xref: /openbmc/linux/arch/arm64/Kconfig (revision bbaf1ff0)
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_USE_CMPXCHG_LOCKREF
82	select ARCH_USE_GNU_PROPERTY
83	select ARCH_USE_MEMTEST
84	select ARCH_USE_QUEUED_RWLOCKS
85	select ARCH_USE_QUEUED_SPINLOCKS
86	select ARCH_USE_SYM_ANNOTATIONS
87	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
88	select ARCH_SUPPORTS_HUGETLBFS
89	select ARCH_SUPPORTS_MEMORY_FAILURE
90	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
91	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
92	select ARCH_SUPPORTS_LTO_CLANG_THIN
93	select ARCH_SUPPORTS_CFI_CLANG
94	select ARCH_SUPPORTS_ATOMIC_RMW
95	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
96	select ARCH_SUPPORTS_NUMA_BALANCING
97	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
98	select ARCH_SUPPORTS_PER_VMA_LOCK
99	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
100	select ARCH_WANT_DEFAULT_BPF_JIT
101	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
102	select ARCH_WANT_FRAME_POINTERS
103	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
104	select ARCH_WANT_LD_ORPHAN_WARN
105	select ARCH_WANTS_NO_INSTR
106	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
107	select ARCH_HAS_UBSAN_SANITIZE_ALL
108	select ARM_AMBA
109	select ARM_ARCH_TIMER
110	select ARM_GIC
111	select AUDIT_ARCH_COMPAT_GENERIC
112	select ARM_GIC_V2M if PCI
113	select ARM_GIC_V3
114	select ARM_GIC_V3_ITS if PCI
115	select ARM_PSCI_FW
116	select BUILDTIME_TABLE_SORT
117	select CLONE_BACKWARDS
118	select COMMON_CLK
119	select CPU_PM if (SUSPEND || CPU_IDLE)
120	select CRC32
121	select DCACHE_WORD_ACCESS
122	select DYNAMIC_FTRACE if FUNCTION_TRACER
123	select DMA_BOUNCE_UNALIGNED_KMALLOC
124	select DMA_DIRECT_REMAP
125	select EDAC_SUPPORT
126	select FRAME_POINTER
127	select FUNCTION_ALIGNMENT_4B
128	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
129	select GENERIC_ALLOCATOR
130	select GENERIC_ARCH_TOPOLOGY
131	select GENERIC_CLOCKEVENTS_BROADCAST
132	select GENERIC_CPU_AUTOPROBE
133	select GENERIC_CPU_VULNERABILITIES
134	select GENERIC_EARLY_IOREMAP
135	select GENERIC_IDLE_POLL_SETUP
136	select GENERIC_IOREMAP
137	select GENERIC_IRQ_IPI
138	select GENERIC_IRQ_PROBE
139	select GENERIC_IRQ_SHOW
140	select GENERIC_IRQ_SHOW_LEVEL
141	select GENERIC_LIB_DEVMEM_IS_ALLOWED
142	select GENERIC_PCI_IOMAP
143	select GENERIC_PTDUMP
144	select GENERIC_SCHED_CLOCK
145	select GENERIC_SMP_IDLE_THREAD
146	select GENERIC_TIME_VSYSCALL
147	select GENERIC_GETTIMEOFDAY
148	select GENERIC_VDSO_TIME_NS
149	select HARDIRQS_SW_RESEND
150	select HAS_IOPORT
151	select HAVE_MOVE_PMD
152	select HAVE_MOVE_PUD
153	select HAVE_PCI
154	select HAVE_ACPI_APEI if (ACPI && EFI)
155	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
156	select HAVE_ARCH_AUDITSYSCALL
157	select HAVE_ARCH_BITREVERSE
158	select HAVE_ARCH_COMPILER_H
159	select HAVE_ARCH_HUGE_VMALLOC
160	select HAVE_ARCH_HUGE_VMAP
161	select HAVE_ARCH_JUMP_LABEL
162	select HAVE_ARCH_JUMP_LABEL_RELATIVE
163	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
164	select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
165	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
166	select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
167	# Some instrumentation may be unsound, hence EXPERT
168	select HAVE_ARCH_KCSAN if EXPERT
169	select HAVE_ARCH_KFENCE
170	select HAVE_ARCH_KGDB
171	select HAVE_ARCH_MMAP_RND_BITS
172	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
173	select HAVE_ARCH_PREL32_RELOCATIONS
174	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
175	select HAVE_ARCH_SECCOMP_FILTER
176	select HAVE_ARCH_STACKLEAK
177	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
178	select HAVE_ARCH_TRACEHOOK
179	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
180	select HAVE_ARCH_VMAP_STACK
181	select HAVE_ARM_SMCCC
182	select HAVE_ASM_MODVERSIONS
183	select HAVE_EBPF_JIT
184	select HAVE_C_RECORDMCOUNT
185	select HAVE_CMPXCHG_DOUBLE
186	select HAVE_CMPXCHG_LOCAL
187	select HAVE_CONTEXT_TRACKING_USER
188	select HAVE_DEBUG_KMEMLEAK
189	select HAVE_DMA_CONTIGUOUS
190	select HAVE_DYNAMIC_FTRACE
191	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
192		if $(cc-option,-fpatchable-function-entry=2)
193	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
194		if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
195	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
196		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
197		    !CC_OPTIMIZE_FOR_SIZE)
198	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
199		if DYNAMIC_FTRACE_WITH_ARGS
200	select HAVE_EFFICIENT_UNALIGNED_ACCESS
201	select HAVE_FAST_GUP
202	select HAVE_FTRACE_MCOUNT_RECORD
203	select HAVE_FUNCTION_TRACER
204	select HAVE_FUNCTION_ERROR_INJECTION
205	select HAVE_FUNCTION_GRAPH_TRACER
206	select HAVE_GCC_PLUGINS
207	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
208		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
209	select HAVE_HW_BREAKPOINT if PERF_EVENTS
210	select HAVE_IOREMAP_PROT
211	select HAVE_IRQ_TIME_ACCOUNTING
212	select HAVE_KVM
213	select HAVE_MOD_ARCH_SPECIFIC
214	select HAVE_NMI
215	select HAVE_PERF_EVENTS
216	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
217	select HAVE_PERF_REGS
218	select HAVE_PERF_USER_STACK_DUMP
219	select HAVE_PREEMPT_DYNAMIC_KEY
220	select HAVE_REGS_AND_STACK_ACCESS_API
221	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
222	select HAVE_FUNCTION_ARG_ACCESS_API
223	select MMU_GATHER_RCU_TABLE_FREE
224	select HAVE_RSEQ
225	select HAVE_STACKPROTECTOR
226	select HAVE_SYSCALL_TRACEPOINTS
227	select HAVE_KPROBES
228	select HAVE_KRETPROBES
229	select HAVE_GENERIC_VDSO
230	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
231	select IRQ_DOMAIN
232	select IRQ_FORCED_THREADING
233	select KASAN_VMALLOC if KASAN
234	select MODULES_USE_ELF_RELA
235	select NEED_DMA_MAP_STATE
236	select NEED_SG_DMA_LENGTH
237	select OF
238	select OF_EARLY_FLATTREE
239	select PCI_DOMAINS_GENERIC if PCI
240	select PCI_ECAM if (ACPI && PCI)
