276	bool "48-bit"
1277
1278config ARM64_VA_BITS_52
1279	bool "52-bit"
1280	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1281	help
1282	  Enable 52-bit virtual addressing for userspace when explicitly
1283	  requested via a hint to mmap(). The kernel will also use 52-bit
1284	  virtual addresses for its own mappings (provided HW support for
1285	  this feature is available, otherwise it reverts to 48-bit).
1286
1287	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1288	  ARMv8.3 Pointer Authentication will result in the PAC being
1289	  reduced from 7 bits to 3 bits, which may have a significant
1290	  impact on its susceptibility to brute-force attacks.
1291
1292	  If unsure, select 48-bit virtual addressing instead.
1293
1294endchoice
1295
1296config ARM64_FORCE_52BIT
1297	bool "Force 52-bit virtual addresses for userspace"
1298	depends on ARM64_VA_BITS_52 && EXPERT
1299	help
1300	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1301	  to maintain compatibility with older software by providing 48-bit VAs
1302	  unless a hint is supplied to mmap.
1303
1304	  This configuration option disables the 48-bit compatibility logic, and
1305	  forces all userspace addresses to be 52-bit on HW that supports it. One
1306	  should only enable this configuration option for stress testing userspace
1307	  memory management code. If unsure say N here.
1308
1309config ARM64_VA_BITS
1310	int
1311	default 36 if ARM64_VA_BITS_36
1312	default 39 if ARM64_VA_BITS_39
1313	default 42 if ARM64_VA_BITS_42
1314	default 47 if ARM64_VA_BITS_47
1315	default 48 if ARM64_VA_BITS_48
1316	default 52 if ARM64_VA_BITS_52
1317
1318choice
1319	prompt "Physical address space size"
1320	default ARM64_PA_BITS_48
1321	help
1322	  Choose the maximum physical address range that the kernel will
1323	  support.
1324
1325config ARM64_PA_BITS_48
1326	bool "48-bit"
1327
1328config ARM64_PA_BITS_52
1329	bool "52-bit (ARMv8.2)"
1330	depends on ARM64_64K_PAGES
1331	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1332	help
1333	  Enable support for a 52-bit physical address space, introduced as
1334	  part of the ARMv8.2-LPA extension.
1335
1336	  With this enabled, the kernel will also continue to work on CPUs that
1337	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1338	  minor performance overhead).
1339
1340endchoice
1341
1342config ARM64_PA_BITS
1343	int
1344	default 48 if ARM64_PA_BITS_48
1345	default 52 if ARM64_PA_BITS_52
1346
1347choice
1348	prompt "Endianness"
1349	default CPU_LITTLE_ENDIAN
1350	help
1351	  Select the endianness of data accesses performed by the CPU. Userspace
1352	  applications will need to be compiled and linked for the endianness
1353	  that is selected here.
1354
1355config CPU_BIG_ENDIAN
1356	bool "Build big-endian kernel"
1357	depends on !LD_IS_LLD || LLD_VERSION >= 130000
1358	help
1359	  Say Y if you plan on running a kernel with a big-endian userspace.
1360
1361config CPU_LITTLE_ENDIAN
1362	bool "Build little-endian kernel"
1363	help
1364	  Say Y if you plan on running a kernel with a little-endian userspace.
1365	  This is usually the case for distributions targeting arm64.
1366
1367endchoice
1368
1369config SCHED_MC
1370	bool "Multi-core scheduler support"
1371	help
1372	  Multi-core scheduler support improves the CPU scheduler's decision
1373	  making when dealing with multi-core CPU chips at a cost of slightly
1374	  increased overhead in some places. If unsure say N here.
1375
1376config SCHED_CLUSTER
1377	bool "Cluster scheduler support"
1378	help
1379	  Cluster scheduler support improves the CPU scheduler's decision
1380	  making when dealing with machines that have clusters of CPUs.
1381	  Cluster usually means a couple of CPUs which are placed closely
1382	  by sharing mid-level caches, last-level cache tags or internal
1383	  busses.
1384
1385config SCHED_SMT
1386	bool "SMT scheduler support"
1387	help
1388	  Improves the CPU scheduler's decision making when dealing with
1389	  MultiThreading at a cost of slightly increased overhead in some
1390	  places. If unsure say N here.
1391
1392config NR_CPUS
1393	int "Maximum number of CPUs (2-4096)"
1394	range 2 4096
1395	default "256"
1396
1397config HOTPLUG_CPU
1398	bool "Support for hot-pluggable CPUs"
1399	select GENERIC_IRQ_MIGRATION
1400	help
1401	  Say Y here to experiment with turning CPUs off and on.  CPUs
1402	  can be controlled through /sys/devices/system/cpu.
