xref: /openbmc/linux/arch/arm64/Kconfig (revision 946e719c)
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_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
206	select HAVE_FUNCTION_GRAPH_TRACER
207	select HAVE_GCC_PLUGINS
208	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
209		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
210	select HAVE_HW_BREAKPOINT if PERF_EVENTS
211	select HAVE_IOREMAP_PROT
212	select HAVE_IRQ_TIME_ACCOUNTING
213	select HAVE_KVM
214	select HAVE_MOD_ARCH_SPECIFIC
215	select HAVE_NMI
216	select HAVE_PERF_EVENTS
217	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
218	select HAVE_PERF_REGS
219	select HAVE_PERF_USER_STACK_DUMP
220	select HAVE_PREEMPT_DYNAMIC_KEY
221	select HAVE_REGS_AND_STACK_ACCESS_API
222	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
223	select HAVE_FUNCTION_ARG_ACCESS_API
224	select MMU_GATHER_RCU_TABLE_FREE
225	select HAVE_RSEQ
226	select HAVE_STACKPROTECTOR
227	select HAVE_SYSCALL_TRACEPOINTS
228	select HAVE_KPROBES
229	select HAVE_KRETPROBES
230	select HAVE_GENERIC_VDSO
231	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
232	select IRQ_DOMAIN
233	select IRQ_FORCED_THREADING
234	select KASAN_VMALLOC if KASAN
235	select LOCK_MM_AND_FIND_VMA
236	select MODULES_USE_ELF_RELA
237	select NEED_DMA_MAP_STATE
238	select NEED_SG_DMA_LENGTH
239	select OF
240	select OF_EARLY_FLATTREE
241	select PCI_DOMAINS_GENERIC if PCI
242	select PCI_ECAM if (ACPI && PCI)
243	select PCI_SYSCALL if PCI
244	select POWER_RESET
245	select POWER_SUPPLY
246	select SPARSE_IRQ
247	select SWIOTLB
248	select SYSCTL_EXCEPTION_TRACE
249	select THREAD_INFO_IN_TASK
250	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
251	select TRACE_IRQFLAGS_SUPPORT
252	select TRACE_IRQFLAGS_NMI_SUPPORT
253	select HAVE_SOFTIRQ_ON_OWN_STACK
254	help
255	  ARM 64-bit (AArch64) Linux support.
256
257config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
258	def_bool CC_IS_CLANG
259	# https://github.com/ClangBuiltLinux/linux/issues/1507
260	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
261	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
262
263config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
264	def_bool CC_IS_GCC
265	depends on $(cc-option,-fpatchable-function-entry=2)
266	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
267
268config 64BIT
269	def_bool y
270
271config MMU
272	def_bool y
273
274config ARM64_PAGE_SHIFT
275	int
276	default 16 if ARM64_64K_PAGES
277	default 14 if ARM64_16K_PAGES
278	default 12
279
280config ARM64_CONT_PTE_SHIFT
281	int
282	default 5 if ARM64_64K_PAGES
283	default 7 if ARM64_16K_PAGES
284	default 4
285
286config ARM64_CONT_PMD_SHIFT
287	int
288	default 5 if ARM64_64K_PAGES
289	default 5 if ARM64_16K_PAGES
290	default 4
291
292config ARCH_MMAP_RND_BITS_MIN
293	default 14 if ARM64_64K_PAGES
294	default 16 if ARM64_16K_PAGES
295	default 18
296
297# max bits determined by the following formula:
298#  VA_BITS - PAGE_SHIFT - 3
299config ARCH_MMAP_RND_BITS_MAX
300	default 19 if ARM64_VA_BITS=36
301	default 24 if ARM64_VA_BITS=39
302	default 27 if ARM64_VA_BITS=42
303	default 30 if ARM64_VA_BITS=47
304	default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
305	default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
306	default 33 if ARM64_VA_BITS=48
307	default 14 if ARM64_64K_PAGES
308	default 16 if ARM64_16K_PAGES
309	default 18
310
311config ARCH_MMAP_RND_COMPAT_BITS_MIN
312	default 7 if ARM64_64K_PAGES
313	default 9 if ARM64_16K_PAGES
314	default 11
315
316config ARCH_MMAP_RND_COMPAT_BITS_MAX
317	default 16
318
319config NO_IOPORT_MAP
320	def_bool y if !PCI
321
322config STACKTRACE_SUPPORT
323	def_bool y
324
325config ILLEGAL_POINTER_VALUE
326	hex
327	default 0xdead000000000000
328
329config LOCKDEP_SUPPORT
330	def_bool y
331
332config GENERIC_BUG
333	def_bool y
334	depends on BUG
335
336config GENERIC_BUG_RELATIVE_POINTERS
337	def_bool y
338	depends on GENERIC_BUG
339
340config GENERIC_HWEIGHT
341	def_bool y
342
343config GENERIC_CSUM
344	def_bool y
345
346config GENERIC_CALIBRATE_DELAY
347	def_bool y
348
349config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
350	def_bool y
351
352config SMP
353	def_bool y
354
355config KERNEL_MODE_NEON
356	def_bool y
357
358config FIX_EARLYCON_MEM
359	def_bool y
360
361config PGTABLE_LEVELS
362	int
363	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
364	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
365	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
366	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
367	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
368	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
369
370config ARCH_SUPPORTS_UPROBES
371	def_bool y
372
373config ARCH_PROC_KCORE_TEXT
374	def_bool y
375
376config BROKEN_GAS_INST
377	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
378
379config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
380	bool
381	# Clang's __builtin_return_adddress() strips the PAC since 12.0.0
382	# https://reviews.llvm.org/D75044
383	default y if CC_IS_CLANG && (CLANG_VERSION >= 120000)
384	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
385	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
386	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
387	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
388	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
389	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
390	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
391	default n
392
393config KASAN_SHADOW_OFFSET
394	hex
395	depends on KASAN_GENERIC || KASAN_SW_TAGS
396	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
397	default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
398	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
399	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
400	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
401	default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
402	default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
403	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
404	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
405	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
406	default 0xffffffffffffffff
407
408config UNWIND_TABLES
409	bool
410
411source "arch/arm64/Kconfig.platforms"
412
413menu "Kernel Features"
414
415menu "ARM errata workarounds via the alternatives framework"
416
417config AMPERE_ERRATUM_AC03_CPU_38
418        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
419	default y
420	help
421	  This option adds an alternative code sequence to work around Ampere
422	  erratum AC03_CPU_38 on AmpereOne.
423
424	  The affected design reports FEAT_HAFDBS as not implemented in
425	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
426	  as required by the architecture. The unadvertised HAFDBS
427	  implementation suffers from an additional erratum where hardware
428	  A/D updates can occur after a PTE has been marked invalid.
429
430	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
431	  which avoids enabling unadvertised hardware Access Flag management
432	  at stage-2.
433
434	  If unsure, say Y.
435
436config ARM64_WORKAROUND_CLEAN_CACHE
437	bool
438
439config ARM64_ERRATUM_826319
440	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
441	default y
442	select ARM64_WORKAROUND_CLEAN_CACHE
443	help
444	  This option adds an alternative code sequence to work around ARM
445	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
446	  AXI master interface and an L2 cache.
447
448	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
449	  and is unable to accept a certain write via this interface, it will
450	  not progress on read data presented on the read data channel and the
451	  system can deadlock.
452
453	  The workaround promotes data cache clean instructions to
454	  data cache clean-and-invalidate.
455	  Please note that this does not necessarily enable the workaround,
456	  as it depends on the alternative framework, which will only patch
457	  the kernel if an affected CPU is detected.
458
459	  If unsure, say Y.
460
461config ARM64_ERRATUM_827319
462	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
463	default y
464	select ARM64_WORKAROUND_CLEAN_CACHE
465	help
466	  This option adds an alternative code sequence to work around ARM
467	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
468	  master interface and an L2 cache.
469
470	  Under certain conditions this erratum can cause a clean line eviction
471	  to occur at the same time as another transaction to the same address
472	  on the AMBA 5 CHI interface, which can cause data corruption if the
473	  interconnect reorders the two transactions.
474
475	  The workaround promotes data cache clean instructions to
476	  data cache clean-and-invalidate.
477	  Please note that this does not necessarily enable the workaround,
478	  as it depends on the alternative framework, which will only patch
479	  the kernel if an affected CPU is detected.
480
481	  If unsure, say Y.
482
483config ARM64_ERRATUM_824069
484	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
485	default y
486	select ARM64_WORKAROUND_CLEAN_CACHE
487	help
488	  This option adds an alternative code sequence to work around ARM
489	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
490	  to a coherent interconnect.