241	select PCI_SYSCALL if PCI
242	select POWER_RESET
243	select POWER_SUPPLY
244	select SPARSE_IRQ
245	select SWIOTLB
246	select SYSCTL_EXCEPTION_TRACE
247	select THREAD_INFO_IN_TASK
248	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
249	select TRACE_IRQFLAGS_SUPPORT
250	select TRACE_IRQFLAGS_NMI_SUPPORT
251	select HAVE_SOFTIRQ_ON_OWN_STACK
252	help
253	  ARM 64-bit (AArch64) Linux support.
254
255config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
256	def_bool CC_IS_CLANG
257	# https://github.com/ClangBuiltLinux/linux/issues/1507
258	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
259	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
260
261config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
262	def_bool CC_IS_GCC
263	depends on $(cc-option,-fpatchable-function-entry=2)
264	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
265
266config 64BIT
267	def_bool y
268
269config MMU
270	def_bool y
271
272config ARM64_PAGE_SHIFT
273	int
274	default 16 if ARM64_64K_PAGES
275	default 14 if ARM64_16K_PAGES
276	default 12
277
278config ARM64_CONT_PTE_SHIFT
279	int
280	default 5 if ARM64_64K_PAGES
281	default 7 if ARM64_16K_PAGES
282	default 4
283
284config ARM64_CONT_PMD_SHIFT
285	int
286	default 5 if ARM64_64K_PAGES
287	default 5 if ARM64_16K_PAGES
288	default 4
289
290config ARCH_MMAP_RND_BITS_MIN
291	default 14 if ARM64_64K_PAGES
292	default 16 if ARM64_16K_PAGES
293	default 18
294
295# max bits determined by the following formula:
296#  VA_BITS - PAGE_SHIFT - 3
297config ARCH_MMAP_RND_BITS_MAX
298	default 19 if ARM64_VA_BITS=36
299	default 24 if ARM64_VA_BITS=39
300	default 27 if ARM64_VA_BITS=42
301	default 30 if ARM64_VA_BITS=47
302	default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
303	default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
304	default 33 if ARM64_VA_BITS=48
305	default 14 if ARM64_64K_PAGES
306	default 16 if ARM64_16K_PAGES
307	default 18
308
309config ARCH_MMAP_RND_COMPAT_BITS_MIN
310	default 7 if ARM64_64K_PAGES
311	default 9 if ARM64_16K_PAGES
312	default 11
313
314config ARCH_MMAP_RND_COMPAT_BITS_MAX
315	default 16
316
317config NO_IOPORT_MAP
318	def_bool y if !PCI
319
320config STACKTRACE_SUPPORT
321	def_bool y
322
323config ILLEGAL_POINTER_VALUE
324	hex
325	default 0xdead000000000000
326
327config LOCKDEP_SUPPORT
328	def_bool y
329
330config GENERIC_BUG
331	def_bool y
332	depends on BUG
333
334config GENERIC_BUG_RELATIVE_POINTERS
335	def_bool y
336	depends on GENERIC_BUG
337
338config GENERIC_HWEIGHT
339	def_bool y
340
341config GENERIC_CSUM
342	def_bool y
343
344config GENERIC_CALIBRATE_DELAY
345	def_bool y
346
347config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
348	def_bool y
349
350config SMP
351	def_bool y
352
353config KERNEL_MODE_NEON
354	def_bool y
355
356config FIX_EARLYCON_MEM
357	def_bool y
358
359config PGTABLE_LEVELS
360	int
361	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
362	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
363	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
364	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
365	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
366	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
367
368config ARCH_SUPPORTS_UPROBES
369	def_bool y
370
371config ARCH_PROC_KCORE_TEXT
372	def_bool y
373
374config BROKEN_GAS_INST
375	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
376
377config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
378	bool
379	# Clang's __builtin_return_adddress() strips the PAC since 12.0.0
380	# https://reviews.llvm.org/D75044
381	default y if CC_IS_CLANG && (CLANG_VERSION >= 120000)
382	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
383	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
384	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
385	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
386	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
387	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
388	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
389	default n
390
391config KASAN_SHADOW_OFFSET
392	hex
393	depends on KASAN_GENERIC || KASAN_SW_TAGS
394	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
395	default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
396	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
397	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
398	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
399	default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
400	default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
401	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
402	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
403	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
404	default 0xffffffffffffffff
405
406config UNWIND_TABLES
407	bool
408
409source "arch/arm64/Kconfig.platforms"
410
411menu "Kernel Features"
412
413menu "ARM errata workarounds via the alternatives framework"
414
415config ARM64_WORKAROUND_CLEAN_CACHE
416	bool
417
418config ARM64_ERRATUM_826319
419	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
420	default y
421	select ARM64_WORKAROUND_CLEAN_CACHE
422	help
423	  This option adds an alternative code sequence to work around ARM
424	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
425	  AXI master interface and an L2 cache.
426
427	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
428	  and is unable to accept a certain write via this interface, it will
429	  not progress on read data presented on the read data channel and the
430	  system can deadlock.
431
432	  The workaround promotes data cache clean instructions to
433	  data cache clean-and-invalidate.
434	  Please note that this does not necessarily enable the workaround,
435	  as it depends on the alternative framework, which will only patch
436	  the kernel if an affected CPU is detected.
437
438	  If unsure, say Y.
439
440config ARM64_ERRATUM_827319
441	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
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 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
447	  master interface and an L2 cache.
448
449	  Under certain conditions this erratum can cause a clean line eviction
450	  to occur at the same time as another transaction to the same address
451	  on the AMBA 5 CHI interface, which can cause data corruption if the
452	  interconnect reorders the two transactions.
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_824069
463	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
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 824069 on Cortex-A53 parts up to r0p2 when it is connected
469	  to a coherent interconnect.
470
471	  If a Cortex-A53 processor is executing a store or prefetch for
472	  write instruction at the same time as a processor in another
473	  cluster is executing a cache maintenance operation to the same
474	  address, then this erratum might cause a clean cache line to be
475	  incorrectly marked as dirty.
476
477	  The workaround promotes data cache clean instructions to
478	  data cache clean-and-invalidate.
479	  Please note that this option does not necessarily enable the
480	  workaround, as it depends on the alternative framework, which will
481	  only patch the kernel if an affected CPU is detected.
482
483	  If unsure, say Y.
484
485config ARM64_ERRATUM_819472
486	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
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 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
492	  present when it is connected to a coherent interconnect.
493
494	  If the processor is executing a load and store exclusive sequence at
495	  the same time as a processor in another cluster is executing a cache
496	  maintenance operation to the same address, then this erratum might
497	  cause data corruption.
498
499	  The workaround promotes data cache clean instructions to
500	  data cache clean-and-invalidate.
501	  Please note that this does not necessarily enable the workaround,
502	  as it depends on the alternative framework, which will only patch
503	  the kernel if an affected CPU is detected.
504
505	  If unsure, say Y.
506
507config ARM64_ERRATUM_832075
508	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
509	default y
510	help
511	  This option adds an alternative code sequence to work around ARM
512	  erratum 832075 on Cortex-A57 parts up to r1p2.
513
514	  Affected Cortex-A57 parts might deadlock when exclusive load/store
515	  instructions to Write-Back memory are mixed with Device loads.
516
517	  The workaround is to promote device loads to use Load-Acquire
518	  semantics.
519	  Please note that this does not necessarily enable the workaround,
520	  as it depends on the alternative framework, which will only patch
521	  the kernel if an affected CPU is detected.
522
523	  If unsure, say Y.
524
525config ARM64_ERRATUM_834220
526	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
527	depends on KVM
528	default y
529	help
530	  This option adds an alternative code sequence to work around ARM
531	  erratum 834220 on Cortex-A57 parts up to r1p2.
532
533	  Affected Cortex-A57 parts might report a Stage 2 translation
534	  fault as the result of a Stage 1 fault for load crossing a
535	  page boundary when there is a permission or device memory
536	  alignment fault at Stage 1 and a translation fault at Stage 2.
537
538	  The workaround is to verify that the Stage 1 translation
539	  doesn't generate a fault before handling the Stage 2 fault.
540	  Please note that this does not necessarily enable the workaround,
541	  as it depends on the alternative framework, which will only patch
542	  the kernel if an affected CPU is detected.
543
544	  If unsure, say Y.
545
546config ARM64_ERRATUM_1742098
547	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
548	depends on COMPAT
549	default y
550	help
551	  This option removes the AES hwcap for aarch32 user-space to
552	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
553
554	  Affected parts may corrupt the AES state if an interrupt is
555	  taken between a pair of AES instructions. These instructions
556	  are only present if the cryptography extensions are present.
557	  All software should have a fallback implementation for CPUs
558	  that don't implement the cryptography extensions.
559
560	  If unsure, say Y.
561
562config ARM64_ERRATUM_845719
563	bool "Cortex-A53: 845719: a load might read incorrect data"
564	depends on COMPAT
565	default y
566	help
567	  This option adds an alternative code sequence to work around ARM
568	  erratum 845719 on Cortex-A53 parts up to r0p4.
569
570	  When running a compat (AArch32) userspace on an affected Cortex-A53
571	  part, a load at EL0 from a virtual address that matches the bottom 32
572	  bits of the virtual address used by a recent load at (AArch64) EL1
573	  might return incorrect data.
574
575	  The workaround is to write the contextidr_el1 register on exception
576	  return to a 32-bit task.
577	  Please note that this does not necessarily enable the workaround,
578	  as it depends on the alternative framework, which will only patch
579	  the kernel if an affected CPU is detected.
580
581	  If unsure, say Y.
582
583config ARM64_ERRATUM_843419
584	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
585	default y
586	help
587	  This option links the kernel with '--fix-cortex-a53-843419' and
588	  enables PLT support to replace certain ADRP instructions, which can
589	  cause subsequent memory accesses to use an incorrect address on
590	  Cortex-A53 parts up to r0p4.
591
592	  If unsure, say Y.
593
594config ARM64_LD_HAS_FIX_ERRATUM_843419
595	def_bool $(ld-option,--fix-cortex-a53-843419)
596
597config ARM64_ERRATUM_1024718
598	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
599	default y
600	help
601	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
602
603	  Affected Cortex-A55 cores (all revisions) could cause incorrect
604	  update of the hardware dirty bit when the DBM/AP bits are updated
605	  without a break-before-make. The workaround is to disable the usage
606	  of hardware DBM locally on the affected cores. CPUs not affected by
607	  this erratum will continue to use the feature.
608
609	  If unsure, say Y.
610
611config ARM64_ERRATUM_1418040
612	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
613	default y
614	depends on COMPAT
615	help
616	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
617	  errata 1188873 and 1418040.
618
619	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
620	  cause register corruption when accessing the timer registers
621	  from AArch32 userspace.
622
623	  If unsure, say Y.
624
625config ARM64_WORKAROUND_SPECULATIVE_AT
626	bool
627
628config ARM64_ERRATUM_1165522
629	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
630	default y
631	select ARM64_WORKAROUND_SPECULATIVE_AT
632	help
633	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
634
635	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
636	  corrupted TLBs by speculating an AT instruction during a guest
637	  context switch.
