xref: /linux/arch/arm64/Kconfig (revision bb29b957eaaa15be33243550d9ee576c2d601669)
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_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
9	select ACPI_IORT if ACPI
10	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
11	select ACPI_MCFG if (ACPI && PCI)
12	select ACPI_SPCR_TABLE if ACPI
13	select ACPI_PPTT if ACPI
14	select ARCH_HAS_DEBUG_WX
15	select ARCH_BINFMT_ELF_EXTRA_PHDRS
16	select ARCH_BINFMT_ELF_STATE
17	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
18	select ARCH_ENABLE_MEMORY_HOTPLUG
19	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
20	select ARCH_HAS_PMD_SOFTLEAVES if TRANSPARENT_HUGEPAGE
21	select ARCH_HAS_CACHE_LINE_SIZE
22	select ARCH_HAS_CC_PLATFORM
23	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
24	select ARCH_HAS_CURRENT_STACK_POINTER
25	select ARCH_HAS_DEBUG_VIRTUAL
26	select ARCH_HAS_DEBUG_VM_PGTABLE
27	select ARCH_HAS_DMA_OPS if XEN
28	select ARCH_HAS_DMA_PREP_COHERENT
29	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
30	select ARCH_HAS_FAST_MULTIPLIER
31	select ARCH_HAS_FORTIFY_SOURCE
32	select ARCH_HAS_GCOV_PROFILE_ALL
33	select ARCH_HAS_GIGANTIC_PAGE
34	select ARCH_HAS_KCOV
35	select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON
36	select ARCH_HAS_KEEPINITRD
37	select ARCH_HAS_LAZY_MMU_MODE
38	select ARCH_HAS_MEMBARRIER_SYNC_CORE
39	select ARCH_HAS_MEM_ENCRYPT
40	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
41	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
42	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
43	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
44	select ARCH_HAS_PREEMPT_LAZY
45	select ARCH_HAS_PTDUMP
46	select ARCH_HAS_PTE_SPECIAL
47	select ARCH_HAS_HW_PTE_YOUNG
48	select ARCH_HAS_SETUP_DMA_OPS
49	select ARCH_HAS_SET_DIRECT_MAP
50	select ARCH_HAS_SET_MEMORY
51	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
52	select ARCH_STACKWALK
53	select ARCH_HAS_STRICT_KERNEL_RWX
54	select ARCH_HAS_STRICT_MODULE_RWX
55	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
56	select ARCH_HAS_SYNC_DMA_FOR_CPU
57	select ARCH_HAS_BATCHED_DMA_SYNC
58	select ARCH_HAS_SYSCALL_WRAPPER
59	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
60	select ARCH_HAS_ZONE_DMA_SET if EXPERT
61	select ARCH_HAVE_ELF_PROT
62	select ARCH_HAVE_NMI_SAFE_CMPXCHG
63	select ARCH_HAVE_TRACE_MMIO_ACCESS
64	select ARCH_KEEP_MEMBLOCK
65	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
66	select ARCH_USE_CMPXCHG_LOCKREF
67	select ARCH_USE_GNU_PROPERTY
68	select ARCH_USE_MEMTEST
69	select ARCH_USE_QUEUED_RWLOCKS
70	select ARCH_USE_QUEUED_SPINLOCKS
71	select ARCH_USE_SYM_ANNOTATIONS
72	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
73	select ARCH_SUPPORTS_HUGETLBFS
74	select ARCH_SUPPORTS_MEMORY_FAILURE
75	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
76	select ARCH_SUPPORTS_LTO_CLANG
77	select ARCH_SUPPORTS_LTO_CLANG_THIN
78	select ARCH_SUPPORTS_CFI
79	select ARCH_SUPPORTS_ATOMIC_RMW
80	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
81	select ARCH_HAS_PTE_PROTNONE
82	select ARCH_SUPPORTS_NUMA_BALANCING
83	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
84	select ARCH_SUPPORTS_PER_VMA_LOCK
85	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
86	select ARCH_SUPPORTS_RMM
87	select ARCH_SUPPORTS_RT
88	select ARCH_SUPPORTS_SCHED_SMT
89	select ARCH_SUPPORTS_SCHED_CLUSTER
90	select ARCH_SUPPORTS_SCHED_MC
91	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
92	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
93	select ARCH_WANT_DEFAULT_BPF_JIT
94	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
95	select ARCH_WANT_FRAME_POINTERS
96	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
97	select ARCH_WANT_LD_ORPHAN_WARN
98	select ARCH_WANTS_EXECMEM_LATE
99	select ARCH_WANTS_NO_INSTR
100	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
101	select ARCH_HAS_UBSAN
102	select ARM_AMBA
103	select ARM_ARCH_TIMER
104	select ARM_GIC
105	select AUDIT_ARCH_COMPAT_GENERIC
106	select ARM_GIC_V2M if PCI
107	select ARM_GIC_V3
108	select ARM_GIC_V3_ITS if PCI