491
492	  If a Cortex-A53 processor is executing a store or prefetch for
493	  write instruction at the same time as a processor in another
494	  cluster is executing a cache maintenance operation to the same
495	  address, then this erratum might cause a clean cache line to be
496	  incorrectly marked as dirty.
497
498	  The workaround promotes data cache clean instructions to
499	  data cache clean-and-invalidate.
500	  Please note that this option does not necessarily enable the
501	  workaround, as it depends on the alternative framework, which will
502	  only patch the kernel if an affected CPU is detected.
503
504	  If unsure, say Y.
505
506config ARM64_ERRATUM_819472
507	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
508	default y
509	select ARM64_WORKAROUND_CLEAN_CACHE
510	help
511	  This option adds an alternative code sequence to work around ARM
512	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
513	  present when it is connected to a coherent interconnect.
514
515	  If the processor is executing a load and store exclusive sequence at
516	  the same time as a processor in another cluster is executing a cache
517	  maintenance operation to the same address, then this erratum might
518	  cause data corruption.
519
520	  The workaround promotes data cache clean instructions to
521	  data cache clean-and-invalidate.
522	  Please note that this does not necessarily enable the workaround,
523	  as it depends on the alternative framework, which will only patch
524	  the kernel if an affected CPU is detected.
525
526	  If unsure, say Y.
527
528config ARM64_ERRATUM_832075
529	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
530	default y
531	help
532	  This option adds an alternative code sequence to work around ARM
533	  erratum 832075 on Cortex-A57 parts up to r1p2.
534
535	  Affected Cortex-A57 parts might deadlock when exclusive load/store
536	  instructions to Write-Back memory are mixed with Device loads.
537
538	  The workaround is to promote device loads to use Load-Acquire
539	  semantics.
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_834220
547	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
548	depends on KVM
549	default y
550	help
551	  This option adds an alternative code sequence to work around ARM
552	  erratum 834220 on Cortex-A57 parts up to r1p2.
553
554	  Affected Cortex-A57 parts might report a Stage 2 translation
555	  fault as the result of a Stage 1 fault for load crossing a
556	  page boundary when there is a permission or device memory
557	  alignment fault at Stage 1 and a translation fault at Stage 2.
558
559	  The workaround is to verify that the Stage 1 translation
560	  doesn't generate a fault before handling the Stage 2 fault.
561	  Please note that this does not necessarily enable the workaround,
562	  as it depends on the alternative framework, which will only patch
563	  the kernel if an affected CPU is detected.
564
565	  If unsure, say Y.
566
567config ARM64_ERRATUM_1742098
568	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
569	depends on COMPAT
570	default y
571	help
572	  This option removes the AES hwcap for aarch32 user-space to
573	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
574
575	  Affected parts may corrupt the AES state if an interrupt is
576	  taken between a pair of AES instructions. These instructions
577	  are only present if the cryptography extensions are present.
578	  All software should have a fallback implementation for CPUs
579	  that don't implement the cryptography extensions.
580
581	  If unsure, say Y.
582
583config ARM64_ERRATUM_845719
584	bool "Cortex-A53: 845719: a load might read incorrect data"
585	depends on COMPAT
586	default y
587	help
588	  This option adds an alternative code sequence to work around ARM
589	  erratum 845719 on Cortex-A53 parts up to r0p4.
590
591	  When running a compat (AArch32) userspace on an affected Cortex-A53
592	  part, a load at EL0 from a virtual address that matches the bottom 32
593	  bits of the virtual address used by a recent load at (AArch64) EL1
594	  might return incorrect data.
595
596	  The workaround is to write the contextidr_el1 register on exception
597	  return to a 32-bit task.
598	  Please note that this does not necessarily enable the workaround,
599	  as it depends on the alternative framework, which will only patch
600	  the kernel if an affected CPU is detected.
601
602	  If unsure, say Y.
603
604config ARM64_ERRATUM_843419
605	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
606	default y
607	help
608	  This option links the kernel with '--fix-cortex-a53-843419' and
609	  enables PLT support to replace certain ADRP instructions, which can
610	  cause subsequent memory accesses to use an incorrect address on
611	  Cortex-A53 parts up to r0p4.
612
613	  If unsure, say Y.
614
615config ARM64_LD_HAS_FIX_ERRATUM_843419
616	def_bool $(ld-option,--fix-cortex-a53-843419)
617
618config ARM64_ERRATUM_1024718
619	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
620	default y
621	help
622	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
623
624	  Affected Cortex-A55 cores (all revisions) could cause incorrect
625	  update of the hardware dirty bit when the DBM/AP bits are updated
626	  without a break-before-make. The workaround is to disable the usage
627	  of hardware DBM locally on the affected cores. CPUs not affected by
628	  this erratum will continue to use the feature.
629
630	  If unsure, say Y.
631
632config ARM64_ERRATUM_1418040
633	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
634	default y
635	depends on COMPAT
636	help
637	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
638	  errata 1188873 and 1418040.
639
640	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
641	  cause register corruption when accessing the timer registers
642	  from AArch32 userspace.
643
644	  If unsure, say Y.
645
646config ARM64_WORKAROUND_SPECULATIVE_AT
647	bool
648
649config ARM64_ERRATUM_1165522
650	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
651	default y
652	select ARM64_WORKAROUND_SPECULATIVE_AT
653	help
654	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
655
656	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
657	  corrupted TLBs by speculating an AT instruction during a guest
658	  context switch.
659
660	  If unsure, say Y.
661
662config ARM64_ERRATUM_1319367
663	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
664	default y
665	select ARM64_WORKAROUND_SPECULATIVE_AT
666	help
667	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
668	  and A72 erratum 1319367
669
670	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
671	  speculating an AT instruction during a guest context switch.
672
673	  If unsure, say Y.
674
675config ARM64_ERRATUM_1530923
676	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
677	default y
678	select ARM64_WORKAROUND_SPECULATIVE_AT
679	help
680	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
681
682	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
683	  corrupted TLBs by speculating an AT instruction during a guest
684	  context switch.
685
686	  If unsure, say Y.
687
688config ARM64_WORKAROUND_REPEAT_TLBI
689	bool
690
691config ARM64_ERRATUM_2441007
692	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
693	default y
694	select ARM64_WORKAROUND_REPEAT_TLBI
695	help
696	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
697
698	  Under very rare circumstances, affected Cortex-A55 CPUs
699	  may not handle a race between a break-before-make sequence on one
700	  CPU, and another CPU accessing the same page. This could allow a
701	  store to a page that has been unmapped.
702
703	  Work around this by adding the affected CPUs to the list that needs
704	  TLB sequences to be done twice.
705
706	  If unsure, say Y.
707
708config ARM64_ERRATUM_1286807
709	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
710	default y
711	select ARM64_WORKAROUND_REPEAT_TLBI
712	help
713	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
714
715	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
716	  address for a cacheable mapping of a location is being
717	  accessed by a core while another core is remapping the virtual
718	  address to a new physical page using the recommended
719	  break-before-make sequence, then under very rare circumstances
720	  TLBI+DSB completes before a read using the translation being
721	  invalidated has been observed by other observers. The
722	  workaround repeats the TLBI+DSB operation.
723
724config ARM64_ERRATUM_1463225
725	bool "Cortex-A76: Software Step might prevent interrupt recognition"
726	default y
727	help
728	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
729
730	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
731	  of a system call instruction (SVC) can prevent recognition of
732	  subsequent interrupts when software stepping is disabled in the
733	  exception handler of the system call and either kernel debugging
734	  is enabled or VHE is in use.
735
736	  Work around the erratum by triggering a dummy step exception
737	  when handling a system call from a task that is being stepped
738	  in a VHE configuration of the kernel.
739
740	  If unsure, say Y.
741
742config ARM64_ERRATUM_1542419
743	bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
744	default y
745	help
746	  This option adds a workaround for ARM Neoverse-N1 erratum
747	  1542419.
748
749	  Affected Neoverse-N1 cores could execute a stale instruction when
750	  modified by another CPU. The workaround depends on a firmware
751	  counterpart.
752
753	  Workaround the issue by hiding the DIC feature from EL0. This
754	  forces user-space to perform cache maintenance.
755
756	  If unsure, say Y.
757
758config ARM64_ERRATUM_1508412
759	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
760	default y
761	help
762	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
763
764	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
765	  of a store-exclusive or read of PAR_EL1 and a load with device or
766	  non-cacheable memory attributes. The workaround depends on a firmware
767	  counterpart.
768
769	  KVM guests must also have the workaround implemented or they can
770	  deadlock the system.
771
772	  Work around the issue by inserting DMB SY barriers around PAR_EL1
773	  register reads and warning KVM users. The DMB barrier is sufficient
774	  to prevent a speculative PAR_EL1 read.