638
639	  If unsure, say Y.
640
641config ARM64_ERRATUM_1319367
642	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
643	default y
644	select ARM64_WORKAROUND_SPECULATIVE_AT
645	help
646	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
647	  and A72 erratum 1319367
648
649	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
650	  speculating an AT instruction during a guest context switch.
651
652	  If unsure, say Y.
653
654config ARM64_ERRATUM_1530923
655	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
656	default y
657	select ARM64_WORKAROUND_SPECULATIVE_AT
658	help
659	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
660
661	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
662	  corrupted TLBs by speculating an AT instruction during a guest
663	  context switch.
664
665	  If unsure, say Y.
666
667config ARM64_WORKAROUND_REPEAT_TLBI
668	bool
669
670config ARM64_ERRATUM_2441007
671	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
672	default y
673	select ARM64_WORKAROUND_REPEAT_TLBI
674	help
675	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
676
677	  Under very rare circumstances, affected Cortex-A55 CPUs
678	  may not handle a race between a break-before-make sequence on one
679	  CPU, and another CPU accessing the same page. This could allow a
680	  store to a page that has been unmapped.
681
682	  Work around this by adding the affected CPUs to the list that needs
683	  TLB sequences to be done twice.
684
685	  If unsure, say Y.
686
687config ARM64_ERRATUM_1286807
688	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
689	default y
690	select ARM64_WORKAROUND_REPEAT_TLBI
691	help
692	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
693
694	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
695	  address for a cacheable mapping of a location is being
696	  accessed by a core while another core is remapping the virtual
697	  address to a new physical page using the recommended
698	  break-before-make sequence, then under very rare circumstances
699	  TLBI+DSB completes before a read using the translation being
700	  invalidated has been observed by other observers. The
701	  workaround repeats the TLBI+DSB operation.
702
703config ARM64_ERRATUM_1463225
704	bool "Cortex-A76: Software Step might prevent interrupt recognition"
705	default y
706	help
707	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
708
709	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
710	  of a system call instruction (SVC) can prevent recognition of
711	  subsequent interrupts when software stepping is disabled in the
712	  exception handler of the system call and either kernel debugging
713	  is enabled or VHE is in use.
714
715	  Work around the erratum by triggering a dummy step exception
716	  when handling a system call from a task that is being stepped
717	  in a VHE configuration of the kernel.
718
719	  If unsure, say Y.
720
721config ARM64_ERRATUM_1542419
722	bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
723	default y
724	help
725	  This option adds a workaround for ARM Neoverse-N1 erratum
726	  1542419.
727
728	  Affected Neoverse-N1 cores could execute a stale instruction when
729	  modified by another CPU. The workaround depends on a firmware
730	  counterpart.
731
732	  Workaround the issue by hiding the DIC feature from EL0. This
733	  forces user-space to perform cache maintenance.
734
735	  If unsure, say Y.
736
737config ARM64_ERRATUM_1508412
738	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
739	default y
740	help
741	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
742
743	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
744	  of a store-exclusive or read of PAR_EL1 and a load with device or
745	  non-cacheable memory attributes. The workaround depends on a firmware
746	  counterpart.
747
748	  KVM guests must also have the workaround implemented or they can
749	  deadlock the system.
750
751	  Work around the issue by inserting DMB SY barriers around PAR_EL1
752	  register reads and warning KVM users. The DMB barrier is sufficient
753	  to prevent a speculative PAR_EL1 read.
754
755	  If unsure, say Y.
756
757config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
758	bool
759
760config ARM64_ERRATUM_2051678
761	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
762	default y
763	help
764	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
765	  Affected Cortex-A510 might not respect the ordering rules for
766	  hardware update of the page table's dirty bit. The workaround
767	  is to not enable the feature on affected CPUs.
768
769	  If unsure, say Y.
770
771config ARM64_ERRATUM_2077057
772	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
773	default y
774	help
775	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
776	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
777	  expected, but a Pointer Authentication trap is taken instead. The
778	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
779	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
780
781	  This can only happen when EL2 is stepping EL1.
782
783	  When these conditions occur, the SPSR_EL2 value is unchanged from the
784	  previous guest entry, and can be restored from the in-memory copy.
785
786	  If unsure, say Y.
787
788config ARM64_ERRATUM_2658417
789	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
790	default y
791	help
792	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
793	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
794	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
795	  A510 CPUs are using shared neon hardware. As the sharing is not
796	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
797	  user-space should not be using these instructions.
798
799	  If unsure, say Y.
800
801config ARM64_ERRATUM_2119858
802	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
803	default y
804	depends on CORESIGHT_TRBE
805	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
806	help
807	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
808
809	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
810	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
811	  the event of a WRAP event.
812
813	  Work around the issue by always making sure we move the TRBPTR_EL1 by
814	  256 bytes before enabling the buffer and filling the first 256 bytes of
815	  the buffer with ETM ignore packets upon disabling.
816
817	  If unsure, say Y.
818
819config ARM64_ERRATUM_2139208
820	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
821	default y
822	depends on CORESIGHT_TRBE
823	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
824	help
825	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
826
827	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
828	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
829	  the event of a WRAP event.
830
831	  Work around the issue by always making sure we move the TRBPTR_EL1 by
832	  256 bytes before enabling the buffer and filling the first 256 bytes of
833	  the buffer with ETM ignore packets upon disabling.
834
835	  If unsure, say Y.
836
837config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
838	bool
839
840config ARM64_ERRATUM_2054223
841	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
842	default y
843	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
844	help
845	  Enable workaround for ARM Cortex-A710 erratum 2054223
846
847	  Affected cores may fail to flush the trace data on a TSB instruction, when
848	  the PE is in trace prohibited state. This will cause losing a few bytes
849	  of the trace cached.
850
851	  Workaround is to issue two TSB consecutively on affected cores.
852
853	  If unsure, say Y.
854
855config ARM64_ERRATUM_2067961
856	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
857	default y
858	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
859	help
860	  Enable workaround for ARM Neoverse-N2 erratum 2067961
861
862	  Affected cores may fail to flush the trace data on a TSB instruction, when
863	  the PE is in trace prohibited state. This will cause losing a few bytes
864	  of the trace cached.
865
866	  Workaround is to issue two TSB consecutively on affected cores.
867
868	  If unsure, say Y.
869
870config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
871	bool
872
873config ARM64_ERRATUM_2253138
874	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
875	depends on CORESIGHT_TRBE
876	default y
877	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
878	help
879	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
880
881	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
882	  for TRBE. Under some conditions, the TRBE might generate a write to the next
883	  virtually addressed page following the last page of the TRBE address space
884	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
885
886	  Work around this in the driver by always making sure that there is a
887	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
888
889	  If unsure, say Y.
890
891config ARM64_ERRATUM_2224489
892	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
893	depends on CORESIGHT_TRBE
894	default y
895	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
896	help
897	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
898
899	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
900	  for TRBE. Under some conditions, the TRBE might generate a write to the next
901	  virtually addressed page following the last page of the TRBE address space
902	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
903
904	  Work around this in the driver by always making sure that there is a
905	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
906
907	  If unsure, say Y.
908
909config ARM64_ERRATUM_2441009
910	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
911	default y
912	select ARM64_WORKAROUND_REPEAT_TLBI
913	help
914	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
915
916	  Under very rare circumstances, affected Cortex-A510 CPUs
917	  may not handle a race between a break-before-make sequence on one
918	  CPU, and another CPU accessing the same page. This could allow a
919	  store to a page that has been unmapped.
920
921	  Work around this by adding the affected CPUs to the list that needs
922	  TLB sequences to be done twice.
923
924	  If unsure, say Y.
925
926config ARM64_ERRATUM_2064142
927	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
928	depends on CORESIGHT_TRBE
929	default y
930	help
931	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
932
933	  Affected Cortex-A510 core might fail to write into system registers after the
934	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
935	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
936	  and TRBTRG_EL1 will be ignored and will not be effected.
937
938	  Work around this in the driver by executing TSB CSYNC and DSB after collection
939	  is stopped and before performing a system register write to one of the affected
940	  registers.
941
942	  If unsure, say Y.
943
944config ARM64_ERRATUM_2038923
945	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
946	depends on CORESIGHT_TRBE
947	default y
948	help
949	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
950
951	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
952	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
953	  might be corrupted. This happens after TRBE buffer has been enabled by setting
954	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
955	  execution changes from a context, in which trace is prohibited to one where it
956	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
957	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
958	  the trace buffer state might be corrupted.
959
960	  Work around this in the driver by preventing an inconsistent view of whether the
961	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
962	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
963	  two ISB instructions if no ERET is to take place.
964
965	  If unsure, say Y.
966
967config ARM64_ERRATUM_1902691
968	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
969	depends on CORESIGHT_TRBE
970	default y
971	help
972	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
973
974	  Affected Cortex-A510 core might cause trace data corruption, when being written
975	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
976	  trace data.
977
978	  Work around this problem in the driver by just preventing TRBE initialization on
979	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
980	  on such implementations. This will cover the kernel for any firmware that doesn't
981	  do this already.
982
983	  If unsure, say Y.
984
985config ARM64_ERRATUM_2457168
986	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
987	depends on ARM64_AMU_EXTN
988	default y
989	help
990	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
991
992	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
993	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
994	  incorrectly giving a significantly higher output value.