1403
1404# Common NUMA Features
1405config NUMA
1406	bool "NUMA Memory Allocation and Scheduler Support"
1407	select GENERIC_ARCH_NUMA
1408	select ACPI_NUMA if ACPI
1409	select OF_NUMA
1410	select HAVE_SETUP_PER_CPU_AREA
1411	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1412	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1413	select USE_PERCPU_NUMA_NODE_ID
1414	help
1415	  Enable NUMA (Non-Uniform Memory Access) support.
1416
1417	  The kernel will try to allocate memory used by a CPU on the
1418	  local memory of the CPU and add some more
1419	  NUMA awareness to the kernel.
1420
1421config NODES_SHIFT
1422	int "Maximum NUMA Nodes (as a power of 2)"
1423	range 1 10
1424	default "4"
1425	depends on NUMA
1426	help
1427	  Specify the maximum number of NUMA Nodes available on the target
1428	  system.  Increases memory reserved to accommodate various tables.
1429
1430source "kernel/Kconfig.hz"
1431
1432config ARCH_SPARSEMEM_ENABLE
1433	def_bool y
1434	select SPARSEMEM_VMEMMAP_ENABLE
1435	select SPARSEMEM_VMEMMAP
1436
1437config HW_PERF_EVENTS
1438	def_bool y
1439	depends on ARM_PMU
1440
1441# Supported by clang >= 7.0 or GCC >= 12.0.0
1442config CC_HAVE_SHADOW_CALL_STACK
1443	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1444
1445config PARAVIRT
1446	bool "Enable paravirtualization code"
1447	help
1448	  This changes the kernel so it can modify itself when it is run
1449	  under a hypervisor, potentially improving performance significantly
1450	  over full virtualization.
1451
1452config PARAVIRT_TIME_ACCOUNTING
1453	bool "Paravirtual steal time accounting"
1454	select PARAVIRT
1455	help
1456	  Select this option to enable fine granularity task steal time
1457	  accounting. Time spent executing other tasks in parallel with
1458	  the current vCPU is discounted from the vCPU power. To account for
1459	  that, there can be a small performance impact.
1460
1461	  If in doubt, say N here.
1462
1463config ARCH_SUPPORTS_KEXEC
1464	def_bool PM_SLEEP_SMP
1465
1466config ARCH_SUPPORTS_KEXEC_FILE
1467	def_bool y
1468
1469config ARCH_SELECTS_KEXEC_FILE
1470	def_bool y
1471	depends on KEXEC_FILE
1472	select HAVE_IMA_KEXEC if IMA
1473
1474config ARCH_SUPPORTS_KEXEC_SIG
1475	def_bool y
1476
1477config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1478	def_bool y
1479
1480config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1481	def_bool y
1482
1483config ARCH_SUPPORTS_CRASH_DUMP
1484	def_bool y
1485
1486config TRANS_TABLE
1487	def_bool y
1488	depends on HIBERNATION || KEXEC_CORE
1489
1490config XEN_DOM0
1491	def_bool y
1492	depends on XEN
1493
1494config XEN
1495	bool "Xen guest support on ARM64"
1496	depends on ARM64 && OF
1497	select SWIOTLB_XEN
1498	select PARAVIRT
1499	help
1500	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1501
1502# include/linux/mmzone.h requires the following to be true:
1503#
1504#   MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1505#
1506# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1507#
1508#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_ORDER  |  default MAX_ORDER |
1509# ----+-------------------+--------------+-----------------+--------------------+
1510# 4K  |       27          |      12      |       15        |         10         |
1511# 16K |       27          |      14      |       13        |         11         |
1512# 64K |       29          |      16      |       13        |         13         |
1513config ARCH_FORCE_MAX_ORDER
1514	int
1515	default "13" if ARM64_64K_PAGES
1516	default "11" if ARM64_16K_PAGES
1517	default "10"
1518	help
1519	  The kernel page allocator limits the size of maximal physically
1520	  contiguous allocations. The limit is called MAX_ORDER and it
1521	  defines the maximal power of two of number of pages that can be
1522	  allocated as a single contiguous block. This option allows
1523	  overriding the default setting when ability to allocate very
1524	  large blocks of physically contiguous memory is required.
1525
1526	  The maximal size of allocation cannot exceed the size of the
1527	  section, so the value of MAX_ORDER should satisfy
1528
1529	    MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1530
1531	  Don't change if unsure.
1532
1533config UNMAP_KERNEL_AT_EL0
1534	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1535	default y
1536	help
1537	  Speculation attacks against some high-performance processors can
1538	  be used to bypass MMU permission checks and leak kernel data to
1539	  userspace. This can be defended against by unmapping the kernel
1540	  when running in userspace, mapping it back in on exception entry
1541	  via a trampoline page in the vector table.
