xref: /openbmc/linux/arch/arm64/Kconfig (revision d3402925)
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_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
99	select ARCH_WANT_DEFAULT_BPF_JIT
100	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
101	select ARCH_WANT_FRAME_POINTERS
102	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
103	select ARCH_WANT_LD_ORPHAN_WARN
104	select ARCH_WANTS_NO_INSTR
105	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
106	select ARCH_HAS_UBSAN_SANITIZE_ALL
107	select ARM_AMBA
108	select ARM_ARCH_TIMER
109	select ARM_GIC
110	select AUDIT_ARCH_COMPAT_GENERIC
111	select ARM_GIC_V2M if PCI
112	select ARM_GIC_V3
113	select ARM_GIC_V3_ITS if PCI
114	select ARM_PSCI_FW
115	select BUILDTIME_TABLE_SORT
116	select CLONE_BACKWARDS
117	select COMMON_CLK
118	select CPU_PM if (SUSPEND || CPU_IDLE)
119	select CRC32
120	select DCACHE_WORD_ACCESS
121	select DYNAMIC_FTRACE if FUNCTION_TRACER
122	select DMA_DIRECT_REMAP
123	select EDAC_SUPPORT
124	select FRAME_POINTER
125	select FUNCTION_ALIGNMENT_4B
126	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
127	select GENERIC_ALLOCATOR
128	select GENERIC_ARCH_TOPOLOGY
129	select GENERIC_CLOCKEVENTS_BROADCAST
130	select GENERIC_CPU_AUTOPROBE
131	select GENERIC_CPU_VULNERABILITIES
132	select GENERIC_EARLY_IOREMAP
133	select GENERIC_IDLE_POLL_SETUP
134	select GENERIC_IOREMAP
135	select GENERIC_IRQ_IPI
136	select GENERIC_IRQ_PROBE
137	select GENERIC_IRQ_SHOW
138	select GENERIC_IRQ_SHOW_LEVEL
139	select GENERIC_LIB_DEVMEM_IS_ALLOWED
140	select GENERIC_PCI_IOMAP
141	select GENERIC_PTDUMP
142	select GENERIC_SCHED_CLOCK
143	select GENERIC_SMP_IDLE_THREAD
144	select GENERIC_TIME_VSYSCALL
145	select GENERIC_GETTIMEOFDAY
146	select GENERIC_VDSO_TIME_NS
147	select HARDIRQS_SW_RESEND
148	select HAVE_MOVE_PMD
149	select HAVE_MOVE_PUD
150	select HAVE_PCI
151	select HAVE_ACPI_APEI if (ACPI && EFI)
152	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
153	select HAVE_ARCH_AUDITSYSCALL
154	select HAVE_ARCH_BITREVERSE
155	select HAVE_ARCH_COMPILER_H
156	select HAVE_ARCH_HUGE_VMALLOC
157	select HAVE_ARCH_HUGE_VMAP
158	select HAVE_ARCH_JUMP_LABEL
159	select HAVE_ARCH_JUMP_LABEL_RELATIVE
160	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
161	select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
162	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
163	select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
164	# Some instrumentation may be unsound, hence EXPERT
165	select HAVE_ARCH_KCSAN if EXPERT
166	select HAVE_ARCH_KFENCE
167	select HAVE_ARCH_KGDB
168	select HAVE_ARCH_MMAP_RND_BITS
169	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
170	select HAVE_ARCH_PREL32_RELOCATIONS
171	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
172	select HAVE_ARCH_SECCOMP_FILTER
173	select HAVE_ARCH_STACKLEAK
174	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
175	select HAVE_ARCH_TRACEHOOK
176	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
177	select HAVE_ARCH_VMAP_STACK
178	select HAVE_ARM_SMCCC
179	select HAVE_ASM_MODVERSIONS
180	select HAVE_EBPF_JIT
181	select HAVE_C_RECORDMCOUNT
182	select HAVE_CMPXCHG_DOUBLE
183	select HAVE_CMPXCHG_LOCAL
184	select HAVE_CONTEXT_TRACKING_USER
185	select HAVE_DEBUG_KMEMLEAK
186	select HAVE_DMA_CONTIGUOUS
187	select HAVE_DYNAMIC_FTRACE
188	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
189		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
190		    !CC_OPTIMIZE_FOR_SIZE)
191	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
192		if DYNAMIC_FTRACE_WITH_ARGS
193	select HAVE_EFFICIENT_UNALIGNED_ACCESS
194	select HAVE_FAST_GUP
195	select HAVE_FTRACE_MCOUNT_RECORD
196	select HAVE_FUNCTION_TRACER
197	select HAVE_FUNCTION_ERROR_INJECTION
198	select HAVE_FUNCTION_GRAPH_TRACER
199	select HAVE_GCC_PLUGINS
200	select HAVE_HW_BREAKPOINT if PERF_EVENTS
201	select HAVE_IOREMAP_PROT
202	select HAVE_IRQ_TIME_ACCOUNTING
203	select HAVE_KVM
204	select HAVE_NMI
205	select HAVE_PERF_EVENTS
206	select HAVE_PERF_REGS
207	select HAVE_PERF_USER_STACK_DUMP
208	select HAVE_PREEMPT_DYNAMIC_KEY
209	select HAVE_REGS_AND_STACK_ACCESS_API
210	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
211	select HAVE_FUNCTION_ARG_ACCESS_API
212	select MMU_GATHER_RCU_TABLE_FREE
213	select HAVE_RSEQ
214	select HAVE_STACKPROTECTOR
215	select HAVE_SYSCALL_TRACEPOINTS
216	select HAVE_KPROBES
217	select HAVE_KRETPROBES
218	select HAVE_GENERIC_VDSO
219	select IRQ_DOMAIN
220	select IRQ_FORCED_THREADING
221	select KASAN_VMALLOC if KASAN
222	select MODULES_USE_ELF_RELA
223	select NEED_DMA_MAP_STATE
224	select NEED_SG_DMA_LENGTH
225	select OF
226	select OF_EARLY_FLATTREE
227	select PCI_DOMAINS_GENERIC if PCI
228	select PCI_ECAM if (ACPI && PCI)
229	select PCI_SYSCALL if PCI
230	select POWER_RESET
231	select POWER_SUPPLY
232	select SPARSE_IRQ
233	select SWIOTLB
234	select SYSCTL_EXCEPTION_TRACE
235	select THREAD_INFO_IN_TASK
236	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
237	select TRACE_IRQFLAGS_SUPPORT
238	select TRACE_IRQFLAGS_NMI_SUPPORT
239	select HAVE_SOFTIRQ_ON_OWN_STACK
240	help
241	  ARM 64-bit (AArch64) Linux support.
242
243config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
244	def_bool CC_IS_CLANG
245	# https://github.com/ClangBuiltLinux/linux/issues/1507
246	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
247	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
248
249config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
250	def_bool CC_IS_GCC
251	depends on $(cc-option,-fpatchable-function-entry=2)
252	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
253
254config 64BIT
255	def_bool y
256
257config MMU
258	def_bool y
259
260config ARM64_PAGE_SHIFT
261	int
262	default 16 if ARM64_64K_PAGES
263	default 14 if ARM64_16K_PAGES
264	default 12
265
266config ARM64_CONT_PTE_SHIFT
267	int
268	default 5 if ARM64_64K_PAGES
269	default 7 if ARM64_16K_PAGES
270	default 4
271
272config ARM64_CONT_PMD_SHIFT
273	int
274	default 5 if ARM64_64K_PAGES
275	default 5 if ARM64_16K_PAGES
276	default 4
277
278config ARCH_MMAP_RND_BITS_MIN
279	default 14 if ARM64_64K_PAGES
280	default 16 if ARM64_16K_PAGES
281	default 18
282
283# max bits determined by the following formula:
284#  VA_BITS - PAGE_SHIFT - 3
285config ARCH_MMAP_RND_BITS_MAX
286	default 19 if ARM64_VA_BITS=36
287	default 24 if ARM64_VA_BITS=39
288	default 27 if ARM64_VA_BITS=42
289	default 30 if ARM64_VA_BITS=47
290	default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
291	default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
292	default 33 if ARM64_VA_BITS=48
293	default 14 if ARM64_64K_PAGES
294	default 16 if ARM64_16K_PAGES
295	default 18
296
297config ARCH_MMAP_RND_COMPAT_BITS_MIN
298	default 7 if ARM64_64K_PAGES
299	default 9 if ARM64_16K_PAGES
300	default 11
301
302config ARCH_MMAP_RND_COMPAT_BITS_MAX
303	default 16
304
305config NO_IOPORT_MAP
306	def_bool y if !PCI
307
308config STACKTRACE_SUPPORT
309	def_bool y
310
311config ILLEGAL_POINTER_VALUE
312	hex
313	default 0xdead000000000000
314
315config LOCKDEP_SUPPORT
316	def_bool y
317
318config GENERIC_BUG
319	def_bool y
320	depends on BUG
321
322config GENERIC_BUG_RELATIVE_POINTERS
323	def_bool y
324	depends on GENERIC_BUG
325
326config GENERIC_HWEIGHT
327	def_bool y
328
329config GENERIC_CSUM
330	def_bool y
331
332config GENERIC_CALIBRATE_DELAY
333	def_bool y
334
335config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
336	def_bool y
337
338config SMP
339	def_bool y
340
341config KERNEL_MODE_NEON
342	def_bool y
343
344config FIX_EARLYCON_MEM
345	def_bool y
346
347config PGTABLE_LEVELS
348	int
349	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
350	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
351	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
352	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
353	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
354	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
355
356config ARCH_SUPPORTS_UPROBES
357	def_bool y
358
359config ARCH_PROC_KCORE_TEXT
360	def_bool y
361
362config BROKEN_GAS_INST
363	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
364
365config KASAN_SHADOW_OFFSET
366	hex
367	depends on KASAN_GENERIC || KASAN_SW_TAGS
368	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
369	default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
370	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
371	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
372	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
373	default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
374	default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
375	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
376	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
377	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
378	default 0xffffffffffffffff
379
380config UNWIND_TABLES
381	bool
382
383source "arch/arm64/Kconfig.platforms"
384
385menu "Kernel Features"
386
387menu "ARM errata workarounds via the alternatives framework"