995
996	  Work around this problem by returning 0 when reading the affected counter in
997	  key locations that results in disabling all users of this counter. This effect
998	  is the same to firmware disabling affected counters.
999
1000	  If unsure, say Y.
1001
1002config ARM64_ERRATUM_2645198
1003	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1004	default y
1005	help
1006	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1007
1008	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1009	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1010	  next instruction abort caused by permission fault.
1011
1012	  Only user-space does executable to non-executable permission transition via
1013	  mprotect() system call. Workaround the problem by doing a break-before-make
1014	  TLB invalidation, for all changes to executable user space mappings.
1015
1016	  If unsure, say Y.
1017
1018config CAVIUM_ERRATUM_22375
1019	bool "Cavium erratum 22375, 24313"
1020	default y
1021	help
1022	  Enable workaround for errata 22375 and 24313.
1023
1024	  This implements two gicv3-its errata workarounds for ThunderX. Both
1025	  with a small impact affecting only ITS table allocation.
1026
1027	    erratum 22375: only alloc 8MB table size
1028	    erratum 24313: ignore memory access type
1029
1030	  The fixes are in ITS initialization and basically ignore memory access
1031	  type and table size provided by the TYPER and BASER registers.
1032
1033	  If unsure, say Y.
1034
1035config CAVIUM_ERRATUM_23144
1036	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1037	depends on NUMA
1038	default y
1039	help
1040	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1041
1042	  If unsure, say Y.
1043
1044config CAVIUM_ERRATUM_23154
1045	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1046	default y
1047	help
1048	  The ThunderX GICv3 implementation requires a modified version for
1049	  reading the IAR status to ensure data synchronization
1050	  (access to icc_iar1_el1 is not sync'ed before and after).
1051
1052	  It also suffers from erratum 38545 (also present on Marvell's
1053	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1054	  spuriously presented to the CPU interface.
1055
1056	  If unsure, say Y.
1057
1058config CAVIUM_ERRATUM_27456
1059	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1060	default y
1061	help
1062	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1063	  instructions may cause the icache to become corrupted if it
1064	  contains data for a non-current ASID.  The fix is to
1065	  invalidate the icache when changing the mm context.
1066
1067	  If unsure, say Y.
1068
1069config CAVIUM_ERRATUM_30115
1070	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1071	default y
1072	help
1073	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1074	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1075	  interrupts in host. Trapping both GICv3 group-0 and group-1
1076	  accesses sidesteps the issue.
1077
1078	  If unsure, say Y.
1079
1080config CAVIUM_TX2_ERRATUM_219
1081	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1082	default y
1083	help
1084	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1085	  TTBR update and the corresponding context synchronizing operation can
1086	  cause a spurious Data Abort to be delivered to any hardware thread in
1087	  the CPU core.
1088
1089	  Work around the issue by avoiding the problematic code sequence and
1090	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1091	  trap handler performs the corresponding register access, skips the
1092	  instruction and ensures context synchronization by virtue of the
1093	  exception return.
1094
1095	  If unsure, say Y.
1096
1097config FUJITSU_ERRATUM_010001
1098	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1099	default y
1100	help
1101	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1102	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1103	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1104	  This fault occurs under a specific hardware condition when a
1105	  load/store instruction performs an address translation using:
1106	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1107	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1108	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1109	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1110
1111	  The workaround is to ensure these bits are clear in TCR_ELx.
1112	  The workaround only affects the Fujitsu-A64FX.
1113
1114	  If unsure, say Y.
1115
1116config HISILICON_ERRATUM_161600802
1117	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1118	default y
1119	help
1120	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1121	  when issued ITS commands such as VMOVP and VMAPP, and requires
1122	  a 128kB offset to be applied to the target address in this commands.
1123
1124	  If unsure, say Y.
1125
1126config QCOM_FALKOR_ERRATUM_1003
1127	bool "Falkor E1003: Incorrect translation due to ASID change"
1128	default y
1129	help
1130	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1131	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1132	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1133	  then only for entries in the walk cache, since the leaf translation
1134	  is unchanged. Work around the erratum by invalidating the walk cache
1135	  entries for the trampoline before entering the kernel proper.
1136
1137config QCOM_FALKOR_ERRATUM_1009
1138	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1139	default y
1140	select ARM64_WORKAROUND_REPEAT_TLBI
1141	help
1142	  On Falkor v1, the CPU may prematurely complete a DSB following a
1143	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1144	  one more time to fix the issue.
1145
1146	  If unsure, say Y.
1147
1148config QCOM_QDF2400_ERRATUM_0065
1149	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1150	default y
1151	help
1152	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1153	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1154	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1155
1156	  If unsure, say Y.
1157
1158config QCOM_FALKOR_ERRATUM_E1041
1159	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1160	default y
1161	help
1162	  Falkor CPU may speculatively fetch instructions from an improper
1163	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1164	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1165
1166	  If unsure, say Y.
1167
1168config NVIDIA_CARMEL_CNP_ERRATUM
1169	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1170	default y
1171	help
1172	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1173	  invalidate shared TLB entries installed by a different core, as it would
1174	  on standard ARM cores.
1175
1176	  If unsure, say Y.
1177
1178config ROCKCHIP_ERRATUM_3588001
1179	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1180	default y
1181	help
1182	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1183	  This means, that its sharability feature may not be used, even though it
1184	  is supported by the IP itself.
1185
1186	  If unsure, say Y.
1187
1188config SOCIONEXT_SYNQUACER_PREITS
1189	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1190	default y
1191	help
1192	  Socionext Synquacer SoCs implement a separate h/w block to generate
1193	  MSI doorbell writes with non-zero values for the device ID.
1194
1195	  If unsure, say Y.
1196
1197endmenu # "ARM errata workarounds via the alternatives framework"
1198
1199choice
1200	prompt "Page size"
1201	default ARM64_4K_PAGES
1202	help
1203	  Page size (translation granule) configuration.
1204
1205config ARM64_4K_PAGES
1206	bool "4KB"
1207	help
1208	  This feature enables 4KB pages support.
1209
1210config ARM64_16K_PAGES
1211	bool "16KB"
1212	help
1213	  The system will use 16KB pages support. AArch32 emulation
1214	  requires applications compiled with 16K (or a multiple of 16K)
1215	  aligned segments.
1216
1217config ARM64_64K_PAGES
1218	bool "64KB"
1219	help
1220	  This feature enables 64KB pages support (4KB by default)
1221	  allowing only two levels of page tables and faster TLB
1222	  look-up. AArch32 emulation requires applications compiled
1223	  with 64K aligned segments.
1224
1225endchoice
1226
1227choice
1228	prompt "Virtual address space size"
1229	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1230	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1231	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1232	help
1233	  Allows choosing one of multiple possible virtual address
1234	  space sizes. The level of translation table is determined by
1235	  a combination of page size and virtual address space size.
1236
1237config ARM64_VA_BITS_36
1238	bool "36-bit" if EXPERT
1239	depends on ARM64_16K_PAGES
1240
1241config ARM64_VA_BITS_39
1242	bool "39-bit"
1243	depends on ARM64_4K_PAGES
1244
1245config ARM64_VA_BITS_42
1246	bool "42-bit"
1247	depends on ARM64_64K_PAGES
1248
1249config ARM64_VA_BITS_47
1250	bool "47-bit"
1251	depends on ARM64_16K_PAGES
1252
1253config ARM64_VA_BITS_48
1254	bool "48-bit"
1255
1256config ARM64_VA_BITS_52
1257	bool "52-bit"
1258	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1259	help
1260	  Enable 52-bit virtual addressing for userspace when explicitly
1261	  requested via a hint to mmap(). The kernel will also use 52-bit
1262	  virtual addresses for its own mappings (provided HW support for
1263	  this feature is available, otherwise it reverts to 48-bit).
1264
1265	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1266	  ARMv8.3 Pointer Authentication will result in the PAC being
1267	  reduced from 7 bits to 3 bits, which may have a significant
1268	  impact on its susceptibility to brute-force attacks.
1269
1270	  If unsure, select 48-bit virtual addressing instead.
1271
1272endchoice
1273
1274config ARM64_FORCE_52BIT
1275	bool "Force 52-bit virtual addresses for userspace"
1276	depends on ARM64_VA_BITS_52 && EXPERT
1277	help
1278	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1279	  to maintain compatibility with older software by providing 48-bit VAs
1280	  unless a hint is supplied to mmap.
1281
1282	  This configuration option disables the 48-bit compatibility logic, and
1283	  forces all userspace addresses to be 52-bit on HW that supports it. One
1284	  should only enable this configuration option for stress testing userspace
1285	  memory management code. If unsure say N here.
1286
1287config ARM64_VA_BITS
1288	int
1289	default 36 if ARM64_VA_BITS_36
1290	default 39 if ARM64_VA_BITS_39
1291	default 42 if ARM64_VA_BITS_42
1292	default 47 if ARM64_VA_BITS_47
1293	default 48 if ARM64_VA_BITS_48
1294	default 52 if ARM64_VA_BITS_52
1295
1296choice
1297	prompt "Physical address space size"
1298	default ARM64_PA_BITS_48
1299	help
1300	  Choose the maximum physical address range that the kernel will
1301	  support.