775
776	  If unsure, say Y.
777
778config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
779	bool
780
781config ARM64_ERRATUM_2051678
782	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
783	default y
784	help
785	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
786	  Affected Cortex-A510 might not respect the ordering rules for
787	  hardware update of the page table's dirty bit. The workaround
788	  is to not enable the feature on affected CPUs.
789
790	  If unsure, say Y.
791
792config ARM64_ERRATUM_2077057
793	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
794	default y
795	help
796	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
797	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
798	  expected, but a Pointer Authentication trap is taken instead. The
799	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
800	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
801
802	  This can only happen when EL2 is stepping EL1.
803
804	  When these conditions occur, the SPSR_EL2 value is unchanged from the
805	  previous guest entry, and can be restored from the in-memory copy.
806
807	  If unsure, say Y.
808
809config ARM64_ERRATUM_2658417
810	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
811	default y
812	help
813	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
814	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
815	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
816	  A510 CPUs are using shared neon hardware. As the sharing is not
817	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
818	  user-space should not be using these instructions.
819
820	  If unsure, say Y.
821
822config ARM64_ERRATUM_2119858
823	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
824	default y
825	depends on CORESIGHT_TRBE
826	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
827	help
828	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
829
830	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
831	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
832	  the event of a WRAP event.
833
834	  Work around the issue by always making sure we move the TRBPTR_EL1 by
835	  256 bytes before enabling the buffer and filling the first 256 bytes of
836	  the buffer with ETM ignore packets upon disabling.
837
838	  If unsure, say Y.
839
840config ARM64_ERRATUM_2139208
841	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
842	default y
843	depends on CORESIGHT_TRBE
844	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
845	help
846	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
847
848	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
849	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
850	  the event of a WRAP event.
851
852	  Work around the issue by always making sure we move the TRBPTR_EL1 by
853	  256 bytes before enabling the buffer and filling the first 256 bytes of
854	  the buffer with ETM ignore packets upon disabling.
855
856	  If unsure, say Y.
857
858config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
859	bool
860
861config ARM64_ERRATUM_2054223
862	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
863	default y
864	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
865	help
866	  Enable workaround for ARM Cortex-A710 erratum 2054223
867
868	  Affected cores may fail to flush the trace data on a TSB instruction, when
869	  the PE is in trace prohibited state. This will cause losing a few bytes
870	  of the trace cached.
871
872	  Workaround is to issue two TSB consecutively on affected cores.
873
874	  If unsure, say Y.
875
876config ARM64_ERRATUM_2067961
877	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
878	default y
879	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
880	help
881	  Enable workaround for ARM Neoverse-N2 erratum 2067961
882
883	  Affected cores may fail to flush the trace data on a TSB instruction, when
884	  the PE is in trace prohibited state. This will cause losing a few bytes
885	  of the trace cached.
886
887	  Workaround is to issue two TSB consecutively on affected cores.
888
889	  If unsure, say Y.
890
891config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
892	bool
893
894config ARM64_ERRATUM_2253138
895	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
896	depends on CORESIGHT_TRBE
897	default y
898	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
899	help
900	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
901
902	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
903	  for TRBE. Under some conditions, the TRBE might generate a write to the next
904	  virtually addressed page following the last page of the TRBE address space
905	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
906
907	  Work around this in the driver by always making sure that there is a
908	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
909
910	  If unsure, say Y.
911
912config ARM64_ERRATUM_2224489
913	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
914	depends on CORESIGHT_TRBE
915	default y
916	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
917	help
918	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
919
920	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
921	  for TRBE. Under some conditions, the TRBE might generate a write to the next
922	  virtually addressed page following the last page of the TRBE address space
923	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
924
925	  Work around this in the driver by always making sure that there is a
926	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
927
928	  If unsure, say Y.
929
930config ARM64_ERRATUM_2441009
931	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
932	default y
933	select ARM64_WORKAROUND_REPEAT_TLBI
934	help
935	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
936
937	  Under very rare circumstances, affected Cortex-A510 CPUs
938	  may not handle a race between a break-before-make sequence on one
939	  CPU, and another CPU accessing the same page. This could allow a
940	  store to a page that has been unmapped.
941
942	  Work around this by adding the affected CPUs to the list that needs
943	  TLB sequences to be done twice.
944
945	  If unsure, say Y.
946
947config ARM64_ERRATUM_2064142
948	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
949	depends on CORESIGHT_TRBE
950	default y
951	help
952	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
953
954	  Affected Cortex-A510 core might fail to write into system registers after the
955	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
956	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
957	  and TRBTRG_EL1 will be ignored and will not be effected.
958
959	  Work around this in the driver by executing TSB CSYNC and DSB after collection
960	  is stopped and before performing a system register write to one of the affected
961	  registers.
962
963	  If unsure, say Y.
964
965config ARM64_ERRATUM_2038923
966	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
967	depends on CORESIGHT_TRBE
968	default y
969	help
970	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
971
972	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
973	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
974	  might be corrupted. This happens after TRBE buffer has been enabled by setting
975	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
976	  execution changes from a context, in which trace is prohibited to one where it
977	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
978	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
979	  the trace buffer state might be corrupted.
980
981	  Work around this in the driver by preventing an inconsistent view of whether the
982	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
983	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
984	  two ISB instructions if no ERET is to take place.
985
986	  If unsure, say Y.
987
988config ARM64_ERRATUM_1902691
989	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
990	depends on CORESIGHT_TRBE
991	default y
992	help
993	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
994
995	  Affected Cortex-A510 core might cause trace data corruption, when being written
996	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
997	  trace data.
998
999	  Work around this problem in the driver by just preventing TRBE initialization on
1000	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1001	  on such implementations. This will cover the kernel for any firmware that doesn't
1002	  do this already.
1003
1004	  If unsure, say Y.
1005
1006config ARM64_ERRATUM_2457168
1007	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1008	depends on ARM64_AMU_EXTN
1009	default y
1010	help
1011	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1012
1013	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1014	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1015	  incorrectly giving a significantly higher output value.
1016
1017	  Work around this problem by returning 0 when reading the affected counter in
1018	  key locations that results in disabling all users of this counter. This effect
1019	  is the same to firmware disabling affected counters.
1020
1021	  If unsure, say Y.
1022
1023config ARM64_ERRATUM_2645198
1024	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1025	default y
1026	help
1027	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1028
1029	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1030	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1031	  next instruction abort caused by permission fault.
1032
1033	  Only user-space does executable to non-executable permission transition via
1034	  mprotect() system call. Workaround the problem by doing a break-before-make
1035	  TLB invalidation, for all changes to executable user space mappings.
1036
1037	  If unsure, say Y.
1038
1039config CAVIUM_ERRATUM_22375
1040	bool "Cavium erratum 22375, 24313"
1041	default y
1042	help
1043	  Enable workaround for errata 22375 and 24313.
1044
1045	  This implements two gicv3-its errata workarounds for ThunderX. Both
1046	  with a small impact affecting only ITS table allocation.
1047
1048	    erratum 22375: only alloc 8MB table size
1049	    erratum 24313: ignore memory access type
1050
1051	  The fixes are in ITS initialization and basically ignore memory access
1052	  type and table size provided by the TYPER and BASER registers.
1053
1054	  If unsure, say Y.
1055
1056config CAVIUM_ERRATUM_23144
1057	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1058	depends on NUMA
1059	default y
1060	help
1061	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1062
1063	  If unsure, say Y.
1064
1065config CAVIUM_ERRATUM_23154
1066	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1067	default y
1068	help
1069	  The ThunderX GICv3 implementation requires a modified version for
1070	  reading the IAR status to ensure data synchronization
1071	  (access to icc_iar1_el1 is not sync'ed before and after).
1072
1073	  It also suffers from erratum 38545 (also present on Marvell's
1074	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1075	  spuriously presented to the CPU interface.
1076
1077	  If unsure, say Y.
1078
1079config CAVIUM_ERRATUM_27456
1080	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1081	default y
1082	help
1083	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1084	  instructions may cause the icache to become corrupted if it
1085	  contains data for a non-current ASID.  The fix is to
1086	  invalidate the icache when changing the mm context.
1087
1088	  If unsure, say Y.
1089
1090config CAVIUM_ERRATUM_30115
1091	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1092	default y
1093	help
1094	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1095	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1096	  interrupts in host. Trapping both GICv3 group-0 and group-1
1097	  accesses sidesteps the issue.
1098
1099	  If unsure, say Y.
1100
1101config CAVIUM_TX2_ERRATUM_219
1102	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1103	default y
1104	help
1105	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1106	  TTBR update and the corresponding context synchronizing operation can
1107	  cause a spurious Data Abort to be delivered to any hardware thread in
1108	  the CPU core.