1542
1543	  If unsure, say Y.
1544
1545config MITIGATE_SPECTRE_BRANCH_HISTORY
1546	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1547	default y
1548	help
1549	  Speculation attacks against some high-performance processors can
1550	  make use of branch history to influence future speculation.
1551	  When taking an exception from user-space, a sequence of branches
1552	  or a firmware call overwrites the branch history.
1553
1554config RODATA_FULL_DEFAULT_ENABLED
1555	bool "Apply r/o permissions of VM areas also to their linear aliases"
1556	default y
1557	help
1558	  Apply read-only attributes of VM areas to the linear alias of
1559	  the backing pages as well. This prevents code or read-only data
1560	  from being modified (inadvertently or intentionally) via another
1561	  mapping of the same memory page. This additional enhancement can
1562	  be turned off at runtime by passing rodata=[off|on] (and turned on
1563	  with rodata=full if this option is set to 'n')
1564
1565	  This requires the linear region to be mapped down to pages,
1566	  which may adversely affect performance in some cases.
1567
1568config ARM64_SW_TTBR0_PAN
1569	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1570	help
1571	  Enabling this option prevents the kernel from accessing
1572	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1573	  zeroed area and reserved ASID. The user access routines
1574	  restore the valid TTBR0_EL1 temporarily.
1575
1576config ARM64_TAGGED_ADDR_ABI
1577	bool "Enable the tagged user addresses syscall ABI"
1578	default y
1579	help
1580	  When this option is enabled, user applications can opt in to a
1581	  relaxed ABI via prctl() allowing tagged addresses to be passed
1582	  to system calls as pointer arguments. For details, see
1583	  Documentation/arch/arm64/tagged-address-abi.rst.
1584
1585menuconfig COMPAT
1586	bool "Kernel support for 32-bit EL0"
1587	depends on ARM64_4K_PAGES || EXPERT
1588	select HAVE_UID16
1589	select OLD_SIGSUSPEND3
1590	select COMPAT_OLD_SIGACTION
1591	help
1592	  This option enables support for a 32-bit EL0 running under a 64-bit
1593	  kernel at EL1. AArch32-specific components such as system calls,
1594	  the user helper functions, VFP support and the ptrace interface are
1595	  handled appropriately by the kernel.
1596
1597	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1598	  that you will only be able to execute AArch32 binaries that were compiled
1599	  with page size aligned segments.
1600
1601	  If you want to execute 32-bit userspace applications, say Y.
1602
1603if COMPAT
1604
1605config KUSER_HELPERS
1606	bool "Enable kuser helpers page for 32-bit applications"
1607	default y
1608	help
1609	  Warning: disabling this option may break 32-bit user programs.
1610
1611	  Provide kuser helpers to compat tasks. The kernel provides
1612	  helper code to userspace in read only form at a fixed location
1613	  to allow userspace to be independent of the CPU type fitted to
1614	  the system. This permits binaries to be run on ARMv4 through
1615	  to ARMv8 without modification.
1616
1617	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1618
1619	  However, the fixed address nature of these helpers can be used
1620	  by ROP (return orientated programming) authors when creating
1621	  exploits.
1622
1623	  If all of the binaries and libraries which run on your platform
1624	  are built specifically for your platform, and make no use of
1625	  these helpers, then you can turn this option off to hinder
1626	  such exploits. However, in that case, if a binary or library
1627	  relying on those helpers is run, it will not function correctly.
1628
1629	  Say N here only if you are absolutely certain that you do not
1630	  need these helpers; otherwise, the safe option is to say Y.
1631
1632config COMPAT_VDSO
1633	bool "Enable vDSO for 32-bit applications"
1634	depends on !CPU_BIG_ENDIAN
1635	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1636	select GENERIC_COMPAT_VDSO
1637	default y
1638	help
1639	  Place in the process address space of 32-bit applications an
1640	  ELF shared object providing fast implementations of gettimeofday
1641	  and clock_gettime.
1642
1643	  You must have a 32-bit build of glibc 2.22 or later for programs
1644	  to seamlessly take advantage of this.
1645
1646config THUMB2_COMPAT_VDSO
1647	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1648	depends on COMPAT_VDSO
1649	default y
1650	help
1651	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1652	  otherwise with '-marm'.
1653
1654config COMPAT_ALIGNMENT_FIXUPS
1655	bool "Fix up misaligned multi-word loads and stores in user space"
1656
1657menuconfig ARMV8_DEPRECATED
1658	bool "Emulate deprecated/obsolete ARMv8 instructions"
1659	depends on SYSCTL
1660	help
1661	  Legacy software support may require certain instructions
1662	  that have been deprecated or obsoleted in the architecture.