1302
1303config ARM64_PA_BITS_48
1304	bool "48-bit"
1305
1306config ARM64_PA_BITS_52
1307	bool "52-bit (ARMv8.2)"
1308	depends on ARM64_64K_PAGES
1309	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1310	help
1311	  Enable support for a 52-bit physical address space, introduced as
1312	  part of the ARMv8.2-LPA extension.
1313
1314	  With this enabled, the kernel will also continue to work on CPUs that
1315	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1316	  minor performance overhead).
1317
1318endchoice
1319
1320config ARM64_PA_BITS
1321	int
1322	default 48 if ARM64_PA_BITS_48
1323	default 52 if ARM64_PA_BITS_52
1324
1325choice
1326	prompt "Endianness"
1327	default CPU_LITTLE_ENDIAN
1328	help
1329	  Select the endianness of data accesses performed by the CPU. Userspace
1330	  applications will need to be compiled and linked for the endianness
1331	  that is selected here.
1332
1333config CPU_BIG_ENDIAN
1334	bool "Build big-endian kernel"
1335	depends on !LD_IS_LLD || LLD_VERSION >= 130000
1336	help
1337	  Say Y if you plan on running a kernel with a big-endian userspace.
1338
1339config CPU_LITTLE_ENDIAN
1340	bool "Build little-endian kernel"
1341	help
1342	  Say Y if you plan on running a kernel with a little-endian userspace.
1343	  This is usually the case for distributions targeting arm64.
1344
1345endchoice
1346
1347config SCHED_MC
1348	bool "Multi-core scheduler support"
1349	help
1350	  Multi-core scheduler support improves the CPU scheduler's decision
1351	  making when dealing with multi-core CPU chips at a cost of slightly
1352	  increased overhead in some places. If unsure say N here.
1353
1354config SCHED_CLUSTER
1355	bool "Cluster scheduler support"
1356	help
1357	  Cluster scheduler support improves the CPU scheduler's decision
1358	  making when dealing with machines that have clusters of CPUs.
1359	  Cluster usually means a couple of CPUs which are placed closely
1360	  by sharing mid-level caches, last-level cache tags or internal
1361	  busses.
1362
1363config SCHED_SMT
1364	bool "SMT scheduler support"
1365	help
1366	  Improves the CPU scheduler's decision making when dealing with
1367	  MultiThreading at a cost of slightly increased overhead in some
1368	  places. If unsure say N here.
1369
1370config NR_CPUS
1371	int "Maximum number of CPUs (2-4096)"
1372	range 2 4096
1373	default "256"
1374
1375config HOTPLUG_CPU
1376	bool "Support for hot-pluggable CPUs"
1377	select GENERIC_IRQ_MIGRATION
1378	help
1379	  Say Y here to experiment with turning CPUs off and on.  CPUs
1380	  can be controlled through /sys/devices/system/cpu.
1381
1382# Common NUMA Features
1383config NUMA
1384	bool "NUMA Memory Allocation and Scheduler Support"
1385	select GENERIC_ARCH_NUMA
1386	select ACPI_NUMA if ACPI
1387	select OF_NUMA
1388	select HAVE_SETUP_PER_CPU_AREA
1389	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1390	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1391	select USE_PERCPU_NUMA_NODE_ID
1392	help
1393	  Enable NUMA (Non-Uniform Memory Access) support.
1394
1395	  The kernel will try to allocate memory used by a CPU on the
1396	  local memory of the CPU and add some more
1397	  NUMA awareness to the kernel.
1398
1399config NODES_SHIFT
1400	int "Maximum NUMA Nodes (as a power of 2)"
1401	range 1 10
1402	default "4"
1403	depends on NUMA
1404	help
1405	  Specify the maximum number of NUMA Nodes available on the target
1406	  system.  Increases memory reserved to accommodate various tables.
1407
1408source "kernel/Kconfig.hz"
1409
1410config ARCH_SPARSEMEM_ENABLE
1411	def_bool y
1412	select SPARSEMEM_VMEMMAP_ENABLE
1413	select SPARSEMEM_VMEMMAP
1414
1415config HW_PERF_EVENTS
1416	def_bool y
1417	depends on ARM_PMU
1418
1419# Supported by clang >= 7.0 or GCC >= 12.0.0
1420config CC_HAVE_SHADOW_CALL_STACK
1421	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1422
1423config PARAVIRT
1424	bool "Enable paravirtualization code"
1425	help
1426	  This changes the kernel so it can modify itself when it is run
1427	  under a hypervisor, potentially improving performance significantly
1428	  over full virtualization.
1429
1430config PARAVIRT_TIME_ACCOUNTING
1431	bool "Paravirtual steal time accounting"
1432	select PARAVIRT
1433	help
1434	  Select this option to enable fine granularity task steal time
1435	  accounting. Time spent executing other tasks in parallel with
1436	  the current vCPU is discounted from the vCPU power. To account for
1437	  that, there can be a small performance impact.
1438
1439	  If in doubt, say N here.
1440
1441config KEXEC
1442	depends on PM_SLEEP_SMP
1443	select KEXEC_CORE
1444	bool "kexec system call"
1445	help
1446	  kexec is a system call that implements the ability to shutdown your
1447	  current kernel, and to start another kernel.  It is like a reboot
1448	  but it is independent of the system firmware.   And like a reboot
1449	  you can start any kernel with it, not just Linux.
1450
1451config KEXEC_FILE
1452	bool "kexec file based system call"
1453	select KEXEC_CORE
1454	select HAVE_IMA_KEXEC if IMA
1455	help
1456	  This is new version of kexec system call. This system call is
1457	  file based and takes file descriptors as system call argument
1458	  for kernel and initramfs as opposed to list of segments as
1459	  accepted by previous system call.
1460
1461config KEXEC_SIG
1462	bool "Verify kernel signature during kexec_file_load() syscall"
1463	depends on KEXEC_FILE
1464	help
1465	  Select this option to verify a signature with loaded kernel
1466	  image. If configured, any attempt of loading a image without
1467	  valid signature will fail.
1468
1469	  In addition to that option, you need to enable signature
1470	  verification for the corresponding kernel image type being
1471	  loaded in order for this to work.
1472
1473config KEXEC_IMAGE_VERIFY_SIG
1474	bool "Enable Image signature verification support"
1475	default y
1476	depends on KEXEC_SIG
1477	depends on EFI && SIGNED_PE_FILE_VERIFICATION
1478	help
1479	  Enable Image signature verification support.
1480
1481comment "Support for PE file signature verification disabled"
1482	depends on KEXEC_SIG
1483	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
1484
1485config CRASH_DUMP
1486	bool "Build kdump crash kernel"
1487	help
1488	  Generate crash dump after being started by kexec. This should
1489	  be normally only set in special crash dump kernels which are
1490	  loaded in the main kernel with kexec-tools into a specially
1491	  reserved region and then later executed after a crash by
1492	  kdump/kexec.
1493
1494	  For more details see Documentation/admin-guide/kdump/kdump.rst
1495
1496config TRANS_TABLE
1497	def_bool y
1498	depends on HIBERNATION || KEXEC_CORE
1499
1500config XEN_DOM0
1501	def_bool y
1502	depends on XEN
1503
1504config XEN
1505	bool "Xen guest support on ARM64"
1506	depends on ARM64 && OF
1507	select SWIOTLB_XEN
1508	select PARAVIRT
1509	help
1510	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1511
1512# include/linux/mmzone.h requires the following to be true:
1513#
1514#   MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1515#
1516# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1517#
1518#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_ORDER  |  default MAX_ORDER |
1519# ----+-------------------+--------------+-----------------+--------------------+
1520# 4K  |       27          |      12      |       15        |         10         |
1521# 16K |       27          |      14      |       13        |         11         |
1522# 64K |       29          |      16      |       13        |         13         |
1523config ARCH_FORCE_MAX_ORDER
1524	int
1525	default "13" if ARM64_64K_PAGES
1526	default "11" if ARM64_16K_PAGES
1527	default "10"
1528	help
1529	  The kernel page allocator limits the size of maximal physically
1530	  contiguous allocations. The limit is called MAX_ORDER and it
1531	  defines the maximal power of two of number of pages that can be
1532	  allocated as a single contiguous block. This option allows
1533	  overriding the default setting when ability to allocate very
1534	  large blocks of physically contiguous memory is required.
1535
1536	  The maximal size of allocation cannot exceed the size of the
1537	  section, so the value of MAX_ORDER should satisfy
1538
1539	    MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1540
1541	  Don't change if unsure.
1542
1543config UNMAP_KERNEL_AT_EL0
1544	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1545	default y
1546	help
1547	  Speculation attacks against some high-performance processors can
1548	  be used to bypass MMU permission checks and leak kernel data to
1549	  userspace. This can be defended against by unmapping the kernel
1550	  when running in userspace, mapping it back in on exception entry
1551	  via a trampoline page in the vector table.
1552
1553	  If unsure, say Y.
1554
1555config MITIGATE_SPECTRE_BRANCH_HISTORY
1556	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1557	default y
1558	help
1559	  Speculation attacks against some high-performance processors can
1560	  make use of branch history to influence future speculation.