1109
1110	  Work around the issue by avoiding the problematic code sequence and
1111	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1112	  trap handler performs the corresponding register access, skips the
1113	  instruction and ensures context synchronization by virtue of the
1114	  exception return.
1115
1116	  If unsure, say Y.
1117
1118config FUJITSU_ERRATUM_010001
1119	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1120	default y
1121	help
1122	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1123	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1124	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1125	  This fault occurs under a specific hardware condition when a
1126	  load/store instruction performs an address translation using:
1127	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1128	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1129	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1130	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1131
1132	  The workaround is to ensure these bits are clear in TCR_ELx.
1133	  The workaround only affects the Fujitsu-A64FX.
1134
1135	  If unsure, say Y.
1136
1137config HISILICON_ERRATUM_161600802
1138	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1139	default y
1140	help
1141	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1142	  when issued ITS commands such as VMOVP and VMAPP, and requires
1143	  a 128kB offset to be applied to the target address in this commands.
1144
1145	  If unsure, say Y.
1146
1147config QCOM_FALKOR_ERRATUM_1003
1148	bool "Falkor E1003: Incorrect translation due to ASID change"
1149	default y
1150	help
1151	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1152	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1153	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1154	  then only for entries in the walk cache, since the leaf translation
1155	  is unchanged. Work around the erratum by invalidating the walk cache
1156	  entries for the trampoline before entering the kernel proper.
1157
1158config QCOM_FALKOR_ERRATUM_1009
1159	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1160	default y
1161	select ARM64_WORKAROUND_REPEAT_TLBI
1162	help
1163	  On Falkor v1, the CPU may prematurely complete a DSB following a
1164	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1165	  one more time to fix the issue.
1166
1167	  If unsure, say Y.
1168
1169config QCOM_QDF2400_ERRATUM_0065
1170	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1171	default y
1172	help
1173	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1174	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1175	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1176
1177	  If unsure, say Y.
1178
1179config QCOM_FALKOR_ERRATUM_E1041
1180	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1181	default y
1182	help
1183	  Falkor CPU may speculatively fetch instructions from an improper
1184	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1185	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1186
1187	  If unsure, say Y.
1188
1189config NVIDIA_CARMEL_CNP_ERRATUM
1190	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1191	default y
1192	help
1193	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1194	  invalidate shared TLB entries installed by a different core, as it would
1195	  on standard ARM cores.
1196
1197	  If unsure, say Y.
1198
1199config ROCKCHIP_ERRATUM_3588001
1200	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1201	default y
1202	help
1203	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1204	  This means, that its sharability feature may not be used, even though it
1205	  is supported by the IP itself.
1206
1207	  If unsure, say Y.
1208
1209config SOCIONEXT_SYNQUACER_PREITS
1210	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1211	default y
1212	help
1213	  Socionext Synquacer SoCs implement a separate h/w block to generate
1214	  MSI doorbell writes with non-zero values for the device ID.
1215
1216	  If unsure, say Y.
1217
1218endmenu # "ARM errata workarounds via the alternatives framework"
1219
1220choice
1221	prompt "Page size"
1222	default ARM64_4K_PAGES
1223	help
1224	  Page size (translation granule) configuration.
1225
1226config ARM64_4K_PAGES
1227	bool "4KB"
1228	help
1229	  This feature enables 4KB pages support.
1230
1231config ARM64_16K_PAGES
1232	bool "16KB"
1233	help
1234	  The system will use 16KB pages support. AArch32 emulation
1235	  requires applications compiled with 16K (or a multiple of 16K)
1236	  aligned segments.
1237
1238config ARM64_64K_PAGES
1239	bool "64KB"
1240	help
1241	  This feature enables 64KB pages support (4KB by default)
1242	  allowing only two levels of page tables and faster TLB
1243	  look-up. AArch32 emulation requires applications compiled
1244	  with 64K aligned segments.
1245
1246endchoice
1247
1248choice
1249	prompt "Virtual address space size"
1250	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1251	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1252	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1253	help
1254	  Allows choosing one of multiple possible virtual address
1255	  space sizes. The level of translation table is determined by
1256	  a combination of page size and virtual address space size.
1257
1258config ARM64_VA_BITS_36
1259	bool "36-bit" if EXPERT
1260	depends on ARM64_16K_PAGES
1261
1262config ARM64_VA_BITS_39
1263	bool "39-bit"
1264	depends on ARM64_4K_PAGES
1265
1266config ARM64_VA_BITS_42
1267	bool "42-bit"
1268	depends on ARM64_64K_PAGES
1269
1270config ARM64_VA_BITS_47
1271	bool "47-bit"
1272	depends on ARM64_16K_PAGES
1273
1274config ARM64_VA_BITS_48
1275	bool "48-bit"
1276
1277config ARM64_VA_BITS_52
1278	bool "52-bit"
1279	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1280	help
1281	  Enable 52-bit virtual addressing for userspace when explicitly
1282	  requested via a hint to mmap(). The kernel will also use 52-bit
1283	  virtual addresses for its own mappings (provided HW support for
1284	  this feature is available, otherwise it reverts to 48-bit).
1285
1286	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1287	  ARMv8.3 Pointer Authentication will result in the PAC being
1288	  reduced from 7 bits to 3 bits, which may have a significant
1289	  impact on its susceptibility to brute-force attacks.
1290
1291	  If unsure, select 48-bit virtual addressing instead.
1292
1293endchoice
1294
1295config ARM64_FORCE_52BIT
1296	bool "Force 52-bit virtual addresses for userspace"
1297	depends on ARM64_VA_BITS_52 && EXPERT
1298	help
1299	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1300	  to maintain compatibility with older software by providing 48-bit VAs
1301	  unless a hint is supplied to mmap.
1302
1303	  This configuration option disables the 48-bit compatibility logic, and
1304	  forces all userspace addresses to be 52-bit on HW that supports it. One
1305	  should only enable this configuration option for stress testing userspace
1306	  memory management code. If unsure say N here.
1307
1308config ARM64_VA_BITS
1309	int
1310	default 36 if ARM64_VA_BITS_36
1311	default 39 if ARM64_VA_BITS_39
1312	default 42 if ARM64_VA_BITS_42
1313	default 47 if ARM64_VA_BITS_47
1314	default 48 if ARM64_VA_BITS_48
1315	default 52 if ARM64_VA_BITS_52
1316
1317choice
1318	prompt "Physical address space size"
1319	default ARM64_PA_BITS_48
1320	help
1321	  Choose the maximum physical address range that the kernel will
1322	  support.
1323
1324config ARM64_PA_BITS_48
1325	bool "48-bit"
1326
1327config ARM64_PA_BITS_52
1328	bool "52-bit (ARMv8.2)"
1329	depends on ARM64_64K_PAGES
1330	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1331	help
1332	  Enable support for a 52-bit physical address space, introduced as
1333	  part of the ARMv8.2-LPA extension.
1334
1335	  With this enabled, the kernel will also continue to work on CPUs that
1336	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1337	  minor performance overhead).
1338
1339endchoice
1340
1341config ARM64_PA_BITS
1342	int
1343	default 48 if ARM64_PA_BITS_48
1344	default 52 if ARM64_PA_BITS_52
1345
1346choice
1347	prompt "Endianness"
1348	default CPU_LITTLE_ENDIAN
1349	help
1350	  Select the endianness of data accesses performed by the CPU. Userspace
1351	  applications will need to be compiled and linked for the endianness
1352	  that is selected here.
1353
1354config CPU_BIG_ENDIAN
1355	bool "Build big-endian kernel"
1356	depends on !LD_IS_LLD || LLD_VERSION >= 130000
1357	help
1358	  Say Y if you plan on running a kernel with a big-endian userspace.
1359
1360config CPU_LITTLE_ENDIAN
1361	bool "Build little-endian kernel"
1362	help
1363	  Say Y if you plan on running a kernel with a little-endian userspace.
1364	  This is usually the case for distributions targeting arm64.
1365
1366endchoice
1367
1368config SCHED_MC
1369	bool "Multi-core scheduler support"
1370	help
1371	  Multi-core scheduler support improves the CPU scheduler's decision
1372	  making when dealing with multi-core CPU chips at a cost of slightly
1373	  increased overhead in some places. If unsure say N here.
1374
1375config SCHED_CLUSTER
1376	bool "Cluster scheduler support"
1377	help
1378	  Cluster scheduler support improves the CPU scheduler's decision
1379	  making when dealing with machines that have clusters of CPUs.
1380	  Cluster usually means a couple of CPUs which are placed closely
1381	  by sharing mid-level caches, last-level cache tags or internal
1382	  busses.