388
389config ARM64_WORKAROUND_CLEAN_CACHE
390	bool
391
392config ARM64_ERRATUM_826319
393	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
394	default y
395	select ARM64_WORKAROUND_CLEAN_CACHE
396	help
397	  This option adds an alternative code sequence to work around ARM
398	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
399	  AXI master interface and an L2 cache.
400
401	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
402	  and is unable to accept a certain write via this interface, it will
403	  not progress on read data presented on the read data channel and the
404	  system can deadlock.
405
406	  The workaround promotes data cache clean instructions to
407	  data cache clean-and-invalidate.
408	  Please note that this does not necessarily enable the workaround,
409	  as it depends on the alternative framework, which will only patch
410	  the kernel if an affected CPU is detected.
411
412	  If unsure, say Y.
413
414config ARM64_ERRATUM_827319
415	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
416	default y
417	select ARM64_WORKAROUND_CLEAN_CACHE
418	help
419	  This option adds an alternative code sequence to work around ARM
420	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
421	  master interface and an L2 cache.
422
423	  Under certain conditions this erratum can cause a clean line eviction
424	  to occur at the same time as another transaction to the same address
425	  on the AMBA 5 CHI interface, which can cause data corruption if the
426	  interconnect reorders the two transactions.
427
428	  The workaround promotes data cache clean instructions to
429	  data cache clean-and-invalidate.
430	  Please note that this does not necessarily enable the workaround,
431	  as it depends on the alternative framework, which will only patch
432	  the kernel if an affected CPU is detected.
433
434	  If unsure, say Y.
435
436config ARM64_ERRATUM_824069
437	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
438	default y
439	select ARM64_WORKAROUND_CLEAN_CACHE
440	help
441	  This option adds an alternative code sequence to work around ARM
442	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
443	  to a coherent interconnect.
444
445	  If a Cortex-A53 processor is executing a store or prefetch for
446	  write instruction at the same time as a processor in another
447	  cluster is executing a cache maintenance operation to the same
448	  address, then this erratum might cause a clean cache line to be
449	  incorrectly marked as dirty.
450
451	  The workaround promotes data cache clean instructions to
452	  data cache clean-and-invalidate.
453	  Please note that this option does not necessarily enable the
454	  workaround, as it depends on the alternative framework, which will
455	  only patch the kernel if an affected CPU is detected.
456
457	  If unsure, say Y.
458
459config ARM64_ERRATUM_819472
460	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
461	default y
462	select ARM64_WORKAROUND_CLEAN_CACHE
463	help
464	  This option adds an alternative code sequence to work around ARM
465	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
466	  present when it is connected to a coherent interconnect.
467
468	  If the processor is executing a load and store exclusive sequence at
469	  the same time as a processor in another cluster is executing a cache
470	  maintenance operation to the same address, then this erratum might
471	  cause data corruption.
472
473	  The workaround promotes data cache clean instructions to
474	  data cache clean-and-invalidate.
475	  Please note that this does not necessarily enable the workaround,
476	  as it depends on the alternative framework, which will only patch
477	  the kernel if an affected CPU is detected.
478
479	  If unsure, say Y.
480
481config ARM64_ERRATUM_832075
482	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
483	default y
484	help
485	  This option adds an alternative code sequence to work around ARM
486	  erratum 832075 on Cortex-A57 parts up to r1p2.
487
488	  Affected Cortex-A57 parts might deadlock when exclusive load/store
489	  instructions to Write-Back memory are mixed with Device loads.
490
491	  The workaround is to promote device loads to use Load-Acquire
492	  semantics.
493	  Please note that this does not necessarily enable the workaround,
494	  as it depends on the alternative framework, which will only patch
495	  the kernel if an affected CPU is detected.
496
497	  If unsure, say Y.
498
499config ARM64_ERRATUM_834220
500	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
501	depends on KVM
502	default y
503	help
504	  This option adds an alternative code sequence to work around ARM
505	  erratum 834220 on Cortex-A57 parts up to r1p2.
506
507	  Affected Cortex-A57 parts might report a Stage 2 translation
508	  fault as the result of a Stage 1 fault for load crossing a
509	  page boundary when there is a permission or device memory
510	  alignment fault at Stage 1 and a translation fault at Stage 2.
511
512	  The workaround is to verify that the Stage 1 translation
513	  doesn't generate a fault before handling the Stage 2 fault.
514	  Please note that this does not necessarily enable the workaround,
515	  as it depends on the alternative framework, which will only patch
516	  the kernel if an affected CPU is detected.
517
518	  If unsure, say Y.
519
520config ARM64_ERRATUM_1742098
521	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
522	depends on COMPAT
523	default y
524	help
525	  This option removes the AES hwcap for aarch32 user-space to
526	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
527
528	  Affected parts may corrupt the AES state if an interrupt is
529	  taken between a pair of AES instructions. These instructions
530	  are only present if the cryptography extensions are present.
531	  All software should have a fallback implementation for CPUs
532	  that don't implement the cryptography extensions.
533
534	  If unsure, say Y.
535
536config ARM64_ERRATUM_845719
537	bool "Cortex-A53: 845719: a load might read incorrect data"
538	depends on COMPAT
539	default y
540	help
541	  This option adds an alternative code sequence to work around ARM
542	  erratum 845719 on Cortex-A53 parts up to r0p4.
543
544	  When running a compat (AArch32) userspace on an affected Cortex-A53
545	  part, a load at EL0 from a virtual address that matches the bottom 32
546	  bits of the virtual address used by a recent load at (AArch64) EL1
547	  might return incorrect data.
548
549	  The workaround is to write the contextidr_el1 register on exception
550	  return to a 32-bit task.
551	  Please note that this does not necessarily enable the workaround,
552	  as it depends on the alternative framework, which will only patch
553	  the kernel if an affected CPU is detected.
554
555	  If unsure, say Y.
556
557config ARM64_ERRATUM_843419
558	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
559	default y
560	select ARM64_MODULE_PLTS if MODULES
561	help
562	  This option links the kernel with '--fix-cortex-a53-843419' and
563	  enables PLT support to replace certain ADRP instructions, which can
564	  cause subsequent memory accesses to use an incorrect address on
565	  Cortex-A53 parts up to r0p4.
566
567	  If unsure, say Y.
568
569config ARM64_LD_HAS_FIX_ERRATUM_843419
570	def_bool $(ld-option,--fix-cortex-a53-843419)
571
572config ARM64_ERRATUM_1024718
573	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
574	default y
575	help
576	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
577
578	  Affected Cortex-A55 cores (all revisions) could cause incorrect
579	  update of the hardware dirty bit when the DBM/AP bits are updated
580	  without a break-before-make. The workaround is to disable the usage
581	  of hardware DBM locally on the affected cores. CPUs not affected by
582	  this erratum will continue to use the feature.
583
584	  If unsure, say Y.
585
586config ARM64_ERRATUM_1418040
587	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
588	default y
589	depends on COMPAT
590	help
591	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
592	  errata 1188873 and 1418040.
593
594	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
595	  cause register corruption when accessing the timer registers
596	  from AArch32 userspace.
597
598	  If unsure, say Y.
599
600config ARM64_WORKAROUND_SPECULATIVE_AT
601	bool
602
603config ARM64_ERRATUM_1165522
604	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
605	default y
606	select ARM64_WORKAROUND_SPECULATIVE_AT
607	help
608	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
609
610	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
611	  corrupted TLBs by speculating an AT instruction during a guest
612	  context switch.
613
614	  If unsure, say Y.
615
616config ARM64_ERRATUM_1319367
617	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
618	default y
619	select ARM64_WORKAROUND_SPECULATIVE_AT
620	help
621	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
622	  and A72 erratum 1319367
623
624	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
625	  speculating an AT instruction during a guest context switch.
626
627	  If unsure, say Y.
628
629config ARM64_ERRATUM_1530923
630	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
631	default y
632	select ARM64_WORKAROUND_SPECULATIVE_AT
633	help
634	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
635
636	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
637	  corrupted TLBs by speculating an AT instruction during a guest
638	  context switch.