1561	  When taking an exception from user-space, a sequence of branches
1562	  or a firmware call overwrites the branch history.
1563
1564config RODATA_FULL_DEFAULT_ENABLED
1565	bool "Apply r/o permissions of VM areas also to their linear aliases"
1566	default y
1567	help
1568	  Apply read-only attributes of VM areas to the linear alias of
1569	  the backing pages as well. This prevents code or read-only data
1570	  from being modified (inadvertently or intentionally) via another
1571	  mapping of the same memory page. This additional enhancement can
1572	  be turned off at runtime by passing rodata=[off|on] (and turned on
1573	  with rodata=full if this option is set to 'n')
1574
1575	  This requires the linear region to be mapped down to pages,
1576	  which may adversely affect performance in some cases.
1577
1578config ARM64_SW_TTBR0_PAN
1579	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1580	help
1581	  Enabling this option prevents the kernel from accessing
1582	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1583	  zeroed area and reserved ASID. The user access routines
1584	  restore the valid TTBR0_EL1 temporarily.
1585
1586config ARM64_TAGGED_ADDR_ABI
1587	bool "Enable the tagged user addresses syscall ABI"
1588	default y
1589	help
1590	  When this option is enabled, user applications can opt in to a
1591	  relaxed ABI via prctl() allowing tagged addresses to be passed
1592	  to system calls as pointer arguments. For details, see
1593	  Documentation/arch/arm64/tagged-address-abi.rst.
1594
1595menuconfig COMPAT
1596	bool "Kernel support for 32-bit EL0"
1597	depends on ARM64_4K_PAGES || EXPERT
1598	select HAVE_UID16
1599	select OLD_SIGSUSPEND3
1600	select COMPAT_OLD_SIGACTION
1601	help
1602	  This option enables support for a 32-bit EL0 running under a 64-bit
1603	  kernel at EL1. AArch32-specific components such as system calls,
1604	  the user helper functions, VFP support and the ptrace interface are
1605	  handled appropriately by the kernel.
1606
1607	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1608	  that you will only be able to execute AArch32 binaries that were compiled
1609	  with page size aligned segments.
1610
1611	  If you want to execute 32-bit userspace applications, say Y.
1612
1613if COMPAT
1614
1615config KUSER_HELPERS
1616	bool "Enable kuser helpers page for 32-bit applications"
1617	default y
1618	help
1619	  Warning: disabling this option may break 32-bit user programs.
1620
1621	  Provide kuser helpers to compat tasks. The kernel provides
1622	  helper code to userspace in read only form at a fixed location
1623	  to allow userspace to be independent of the CPU type fitted to
1624	  the system. This permits binaries to be run on ARMv4 through
1625	  to ARMv8 without modification.
1626
1627	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1628
1629	  However, the fixed address nature of these helpers can be used
1630	  by ROP (return orientated programming) authors when creating
1631	  exploits.
1632
1633	  If all of the binaries and libraries which run on your platform
1634	  are built specifically for your platform, and make no use of
1635	  these helpers, then you can turn this option off to hinder
1636	  such exploits. However, in that case, if a binary or library
1637	  relying on those helpers is run, it will not function correctly.
1638
1639	  Say N here only if you are absolutely certain that you do not
1640	  need these helpers; otherwise, the safe option is to say Y.
1641
1642config COMPAT_VDSO
1643	bool "Enable vDSO for 32-bit applications"
1644	depends on !CPU_BIG_ENDIAN
1645	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1646	select GENERIC_COMPAT_VDSO
1647	default y
1648	help
1649	  Place in the process address space of 32-bit applications an
1650	  ELF shared object providing fast implementations of gettimeofday
1651	  and clock_gettime.
1652
1653	  You must have a 32-bit build of glibc 2.22 or later for programs
1654	  to seamlessly take advantage of this.
1655
1656config THUMB2_COMPAT_VDSO
1657	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1658	depends on COMPAT_VDSO
1659	default y
1660	help
1661	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1662	  otherwise with '-marm'.
1663
1664config COMPAT_ALIGNMENT_FIXUPS
1665	bool "Fix up misaligned multi-word loads and stores in user space"
1666
1667menuconfig ARMV8_DEPRECATED
1668	bool "Emulate deprecated/obsolete ARMv8 instructions"
1669	depends on SYSCTL
1670	help
1671	  Legacy software support may require certain instructions
1672	  that have been deprecated or obsoleted in the architecture.
1673
1674	  Enable this config to enable selective emulation of these
1675	  features.
1676
1677	  If unsure, say Y
1678
1679if ARMV8_DEPRECATED
1680
1681config SWP_EMULATION
1682	bool "Emulate SWP/SWPB instructions"
1683	help
1684	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1685	  they are always undefined. Say Y here to enable software
1686	  emulation of these instructions for userspace using LDXR/STXR.
1687	  This feature can be controlled at runtime with the abi.swp
1688	  sysctl which is disabled by default.
1689
1690	  In some older versions of glibc [<=2.8] SWP is used during futex
1691	  trylock() operations with the assumption that the code will not
1692	  be preempted. This invalid assumption may be more likely to fail
1693	  with SWP emulation enabled, leading to deadlock of the user
1694	  application.
1695
1696	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1697	  on an external transaction monitoring block called a global
1698	  monitor to maintain update atomicity. If your system does not
1699	  implement a global monitor, this option can cause programs that
1700	  perform SWP operations to uncached memory to deadlock.
1701
1702	  If unsure, say Y
1703
1704config CP15_BARRIER_EMULATION
1705	bool "Emulate CP15 Barrier instructions"
1706	help
1707	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1708	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1709	  strongly recommended to use the ISB, DSB, and DMB
1710	  instructions instead.
1711
1712	  Say Y here to enable software emulation of these
1713	  instructions for AArch32 userspace code. When this option is
1714	  enabled, CP15 barrier usage is traced which can help
1715	  identify software that needs updating. This feature can be
1716	  controlled at runtime with the abi.cp15_barrier sysctl.
1717
1718	  If unsure, say Y
1719
1720config SETEND_EMULATION
1721	bool "Emulate SETEND instruction"
1722	help
1723	  The SETEND instruction alters the data-endianness of the
1724	  AArch32 EL0, and is deprecated in ARMv8.
1725
1726	  Say Y here to enable software emulation of the instruction
1727	  for AArch32 userspace code. This feature can be controlled
1728	  at runtime with the abi.setend sysctl.
1729
1730	  Note: All the cpus on the system must have mixed endian support at EL0
1731	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1732	  endian - is hotplugged in after this feature has been enabled, there could
1733	  be unexpected results in the applications.
1734
1735	  If unsure, say Y
1736endif # ARMV8_DEPRECATED
1737
1738endif # COMPAT
1739
1740menu "ARMv8.1 architectural features"
1741
1742config ARM64_HW_AFDBM
1743	bool "Support for hardware updates of the Access and Dirty page flags"
1744	default y
1745	help
1746	  The ARMv8.1 architecture extensions introduce support for
1747	  hardware updates of the access and dirty information in page
1748	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1749	  capable processors, accesses to pages with PTE_AF cleared will
1750	  set this bit instead of raising an access flag fault.
1751	  Similarly, writes to read-only pages with the DBM bit set will
1752	  clear the read-only bit (AP[2]) instead of raising a
1753	  permission fault.
1754
1755	  Kernels built with this configuration option enabled continue
1756	  to work on pre-ARMv8.1 hardware and the performance impact is
1757	  minimal. If unsure, say Y.
1758
1759config ARM64_PAN
1760	bool "Enable support for Privileged Access Never (PAN)"
1761	default y
1762	help
1763	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1764	  prevents the kernel or hypervisor from accessing user-space (EL0)
1765	  memory directly.
1766
1767	  Choosing this option will cause any unprotected (not using
1768	  copy_to_user et al) memory access to fail with a permission fault.
1769
1770	  The feature is detected at runtime, and will remain as a 'nop'
1771	  instruction if the cpu does not implement the feature.
1772
1773config AS_HAS_LDAPR
1774	def_bool $(as-instr,.arch_extension rcpc)
1775
1776config AS_HAS_LSE_ATOMICS
1777	def_bool $(as-instr,.arch_extension lse)
1778
1779config ARM64_LSE_ATOMICS
1780	bool
1781	default ARM64_USE_LSE_ATOMICS
1782	depends on AS_HAS_LSE_ATOMICS
1783
1784config ARM64_USE_LSE_ATOMICS
1785	bool "Atomic instructions"
1786	default y
1787	help
1788	  As part of the Large System Extensions, ARMv8.1 introduces new
1789	  atomic instructions that are designed specifically to scale in
1790	  very large systems.
1791
1792	  Say Y here to make use of these instructions for the in-kernel
1793	  atomic routines. This incurs a small overhead on CPUs that do
1794	  not support these instructions and requires the kernel to be
1795	  built with binutils >= 2.25 in order for the new instructions
1796	  to be used.