1383
1384config SCHED_SMT
1385	bool "SMT scheduler support"
1386	help
1387	  Improves the CPU scheduler's decision making when dealing with
1388	  MultiThreading at a cost of slightly increased overhead in some
1389	  places. If unsure say N here.
1390
1391config NR_CPUS
1392	int "Maximum number of CPUs (2-4096)"
1393	range 2 4096
1394	default "256"
1395
1396config HOTPLUG_CPU
1397	bool "Support for hot-pluggable CPUs"
1398	select GENERIC_IRQ_MIGRATION
1399	help
1400	  Say Y here to experiment with turning CPUs off and on.  CPUs
1401	  can be controlled through /sys/devices/system/cpu.
1402
1403# Common NUMA Features
1404config NUMA
1405	bool "NUMA Memory Allocation and Scheduler Support"
1406	select GENERIC_ARCH_NUMA
1407	select ACPI_NUMA if ACPI
1408	select OF_NUMA
1409	select HAVE_SETUP_PER_CPU_AREA
1410	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1411	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1412	select USE_PERCPU_NUMA_NODE_ID
1413	help
1414	  Enable NUMA (Non-Uniform Memory Access) support.
1415
1416	  The kernel will try to allocate memory used by a CPU on the
1417	  local memory of the CPU and add some more
1418	  NUMA awareness to the kernel.
1419
1420config NODES_SHIFT
1421	int "Maximum NUMA Nodes (as a power of 2)"
1422	range 1 10
1423	default "4"
1424	depends on NUMA
1425	help
1426	  Specify the maximum number of NUMA Nodes available on the target
1427	  system.  Increases memory reserved to accommodate various tables.
1428
1429source "kernel/Kconfig.hz"
1430
1431config ARCH_SPARSEMEM_ENABLE
1432	def_bool y
1433	select SPARSEMEM_VMEMMAP_ENABLE
1434	select SPARSEMEM_VMEMMAP
1435
1436config HW_PERF_EVENTS
1437	def_bool y
1438	depends on ARM_PMU
1439
1440# Supported by clang >= 7.0 or GCC >= 12.0.0
1441config CC_HAVE_SHADOW_CALL_STACK
1442	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1443
1444config PARAVIRT
1445	bool "Enable paravirtualization code"
1446	help
1447	  This changes the kernel so it can modify itself when it is run
1448	  under a hypervisor, potentially improving performance significantly
1449	  over full virtualization.
1450
1451config PARAVIRT_TIME_ACCOUNTING
1452	bool "Paravirtual steal time accounting"
1453	select PARAVIRT
1454	help
1455	  Select this option to enable fine granularity task steal time
1456	  accounting. Time spent executing other tasks in parallel with
1457	  the current vCPU is discounted from the vCPU power. To account for
1458	  that, there can be a small performance impact.
1459
1460	  If in doubt, say N here.
1461
1462config KEXEC
1463	depends on PM_SLEEP_SMP
1464	select KEXEC_CORE
1465	bool "kexec system call"
1466	help
1467	  kexec is a system call that implements the ability to shutdown your
1468	  current kernel, and to start another kernel.  It is like a reboot
1469	  but it is independent of the system firmware.   And like a reboot
1470	  you can start any kernel with it, not just Linux.
1471
1472config KEXEC_FILE
1473	bool "kexec file based system call"
1474	select KEXEC_CORE
1475	select HAVE_IMA_KEXEC if IMA
1476	help
1477	  This is new version of kexec system call. This system call is
1478	  file based and takes file descriptors as system call argument
1479	  for kernel and initramfs as opposed to list of segments as
1480	  accepted by previous system call.
1481
1482config KEXEC_SIG
1483	bool "Verify kernel signature during kexec_file_load() syscall"
1484	depends on KEXEC_FILE
1485	help
1486	  Select this option to verify a signature with loaded kernel
1487	  image. If configured, any attempt of loading a image without
1488	  valid signature will fail.
1489
1490	  In addition to that option, you need to enable signature
1491	  verification for the corresponding kernel image type being
1492	  loaded in order for this to work.
1493
1494config KEXEC_IMAGE_VERIFY_SIG
1495	bool "Enable Image signature verification support"
1496	default y
1497	depends on KEXEC_SIG
1498	depends on EFI && SIGNED_PE_FILE_VERIFICATION
1499	help
1500	  Enable Image signature verification support.
1501
1502comment "Support for PE file signature verification disabled"
1503	depends on KEXEC_SIG
1504	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
1505
1506config CRASH_DUMP
1507	bool "Build kdump crash kernel"
1508	help
1509	  Generate crash dump after being started by kexec. This should
1510	  be normally only set in special crash dump kernels which are
1511	  loaded in the main kernel with kexec-tools into a specially
1512	  reserved region and then later executed after a crash by
1513	  kdump/kexec.
1514
1515	  For more details see Documentation/admin-guide/kdump/kdump.rst
1516
1517config TRANS_TABLE
1518	def_bool y
1519	depends on HIBERNATION || KEXEC_CORE
1520
1521config XEN_DOM0
1522	def_bool y
1523	depends on XEN
1524
1525config XEN
1526	bool "Xen guest support on ARM64"
1527	depends on ARM64 && OF
1528	select SWIOTLB_XEN
1529	select PARAVIRT
1530	help
1531	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1532
1533# include/linux/mmzone.h requires the following to be true:
1534#
1535#   MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1536#
1537# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1538#
1539#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_ORDER  |  default MAX_ORDER |
1540# ----+-------------------+--------------+-----------------+--------------------+
1541# 4K  |       27          |      12      |       15        |         10         |
1542# 16K |       27          |      14      |       13        |         11         |
1543# 64K |       29          |      16      |       13        |         13         |
1544config ARCH_FORCE_MAX_ORDER
1545	int
1546	default "13" if ARM64_64K_PAGES
1547	default "11" if ARM64_16K_PAGES
1548	default "10"
1549	help
1550	  The kernel page allocator limits the size of maximal physically
1551	  contiguous allocations. The limit is called MAX_ORDER and it
1552	  defines the maximal power of two of number of pages that can be
1553	  allocated as a single contiguous block. This option allows
1554	  overriding the default setting when ability to allocate very
1555	  large blocks of physically contiguous memory is required.
1556
1557	  The maximal size of allocation cannot exceed the size of the
1558	  section, so the value of MAX_ORDER should satisfy
1559
1560	    MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1561
1562	  Don't change if unsure.
1563
1564config UNMAP_KERNEL_AT_EL0
1565	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1566	default y
1567	help
1568	  Speculation attacks against some high-performance processors can
1569	  be used to bypass MMU permission checks and leak kernel data to
1570	  userspace. This can be defended against by unmapping the kernel
1571	  when running in userspace, mapping it back in on exception entry
1572	  via a trampoline page in the vector table.
1573
1574	  If unsure, say Y.
1575
1576config MITIGATE_SPECTRE_BRANCH_HISTORY
1577	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1578	default y
1579	help
1580	  Speculation attacks against some high-performance processors can
1581	  make use of branch history to influence future speculation.
1582	  When taking an exception from user-space, a sequence of branches
1583	  or a firmware call overwrites the branch history.
1584
1585config RODATA_FULL_DEFAULT_ENABLED
1586	bool "Apply r/o permissions of VM areas also to their linear aliases"
1587	default y
1588	help
1589	  Apply read-only attributes of VM areas to the linear alias of
1590	  the backing pages as well. This prevents code or read-only data
1591	  from being modified (inadvertently or intentionally) via another
1592	  mapping of the same memory page. This additional enhancement can
1593	  be turned off at runtime by passing rodata=[off|on] (and turned on
1594	  with rodata=full if this option is set to 'n')
1595
1596	  This requires the linear region to be mapped down to pages,
1597	  which may adversely affect performance in some cases.
1598
1599config ARM64_SW_TTBR0_PAN
1600	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1601	help
1602	  Enabling this option prevents the kernel from accessing
1603	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1604	  zeroed area and reserved ASID. The user access routines
1605	  restore the valid TTBR0_EL1 temporarily.
1606
1607config ARM64_TAGGED_ADDR_ABI
1608	bool "Enable the tagged user addresses syscall ABI"
1609	default y
1610	help
1611	  When this option is enabled, user applications can opt in to a
1612	  relaxed ABI via prctl() allowing tagged addresses to be passed
1613	  to system calls as pointer arguments. For details, see
1614	  Documentation/arch/arm64/tagged-address-abi.rst.
1615
1616menuconfig COMPAT
1617	bool "Kernel support for 32-bit EL0"
1618	depends on ARM64_4K_PAGES || EXPERT
1619	select HAVE_UID16
1620	select OLD_SIGSUSPEND3
1621	select COMPAT_OLD_SIGACTION
1622	help
1623	  This option enables support for a 32-bit EL0 running under a 64-bit
1624	  kernel at EL1. AArch32-specific components such as system calls,
1625	  the user helper functions, VFP support and the ptrace interface are
1626	  handled appropriately by the kernel.