639
640	  If unsure, say Y.
641
642config ARM64_WORKAROUND_REPEAT_TLBI
643	bool
644
645config ARM64_ERRATUM_2441007
646	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
647	default y
648	select ARM64_WORKAROUND_REPEAT_TLBI
649	help
650	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
651
652	  Under very rare circumstances, affected Cortex-A55 CPUs
653	  may not handle a race between a break-before-make sequence on one
654	  CPU, and another CPU accessing the same page. This could allow a
655	  store to a page that has been unmapped.
656
657	  Work around this by adding the affected CPUs to the list that needs
658	  TLB sequences to be done twice.
659
660	  If unsure, say Y.
661
662config ARM64_ERRATUM_1286807
663	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
664	default y
665	select ARM64_WORKAROUND_REPEAT_TLBI
666	help
667	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
668
669	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
670	  address for a cacheable mapping of a location is being
671	  accessed by a core while another core is remapping the virtual
672	  address to a new physical page using the recommended
673	  break-before-make sequence, then under very rare circumstances
674	  TLBI+DSB completes before a read using the translation being
675	  invalidated has been observed by other observers. The
676	  workaround repeats the TLBI+DSB operation.
677
678config ARM64_ERRATUM_1463225
679	bool "Cortex-A76: Software Step might prevent interrupt recognition"
680	default y
681	help
682	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
683
684	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
685	  of a system call instruction (SVC) can prevent recognition of
686	  subsequent interrupts when software stepping is disabled in the
687	  exception handler of the system call and either kernel debugging
688	  is enabled or VHE is in use.
689
690	  Work around the erratum by triggering a dummy step exception
691	  when handling a system call from a task that is being stepped
692	  in a VHE configuration of the kernel.
693
694	  If unsure, say Y.
695
696config ARM64_ERRATUM_1542419
697	bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
698	default y
699	help
700	  This option adds a workaround for ARM Neoverse-N1 erratum
701	  1542419.
702
703	  Affected Neoverse-N1 cores could execute a stale instruction when
704	  modified by another CPU. The workaround depends on a firmware
705	  counterpart.
706
707	  Workaround the issue by hiding the DIC feature from EL0. This
708	  forces user-space to perform cache maintenance.
709
710	  If unsure, say Y.
711
712config ARM64_ERRATUM_1508412
713	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
714	default y
715	help
716	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
717
718	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
719	  of a store-exclusive or read of PAR_EL1 and a load with device or
720	  non-cacheable memory attributes. The workaround depends on a firmware
721	  counterpart.
722
723	  KVM guests must also have the workaround implemented or they can
724	  deadlock the system.
725
726	  Work around the issue by inserting DMB SY barriers around PAR_EL1
727	  register reads and warning KVM users. The DMB barrier is sufficient
728	  to prevent a speculative PAR_EL1 read.
729
730	  If unsure, say Y.
731
732config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
733	bool
734
735config ARM64_ERRATUM_2051678
736	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
737	default y
738	help
739	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
740	  Affected Cortex-A510 might not respect the ordering rules for
741	  hardware update of the page table's dirty bit. The workaround
742	  is to not enable the feature on affected CPUs.
743
744	  If unsure, say Y.
745
746config ARM64_ERRATUM_2077057
747	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
748	default y
749	help
750	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
751	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
752	  expected, but a Pointer Authentication trap is taken instead. The
753	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
754	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
755
756	  This can only happen when EL2 is stepping EL1.
757
758	  When these conditions occur, the SPSR_EL2 value is unchanged from the
759	  previous guest entry, and can be restored from the in-memory copy.
760
761	  If unsure, say Y.
762
763config ARM64_ERRATUM_2658417
764	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
765	default y
766	help
767	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
768	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
769	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
770	  A510 CPUs are using shared neon hardware. As the sharing is not
771	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
772	  user-space should not be using these instructions.
773
774	  If unsure, say Y.
775
776config ARM64_ERRATUM_2119858
777	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
778	default y
779	depends on CORESIGHT_TRBE
780	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
781	help
782	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
783
784	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
785	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
786	  the event of a WRAP event.
787
788	  Work around the issue by always making sure we move the TRBPTR_EL1 by
789	  256 bytes before enabling the buffer and filling the first 256 bytes of
790	  the buffer with ETM ignore packets upon disabling.
791
792	  If unsure, say Y.
793
794config ARM64_ERRATUM_2139208
795	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
796	default y
797	depends on CORESIGHT_TRBE
798	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
799	help
800	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
801
802	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
803	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
804	  the event of a WRAP event.
805
806	  Work around the issue by always making sure we move the TRBPTR_EL1 by
807	  256 bytes before enabling the buffer and filling the first 256 bytes of
808	  the buffer with ETM ignore packets upon disabling.
809
810	  If unsure, say Y.
811
812config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
813	bool
814
815config ARM64_ERRATUM_2054223
816	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
817	default y
818	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
819	help
820	  Enable workaround for ARM Cortex-A710 erratum 2054223
821
822	  Affected cores may fail to flush the trace data on a TSB instruction, when
823	  the PE is in trace prohibited state. This will cause losing a few bytes
824	  of the trace cached.
825
826	  Workaround is to issue two TSB consecutively on affected cores.
827
828	  If unsure, say Y.
829
830config ARM64_ERRATUM_2067961
831	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
832	default y
833	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
834	help
835	  Enable workaround for ARM Neoverse-N2 erratum 2067961
836
837	  Affected cores may fail to flush the trace data on a TSB instruction, when
838	  the PE is in trace prohibited state. This will cause losing a few bytes
839	  of the trace cached.
840
841	  Workaround is to issue two TSB consecutively on affected cores.
842
843	  If unsure, say Y.
844
845config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
846	bool
847
848config ARM64_ERRATUM_2253138
849	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
850	depends on CORESIGHT_TRBE
851	default y
852	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
853	help
854	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
855
856	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
857	  for TRBE. Under some conditions, the TRBE might generate a write to the next
858	  virtually addressed page following the last page of the TRBE address space
859	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
860
861	  Work around this in the driver by always making sure that there is a
862	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
863
864	  If unsure, say Y.
865
866config ARM64_ERRATUM_2224489
867	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
868	depends on CORESIGHT_TRBE
869	default y
870	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
871	help
872	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
873
874	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
875	  for TRBE. Under some conditions, the TRBE might generate a write to the next
876	  virtually addressed page following the last page of the TRBE address space
877	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
878
879	  Work around this in the driver by always making sure that there is a
880	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
881
882	  If unsure, say Y.
883
884config ARM64_ERRATUM_2441009
885	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
886	default y
887	select ARM64_WORKAROUND_REPEAT_TLBI
888	help
889	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
890
891	  Under very rare circumstances, affected Cortex-A510 CPUs
892	  may not handle a race between a break-before-make sequence on one
893	  CPU, and another CPU accessing the same page. This could allow a
894	  store to a page that has been unmapped.
895
896	  Work around this by adding the affected CPUs to the list that needs
897	  TLB sequences to be done twice.
898
899	  If unsure, say Y.
900
901config ARM64_ERRATUM_2064142
902	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
903	depends on CORESIGHT_TRBE
904	default y
905	help
906	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
907
908	  Affected Cortex-A510 core might fail to write into system registers after the
909	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
910	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
911	  and TRBTRG_EL1 will be ignored and will not be effected.
912
913	  Work around this in the driver by executing TSB CSYNC and DSB after collection
914	  is stopped and before performing a system register write to one of the affected
915	  registers.
916
917	  If unsure, say Y.
918
919config ARM64_ERRATUM_2038923
920	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
921	depends on CORESIGHT_TRBE
922	default y
923	help
924	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
925
926	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
927	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
928	  might be corrupted. This happens after TRBE buffer has been enabled by setting
929	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
930	  execution changes from a context, in which trace is prohibited to one where it
931	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
932	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
933	  the trace buffer state might be corrupted.
934
935	  Work around this in the driver by preventing an inconsistent view of whether the
936	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
937	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
938	  two ISB instructions if no ERET is to take place.
939
940	  If unsure, say Y.
941
942config ARM64_ERRATUM_1902691
943	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
944	depends on CORESIGHT_TRBE
945	default y
946	help
947	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
948
949	  Affected Cortex-A510 core might cause trace data corruption, when being written
950	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
951	  trace data.
952
953	  Work around this problem in the driver by just preventing TRBE initialization on
954	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
955	  on such implementations. This will cover the kernel for any firmware that doesn't
956	  do this already.
957
958	  If unsure, say Y.
959
960config ARM64_ERRATUM_2457168
961	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
962	depends on ARM64_AMU_EXTN
963	default y
964	help
965	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
966
967	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
968	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
969	  incorrectly giving a significantly higher output value.
970
971	  Work around this problem by returning 0 when reading the affected counter in
972	  key locations that results in disabling all users of this counter. This effect
973	  is the same to firmware disabling affected counters.