1663
1664	  Enable this config to enable selective emulation of these
1665	  features.
1666
1667	  If unsure, say Y
1668
1669if ARMV8_DEPRECATED
1670
1671config SWP_EMULATION
1672	bool "Emulate SWP/SWPB instructions"
1673	help
1674	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1675	  they are always undefined. Say Y here to enable software
1676	  emulation of these instructions for userspace using LDXR/STXR.
1677	  This feature can be controlled at runtime with the abi.swp
1678	  sysctl which is disabled by default.
1679
1680	  In some older versions of glibc [<=2.8] SWP is used during futex
1681	  trylock() operations with the assumption that the code will not
1682	  be preempted. This invalid assumption may be more likely to fail
1683	  with SWP emulation enabled, leading to deadlock of the user
1684	  application.
1685
1686	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1687	  on an external transaction monitoring block called a global
1688	  monitor to maintain update atomicity. If your system does not
1689	  implement a global monitor, this option can cause programs that
1690	  perform SWP operations to uncached memory to deadlock.
1691
1692	  If unsure, say Y
1693
1694config CP15_BARRIER_EMULATION
1695	bool "Emulate CP15 Barrier instructions"
1696	help
1697	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1698	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1699	  strongly recommended to use the ISB, DSB, and DMB
1700	  instructions instead.
1701
1702	  Say Y here to enable software emulation of these
1703	  instructions for AArch32 userspace code. When this option is
1704	  enabled, CP15 barrier usage is traced which can help
1705	  identify software that needs updating. This feature can be
1706	  controlled at runtime with the abi.cp15_barrier sysctl.
1707
1708	  If unsure, say Y
1709
1710config SETEND_EMULATION
1711	bool "Emulate SETEND instruction"
1712	help
1713	  The SETEND instruction alters the data-endianness of the
1714	  AArch32 EL0, and is deprecated in ARMv8.
1715
1716	  Say Y here to enable software emulation of the instruction
1717	  for AArch32 userspace code. This feature can be controlled
1718	  at runtime with the abi.setend sysctl.
1719
1720	  Note: All the cpus on the system must have mixed endian support at EL0
1721	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1722	  endian - is hotplugged in after this feature has been enabled, there could
1723	  be unexpected results in the applications.
1724
1725	  If unsure, say Y
1726endif # ARMV8_DEPRECATED
1727
1728endif # COMPAT
1729
1730menu "ARMv8.1 architectural features"
1731
1732config ARM64_HW_AFDBM
1733	bool "Support for hardware updates of the Access and Dirty page flags"
1734	default y
1735	help
1736	  The ARMv8.1 architecture extensions introduce support for
1737	  hardware updates of the access and dirty information in page
1738	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1739	  capable processors, accesses to pages with PTE_AF cleared will
1740	  set this bit instead of raising an access flag fault.
1741	  Similarly, writes to read-only pages with the DBM bit set will
1742	  clear the read-only bit (AP[2]) instead of raising a
1743	  permission fault.
1744
1745	  Kernels built with this configuration option enabled continue
1746	  to work on pre-ARMv8.1 hardware and the performance impact is
1747	  minimal. If unsure, say Y.
1748
1749config ARM64_PAN
1750	bool "Enable support for Privileged Access Never (PAN)"
1751	default y
1752	help
1753	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1754	  prevents the kernel or hypervisor from accessing user-space (EL0)
1755	  memory directly.
1756
1757	  Choosing this option will cause any unprotected (not using
1758	  copy_to_user et al) memory access to fail with a permission fault.
1759
1760	  The feature is detected at runtime, and will remain as a 'nop'
1761	  instruction if the cpu does not implement the feature.
1762
1763config AS_HAS_LSE_ATOMICS
1764	def_bool $(as-instr,.arch_extension lse)
1765
1766config ARM64_LSE_ATOMICS
1767	bool
1768	default ARM64_USE_LSE_ATOMICS
1769	depends on AS_HAS_LSE_ATOMICS
1770
1771config ARM64_USE_LSE_ATOMICS
1772	bool "Atomic instructions"
1773	default y
1774	help
1775	  As part of the Large System Extensions, ARMv8.1 introduces new
1776	  atomic instructions that are designed specifically to scale in
1777	  very large systems.
1778
1779	  Say Y here to make use of these instructions for the in-kernel
1780	  atomic routines. This incurs a small overhead on CPUs that do
1781	  not support these instructions and requires the kernel to be
1782	  built with binutils >= 2.25 in order for the new instructions
1783	  to be used.