1797
1798endmenu # "ARMv8.1 architectural features"
1799
1800menu "ARMv8.2 architectural features"
1801
1802config AS_HAS_ARMV8_2
1803	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1804
1805config AS_HAS_SHA3
1806	def_bool $(as-instr,.arch armv8.2-a+sha3)
1807
1808config ARM64_PMEM
1809	bool "Enable support for persistent memory"
1810	select ARCH_HAS_PMEM_API
1811	select ARCH_HAS_UACCESS_FLUSHCACHE
1812	help
1813	  Say Y to enable support for the persistent memory API based on the
1814	  ARMv8.2 DCPoP feature.
1815
1816	  The feature is detected at runtime, and the kernel will use DC CVAC
1817	  operations if DC CVAP is not supported (following the behaviour of
1818	  DC CVAP itself if the system does not define a point of persistence).
1819
1820config ARM64_RAS_EXTN
1821	bool "Enable support for RAS CPU Extensions"
1822	default y
1823	help
1824	  CPUs that support the Reliability, Availability and Serviceability
1825	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1826	  errors, classify them and report them to software.
1827
1828	  On CPUs with these extensions system software can use additional
1829	  barriers to determine if faults are pending and read the
1830	  classification from a new set of registers.
1831
1832	  Selecting this feature will allow the kernel to use these barriers
1833	  and access the new registers if the system supports the extension.
1834	  Platform RAS features may additionally depend on firmware support.
1835
1836config ARM64_CNP
1837	bool "Enable support for Common Not Private (CNP) translations"
1838	default y
1839	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1840	help
1841	  Common Not Private (CNP) allows translation table entries to
1842	  be shared between different PEs in the same inner shareable
1843	  domain, so the hardware can use this fact to optimise the
1844	  caching of such entries in the TLB.
1845
1846	  Selecting this option allows the CNP feature to be detected
1847	  at runtime, and does not affect PEs that do not implement
1848	  this feature.
1849
1850endmenu # "ARMv8.2 architectural features"
1851
1852menu "ARMv8.3 architectural features"
1853
1854config ARM64_PTR_AUTH
1855	bool "Enable support for pointer authentication"
1856	default y
1857	help
1858	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1859	  instructions for signing and authenticating pointers against secret
1860	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1861	  and other attacks.
1862
1863	  This option enables these instructions at EL0 (i.e. for userspace).
1864	  Choosing this option will cause the kernel to initialise secret keys
1865	  for each process at exec() time, with these keys being
1866	  context-switched along with the process.
1867
1868	  The feature is detected at runtime. If the feature is not present in
1869	  hardware it will not be advertised to userspace/KVM guest nor will it
1870	  be enabled.
1871
1872	  If the feature is present on the boot CPU but not on a late CPU, then
1873	  the late CPU will be parked. Also, if the boot CPU does not have
1874	  address auth and the late CPU has then the late CPU will still boot
1875	  but with the feature disabled. On such a system, this option should
1876	  not be selected.
1877
1878config ARM64_PTR_AUTH_KERNEL
1879	bool "Use pointer authentication for kernel"
1880	default y
1881	depends on ARM64_PTR_AUTH
1882	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1883	# Modern compilers insert a .note.gnu.property section note for PAC
1884	# which is only understood by binutils starting with version 2.33.1.
1885	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1886	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1887	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1888	help
1889	  If the compiler supports the -mbranch-protection or
1890	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1891	  will cause the kernel itself to be compiled with return address
1892	  protection. In this case, and if the target hardware is known to
1893	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1894	  disabled with minimal loss of protection.
1895
1896	  This feature works with FUNCTION_GRAPH_TRACER option only if
1897	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
1898
1899config CC_HAS_BRANCH_PROT_PAC_RET
1900	# GCC 9 or later, clang 8 or later
1901	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1902
1903config CC_HAS_SIGN_RETURN_ADDRESS
1904	# GCC 7, 8
1905	def_bool $(cc-option,-msign-return-address=all)
1906
1907config AS_HAS_ARMV8_3
1908	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1909
1910config AS_HAS_CFI_NEGATE_RA_STATE
1911	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1912
1913endmenu # "ARMv8.3 architectural features"
1914
1915menu "ARMv8.4 architectural features"
1916
1917config ARM64_AMU_EXTN
1918	bool "Enable support for the Activity Monitors Unit CPU extension"
1919	default y
1920	help
1921	  The activity monitors extension is an optional extension introduced
1922	  by the ARMv8.4 CPU architecture. This enables support for version 1
1923	  of the activity monitors architecture, AMUv1.
1924
1925	  To enable the use of this extension on CPUs that implement it, say Y.
1926
1927	  Note that for architectural reasons, firmware _must_ implement AMU
1928	  support when running on CPUs that present the activity monitors
1929	  extension. The required support is present in:
1930	    * Version 1.5 and later of the ARM Trusted Firmware
1931
1932	  For kernels that have this configuration enabled but boot with broken
1933	  firmware, you may need to say N here until the firmware is fixed.
1934	  Otherwise you may experience firmware panics or lockups when
1935	  accessing the counter registers. Even if you are not observing these
1936	  symptoms, the values returned by the register reads might not
1937	  correctly reflect reality. Most commonly, the value read will be 0,
1938	  indicating that the counter is not enabled.
1939
1940config AS_HAS_ARMV8_4
1941	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1942
1943config ARM64_TLB_RANGE
1944	bool "Enable support for tlbi range feature"
1945	default y
1946	depends on AS_HAS_ARMV8_4
1947	help
1948	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1949	  range of input addresses.
1950
1951	  The feature introduces new assembly instructions, and they were
1952	  support when binutils >= 2.30.
1953
1954endmenu # "ARMv8.4 architectural features"
1955
1956menu "ARMv8.5 architectural features"
1957
1958config AS_HAS_ARMV8_5
1959	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1960
1961config ARM64_BTI
1962	bool "Branch Target Identification support"
1963	default y
1964	help
1965	  Branch Target Identification (part of the ARMv8.5 Extensions)
1966	  provides a mechanism to limit the set of locations to which computed
1967	  branch instructions such as BR or BLR can jump.
1968
1969	  To make use of BTI on CPUs that support it, say Y.
1970
1971	  BTI is intended to provide complementary protection to other control
1972	  flow integrity protection mechanisms, such as the Pointer
1973	  authentication mechanism provided as part of the ARMv8.3 Extensions.
1974	  For this reason, it does not make sense to enable this option without
1975	  also enabling support for pointer authentication.  Thus, when
1976	  enabling this option you should also select ARM64_PTR_AUTH=y.
1977
1978	  Userspace binaries must also be specifically compiled to make use of
1979	  this mechanism.  If you say N here or the hardware does not support
1980	  BTI, such binaries can still run, but you get no additional
1981	  enforcement of branch destinations.
1982
1983config ARM64_BTI_KERNEL
1984	bool "Use Branch Target Identification for kernel"
1985	default y
1986	depends on ARM64_BTI
1987	depends on ARM64_PTR_AUTH_KERNEL
1988	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1989	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1990	depends on !CC_IS_GCC || GCC_VERSION >= 100100
1991	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
1992	depends on !CC_IS_GCC
1993	# https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
1994	depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
1995	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1996	help
1997	  Build the kernel with Branch Target Identification annotations
1998	  and enable enforcement of this for kernel code. When this option
1999	  is enabled and the system supports BTI all kernel code including
2000	  modular code must have BTI enabled.
2001
2002config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2003	# GCC 9 or later, clang 8 or later
2004	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2005
2006config ARM64_E0PD
2007	bool "Enable support for E0PD"
2008	default y
2009	help
2010	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2011	  that EL0 accesses made via TTBR1 always fault in constant time,
2012	  providing similar benefits to KASLR as those provided by KPTI, but
2013	  with lower overhead and without disrupting legitimate access to
2014	  kernel memory such as SPE.
2015
2016	  This option enables E0PD for TTBR1 where available.
2017
2018config ARM64_AS_HAS_MTE
2019	# Initial support for MTE went in binutils 2.32.0, checked with
2020	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2021	# as a late addition to the final architecture spec (LDGM/STGM)
2022	# is only supported in the newer 2.32.x and 2.33 binutils
2023	# versions, hence the extra "stgm" instruction check below.
2024	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2025
2026config ARM64_MTE
2027	bool "Memory Tagging Extension support"
2028	default y
2029	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2030	depends on AS_HAS_ARMV8_5
2031	depends on AS_HAS_LSE_ATOMICS
2032	# Required for tag checking in the uaccess routines
2033	depends on ARM64_PAN
2034	select ARCH_HAS_SUBPAGE_FAULTS
2035	select ARCH_USES_HIGH_VMA_FLAGS
2036	select ARCH_USES_PG_ARCH_X
2037	help
2038	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2039	  architectural support for run-time, always-on detection of
2040	  various classes of memory error to aid with software debugging
2041	  to eliminate vulnerabilities arising from memory-unsafe
2042	  languages.
2043
2044	  This option enables the support for the Memory Tagging
2045	  Extension at EL0 (i.e. for userspace).
2046
2047	  Selecting this option allows the feature to be detected at
2048	  runtime. Any secondary CPU not implementing this feature will
2049	  not be allowed a late bring-up.