974
975	  If unsure, say Y.
976
977config ARM64_ERRATUM_2645198
978	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
979	default y
980	help
981	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
982
983	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
984	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
985	  next instruction abort caused by permission fault.
986
987	  Only user-space does executable to non-executable permission transition via
988	  mprotect() system call. Workaround the problem by doing a break-before-make
989	  TLB invalidation, for all changes to executable user space mappings.
990
991	  If unsure, say Y.
992
993config CAVIUM_ERRATUM_22375
994	bool "Cavium erratum 22375, 24313"
995	default y
996	help
997	  Enable workaround for errata 22375 and 24313.
998
999	  This implements two gicv3-its errata workarounds for ThunderX. Both
1000	  with a small impact affecting only ITS table allocation.
1001
1002	    erratum 22375: only alloc 8MB table size
1003	    erratum 24313: ignore memory access type
1004
1005	  The fixes are in ITS initialization and basically ignore memory access
1006	  type and table size provided by the TYPER and BASER registers.
1007
1008	  If unsure, say Y.
1009
1010config CAVIUM_ERRATUM_23144
1011	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1012	depends on NUMA
1013	default y
1014	help
1015	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1016
1017	  If unsure, say Y.
1018
1019config CAVIUM_ERRATUM_23154
1020	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1021	default y
1022	help
1023	  The ThunderX GICv3 implementation requires a modified version for
1024	  reading the IAR status to ensure data synchronization
1025	  (access to icc_iar1_el1 is not sync'ed before and after).
1026
1027	  It also suffers from erratum 38545 (also present on Marvell's
1028	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1029	  spuriously presented to the CPU interface.
1030
1031	  If unsure, say Y.
1032
1033config CAVIUM_ERRATUM_27456
1034	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1035	default y
1036	help
1037	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1038	  instructions may cause the icache to become corrupted if it
1039	  contains data for a non-current ASID.  The fix is to
1040	  invalidate the icache when changing the mm context.
1041
1042	  If unsure, say Y.
1043
1044config CAVIUM_ERRATUM_30115
1045	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1046	default y
1047	help
1048	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1049	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1050	  interrupts in host. Trapping both GICv3 group-0 and group-1
1051	  accesses sidesteps the issue.
1052
1053	  If unsure, say Y.
1054
1055config CAVIUM_TX2_ERRATUM_219
1056	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1057	default y
1058	help
1059	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1060	  TTBR update and the corresponding context synchronizing operation can
1061	  cause a spurious Data Abort to be delivered to any hardware thread in
1062	  the CPU core.
1063
1064	  Work around the issue by avoiding the problematic code sequence and
1065	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1066	  trap handler performs the corresponding register access, skips the
1067	  instruction and ensures context synchronization by virtue of the
1068	  exception return.
1069
1070	  If unsure, say Y.
1071
1072config FUJITSU_ERRATUM_010001
1073	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1074	default y
1075	help
1076	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1077	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1078	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1079	  This fault occurs under a specific hardware condition when a
1080	  load/store instruction performs an address translation using:
1081	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1082	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1083	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1084	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1085
1086	  The workaround is to ensure these bits are clear in TCR_ELx.
1087	  The workaround only affects the Fujitsu-A64FX.
1088
1089	  If unsure, say Y.
1090
1091config HISILICON_ERRATUM_161600802
1092	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1093	default y
1094	help
1095	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1096	  when issued ITS commands such as VMOVP and VMAPP, and requires
1097	  a 128kB offset to be applied to the target address in this commands.
1098
1099	  If unsure, say Y.
1100
1101config QCOM_FALKOR_ERRATUM_1003
1102	bool "Falkor E1003: Incorrect translation due to ASID change"
1103	default y
1104	help
1105	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1106	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1107	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1108	  then only for entries in the walk cache, since the leaf translation
1109	  is unchanged. Work around the erratum by invalidating the walk cache
1110	  entries for the trampoline before entering the kernel proper.
1111
1112config QCOM_FALKOR_ERRATUM_1009
1113	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1114	default y
1115	select ARM64_WORKAROUND_REPEAT_TLBI
1116	help
1117	  On Falkor v1, the CPU may prematurely complete a DSB following a
1118	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1119	  one more time to fix the issue.
1120
1121	  If unsure, say Y.
1122
1123config QCOM_QDF2400_ERRATUM_0065
1124	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1125	default y
1126	help
1127	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1128	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1129	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1130
1131	  If unsure, say Y.
1132
1133config QCOM_FALKOR_ERRATUM_E1041
1134	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1135	default y
1136	help
1137	  Falkor CPU may speculatively fetch instructions from an improper
1138	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1139	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1140
1141	  If unsure, say Y.
1142
1143config NVIDIA_CARMEL_CNP_ERRATUM
1144	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1145	default y
1146	help
1147	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1148	  invalidate shared TLB entries installed by a different core, as it would
1149	  on standard ARM cores.
1150
1151	  If unsure, say Y.
1152
1153config SOCIONEXT_SYNQUACER_PREITS
1154	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1155	default y
1156	help
1157	  Socionext Synquacer SoCs implement a separate h/w block to generate
1158	  MSI doorbell writes with non-zero values for the device ID.
1159
1160	  If unsure, say Y.
1161
1162endmenu # "ARM errata workarounds via the alternatives framework"
1163
1164choice
1165	prompt "Page size"
1166	default ARM64_4K_PAGES
1167	help
1168	  Page size (translation granule) configuration.
1169
1170config ARM64_4K_PAGES
1171	bool "4KB"
1172	help
1173	  This feature enables 4KB pages support.
1174
1175config ARM64_16K_PAGES
1176	bool "16KB"
1177	help
1178	  The system will use 16KB pages support. AArch32 emulation
1179	  requires applications compiled with 16K (or a multiple of 16K)
1180	  aligned segments.
1181
1182config ARM64_64K_PAGES
1183	bool "64KB"
1184	help
1185	  This feature enables 64KB pages support (4KB by default)
1186	  allowing only two levels of page tables and faster TLB
1187	  look-up. AArch32 emulation requires applications compiled
1188	  with 64K aligned segments.
1189
1190endchoice
1191
1192choice
1193	prompt "Virtual address space size"
1194	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1195	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1196	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1197	help
1198	  Allows choosing one of multiple possible virtual address
1199	  space sizes. The level of translation table is determined by
1200	  a combination of page size and virtual address space size.
1201
1202config ARM64_VA_BITS_36
1203	bool "36-bit" if EXPERT
1204	depends on ARM64_16K_PAGES
1205
1206config ARM64_VA_BITS_39
1207	bool "39-bit"
1208	depends on ARM64_4K_PAGES
1209
1210config ARM64_VA_BITS_42
1211	bool "42-bit"
1212	depends on ARM64_64K_PAGES
1213
1214config ARM64_VA_BITS_47
1215	bool "47-bit"
1216	depends on ARM64_16K_PAGES
1217
1218config ARM64_VA_BITS_48
1219	bool "48-bit"
1220
1221config ARM64_VA_BITS_52
1222	bool "52-bit"
1223	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1224	help
1225	  Enable 52-bit virtual addressing for userspace when explicitly
1226	  requested via a hint to mmap(). The kernel will also use 52-bit
1227	  virtual addresses for its own mappings (provided HW support for
1228	  this feature is available, otherwise it reverts to 48-bit).
1229
1230	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1231	  ARMv8.3 Pointer Authentication will result in the PAC being
1232	  reduced from 7 bits to 3 bits, which may have a significant
1233	  impact on its susceptibility to brute-force attacks.
1234
1235	  If unsure, select 48-bit virtual addressing instead.
1236
1237endchoice
1238
1239config ARM64_FORCE_52BIT
1240	bool "Force 52-bit virtual addresses for userspace"
1241	depends on ARM64_VA_BITS_52 && EXPERT
1242	help
1243	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1244	  to maintain compatibility with older software by providing 48-bit VAs
1245	  unless a hint is supplied to mmap.
1246
1247	  This configuration option disables the 48-bit compatibility logic, and
1248	  forces all userspace addresses to be 52-bit on HW that supports it. One
1249	  should only enable this configuration option for stress testing userspace
1250	  memory management code. If unsure say N here.
1251
1252config ARM64_VA_BITS
1253	int
1254	default 36 if ARM64_VA_BITS_36
1255	default 39 if ARM64_VA_BITS_39
1256	default 42 if ARM64_VA_BITS_42
1257	default 47 if ARM64_VA_BITS_47
1258	default 48 if ARM64_VA_BITS_48
1259	default 52 if ARM64_VA_BITS_52
1260
1261choice
1262	prompt "Physical address space size"
1263	default ARM64_PA_BITS_48
1264	help
1265	  Choose the maximum physical address range that the kernel will
1266	  support.
1267
1268config ARM64_PA_BITS_48
1269	bool "48-bit"
1270
1271config ARM64_PA_BITS_52
1272	bool "52-bit (ARMv8.2)"
1273	depends on ARM64_64K_PAGES
1274	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1275	help
1276	  Enable support for a 52-bit physical address space, introduced as
1277	  part of the ARMv8.2-LPA extension.
1278
1279	  With this enabled, the kernel will also continue to work on CPUs that
1280	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1281	  minor performance overhead).