1784
1785endmenu # "ARMv8.1 architectural features"
1786
1787menu "ARMv8.2 architectural features"
1788
1789config AS_HAS_ARMV8_2
1790	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1791
1792config AS_HAS_SHA3
1793	def_bool $(as-instr,.arch armv8.2-a+sha3)
1794
1795config ARM64_PMEM
1796	bool "Enable support for persistent memory"
1797	select ARCH_HAS_PMEM_API
1798	select ARCH_HAS_UACCESS_FLUSHCACHE
1799	help
1800	  Say Y to enable support for the persistent memory API based on the
1801	  ARMv8.2 DCPoP feature.
1802
1803	  The feature is detected at runtime, and the kernel will use DC CVAC
1804	  operations if DC CVAP is not supported (following the behaviour of
1805	  DC CVAP itself if the system does not define a point of persistence).
1806
1807config ARM64_RAS_EXTN
1808	bool "Enable support for RAS CPU Extensions"
1809	default y
1810	help
1811	  CPUs that support the Reliability, Availability and Serviceability
1812	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1813	  errors, classify them and report them to software.
1814
1815	  On CPUs with these extensions system software can use additional
1816	  barriers to determine if faults are pending and read the
1817	  classification from a new set of registers.
1818
1819	  Selecting this feature will allow the kernel to use these barriers
1820	  and access the new registers if the system supports the extension.
1821	  Platform RAS features may additionally depend on firmware support.
1822
1823config ARM64_CNP
1824	bool "Enable support for Common Not Private (CNP) translations"
1825	default y
1826	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1827	help
1828	  Common Not Private (CNP) allows translation table entries to
1829	  be shared between different PEs in the same inner shareable
1830	  domain, so the hardware can use this fact to optimise the
1831	  caching of such entries in the TLB.
1832
1833	  Selecting this option allows the CNP feature to be detected
1834	  at runtime, and does not affect PEs that do not implement
1835	  this feature.
1836
1837endmenu # "ARMv8.2 architectural features"
1838
1839menu "ARMv8.3 architectural features"
1840
1841config ARM64_PTR_AUTH
1842	bool "Enable support for pointer authentication"
1843	default y
1844	help
1845	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1846	  instructions for signing and authenticating pointers against secret
1847	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1848	  and other attacks.
1849
1850	  This option enables these instructions at EL0 (i.e. for userspace).
1851	  Choosing this option will cause the kernel to initialise secret keys
1852	  for each process at exec() time, with these keys being
1853	  context-switched along with the process.
1854
1855	  The feature is detected at runtime. If the feature is not present in
1856	  hardware it will not be advertised to userspace/KVM guest nor will it
1857	  be enabled.
1858
1859	  If the feature is present on the boot CPU but not on a late CPU, then
1860	  the late CPU will be parked. Also, if the boot CPU does not have
1861	  address auth and the late CPU has then the late CPU will still boot
1862	  but with the feature disabled. On such a system, this option should
1863	  not be selected.
1864
1865config ARM64_PTR_AUTH_KERNEL
1866	bool "Use pointer authentication for kernel"
1867	default y
1868	depends on ARM64_PTR_AUTH
1869	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1870	# Modern compilers insert a .note.gnu.property section note for PAC
1871	# which is only understood by binutils starting with version 2.33.1.
1872	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1873	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1874	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1875	help
1876	  If the compiler supports the -mbranch-protection or
1877	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1878	  will cause the kernel itself to be compiled with return address
1879	  protection. In this case, and if the target hardware is known to
1880	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1881	  disabled with minimal loss of protection.
1882
1883	  This feature works with FUNCTION_GRAPH_TRACER option only if
1884	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
1885
1886config CC_HAS_BRANCH_PROT_PAC_RET
1887	# GCC 9 or later, clang 8 or later
1888	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1889
1890config CC_HAS_SIGN_RETURN_ADDRESS
1891	# GCC 7, 8
1892	def_bool $(cc-option,-msign-return-address=all)
1893
1894config AS_HAS_ARMV8_3
1895	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1896
1897config AS_HAS_CFI_NEGATE_RA_STATE
1898	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1899
1900config AS_HAS_LDAPR
1901	def_bool $(as-instr,.arch_extension rcpc)
1902
1903endmenu # "ARMv8.3 architectural features"
1904
1905menu "ARMv8.4 architectural features"
1906
1907config ARM64_AMU_EXTN
1908	bool "Enable support for the Activity Monitors Unit CPU extension"
1909	default y
1910	help
1911	  The activity monitors extension is an optional extension introduced
1912	  by the ARMv8.4 CPU architecture. This enables support for version 1
1913	  of the activity monitors architecture, AMUv1.
1914
1915	  To enable the use of this extension on CPUs that implement it, say Y.
1916
1917	  Note that for architectural reasons, firmware _must_ implement AMU
1918	  support when running on CPUs that present the activity monitors
1919	  extension. The required support is present in:
1920	    * Version 1.5 and later of the ARM Trusted Firmware
1921
1922	  For kernels that have this configuration enabled but boot with broken
1923	  firmware, you may need to say N here until the firmware is fixed.