1627
1628	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1629	  that you will only be able to execute AArch32 binaries that were compiled
1630	  with page size aligned segments.
1631
1632	  If you want to execute 32-bit userspace applications, say Y.
1633
1634if COMPAT
1635
1636config KUSER_HELPERS
1637	bool "Enable kuser helpers page for 32-bit applications"
1638	default y
1639	help
1640	  Warning: disabling this option may break 32-bit user programs.
1641
1642	  Provide kuser helpers to compat tasks. The kernel provides
1643	  helper code to userspace in read only form at a fixed location
1644	  to allow userspace to be independent of the CPU type fitted to
1645	  the system. This permits binaries to be run on ARMv4 through
1646	  to ARMv8 without modification.
1647
1648	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1649
1650	  However, the fixed address nature of these helpers can be used
1651	  by ROP (return orientated programming) authors when creating
1652	  exploits.
1653
1654	  If all of the binaries and libraries which run on your platform
1655	  are built specifically for your platform, and make no use of
1656	  these helpers, then you can turn this option off to hinder
1657	  such exploits. However, in that case, if a binary or library
1658	  relying on those helpers is run, it will not function correctly.
1659
1660	  Say N here only if you are absolutely certain that you do not
1661	  need these helpers; otherwise, the safe option is to say Y.
1662
1663config COMPAT_VDSO
1664	bool "Enable vDSO for 32-bit applications"
1665	depends on !CPU_BIG_ENDIAN
1666	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1667	select GENERIC_COMPAT_VDSO
1668	default y
1669	help
1670	  Place in the process address space of 32-bit applications an
1671	  ELF shared object providing fast implementations of gettimeofday
1672	  and clock_gettime.
1673
1674	  You must have a 32-bit build of glibc 2.22 or later for programs
1675	  to seamlessly take advantage of this.
1676
1677config THUMB2_COMPAT_VDSO
1678	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1679	depends on COMPAT_VDSO
1680	default y
1681	help
1682	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1683	  otherwise with '-marm'.
1684
1685config COMPAT_ALIGNMENT_FIXUPS
1686	bool "Fix up misaligned multi-word loads and stores in user space"
1687
1688menuconfig ARMV8_DEPRECATED
1689	bool "Emulate deprecated/obsolete ARMv8 instructions"
1690	depends on SYSCTL
1691	help
1692	  Legacy software support may require certain instructions
1693	  that have been deprecated or obsoleted in the architecture.
1694
1695	  Enable this config to enable selective emulation of these
1696	  features.
1697
1698	  If unsure, say Y
1699
1700if ARMV8_DEPRECATED
1701
1702config SWP_EMULATION
1703	bool "Emulate SWP/SWPB instructions"
1704	help
1705	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1706	  they are always undefined. Say Y here to enable software
1707	  emulation of these instructions for userspace using LDXR/STXR.
1708	  This feature can be controlled at runtime with the abi.swp
1709	  sysctl which is disabled by default.
1710
1711	  In some older versions of glibc [<=2.8] SWP is used during futex
1712	  trylock() operations with the assumption that the code will not
1713	  be preempted. This invalid assumption may be more likely to fail
1714	  with SWP emulation enabled, leading to deadlock of the user
1715	  application.
1716
1717	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1718	  on an external transaction monitoring block called a global
1719	  monitor to maintain update atomicity. If your system does not
1720	  implement a global monitor, this option can cause programs that
1721	  perform SWP operations to uncached memory to deadlock.
1722
1723	  If unsure, say Y
1724
1725config CP15_BARRIER_EMULATION
1726	bool "Emulate CP15 Barrier instructions"
1727	help
1728	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1729	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1730	  strongly recommended to use the ISB, DSB, and DMB
1731	  instructions instead.
1732
1733	  Say Y here to enable software emulation of these
1734	  instructions for AArch32 userspace code. When this option is
1735	  enabled, CP15 barrier usage is traced which can help
1736	  identify software that needs updating. This feature can be
1737	  controlled at runtime with the abi.cp15_barrier sysctl.
1738
1739	  If unsure, say Y
1740
1741config SETEND_EMULATION
1742	bool "Emulate SETEND instruction"
1743	help
1744	  The SETEND instruction alters the data-endianness of the
1745	  AArch32 EL0, and is deprecated in ARMv8.
1746
1747	  Say Y here to enable software emulation of the instruction
1748	  for AArch32 userspace code. This feature can be controlled
1749	  at runtime with the abi.setend sysctl.
1750
1751	  Note: All the cpus on the system must have mixed endian support at EL0
1752	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1753	  endian - is hotplugged in after this feature has been enabled, there could
1754	  be unexpected results in the applications.
1755
1756	  If unsure, say Y
1757endif # ARMV8_DEPRECATED
1758
1759endif # COMPAT
1760
1761menu "ARMv8.1 architectural features"
1762
1763config ARM64_HW_AFDBM
1764	bool "Support for hardware updates of the Access and Dirty page flags"
1765	default y
1766	help
1767	  The ARMv8.1 architecture extensions introduce support for
1768	  hardware updates of the access and dirty information in page
1769	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1770	  capable processors, accesses to pages with PTE_AF cleared will
1771	  set this bit instead of raising an access flag fault.
1772	  Similarly, writes to read-only pages with the DBM bit set will
1773	  clear the read-only bit (AP[2]) instead of raising a
1774	  permission fault.
1775
1776	  Kernels built with this configuration option enabled continue
1777	  to work on pre-ARMv8.1 hardware and the performance impact is
1778	  minimal. If unsure, say Y.
1779
1780config ARM64_PAN
1781	bool "Enable support for Privileged Access Never (PAN)"
1782	default y
1783	help
1784	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1785	  prevents the kernel or hypervisor from accessing user-space (EL0)
1786	  memory directly.
1787
1788	  Choosing this option will cause any unprotected (not using
1789	  copy_to_user et al) memory access to fail with a permission fault.
1790
1791	  The feature is detected at runtime, and will remain as a 'nop'
1792	  instruction if the cpu does not implement the feature.
1793
1794config AS_HAS_LDAPR
1795	def_bool $(as-instr,.arch_extension rcpc)
1796
1797config AS_HAS_LSE_ATOMICS
1798	def_bool $(as-instr,.arch_extension lse)
1799
1800config ARM64_LSE_ATOMICS
1801	bool
1802	default ARM64_USE_LSE_ATOMICS
1803	depends on AS_HAS_LSE_ATOMICS
1804
1805config ARM64_USE_LSE_ATOMICS
1806	bool "Atomic instructions"
1807	default y
1808	help
1809	  As part of the Large System Extensions, ARMv8.1 introduces new
1810	  atomic instructions that are designed specifically to scale in
1811	  very large systems.
1812
1813	  Say Y here to make use of these instructions for the in-kernel
1814	  atomic routines. This incurs a small overhead on CPUs that do
1815	  not support these instructions and requires the kernel to be
1816	  built with binutils >= 2.25 in order for the new instructions
1817	  to be used.
1818
1819endmenu # "ARMv8.1 architectural features"
1820
1821menu "ARMv8.2 architectural features"
1822
1823config AS_HAS_ARMV8_2
1824	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1825
1826config AS_HAS_SHA3
1827	def_bool $(as-instr,.arch armv8.2-a+sha3)
1828
1829config ARM64_PMEM
1830	bool "Enable support for persistent memory"
1831	select ARCH_HAS_PMEM_API
1832	select ARCH_HAS_UACCESS_FLUSHCACHE
1833	help
1834	  Say Y to enable support for the persistent memory API based on the
1835	  ARMv8.2 DCPoP feature.
1836
1837	  The feature is detected at runtime, and the kernel will use DC CVAC
1838	  operations if DC CVAP is not supported (following the behaviour of
1839	  DC CVAP itself if the system does not define a point of persistence).
1840
1841config ARM64_RAS_EXTN
1842	bool "Enable support for RAS CPU Extensions"
1843	default y
1844	help
1845	  CPUs that support the Reliability, Availability and Serviceability
1846	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1847	  errors, classify them and report them to software.
1848
1849	  On CPUs with these extensions system software can use additional
1850	  barriers to determine if faults are pending and read the
1851	  classification from a new set of registers.
1852
1853	  Selecting this feature will allow the kernel to use these barriers
1854	  and access the new registers if the system supports the extension.