1282
1283endchoice
1284
1285config ARM64_PA_BITS
1286	int
1287	default 48 if ARM64_PA_BITS_48
1288	default 52 if ARM64_PA_BITS_52
1289
1290choice
1291	prompt "Endianness"
1292	default CPU_LITTLE_ENDIAN
1293	help
1294	  Select the endianness of data accesses performed by the CPU. Userspace
1295	  applications will need to be compiled and linked for the endianness
1296	  that is selected here.
1297
1298config CPU_BIG_ENDIAN
1299	bool "Build big-endian kernel"
1300	depends on !LD_IS_LLD || LLD_VERSION >= 130000
1301	help
1302	  Say Y if you plan on running a kernel with a big-endian userspace.
1303
1304config CPU_LITTLE_ENDIAN
1305	bool "Build little-endian kernel"
1306	help
1307	  Say Y if you plan on running a kernel with a little-endian userspace.
1308	  This is usually the case for distributions targeting arm64.
1309
1310endchoice
1311
1312config SCHED_MC
1313	bool "Multi-core scheduler support"
1314	help
1315	  Multi-core scheduler support improves the CPU scheduler's decision
1316	  making when dealing with multi-core CPU chips at a cost of slightly
1317	  increased overhead in some places. If unsure say N here.
1318
1319config SCHED_CLUSTER
1320	bool "Cluster scheduler support"
1321	help
1322	  Cluster scheduler support improves the CPU scheduler's decision
1323	  making when dealing with machines that have clusters of CPUs.
1324	  Cluster usually means a couple of CPUs which are placed closely
1325	  by sharing mid-level caches, last-level cache tags or internal
1326	  busses.
1327
1328config SCHED_SMT
1329	bool "SMT scheduler support"
1330	help
1331	  Improves the CPU scheduler's decision making when dealing with
1332	  MultiThreading at a cost of slightly increased overhead in some
1333	  places. If unsure say N here.
1334
1335config NR_CPUS
1336	int "Maximum number of CPUs (2-4096)"
1337	range 2 4096
1338	default "256"
1339
1340config HOTPLUG_CPU
1341	bool "Support for hot-pluggable CPUs"
1342	select GENERIC_IRQ_MIGRATION
1343	help
1344	  Say Y here to experiment with turning CPUs off and on.  CPUs
1345	  can be controlled through /sys/devices/system/cpu.
1346
1347# Common NUMA Features
1348config NUMA
1349	bool "NUMA Memory Allocation and Scheduler Support"
1350	select GENERIC_ARCH_NUMA
1351	select ACPI_NUMA if ACPI
1352	select OF_NUMA
1353	select HAVE_SETUP_PER_CPU_AREA
1354	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1355	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1356	select USE_PERCPU_NUMA_NODE_ID
1357	help
1358	  Enable NUMA (Non-Uniform Memory Access) support.
1359
1360	  The kernel will try to allocate memory used by a CPU on the
1361	  local memory of the CPU and add some more
1362	  NUMA awareness to the kernel.
1363
1364config NODES_SHIFT
1365	int "Maximum NUMA Nodes (as a power of 2)"
1366	range 1 10
1367	default "4"
1368	depends on NUMA
1369	help
1370	  Specify the maximum number of NUMA Nodes available on the target
1371	  system.  Increases memory reserved to accommodate various tables.
1372
1373source "kernel/Kconfig.hz"
1374
1375config ARCH_SPARSEMEM_ENABLE
1376	def_bool y
1377	select SPARSEMEM_VMEMMAP_ENABLE
1378	select SPARSEMEM_VMEMMAP
1379
1380config HW_PERF_EVENTS
1381	def_bool y
1382	depends on ARM_PMU
1383
1384# Supported by clang >= 7.0 or GCC >= 12.0.0
1385config CC_HAVE_SHADOW_CALL_STACK
1386	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1387
1388config PARAVIRT
1389	bool "Enable paravirtualization code"
1390	help
1391	  This changes the kernel so it can modify itself when it is run
1392	  under a hypervisor, potentially improving performance significantly
1393	  over full virtualization.
1394
1395config PARAVIRT_TIME_ACCOUNTING
1396	bool "Paravirtual steal time accounting"
1397	select PARAVIRT
1398	help
1399	  Select this option to enable fine granularity task steal time
1400	  accounting. Time spent executing other tasks in parallel with
1401	  the current vCPU is discounted from the vCPU power. To account for
1402	  that, there can be a small performance impact.
1403
1404	  If in doubt, say N here.
1405
1406config KEXEC
1407	depends on PM_SLEEP_SMP
1408	select KEXEC_CORE
1409	bool "kexec system call"
1410	help
1411	  kexec is a system call that implements the ability to shutdown your
1412	  current kernel, and to start another kernel.  It is like a reboot
1413	  but it is independent of the system firmware.   And like a reboot
1414	  you can start any kernel with it, not just Linux.
1415
1416config KEXEC_FILE
1417	bool "kexec file based system call"
1418	select KEXEC_CORE
1419	select HAVE_IMA_KEXEC if IMA
1420	help
1421	  This is new version of kexec system call. This system call is
1422	  file based and takes file descriptors as system call argument
1423	  for kernel and initramfs as opposed to list of segments as
1424	  accepted by previous system call.
1425
1426config KEXEC_SIG
1427	bool "Verify kernel signature during kexec_file_load() syscall"
1428	depends on KEXEC_FILE
1429	help
1430	  Select this option to verify a signature with loaded kernel
1431	  image. If configured, any attempt of loading a image without
1432	  valid signature will fail.
1433
1434	  In addition to that option, you need to enable signature
1435	  verification for the corresponding kernel image type being
1436	  loaded in order for this to work.
1437
1438config KEXEC_IMAGE_VERIFY_SIG
1439	bool "Enable Image signature verification support"
1440	default y
1441	depends on KEXEC_SIG
1442	depends on EFI && SIGNED_PE_FILE_VERIFICATION
1443	help
1444	  Enable Image signature verification support.
1445
1446comment "Support for PE file signature verification disabled"
1447	depends on KEXEC_SIG
1448	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
1449
1450config CRASH_DUMP
1451	bool "Build kdump crash kernel"
1452	help
1453	  Generate crash dump after being started by kexec. This should
1454	  be normally only set in special crash dump kernels which are
1455	  loaded in the main kernel with kexec-tools into a specially
1456	  reserved region and then later executed after a crash by
1457	  kdump/kexec.
1458
1459	  For more details see Documentation/admin-guide/kdump/kdump.rst
1460
1461config TRANS_TABLE
1462	def_bool y
1463	depends on HIBERNATION || KEXEC_CORE
1464
1465config XEN_DOM0
1466	def_bool y
1467	depends on XEN
1468
1469config XEN
1470	bool "Xen guest support on ARM64"
1471	depends on ARM64 && OF
1472	select SWIOTLB_XEN
1473	select PARAVIRT
1474	help
1475	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1476
1477# include/linux/mmzone.h requires the following to be true:
1478#
1479#   MAX_ORDER - 1 + PAGE_SHIFT <= SECTION_SIZE_BITS
1480#
1481# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS + 1 - PAGE_SHIFT:
1482#
1483#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_ORDER  |  default MAX_ORDER |
1484# ----+-------------------+--------------+-----------------+--------------------+
1485# 4K  |       27          |      12      |       16        |         11         |
1486# 16K |       27          |      14      |       14        |         12         |
1487# 64K |       29          |      16      |       14        |         14         |
1488config ARCH_FORCE_MAX_ORDER
1489	int "Maximum zone order" if ARM64_4K_PAGES || ARM64_16K_PAGES
1490	default "14" if ARM64_64K_PAGES
1491	range 12 14 if ARM64_16K_PAGES
1492	default "12" if ARM64_16K_PAGES
1493	range 11 16 if ARM64_4K_PAGES
1494	default "11"
1495	help
1496	  The kernel memory allocator divides physically contiguous memory
1497	  blocks into "zones", where each zone is a power of two number of
1498	  pages.  This option selects the largest power of two that the kernel
1499	  keeps in the memory allocator.  If you need to allocate very large
1500	  blocks of physically contiguous memory, then you may need to
1501	  increase this value.
1502
1503	  This config option is actually maximum order plus one. For example,
1504	  a value of 11 means that the largest free memory block is 2^10 pages.
1505
1506	  We make sure that we can allocate up to a HugePage size for each configuration.
1507	  Hence we have :
1508		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1509
1510	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1511	  4M allocations matching the default size used by generic code.
1512
1513config UNMAP_KERNEL_AT_EL0
1514	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1515	default y
1516	help
1517	  Speculation attacks against some high-performance processors can
1518	  be used to bypass MMU permission checks and leak kernel data to
1519	  userspace. This can be defended against by unmapping the kernel
1520	  when running in userspace, mapping it back in on exception entry
1521	  via a trampoline page in the vector table.
1522
1523	  If unsure, say Y.
1524
1525config MITIGATE_SPECTRE_BRANCH_HISTORY
1526	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1527	default y
1528	help
1529	  Speculation attacks against some high-performance processors can
1530	  make use of branch history to influence future speculation.