1924	  Otherwise you may experience firmware panics or lockups when
1925	  accessing the counter registers. Even if you are not observing these
1926	  symptoms, the values returned by the register reads might not
1927	  correctly reflect reality. Most commonly, the value read will be 0,
1928	  indicating that the counter is not enabled.
1929
1930config AS_HAS_ARMV8_4
1931	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1932
1933config ARM64_TLB_RANGE
1934	bool "Enable support for tlbi range feature"
1935	default y
1936	depends on AS_HAS_ARMV8_4
1937	help
1938	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1939	  range of input addresses.
1940
1941	  The feature introduces new assembly instructions, and they were
1942	  support when binutils >= 2.30.
1943
1944endmenu # "ARMv8.4 architectural features"
1945
1946menu "ARMv8.5 architectural features"
1947
1948config AS_HAS_ARMV8_5
1949	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1950
1951config ARM64_BTI
1952	bool "Branch Target Identification support"
1953	default y
1954	help
1955	  Branch Target Identification (part of the ARMv8.5 Extensions)
1956	  provides a mechanism to limit the set of locations to which computed
1957	  branch instructions such as BR or BLR can jump.
1958
1959	  To make use of BTI on CPUs that support it, say Y.
1960
1961	  BTI is intended to provide complementary protection to other control
1962	  flow integrity protection mechanisms, such as the Pointer
1963	  authentication mechanism provided as part of the ARMv8.3 Extensions.
1964	  For this reason, it does not make sense to enable this option without
1965	  also enabling support for pointer authentication.  Thus, when
1966	  enabling this option you should also select ARM64_PTR_AUTH=y.
1967
1968	  Userspace binaries must also be specifically compiled to make use of
1969	  this mechanism.  If you say N here or the hardware does not support
1970	  BTI, such binaries can still run, but you get no additional
1971	  enforcement of branch destinations.
1972
1973config ARM64_BTI_KERNEL
1974	bool "Use Branch Target Identification for kernel"
1975	default y
1976	depends on ARM64_BTI
1977	depends on ARM64_PTR_AUTH_KERNEL
1978	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1979	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1980	depends on !CC_IS_GCC || GCC_VERSION >= 100100
1981	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
1982	depends on !CC_IS_GCC
1983	# https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
1984	depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
1985	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1986	help
1987	  Build the kernel with Branch Target Identification annotations
1988	  and enable enforcement of this for kernel code. When this option
1989	  is enabled and the system supports BTI all kernel code including
1990	  modular code must have BTI enabled.
1991
1992config CC_HAS_BRANCH_PROT_PAC_RET_BTI
1993	# GCC 9 or later, clang 8 or later
1994	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
1995
1996config ARM64_E0PD
1997	bool "Enable support for E0PD"
1998	default y
1999	help
2000	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2001	  that EL0 accesses made via TTBR1 always fault in constant time,
2002	  providing similar benefits to KASLR as those provided by KPTI, but
2003	  with lower overhead and without disrupting legitimate access to
2004	  kernel memory such as SPE.
2005
2006	  This option enables E0PD for TTBR1 where available.
2007
2008config ARM64_AS_HAS_MTE
2009	# Initial support for MTE went in binutils 2.32.0, checked with
2010	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2011	# as a late addition to the final architecture spec (LDGM/STGM)
2012	# is only supported in the newer 2.32.x and 2.33 binutils
2013	# versions, hence the extra "stgm" instruction check below.
2014	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2015
2016config ARM64_MTE
2017	bool "Memory Tagging Extension support"
2018	default y
2019	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2020	depends on AS_HAS_ARMV8_5
2021	depends on AS_HAS_LSE_ATOMICS
2022	# Required for tag checking in the uaccess routines
2023	depends on ARM64_PAN
2024	select ARCH_HAS_SUBPAGE_FAULTS
2025	select ARCH_USES_HIGH_VMA_FLAGS
2026	select ARCH_USES_PG_ARCH_X
2027	help
2028	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2029	  architectural support for run-time, always-on detection of
2030	  various classes of memory error to aid with software debugging
2031	  to eliminate vulnerabilities arising from memory-unsafe
2032	  languages.
2033
2034	  This option enables the support for the Memory Tagging
2035	  Extension at EL0 (i.e. for userspace).
2036
2037	  Selecting this option allows the feature to be detected at
2038	  runtime. Any secondary CPU not implementing this feature will
2039	  not be allowed a late bring-up.