2050
2051	  Userspace binaries that want to use this feature must
2052	  explicitly opt in. The mechanism for the userspace is
2053	  described in:
2054
2055	  Documentation/arch/arm64/memory-tagging-extension.rst.
2056
2057endmenu # "ARMv8.5 architectural features"
2058
2059menu "ARMv8.7 architectural features"
2060
2061config ARM64_EPAN
2062	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2063	default y
2064	depends on ARM64_PAN
2065	help
2066	  Enhanced Privileged Access Never (EPAN) allows Privileged
2067	  Access Never to be used with Execute-only mappings.
2068
2069	  The feature is detected at runtime, and will remain disabled
2070	  if the cpu does not implement the feature.
2071endmenu # "ARMv8.7 architectural features"
2072
2073config ARM64_SVE
2074	bool "ARM Scalable Vector Extension support"
2075	default y
2076	help
2077	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2078	  execution state which complements and extends the SIMD functionality
2079	  of the base architecture to support much larger vectors and to enable
2080	  additional vectorisation opportunities.
2081
2082	  To enable use of this extension on CPUs that implement it, say Y.
2083
2084	  On CPUs that support the SVE2 extensions, this option will enable
2085	  those too.
2086
2087	  Note that for architectural reasons, firmware _must_ implement SVE
2088	  support when running on SVE capable hardware.  The required support
2089	  is present in:
2090
2091	    * version 1.5 and later of the ARM Trusted Firmware
2092	    * the AArch64 boot wrapper since commit 5e1261e08abf
2093	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2094
2095	  For other firmware implementations, consult the firmware documentation
2096	  or vendor.
2097
2098	  If you need the kernel to boot on SVE-capable hardware with broken
2099	  firmware, you may need to say N here until you get your firmware
2100	  fixed.  Otherwise, you may experience firmware panics or lockups when
2101	  booting the kernel.  If unsure and you are not observing these
2102	  symptoms, you should assume that it is safe to say Y.
2103
2104config ARM64_SME
2105	bool "ARM Scalable Matrix Extension support"
2106	default y
2107	depends on ARM64_SVE
2108	help
2109	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2110	  execution state which utilises a substantial subset of the SVE
2111	  instruction set, together with the addition of new architectural
2112	  register state capable of holding two dimensional matrix tiles to
2113	  enable various matrix operations.
2114
2115config ARM64_PSEUDO_NMI
2116	bool "Support for NMI-like interrupts"
2117	select ARM_GIC_V3
2118	help
2119	  Adds support for mimicking Non-Maskable Interrupts through the use of
2120	  GIC interrupt priority. This support requires version 3 or later of
2121	  ARM GIC.
2122
2123	  This high priority configuration for interrupts needs to be
2124	  explicitly enabled by setting the kernel parameter
2125	  "irqchip.gicv3_pseudo_nmi" to 1.
2126
2127	  If unsure, say N
2128
2129if ARM64_PSEUDO_NMI
2130config ARM64_DEBUG_PRIORITY_MASKING
2131	bool "Debug interrupt priority masking"
2132	help
2133	  This adds runtime checks to functions enabling/disabling
2134	  interrupts when using priority masking. The additional checks verify
2135	  the validity of ICC_PMR_EL1 when calling concerned functions.
2136
2137	  If unsure, say N
2138endif # ARM64_PSEUDO_NMI
2139
2140config RELOCATABLE
2141	bool "Build a relocatable kernel image" if EXPERT
2142	select ARCH_HAS_RELR
2143	default y
2144	help
2145	  This builds the kernel as a Position Independent Executable (PIE),
2146	  which retains all relocation metadata required to relocate the
2147	  kernel binary at runtime to a different virtual address than the
2148	  address it was linked at.
2149	  Since AArch64 uses the RELA relocation format, this requires a
2150	  relocation pass at runtime even if the kernel is loaded at the
2151	  same address it was linked at.
2152
2153config RANDOMIZE_BASE
2154	bool "Randomize the address of the kernel image"
2155	select RELOCATABLE
2156	help
2157	  Randomizes the virtual address at which the kernel image is
2158	  loaded, as a security feature that deters exploit attempts
2159	  relying on knowledge of the location of kernel internals.
2160
2161	  It is the bootloader's job to provide entropy, by passing a
2162	  random u64 value in /chosen/kaslr-seed at kernel entry.
2163
2164	  When booting via the UEFI stub, it will invoke the firmware's
2165	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2166	  to the kernel proper. In addition, it will randomise the physical
2167	  location of the kernel Image as well.
2168
2169	  If unsure, say N.
2170
2171config RANDOMIZE_MODULE_REGION_FULL
2172	bool "Randomize the module region over a 2 GB range"
2173	depends on RANDOMIZE_BASE
2174	default y
2175	help
2176	  Randomizes the location of the module region inside a 2 GB window
2177	  covering the core kernel. This way, it is less likely for modules
2178	  to leak information about the location of core kernel data structures
2179	  but it does imply that function calls between modules and the core
2180	  kernel will need to be resolved via veneers in the module PLT.
2181
2182	  When this option is not set, the module region will be randomized over
2183	  a limited range that contains the [_stext, _etext] interval of the
2184	  core kernel, so branch relocations are almost always in range unless
2185	  the region is exhausted. In this particular case of region
2186	  exhaustion, modules might be able to fall back to a larger 2GB area.
2187
2188config CC_HAVE_STACKPROTECTOR_SYSREG
2189	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2190
2191config STACKPROTECTOR_PER_TASK
2192	def_bool y
2193	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2194
2195config UNWIND_PATCH_PAC_INTO_SCS
2196	bool "Enable shadow call stack dynamically using code patching"
2197	# needs Clang with https://reviews.llvm.org/D111780 incorporated
2198	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2199	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2200	depends on SHADOW_CALL_STACK
2201	select UNWIND_TABLES
2202	select DYNAMIC_SCS
2203
2204endmenu # "Kernel Features"
2205
2206menu "Boot options"
2207
2208config ARM64_ACPI_PARKING_PROTOCOL
2209	bool "Enable support for the ARM64 ACPI parking protocol"
2210	depends on ACPI
2211	help
2212	  Enable support for the ARM64 ACPI parking protocol. If disabled
2213	  the kernel will not allow booting through the ARM64 ACPI parking
2214	  protocol even if the corresponding data is present in the ACPI
2215	  MADT table.
2216
2217config CMDLINE
2218	string "Default kernel command string"
2219	default ""
2220	help
2221	  Provide a set of default command-line options at build time by
2222	  entering them here. As a minimum, you should specify the the
2223	  root device (e.g. root=/dev/nfs).
2224
2225choice
2226	prompt "Kernel command line type" if CMDLINE != ""
2227	default CMDLINE_FROM_BOOTLOADER
2228	help
2229	  Choose how the kernel will handle the provided default kernel
2230	  command line string.
2231
2232config CMDLINE_FROM_BOOTLOADER
2233	bool "Use bootloader kernel arguments if available"
2234	help
2235	  Uses the command-line options passed by the boot loader. If
2236	  the boot loader doesn't provide any, the default kernel command
2237	  string provided in CMDLINE will be used.
2238
2239config CMDLINE_FORCE
2240	bool "Always use the default kernel command string"
2241	help
2242	  Always use the default kernel command string, even if the boot
2243	  loader passes other arguments to the kernel.
2244	  This is useful if you cannot or don't want to change the
2245	  command-line options your boot loader passes to the kernel.
2246
2247endchoice
2248
2249config EFI_STUB
2250	bool
2251
2252config EFI
2253	bool "UEFI runtime support"
2254	depends on OF && !CPU_BIG_ENDIAN
2255	depends on KERNEL_MODE_NEON
2256	select ARCH_SUPPORTS_ACPI
2257	select LIBFDT
2258	select UCS2_STRING
2259	select EFI_PARAMS_FROM_FDT
2260	select EFI_RUNTIME_WRAPPERS
2261	select EFI_STUB
2262	select EFI_GENERIC_STUB
2263	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2264	default y
2265	help
2266	  This option provides support for runtime services provided
2267	  by UEFI firmware (such as non-volatile variables, realtime
2268	  clock, and platform reset). A UEFI stub is also provided to
2269	  allow the kernel to be booted as an EFI application. This
2270	  is only useful on systems that have UEFI firmware.
2271
2272config DMI
2273	bool "Enable support for SMBIOS (DMI) tables"
2274	depends on EFI
2275	default y
2276	help
2277	  This enables SMBIOS/DMI feature for systems.
2278
2279	  This option is only useful on systems that have UEFI firmware.
2280	  However, even with this option, the resultant kernel should
2281	  continue to boot on existing non-UEFI platforms.
2282
2283endmenu # "Boot options"
2284
2285menu "Power management options"
2286
2287source "kernel/power/Kconfig"
2288
2289config ARCH_HIBERNATION_POSSIBLE
2290	def_bool y
2291	depends on CPU_PM
2292
2293config ARCH_HIBERNATION_HEADER
2294	def_bool y
2295	depends on HIBERNATION
2296
2297config ARCH_SUSPEND_POSSIBLE
2298	def_bool y
2299
2300endmenu # "Power management options"
2301
2302menu "CPU Power Management"
2303
2304source "drivers/cpuidle/Kconfig"
2305
2306source "drivers/cpufreq/Kconfig"
2307
2308endmenu # "CPU Power Management"
2309
2310source "drivers/acpi/Kconfig"
2311
2312source "arch/arm64/kvm/Kconfig"
2313
2314