1531	  When taking an exception from user-space, a sequence of branches
1532	  or a firmware call overwrites the branch history.
1533
1534config RODATA_FULL_DEFAULT_ENABLED
1535	bool "Apply r/o permissions of VM areas also to their linear aliases"
1536	default y
1537	help
1538	  Apply read-only attributes of VM areas to the linear alias of
1539	  the backing pages as well. This prevents code or read-only data
1540	  from being modified (inadvertently or intentionally) via another
1541	  mapping of the same memory page. This additional enhancement can
1542	  be turned off at runtime by passing rodata=[off|on] (and turned on
1543	  with rodata=full if this option is set to 'n')
1544
1545	  This requires the linear region to be mapped down to pages,
1546	  which may adversely affect performance in some cases.
1547
1548config ARM64_SW_TTBR0_PAN
1549	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1550	help
1551	  Enabling this option prevents the kernel from accessing
1552	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1553	  zeroed area and reserved ASID. The user access routines
1554	  restore the valid TTBR0_EL1 temporarily.
1555
1556config ARM64_TAGGED_ADDR_ABI
1557	bool "Enable the tagged user addresses syscall ABI"
1558	default y
1559	help
1560	  When this option is enabled, user applications can opt in to a
1561	  relaxed ABI via prctl() allowing tagged addresses to be passed
1562	  to system calls as pointer arguments. For details, see
1563	  Documentation/arm64/tagged-address-abi.rst.
1564
1565menuconfig COMPAT
1566	bool "Kernel support for 32-bit EL0"
1567	depends on ARM64_4K_PAGES || EXPERT
1568	select HAVE_UID16
1569	select OLD_SIGSUSPEND3
1570	select COMPAT_OLD_SIGACTION
1571	help
1572	  This option enables support for a 32-bit EL0 running under a 64-bit
1573	  kernel at EL1. AArch32-specific components such as system calls,
1574	  the user helper functions, VFP support and the ptrace interface are
1575	  handled appropriately by the kernel.
1576
1577	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1578	  that you will only be able to execute AArch32 binaries that were compiled
1579	  with page size aligned segments.
1580
1581	  If you want to execute 32-bit userspace applications, say Y.
1582
1583if COMPAT
1584
1585config KUSER_HELPERS
1586	bool "Enable kuser helpers page for 32-bit applications"
1587	default y
1588	help
1589	  Warning: disabling this option may break 32-bit user programs.
1590
1591	  Provide kuser helpers to compat tasks. The kernel provides
1592	  helper code to userspace in read only form at a fixed location
1593	  to allow userspace to be independent of the CPU type fitted to
1594	  the system. This permits binaries to be run on ARMv4 through
1595	  to ARMv8 without modification.
1596
1597	  See Documentation/arm/kernel_user_helpers.rst for details.
1598
1599	  However, the fixed address nature of these helpers can be used
1600	  by ROP (return orientated programming) authors when creating
1601	  exploits.
1602
1603	  If all of the binaries and libraries which run on your platform
1604	  are built specifically for your platform, and make no use of
1605	  these helpers, then you can turn this option off to hinder
1606	  such exploits. However, in that case, if a binary or library
1607	  relying on those helpers is run, it will not function correctly.
1608
1609	  Say N here only if you are absolutely certain that you do not
1610	  need these helpers; otherwise, the safe option is to say Y.
1611
1612config COMPAT_VDSO
1613	bool "Enable vDSO for 32-bit applications"
1614	depends on !CPU_BIG_ENDIAN
1615	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1616	select GENERIC_COMPAT_VDSO
1617	default y
1618	help
1619	  Place in the process address space of 32-bit applications an
1620	  ELF shared object providing fast implementations of gettimeofday
1621	  and clock_gettime.
1622
1623	  You must have a 32-bit build of glibc 2.22 or later for programs
1624	  to seamlessly take advantage of this.
1625
1626config THUMB2_COMPAT_VDSO
1627	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1628	depends on COMPAT_VDSO
1629	default y
1630	help
1631	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1632	  otherwise with '-marm'.
1633
1634config COMPAT_ALIGNMENT_FIXUPS
1635	bool "Fix up misaligned multi-word loads and stores in user space"
1636
1637menuconfig ARMV8_DEPRECATED
1638	bool "Emulate deprecated/obsolete ARMv8 instructions"
1639	depends on SYSCTL
1640	help
1641	  Legacy software support may require certain instructions
1642	  that have been deprecated or obsoleted in the architecture.
1643
1644	  Enable this config to enable selective emulation of these
1645	  features.
1646
1647	  If unsure, say Y
1648
1649if ARMV8_DEPRECATED
1650
1651config SWP_EMULATION
1652	bool "Emulate SWP/SWPB instructions"
1653	help
1654	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1655	  they are always undefined. Say Y here to enable software
1656	  emulation of these instructions for userspace using LDXR/STXR.
1657	  This feature can be controlled at runtime with the abi.swp
1658	  sysctl which is disabled by default.
1659
1660	  In some older versions of glibc [<=2.8] SWP is used during futex
1661	  trylock() operations with the assumption that the code will not
1662	  be preempted. This invalid assumption may be more likely to fail
1663	  with SWP emulation enabled, leading to deadlock of the user
1664	  application.
1665
1666	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1667	  on an external transaction monitoring block called a global
1668	  monitor to maintain update atomicity. If your system does not
1669	  implement a global monitor, this option can cause programs that
1670	  perform SWP operations to uncached memory to deadlock.
1671
1672	  If unsure, say Y
1673
1674config CP15_BARRIER_EMULATION
1675	bool "Emulate CP15 Barrier instructions"
1676	help
1677	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1678	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1679	  strongly recommended to use the ISB, DSB, and DMB
1680	  instructions instead.
1681
1682	  Say Y here to enable software emulation of these
1683	  instructions for AArch32 userspace code. When this option is
1684	  enabled, CP15 barrier usage is traced which can help
1685	  identify software that needs updating. This feature can be
1686	  controlled at runtime with the abi.cp15_barrier sysctl.
1687
1688	  If unsure, say Y
1689
1690config SETEND_EMULATION
1691	bool "Emulate SETEND instruction"
1692	help
1693	  The SETEND instruction alters the data-endianness of the
1694	  AArch32 EL0, and is deprecated in ARMv8.
1695
1696	  Say Y here to enable software emulation of the instruction
1697	  for AArch32 userspace code. This feature can be controlled
1698	  at runtime with the abi.setend sysctl.
1699
1700	  Note: All the cpus on the system must have mixed endian support at EL0
1701	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1702	  endian - is hotplugged in after this feature has been enabled, there could
1703	  be unexpected results in the applications.
1704
1705	  If unsure, say Y
1706endif # ARMV8_DEPRECATED
1707
1708endif # COMPAT
1709
1710menu "ARMv8.1 architectural features"
1711
1712config ARM64_HW_AFDBM
1713	bool "Support for hardware updates of the Access and Dirty page flags"
1714	default y
1715	help
1716	  The ARMv8.1 architecture extensions introduce support for
1717	  hardware updates of the access and dirty information in page
1718	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1719	  capable processors, accesses to pages with PTE_AF cleared will
1720	  set this bit instead of raising an access flag fault.
1721	  Similarly, writes to read-only pages with the DBM bit set will
1722	  clear the read-only bit (AP[2]) instead of raising a
1723	  permission fault.
1724
1725	  Kernels built with this configuration option enabled continue
1726	  to work on pre-ARMv8.1 hardware and the performance impact is
1727	  minimal. If unsure, say Y.
1728
1729config ARM64_PAN
1730	bool "Enable support for Privileged Access Never (PAN)"
1731	default y
1732	help
1733	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1734	  prevents the kernel or hypervisor from accessing user-space (EL0)
1735	  memory directly.
1736
1737	  Choosing this option will cause any unprotected (not using
1738	  copy_to_user et al) memory access to fail with a permission fault.
1739
1740	  The feature is detected at runtime, and will remain as a 'nop'
1741	  instruction if the cpu does not implement the feature.
1742
1743config AS_HAS_LDAPR
1744	def_bool $(as-instr,.arch_extension rcpc)
1745
1746config AS_HAS_LSE_ATOMICS
1747	def_bool $(as-instr,.arch_extension lse)
1748
1749config ARM64_LSE_ATOMICS
1750	bool
1751	default ARM64_USE_LSE_ATOMICS
1752	depends on AS_HAS_LSE_ATOMICS
1753
1754config ARM64_USE_LSE_ATOMICS
1755	bool "Atomic instructions"
1756	default y
1757	help
1758	  As part of the Large System Extensions, ARMv8.1 introduces new
1759	  atomic instructions that are designed specifically to scale in
1760	  very large systems.
1761
1762	  Say Y here to make use of these instructions for the in-kernel
1763	  atomic routines. This incurs a small overhead on CPUs that do
1764	  not support these instructions and requires the kernel to be
1765	  built with binutils >= 2.25 in order for the new instructions
1766	  to be used.