2040
2041	  Userspace binaries that want to use this feature must
2042	  explicitly opt in. The mechanism for the userspace is
2043	  described in:
2044
2045	  Documentation/arch/arm64/memory-tagging-extension.rst.
2046
2047endmenu # "ARMv8.5 architectural features"
2048
2049menu "ARMv8.7 architectural features"
2050
2051config ARM64_EPAN
2052	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2053	default y
2054	depends on ARM64_PAN
2055	help
2056	  Enhanced Privileged Access Never (EPAN) allows Privileged
2057	  Access Never to be used with Execute-only mappings.
2058
2059	  The feature is detected at runtime, and will remain disabled
2060	  if the cpu does not implement the feature.
2061endmenu # "ARMv8.7 architectural features"
2062
2063config ARM64_SVE
2064	bool "ARM Scalable Vector Extension support"
2065	default y
2066	help
2067	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2068	  execution state which complements and extends the SIMD functionality
2069	  of the base architecture to support much larger vectors and to enable
2070	  additional vectorisation opportunities.
2071
2072	  To enable use of this extension on CPUs that implement it, say Y.
2073
2074	  On CPUs that support the SVE2 extensions, this option will enable
2075	  those too.
2076
2077	  Note that for architectural reasons, firmware _must_ implement SVE
2078	  support when running on SVE capable hardware.  The required support
2079	  is present in:
2080
2081	    * version 1.5 and later of the ARM Trusted Firmware
2082	    * the AArch64 boot wrapper since commit 5e1261e08abf
2083	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2084
2085	  For other firmware implementations, consult the firmware documentation
2086	  or vendor.
2087
2088	  If you need the kernel to boot on SVE-capable hardware with broken
2089	  firmware, you may need to say N here until you get your firmware
2090	  fixed.  Otherwise, you may experience firmware panics or lockups when
2091	  booting the kernel.  If unsure and you are not observing these
2092	  symptoms, you should assume that it is safe to say Y.
2093
2094config ARM64_SME
2095	bool "ARM Scalable Matrix Extension support"
2096	default y
2097	depends on ARM64_SVE
2098	help
2099	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2100	  execution state which utilises a substantial subset of the SVE
2101	  instruction set, together with the addition of new architectural
2102	  register state capable of holding two dimensional matrix tiles to
2103	  enable various matrix operations.
2104
2105config ARM64_PSEUDO_NMI
2106	bool "Support for NMI-like interrupts"
2107	select ARM_GIC_V3
2108	help
2109	  Adds support for mimicking Non-Maskable Interrupts through the use of
2110	  GIC interrupt priority. This support requires version 3 or later of
2111	  ARM GIC.
2112
2113	  This high priority configuration for interrupts needs to be
2114	  explicitly enabled by setting the kernel parameter
2115	  "irqchip.gicv3_pseudo_nmi" to 1.
2116
2117	  If unsure, say N
2118
2119if ARM64_PSEUDO_NMI
2120config ARM64_DEBUG_PRIORITY_MASKING
2121	bool "Debug interrupt priority masking"
2122	help
2123	  This adds runtime checks to functions enabling/disabling
2124	  interrupts when using priority masking. The additional checks verify
2125	  the validity of ICC_PMR_EL1 when calling concerned functions.
2126
2127	  If unsure, say N
2128endif # ARM64_PSEUDO_NMI
2129
2130config RELOCATABLE
2131	bool "Build a relocatable kernel image" if EXPERT
2132	select ARCH_HAS_RELR
2133	default y
2134	help
2135	  This builds the kernel as a Position Independent Executable (PIE),
2136	  which retains all relocation metadata required to relocate the
2137	  kernel binary at runtime to a different virtual address than the
2138	  address it was linked at.
2139	  Since AArch64 uses the RELA relocation format, this requires a
2140	  relocation pass at runtime even if the kernel is loaded at the
2141	  same address it was linked at.
2142
2143config RANDOMIZE_BASE
2144	bool "Randomize the address of the kernel image"
2145	select RELOCATABLE
2146	help
2147	  Randomizes the virtual address at which the kernel image is
2148	  loaded, as a security feature that deters exploit attempts
2149	  relying on knowledge of the location of kernel internals.
2150
2151	  It is the bootloader's job to provide entropy, by passing a
2152	  random u64 value in /chosen/kaslr-seed at kernel entry.
2153
2154	  When booting via the UEFI stub, it will invoke the firmware's
2155	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2156	  to the kernel proper. In addition, it will randomise the physical
2157	  location of the kernel Image as well.
2158
2159	  If unsure, say N.
2160
2161config RANDOMIZE_MODULE_REGION_FULL
2162	bool "Randomize the module region over a 2 GB range"
2163	depends on RANDOMIZE_BASE
2164	default y
2165	help
2166	  Randomizes the location of the module region inside a 2 GB window
2167	  covering the core kernel. This way, it is less likely for modules
2168	  to leak information about the location of core kernel data structures
2169	  but it does imply that function calls between modules and the core
2170	  kernel will need to be resolved via veneers in the module PLT.