1855	  Platform RAS features may additionally depend on firmware support.
1856
1857config ARM64_CNP
1858	bool "Enable support for Common Not Private (CNP) translations"
1859	default y
1860	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1861	help
1862	  Common Not Private (CNP) allows translation table entries to
1863	  be shared between different PEs in the same inner shareable
1864	  domain, so the hardware can use this fact to optimise the
1865	  caching of such entries in the TLB.
1866
1867	  Selecting this option allows the CNP feature to be detected
1868	  at runtime, and does not affect PEs that do not implement
1869	  this feature.
1870
1871endmenu # "ARMv8.2 architectural features"
1872
1873menu "ARMv8.3 architectural features"
1874
1875config ARM64_PTR_AUTH
1876	bool "Enable support for pointer authentication"
1877	default y
1878	help
1879	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1880	  instructions for signing and authenticating pointers against secret
1881	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1882	  and other attacks.
1883
1884	  This option enables these instructions at EL0 (i.e. for userspace).
1885	  Choosing this option will cause the kernel to initialise secret keys
1886	  for each process at exec() time, with these keys being
1887	  context-switched along with the process.
1888
1889	  The feature is detected at runtime. If the feature is not present in
1890	  hardware it will not be advertised to userspace/KVM guest nor will it
1891	  be enabled.
1892
1893	  If the feature is present on the boot CPU but not on a late CPU, then
1894	  the late CPU will be parked. Also, if the boot CPU does not have
1895	  address auth and the late CPU has then the late CPU will still boot
1896	  but with the feature disabled. On such a system, this option should
1897	  not be selected.
1898
1899config ARM64_PTR_AUTH_KERNEL
1900	bool "Use pointer authentication for kernel"
1901	default y
1902	depends on ARM64_PTR_AUTH
1903	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1904	# Modern compilers insert a .note.gnu.property section note for PAC
1905	# which is only understood by binutils starting with version 2.33.1.
1906	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1907	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1908	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1909	help
1910	  If the compiler supports the -mbranch-protection or
1911	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1912	  will cause the kernel itself to be compiled with return address
1913	  protection. In this case, and if the target hardware is known to
1914	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1915	  disabled with minimal loss of protection.
1916
1917	  This feature works with FUNCTION_GRAPH_TRACER option only if
1918	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
1919
1920config CC_HAS_BRANCH_PROT_PAC_RET
1921	# GCC 9 or later, clang 8 or later
1922	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1923
1924config CC_HAS_SIGN_RETURN_ADDRESS
1925	# GCC 7, 8
1926	def_bool $(cc-option,-msign-return-address=all)
1927
1928config AS_HAS_ARMV8_3
1929	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1930
1931config AS_HAS_CFI_NEGATE_RA_STATE
1932	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1933
1934endmenu # "ARMv8.3 architectural features"
1935
1936menu "ARMv8.4 architectural features"
1937
1938config ARM64_AMU_EXTN
1939	bool "Enable support for the Activity Monitors Unit CPU extension"
1940	default y
1941	help
1942	  The activity monitors extension is an optional extension introduced
1943	  by the ARMv8.4 CPU architecture. This enables support for version 1
1944	  of the activity monitors architecture, AMUv1.
1945
1946	  To enable the use of this extension on CPUs that implement it, say Y.
1947
1948	  Note that for architectural reasons, firmware _must_ implement AMU
1949	  support when running on CPUs that present the activity monitors
1950	  extension. The required support is present in:
1951	    * Version 1.5 and later of the ARM Trusted Firmware
1952
1953	  For kernels that have this configuration enabled but boot with broken
1954	  firmware, you may need to say N here until the firmware is fixed.
1955	  Otherwise you may experience firmware panics or lockups when
1956	  accessing the counter registers. Even if you are not observing these
1957	  symptoms, the values returned by the register reads might not
1958	  correctly reflect reality. Most commonly, the value read will be 0,
1959	  indicating that the counter is not enabled.
1960
1961config AS_HAS_ARMV8_4
1962	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1963
1964config ARM64_TLB_RANGE
1965	bool "Enable support for tlbi range feature"
1966	default y
1967	depends on AS_HAS_ARMV8_4
1968	help
1969	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1970	  range of input addresses.
1971
1972	  The feature introduces new assembly instructions, and they were
1973	  support when binutils >= 2.30.
1974
1975endmenu # "ARMv8.4 architectural features"
1976
1977menu "ARMv8.5 architectural features"
1978
1979config AS_HAS_ARMV8_5
1980	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1981
1982config ARM64_BTI
1983	bool "Branch Target Identification support"
1984	default y
1985	help
1986	  Branch Target Identification (part of the ARMv8.5 Extensions)
1987	  provides a mechanism to limit the set of locations to which computed
1988	  branch instructions such as BR or BLR can jump.
1989
1990	  To make use of BTI on CPUs that support it, say Y.
1991
1992	  BTI is intended to provide complementary protection to other control
1993	  flow integrity protection mechanisms, such as the Pointer
1994	  authentication mechanism provided as part of the ARMv8.3 Extensions.
1995	  For this reason, it does not make sense to enable this option without
1996	  also enabling support for pointer authentication.  Thus, when
1997	  enabling this option you should also select ARM64_PTR_AUTH=y.
1998
1999	  Userspace binaries must also be specifically compiled to make use of
2000	  this mechanism.  If you say N here or the hardware does not support
2001	  BTI, such binaries can still run, but you get no additional
2002	  enforcement of branch destinations.
2003
2004config ARM64_BTI_KERNEL
2005	bool "Use Branch Target Identification for kernel"
2006	default y
2007	depends on ARM64_BTI
2008	depends on ARM64_PTR_AUTH_KERNEL
2009	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2010	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2011	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2012	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2013	depends on !CC_IS_GCC
2014	# https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
2015	depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
2016	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2017	help
2018	  Build the kernel with Branch Target Identification annotations
2019	  and enable enforcement of this for kernel code. When this option
2020	  is enabled and the system supports BTI all kernel code including
2021	  modular code must have BTI enabled.
2022
2023config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2024	# GCC 9 or later, clang 8 or later
2025	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2026
2027config ARM64_E0PD
2028	bool "Enable support for E0PD"
2029	default y
2030	help
2031	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2032	  that EL0 accesses made via TTBR1 always fault in constant time,
2033	  providing similar benefits to KASLR as those provided by KPTI, but
2034	  with lower overhead and without disrupting legitimate access to
2035	  kernel memory such as SPE.
2036
2037	  This option enables E0PD for TTBR1 where available.
2038
2039config ARM64_AS_HAS_MTE
2040	# Initial support for MTE went in binutils 2.32.0, checked with
2041	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2042	# as a late addition to the final architecture spec (LDGM/STGM)
2043	# is only supported in the newer 2.32.x and 2.33 binutils
2044	# versions, hence the extra "stgm" instruction check below.
2045	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2046
2047config ARM64_MTE
2048	bool "Memory Tagging Extension support"
2049	default y
2050	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2051	depends on AS_HAS_ARMV8_5
2052	depends on AS_HAS_LSE_ATOMICS
2053	# Required for tag checking in the uaccess routines
2054	depends on ARM64_PAN
2055	select ARCH_HAS_SUBPAGE_FAULTS
2056	select ARCH_USES_HIGH_VMA_FLAGS
2057	select ARCH_USES_PG_ARCH_X
2058	help
2059	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2060	  architectural support for run-time, always-on detection of
2061	  various classes of memory error to aid with software debugging
2062	  to eliminate vulnerabilities arising from memory-unsafe
2063	  languages.
2064
2065	  This option enables the support for the Memory Tagging
2066	  Extension at EL0 (i.e. for userspace).
2067
2068	  Selecting this option allows the feature to be detected at
2069	  runtime. Any secondary CPU not implementing this feature will
2070	  not be allowed a late bring-up.
2071
2072	  Userspace binaries that want to use this feature must
2073	  explicitly opt in. The mechanism for the userspace is
2074	  described in:
2075
2076	  Documentation/arch/arm64/memory-tagging-extension.rst.
2077
2078endmenu # "ARMv8.5 architectural features"
2079
2080menu "ARMv8.7 architectural features"
2081
2082config ARM64_EPAN
2083	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2084	default y
2085	depends on ARM64_PAN
2086	help
2087	  Enhanced Privileged Access Never (EPAN) allows Privileged
2088	  Access Never to be used with Execute-only mappings.
2089
2090	  The feature is detected at runtime, and will remain disabled
2091	  if the cpu does not implement the feature.