1767
1768endmenu # "ARMv8.1 architectural features"
1769
1770menu "ARMv8.2 architectural features"
1771
1772config AS_HAS_ARMV8_2
1773	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1774
1775config AS_HAS_SHA3
1776	def_bool $(as-instr,.arch armv8.2-a+sha3)
1777
1778config ARM64_PMEM
1779	bool "Enable support for persistent memory"
1780	select ARCH_HAS_PMEM_API
1781	select ARCH_HAS_UACCESS_FLUSHCACHE
1782	help
1783	  Say Y to enable support for the persistent memory API based on the
1784	  ARMv8.2 DCPoP feature.
1785
1786	  The feature is detected at runtime, and the kernel will use DC CVAC
1787	  operations if DC CVAP is not supported (following the behaviour of
1788	  DC CVAP itself if the system does not define a point of persistence).
1789
1790config ARM64_RAS_EXTN
1791	bool "Enable support for RAS CPU Extensions"
1792	default y
1793	help
1794	  CPUs that support the Reliability, Availability and Serviceability
1795	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1796	  errors, classify them and report them to software.
1797
1798	  On CPUs with these extensions system software can use additional
1799	  barriers to determine if faults are pending and read the
1800	  classification from a new set of registers.
1801
1802	  Selecting this feature will allow the kernel to use these barriers
1803	  and access the new registers if the system supports the extension.
1804	  Platform RAS features may additionally depend on firmware support.
1805
1806config ARM64_CNP
1807	bool "Enable support for Common Not Private (CNP) translations"
1808	default y
1809	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1810	help
1811	  Common Not Private (CNP) allows translation table entries to
1812	  be shared between different PEs in the same inner shareable
1813	  domain, so the hardware can use this fact to optimise the
1814	  caching of such entries in the TLB.
1815
1816	  Selecting this option allows the CNP feature to be detected
1817	  at runtime, and does not affect PEs that do not implement
1818	  this feature.
1819
1820endmenu # "ARMv8.2 architectural features"
1821
1822menu "ARMv8.3 architectural features"
1823
1824config ARM64_PTR_AUTH
1825	bool "Enable support for pointer authentication"
1826	default y
1827	help
1828	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1829	  instructions for signing and authenticating pointers against secret
1830	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1831	  and other attacks.
1832
1833	  This option enables these instructions at EL0 (i.e. for userspace).
1834	  Choosing this option will cause the kernel to initialise secret keys
1835	  for each process at exec() time, with these keys being
1836	  context-switched along with the process.
1837
1838	  The feature is detected at runtime. If the feature is not present in
1839	  hardware it will not be advertised to userspace/KVM guest nor will it
1840	  be enabled.
1841
1842	  If the feature is present on the boot CPU but not on a late CPU, then
1843	  the late CPU will be parked. Also, if the boot CPU does not have
1844	  address auth and the late CPU has then the late CPU will still boot
1845	  but with the feature disabled. On such a system, this option should
1846	  not be selected.
1847
1848config ARM64_PTR_AUTH_KERNEL
1849	bool "Use pointer authentication for kernel"
1850	default y
1851	depends on ARM64_PTR_AUTH
1852	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1853	# Modern compilers insert a .note.gnu.property section note for PAC
1854	# which is only understood by binutils starting with version 2.33.1.
1855	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1856	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1857	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1858	help
1859	  If the compiler supports the -mbranch-protection or
1860	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1861	  will cause the kernel itself to be compiled with return address
1862	  protection. In this case, and if the target hardware is known to
1863	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1864	  disabled with minimal loss of protection.
1865
1866	  This feature works with FUNCTION_GRAPH_TRACER option only if
1867	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
1868
1869config CC_HAS_BRANCH_PROT_PAC_RET
1870	# GCC 9 or later, clang 8 or later
1871	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1872
1873config CC_HAS_SIGN_RETURN_ADDRESS
1874	# GCC 7, 8
1875	def_bool $(cc-option,-msign-return-address=all)
1876
1877config AS_HAS_ARMV8_3
1878	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1879
1880config AS_HAS_CFI_NEGATE_RA_STATE
1881	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1882
1883endmenu # "ARMv8.3 architectural features"
1884
1885menu "ARMv8.4 architectural features"
1886
1887config ARM64_AMU_EXTN
1888	bool "Enable support for the Activity Monitors Unit CPU extension"
1889	default y
1890	help
1891	  The activity monitors extension is an optional extension introduced
1892	  by the ARMv8.4 CPU architecture. This enables support for version 1
1893	  of the activity monitors architecture, AMUv1.
1894
1895	  To enable the use of this extension on CPUs that implement it, say Y.
1896
1897	  Note that for architectural reasons, firmware _must_ implement AMU
1898	  support when running on CPUs that present the activity monitors
1899	  extension. The required support is present in:
1900	    * Version 1.5 and later of the ARM Trusted Firmware
1901
1902	  For kernels that have this configuration enabled but boot with broken
1903	  firmware, you may need to say N here until the firmware is fixed.
1904	  Otherwise you may experience firmware panics or lockups when
1905	  accessing the counter registers. Even if you are not observing these
1906	  symptoms, the values returned by the register reads might not
1907	  correctly reflect reality. Most commonly, the value read will be 0,
1908	  indicating that the counter is not enabled.
1909
1910config AS_HAS_ARMV8_4
1911	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1912
1913config ARM64_TLB_RANGE
1914	bool "Enable support for tlbi range feature"
1915	default y
1916	depends on AS_HAS_ARMV8_4
1917	help
1918	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1919	  range of input addresses.
1920
1921	  The feature introduces new assembly instructions, and they were
1922	  support when binutils >= 2.30.
1923
1924endmenu # "ARMv8.4 architectural features"
1925
1926menu "ARMv8.5 architectural features"
1927
1928config AS_HAS_ARMV8_5
1929	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1930
1931config ARM64_BTI
1932	bool "Branch Target Identification support"
1933	default y
1934	help
1935	  Branch Target Identification (part of the ARMv8.5 Extensions)
1936	  provides a mechanism to limit the set of locations to which computed
1937	  branch instructions such as BR or BLR can jump.
1938
1939	  To make use of BTI on CPUs that support it, say Y.
1940
1941	  BTI is intended to provide complementary protection to other control
1942	  flow integrity protection mechanisms, such as the Pointer
1943	  authentication mechanism provided as part of the ARMv8.3 Extensions.
1944	  For this reason, it does not make sense to enable this option without
1945	  also enabling support for pointer authentication.  Thus, when
1946	  enabling this option you should also select ARM64_PTR_AUTH=y.
1947
1948	  Userspace binaries must also be specifically compiled to make use of
1949	  this mechanism.  If you say N here or the hardware does not support
1950	  BTI, such binaries can still run, but you get no additional
1951	  enforcement of branch destinations.
1952
1953config ARM64_BTI_KERNEL
1954	bool "Use Branch Target Identification for kernel"
1955	default y
1956	depends on ARM64_BTI
1957	depends on ARM64_PTR_AUTH_KERNEL
1958	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1959	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1960	depends on !CC_IS_GCC || GCC_VERSION >= 100100
1961	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
1962	depends on !CC_IS_GCC
1963	# https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
1964	depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
1965	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1966	help
1967	  Build the kernel with Branch Target Identification annotations
1968	  and enable enforcement of this for kernel code. When this option
1969	  is enabled and the system supports BTI all kernel code including
1970	  modular code must have BTI enabled.
1971
1972config CC_HAS_BRANCH_PROT_PAC_RET_BTI
1973	# GCC 9 or later, clang 8 or later
1974	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
1975
1976config ARM64_E0PD
1977	bool "Enable support for E0PD"
1978	default y
1979	help
1980	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
1981	  that EL0 accesses made via TTBR1 always fault in constant time,
1982	  providing similar benefits to KASLR as those provided by KPTI, but
1983	  with lower overhead and without disrupting legitimate access to
1984	  kernel memory such as SPE.
1985
1986	  This option enables E0PD for TTBR1 where available.
1987
1988config ARM64_AS_HAS_MTE
1989	# Initial support for MTE went in binutils 2.32.0, checked with
1990	# ".arch armv8.5-a+memtag" below. However, this was incomplete
1991	# as a late addition to the final architecture spec (LDGM/STGM)
1992	# is only supported in the newer 2.32.x and 2.33 binutils
1993	# versions, hence the extra "stgm" instruction check below.
1994	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
1995
1996config ARM64_MTE
1997	bool "Memory Tagging Extension support"
1998	default y
1999	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2000	depends on AS_HAS_ARMV8_5
2001	depends on AS_HAS_LSE_ATOMICS
2002	# Required for tag checking in the uaccess routines
2003	depends on ARM64_PAN
2004	select ARCH_HAS_SUBPAGE_FAULTS
2005	select ARCH_USES_HIGH_VMA_FLAGS
2006	select ARCH_USES_PG_ARCH_X
2007	help
2008	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2009	  architectural support for run-time, always-on detection of
2010	  various classes of memory error to aid with software debugging
2011	  to eliminate vulnerabilities arising from memory-unsafe
2012	  languages.