2171
2172	  When this option is not set, the module region will be randomized over
2173	  a limited range that contains the [_stext, _etext] interval of the
2174	  core kernel, so branch relocations are almost always in range unless
2175	  the region is exhausted. In this particular case of region
2176	  exhaustion, modules might be able to fall back to a larger 2GB area.
2177
2178config CC_HAVE_STACKPROTECTOR_SYSREG
2179	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2180
2181config STACKPROTECTOR_PER_TASK
2182	def_bool y
2183	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2184
2185config UNWIND_PATCH_PAC_INTO_SCS
2186	bool "Enable shadow call stack dynamically using code patching"
2187	# needs Clang with https://reviews.llvm.org/D111780 incorporated
2188	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2189	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2190	depends on SHADOW_CALL_STACK
2191	select UNWIND_TABLES
2192	select DYNAMIC_SCS
2193
2194endmenu # "Kernel Features"
2195
2196menu "Boot options"
2197
2198config ARM64_ACPI_PARKING_PROTOCOL
2199	bool "Enable support for the ARM64 ACPI parking protocol"
2200	depends on ACPI
2201	help
2202	  Enable support for the ARM64 ACPI parking protocol. If disabled
2203	  the kernel will not allow booting through the ARM64 ACPI parking
2204	  protocol even if the corresponding data is present in the ACPI
2205	  MADT table.
2206
2207config CMDLINE
2208	string "Default kernel command string"
2209	default ""
2210	help
2211	  Provide a set of default command-line options at build time by
2212	  entering them here. As a minimum, you should specify the the
2213	  root device (e.g. root=/dev/nfs).
2214
2215choice
2216	prompt "Kernel command line type" if CMDLINE != ""
2217	default CMDLINE_FROM_BOOTLOADER
2218	help
2219	  Choose how the kernel will handle the provided default kernel
2220	  command line string.
2221
2222config CMDLINE_FROM_BOOTLOADER
2223	bool "Use bootloader kernel arguments if available"
2224	help
2225	  Uses the command-line options passed by the boot loader. If
2226	  the boot loader doesn't provide any, the default kernel command
2227	  string provided in CMDLINE will be used.
2228
2229config CMDLINE_FORCE
2230	bool "Always use the default kernel command string"
2231	help
2232	  Always use the default kernel command string, even if the boot
2233	  loader passes other arguments to the kernel.
2234	  This is useful if you cannot or don't want to change the
2235	  command-line options your boot loader passes to the kernel.
2236
2237endchoice
2238
2239config EFI_STUB
2240	bool
2241
2242config EFI
2243	bool "UEFI runtime support"
2244	depends on OF && !CPU_BIG_ENDIAN
2245	depends on KERNEL_MODE_NEON
2246	select ARCH_SUPPORTS_ACPI
2247	select LIBFDT
2248	select UCS2_STRING
2249	select EFI_PARAMS_FROM_FDT
2250	select EFI_RUNTIME_WRAPPERS
2251	select EFI_STUB
2252	select EFI_GENERIC_STUB
2253	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2254	default y
2255	help
2256	  This option provides support for runtime services provided
2257	  by UEFI firmware (such as non-volatile variables, realtime
2258	  clock, and platform reset). A UEFI stub is also provided to
2259	  allow the kernel to be booted as an EFI application. This
2260	  is only useful on systems that have UEFI firmware.
2261
2262config DMI
2263	bool "Enable support for SMBIOS (DMI) tables"
2264	depends on EFI
2265	default y
2266	help
2267	  This enables SMBIOS/DMI feature for systems.
2268
2269	  This option is only useful on systems that have UEFI firmware.
2270	  However, even with this option, the resultant kernel should
2271	  continue to boot on existing non-UEFI platforms.
2272
2273endmenu # "Boot options"
2274
2275menu "Power management options"
2276
2277source "kernel/power/Kconfig"
2278
2279config ARCH_HIBERNATION_POSSIBLE
2280	def_bool y
2281	depends on CPU_PM
2282
2283config ARCH_HIBERNATION_HEADER
2284	def_bool y
2285	depends on HIBERNATION
2286
2287config ARCH_SUSPEND_POSSIBLE
2288	def_bool y
2289
2290endmenu # "Power management options"
2291
2292menu "CPU Power Management"
2293
2294source "drivers/cpuidle/Kconfig"
2295
2296source "drivers/cpufreq/Kconfig"
2297
2298endmenu # "CPU Power Management"
2299
2300source "drivers/acpi/Kconfig"
2301
2302source "arch/arm64/kvm/Kconfig"
2303
2304