2092endmenu # "ARMv8.7 architectural features"
2093
2094config ARM64_SVE
2095	bool "ARM Scalable Vector Extension support"
2096	default y
2097	help
2098	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2099	  execution state which complements and extends the SIMD functionality
2100	  of the base architecture to support much larger vectors and to enable
2101	  additional vectorisation opportunities.
2102
2103	  To enable use of this extension on CPUs that implement it, say Y.
2104
2105	  On CPUs that support the SVE2 extensions, this option will enable
2106	  those too.
2107
2108	  Note that for architectural reasons, firmware _must_ implement SVE
2109	  support when running on SVE capable hardware.  The required support
2110	  is present in:
2111
2112	    * version 1.5 and later of the ARM Trusted Firmware
2113	    * the AArch64 boot wrapper since commit 5e1261e08abf
2114	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2115
2116	  For other firmware implementations, consult the firmware documentation
2117	  or vendor.
2118
2119	  If you need the kernel to boot on SVE-capable hardware with broken
2120	  firmware, you may need to say N here until you get your firmware
2121	  fixed.  Otherwise, you may experience firmware panics or lockups when
2122	  booting the kernel.  If unsure and you are not observing these
2123	  symptoms, you should assume that it is safe to say Y.
2124
2125config ARM64_SME
2126	bool "ARM Scalable Matrix Extension support"
2127	default y
2128	depends on ARM64_SVE
2129	help
2130	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2131	  execution state which utilises a substantial subset of the SVE
2132	  instruction set, together with the addition of new architectural
2133	  register state capable of holding two dimensional matrix tiles to
2134	  enable various matrix operations.
2135
2136config ARM64_PSEUDO_NMI
2137	bool "Support for NMI-like interrupts"
2138	select ARM_GIC_V3
2139	help
2140	  Adds support for mimicking Non-Maskable Interrupts through the use of
2141	  GIC interrupt priority. This support requires version 3 or later of
2142	  ARM GIC.
2143
2144	  This high priority configuration for interrupts needs to be
2145	  explicitly enabled by setting the kernel parameter
2146	  "irqchip.gicv3_pseudo_nmi" to 1.
2147
2148	  If unsure, say N
2149
2150if ARM64_PSEUDO_NMI
2151config ARM64_DEBUG_PRIORITY_MASKING
2152	bool "Debug interrupt priority masking"
2153	help
2154	  This adds runtime checks to functions enabling/disabling
2155	  interrupts when using priority masking. The additional checks verify
2156	  the validity of ICC_PMR_EL1 when calling concerned functions.
2157
2158	  If unsure, say N
2159endif # ARM64_PSEUDO_NMI
2160
2161config RELOCATABLE
2162	bool "Build a relocatable kernel image" if EXPERT
2163	select ARCH_HAS_RELR
2164	default y
2165	help
2166	  This builds the kernel as a Position Independent Executable (PIE),
2167	  which retains all relocation metadata required to relocate the
2168	  kernel binary at runtime to a different virtual address than the
2169	  address it was linked at.
2170	  Since AArch64 uses the RELA relocation format, this requires a
2171	  relocation pass at runtime even if the kernel is loaded at the
2172	  same address it was linked at.
2173
2174config RANDOMIZE_BASE
2175	bool "Randomize the address of the kernel image"
2176	select RELOCATABLE
2177	help
2178	  Randomizes the virtual address at which the kernel image is
2179	  loaded, as a security feature that deters exploit attempts
2180	  relying on knowledge of the location of kernel internals.
2181
2182	  It is the bootloader's job to provide entropy, by passing a
2183	  random u64 value in /chosen/kaslr-seed at kernel entry.
2184
2185	  When booting via the UEFI stub, it will invoke the firmware's
2186	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2187	  to the kernel proper. In addition, it will randomise the physical
2188	  location of the kernel Image as well.
2189
2190	  If unsure, say N.
2191
2192config RANDOMIZE_MODULE_REGION_FULL
2193	bool "Randomize the module region over a 2 GB range"
2194	depends on RANDOMIZE_BASE
2195	default y
2196	help
2197	  Randomizes the location of the module region inside a 2 GB window
2198	  covering the core kernel. This way, it is less likely for modules
2199	  to leak information about the location of core kernel data structures
2200	  but it does imply that function calls between modules and the core
2201	  kernel will need to be resolved via veneers in the module PLT.
2202
2203	  When this option is not set, the module region will be randomized over
2204	  a limited range that contains the [_stext, _etext] interval of the
2205	  core kernel, so branch relocations are almost always in range unless
2206	  the region is exhausted. In this particular case of region
2207	  exhaustion, modules might be able to fall back to a larger 2GB area.
2208
2209config CC_HAVE_STACKPROTECTOR_SYSREG
2210	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2211
2212config STACKPROTECTOR_PER_TASK
2213	def_bool y
2214	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2215
2216config UNWIND_PATCH_PAC_INTO_SCS
2217	bool "Enable shadow call stack dynamically using code patching"
2218	# needs Clang with https://reviews.llvm.org/D111780 incorporated
2219	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2220	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2221	depends on SHADOW_CALL_STACK
2222	select UNWIND_TABLES
2223	select DYNAMIC_SCS
2224
2225endmenu # "Kernel Features"
2226
2227menu "Boot options"
2228
2229config ARM64_ACPI_PARKING_PROTOCOL
2230	bool "Enable support for the ARM64 ACPI parking protocol"
2231	depends on ACPI
2232	help
2233	  Enable support for the ARM64 ACPI parking protocol. If disabled
2234	  the kernel will not allow booting through the ARM64 ACPI parking
2235	  protocol even if the corresponding data is present in the ACPI
2236	  MADT table.
2237
2238config CMDLINE
2239	string "Default kernel command string"
2240	default ""
2241	help
2242	  Provide a set of default command-line options at build time by
2243	  entering them here. As a minimum, you should specify the the
2244	  root device (e.g. root=/dev/nfs).
2245
2246choice
2247	prompt "Kernel command line type" if CMDLINE != ""
2248	default CMDLINE_FROM_BOOTLOADER
2249	help
2250	  Choose how the kernel will handle the provided default kernel
2251	  command line string.
2252
2253config CMDLINE_FROM_BOOTLOADER
2254	bool "Use bootloader kernel arguments if available"
2255	help
2256	  Uses the command-line options passed by the boot loader. If
2257	  the boot loader doesn't provide any, the default kernel command
2258	  string provided in CMDLINE will be used.
2259
2260config CMDLINE_FORCE
2261	bool "Always use the default kernel command string"
2262	help
2263	  Always use the default kernel command string, even if the boot
2264	  loader passes other arguments to the kernel.
2265	  This is useful if you cannot or don't want to change the
2266	  command-line options your boot loader passes to the kernel.
2267
2268endchoice
2269
2270config EFI_STUB
2271	bool
2272
2273config EFI
2274	bool "UEFI runtime support"
2275	depends on OF && !CPU_BIG_ENDIAN
2276	depends on KERNEL_MODE_NEON
2277	select ARCH_SUPPORTS_ACPI
2278	select LIBFDT
2279	select UCS2_STRING
2280	select EFI_PARAMS_FROM_FDT
2281	select EFI_RUNTIME_WRAPPERS
2282	select EFI_STUB
2283	select EFI_GENERIC_STUB
2284	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2285	default y
2286	help
2287	  This option provides support for runtime services provided
2288	  by UEFI firmware (such as non-volatile variables, realtime
2289	  clock, and platform reset). A UEFI stub is also provided to
2290	  allow the kernel to be booted as an EFI application. This
2291	  is only useful on systems that have UEFI firmware.
2292
2293config DMI
2294	bool "Enable support for SMBIOS (DMI) tables"
2295	depends on EFI
2296	default y
2297	help
2298	  This enables SMBIOS/DMI feature for systems.
2299
2300	  This option is only useful on systems that have UEFI firmware.
2301	  However, even with this option, the resultant kernel should
2302	  continue to boot on existing non-UEFI platforms.
2303
2304endmenu # "Boot options"
2305
2306menu "Power management options"
2307
2308source "kernel/power/Kconfig"
2309
2310config ARCH_HIBERNATION_POSSIBLE
2311	def_bool y
2312	depends on CPU_PM
2313
2314config ARCH_HIBERNATION_HEADER
2315	def_bool y
2316	depends on HIBERNATION
2317
2318config ARCH_SUSPEND_POSSIBLE
2319	def_bool y
2320
2321endmenu # "Power management options"
2322
2323menu "CPU Power Management"
2324
2325source "drivers/cpuidle/Kconfig"
2326
2327source "drivers/cpufreq/Kconfig"
2328
2329endmenu # "CPU Power Management"
2330
2331source "drivers/acpi/Kconfig"
2332
2333source "arch/arm64/kvm/Kconfig"
2334
2335