2013
2014	  This option enables the support for the Memory Tagging
2015	  Extension at EL0 (i.e. for userspace).
2016
2017	  Selecting this option allows the feature to be detected at
2018	  runtime. Any secondary CPU not implementing this feature will
2019	  not be allowed a late bring-up.
2020
2021	  Userspace binaries that want to use this feature must
2022	  explicitly opt in. The mechanism for the userspace is
2023	  described in:
2024
2025	  Documentation/arm64/memory-tagging-extension.rst.
2026
2027endmenu # "ARMv8.5 architectural features"
2028
2029menu "ARMv8.7 architectural features"
2030
2031config ARM64_EPAN
2032	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2033	default y
2034	depends on ARM64_PAN
2035	help
2036	  Enhanced Privileged Access Never (EPAN) allows Privileged
2037	  Access Never to be used with Execute-only mappings.
2038
2039	  The feature is detected at runtime, and will remain disabled
2040	  if the cpu does not implement the feature.
2041endmenu # "ARMv8.7 architectural features"
2042
2043config ARM64_SVE
2044	bool "ARM Scalable Vector Extension support"
2045	default y
2046	help
2047	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2048	  execution state which complements and extends the SIMD functionality
2049	  of the base architecture to support much larger vectors and to enable
2050	  additional vectorisation opportunities.
2051
2052	  To enable use of this extension on CPUs that implement it, say Y.
2053
2054	  On CPUs that support the SVE2 extensions, this option will enable
2055	  those too.
2056
2057	  Note that for architectural reasons, firmware _must_ implement SVE
2058	  support when running on SVE capable hardware.  The required support
2059	  is present in:
2060
2061	    * version 1.5 and later of the ARM Trusted Firmware
2062	    * the AArch64 boot wrapper since commit 5e1261e08abf
2063	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2064
2065	  For other firmware implementations, consult the firmware documentation
2066	  or vendor.
2067
2068	  If you need the kernel to boot on SVE-capable hardware with broken
2069	  firmware, you may need to say N here until you get your firmware
2070	  fixed.  Otherwise, you may experience firmware panics or lockups when
2071	  booting the kernel.  If unsure and you are not observing these
2072	  symptoms, you should assume that it is safe to say Y.
2073
2074config ARM64_SME
2075	bool "ARM Scalable Matrix Extension support"
2076	default y
2077	depends on ARM64_SVE
2078	help
2079	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2080	  execution state which utilises a substantial subset of the SVE
2081	  instruction set, together with the addition of new architectural
2082	  register state capable of holding two dimensional matrix tiles to
2083	  enable various matrix operations.
2084
2085config ARM64_MODULE_PLTS
2086	bool "Use PLTs to allow module memory to spill over into vmalloc area"
2087	depends on MODULES
2088	select HAVE_MOD_ARCH_SPECIFIC
2089	help
2090	  Allocate PLTs when loading modules so that jumps and calls whose
2091	  targets are too far away for their relative offsets to be encoded
2092	  in the instructions themselves can be bounced via veneers in the
2093	  module's PLT. This allows modules to be allocated in the generic
2094	  vmalloc area after the dedicated module memory area has been
2095	  exhausted.
2096
2097	  When running with address space randomization (KASLR), the module
2098	  region itself may be too far away for ordinary relative jumps and
2099	  calls, and so in that case, module PLTs are required and cannot be
2100	  disabled.
2101
2102	  Specific errata workaround(s) might also force module PLTs to be
2103	  enabled (ARM64_ERRATUM_843419).
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 ARM64_MODULE_PLTS if MODULES
2146	select RELOCATABLE
2147	help
2148	  Randomizes the virtual address at which the kernel image is
2149	  loaded, as a security feature that deters exploit attempts
2150	  relying on knowledge of the location of kernel internals.
2151
2152	  It is the bootloader's job to provide entropy, by passing a
2153	  random u64 value in /chosen/kaslr-seed at kernel entry.
2154
2155	  When booting via the UEFI stub, it will invoke the firmware's
2156	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2157	  to the kernel proper. In addition, it will randomise the physical
2158	  location of the kernel Image as well.
2159
2160	  If unsure, say N.
2161
2162config RANDOMIZE_MODULE_REGION_FULL
2163	bool "Randomize the module region over a 2 GB range"
2164	depends on RANDOMIZE_BASE
2165	default y
2166	help
2167	  Randomizes the location of the module region inside a 2 GB window
2168	  covering the core kernel. This way, it is less likely for modules
2169	  to leak information about the location of core kernel data structures
2170	  but it does imply that function calls between modules and the core
2171	  kernel will need to be resolved via veneers in the module PLT.
2172
2173	  When this option is not set, the module region will be randomized over
2174	  a limited range that contains the [_stext, _etext] interval of the
2175	  core kernel, so branch relocations are almost always in range unless
2176	  ARM64_MODULE_PLTS is enabled and the region is exhausted. In this
2177	  particular case of region exhaustion, modules might be able to fall
2178	  back to a larger 2GB area.
2179
2180config CC_HAVE_STACKPROTECTOR_SYSREG
2181	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2182
2183config STACKPROTECTOR_PER_TASK
2184	def_bool y
2185	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2186
2187config UNWIND_PATCH_PAC_INTO_SCS
2188	bool "Enable shadow call stack dynamically using code patching"
2189	# needs Clang with https://reviews.llvm.org/D111780 incorporated
2190	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2191	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2192	depends on SHADOW_CALL_STACK
2193	select UNWIND_TABLES
2194	select DYNAMIC_SCS
2195
2196endmenu # "Kernel Features"
2197
2198menu "Boot options"
2199
2200config ARM64_ACPI_PARKING_PROTOCOL
2201	bool "Enable support for the ARM64 ACPI parking protocol"
2202	depends on ACPI
2203	help
2204	  Enable support for the ARM64 ACPI parking protocol. If disabled
2205	  the kernel will not allow booting through the ARM64 ACPI parking
2206	  protocol even if the corresponding data is present in the ACPI
2207	  MADT table.
2208
2209config CMDLINE
2210	string "Default kernel command string"
2211	default ""
2212	help
2213	  Provide a set of default command-line options at build time by
2214	  entering them here. As a minimum, you should specify the the
2215	  root device (e.g. root=/dev/nfs).
2216
2217choice
2218	prompt "Kernel command line type" if CMDLINE != ""
2219	default CMDLINE_FROM_BOOTLOADER
2220	help
2221	  Choose how the kernel will handle the provided default kernel
2222	  command line string.
2223
2224config CMDLINE_FROM_BOOTLOADER
2225	bool "Use bootloader kernel arguments if available"
2226	help
2227	  Uses the command-line options passed by the boot loader. If
2228	  the boot loader doesn't provide any, the default kernel command
2229	  string provided in CMDLINE will be used.
2230
2231config CMDLINE_FORCE
2232	bool "Always use the default kernel command string"
2233	help
2234	  Always use the default kernel command string, even if the boot
2235	  loader passes other arguments to the kernel.
2236	  This is useful if you cannot or don't want to change the
2237	  command-line options your boot loader passes to the kernel.
2238
2239endchoice
2240
2241config EFI_STUB
2242	bool
2243
2244config EFI
2245	bool "UEFI runtime support"
2246	depends on OF && !CPU_BIG_ENDIAN
2247	depends on KERNEL_MODE_NEON
2248	select ARCH_SUPPORTS_ACPI
2249	select LIBFDT
2250	select UCS2_STRING
2251	select EFI_PARAMS_FROM_FDT
2252	select EFI_RUNTIME_WRAPPERS
2253	select EFI_STUB
2254	select EFI_GENERIC_STUB
2255	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2256	default y
2257	help
2258	  This option provides support for runtime services provided
2259	  by UEFI firmware (such as non-volatile variables, realtime
2260	  clock, and platform reset). A UEFI stub is also provided to
2261	  allow the kernel to be booted as an EFI application. This
2262	  is only useful on systems that have UEFI firmware.
2263
2264config DMI
2265	bool "Enable support for SMBIOS (DMI) tables"
2266	depends on EFI
2267	default y
2268	help
2269	  This enables SMBIOS/DMI feature for systems.
2270
2271	  This option is only useful on systems that have UEFI firmware.
2272	  However, even with this option, the resultant kernel should
2273	  continue to boot on existing non-UEFI platforms.
2274
2275endmenu # "Boot options"
2276
2277menu "Power management options"
2278
2279source "kernel/power/Kconfig"
2280
2281config ARCH_HIBERNATION_POSSIBLE
2282	def_bool y
2283	depends on CPU_PM
2284
2285config ARCH_HIBERNATION_HEADER
2286	def_bool y
2287	depends on HIBERNATION
2288
2289config ARCH_SUSPEND_POSSIBLE
2290	def_bool y
2291
2292endmenu # "Power management options"
2293
2294menu "CPU Power Management"
2295
2296source "drivers/cpuidle/Kconfig"
2297
2298source "drivers/cpufreq/Kconfig"
2299
2300endmenu # "CPU Power Management"
2301
2302source "drivers/acpi/Kconfig"
2303
2304source "arch/arm64/kvm/Kconfig"
2305
2306