109	select ARM_GIC_V5
110	select ARM_PSCI_FW
111	select BUILDTIME_TABLE_SORT
112	select CLONE_BACKWARDS
113	select COMMON_CLK
114	select CPU_PM if (SUSPEND || CPU_IDLE)
115	select CPUMASK_OFFSTACK if NR_CPUS > 256
116	select DCACHE_WORD_ACCESS
117	select HAVE_EXTRA_IPI_TRACEPOINTS
118	select DYNAMIC_FTRACE if FUNCTION_TRACER
119	select DMA_BOUNCE_UNALIGNED_KMALLOC
120	select DMA_DIRECT_REMAP
121	select EDAC_SUPPORT
122	select FRAME_POINTER
123	select FUNCTION_ALIGNMENT_4B
124	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
125	select GENERIC_ALLOCATOR
126	select GENERIC_ARCH_TOPOLOGY
127	select GENERIC_CLOCKEVENTS_BROADCAST
128	select GENERIC_CPU_AUTOPROBE
129	select GENERIC_CPU_CACHE_MAINTENANCE
130	select GENERIC_CPU_DEVICES
131	select GENERIC_CPU_VULNERABILITIES
132	select GENERIC_EARLY_IOREMAP
133	select GENERIC_IDLE_POLL_SETUP
134	select GENERIC_IOREMAP
135	select GENERIC_IRQ_ENTRY
136	select GENERIC_IRQ_IPI
137	select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
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_SCHED_CLOCK
144	select GENERIC_SMP_IDLE_THREAD
145	select GENERIC_GETTIMEOFDAY
146	select HARDIRQS_SW_RESEND
147	select HAS_IOPORT
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
153	select HAVE_ARCH_AUDITSYSCALL
154	select HAVE_ARCH_BITREVERSE if 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
161	select HAVE_ARCH_KASAN_VMALLOC
162	select HAVE_ARCH_KASAN_SW_TAGS
163	select HAVE_ARCH_KASAN_HW_TAGS if 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_KSTACK_ERASE
169	select HAVE_ARCH_MMAP_RND_BITS
170	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
171	select HAVE_ARCH_PREL32_RELOCATIONS
172	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
173	select HAVE_ARCH_SECCOMP_FILTER
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_ARGS \
189		if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
190		    CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
191	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
192		if DYNAMIC_FTRACE_WITH_ARGS
193	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
194		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \
195		    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
196	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
197		if DYNAMIC_FTRACE_WITH_ARGS
198	select HAVE_SAMPLE_FTRACE_DIRECT
199	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
200	select HAVE_BUILDTIME_MCOUNT_SORT
201	select HAVE_EFFICIENT_UNALIGNED_ACCESS
202	select HAVE_GUP_FAST
203	select HAVE_FTRACE_GRAPH_FUNC
204	select HAVE_FUNCTION_TRACER
205	select HAVE_FUNCTION_ERROR_INJECTION
206	select HAVE_FUNCTION_GRAPH_FREGS
207	select HAVE_FUNCTION_GRAPH_TRACER
208	select HAVE_GCC_PLUGINS
209	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
210		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
211	select HAVE_HW_BREAKPOINT if PERF_EVENTS
212	select HAVE_IOREMAP_PROT
213	select HAVE_IRQ_TIME_ACCOUNTING
214	select HAVE_LIVEPATCH
215	select HAVE_MOD_ARCH_SPECIFIC
216	select HAVE_NMI
217	select HAVE_PERF_EVENTS
218	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
219	select HAVE_PERF_REGS
220	select HAVE_PERF_USER_STACK_DUMP
221	select HAVE_REGS_AND_STACK_ACCESS_API
222	select HAVE_RELIABLE_STACKTRACE
223	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
224	select HAVE_FUNCTION_ARG_ACCESS_API
225	select MMU_GATHER_RCU_TABLE_FREE
226	select HAVE_RSEQ
227	select HAVE_RUST
228	select HAVE_STACKPROTECTOR
229	select HAVE_STATIC_CALL if CFI
230	select HAVE_SYSCALL_TRACEPOINTS
231	select HAVE_KPROBES
232	select HAVE_KRETPROBES
233	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
234	select HOTPLUG_SMT if HOTPLUG_CPU
235	select IRQ_DOMAIN
236	select IRQ_FORCED_THREADING
237	select JUMP_LABEL
238	select KASAN_VMALLOC if KASAN
239	select LOCK_MM_AND_FIND_VMA
240	select MODULES_USE_ELF_RELA
241	select NEED_DMA_MAP_STATE
242	select NEED_SG_DMA_LENGTH
243	select OF
244	select OF_EARLY_FLATTREE
245	select PCI_DOMAINS_GENERIC if PCI
246	select PCI_ECAM if (ACPI && PCI)
247	select PCI_SYSCALL if PCI
248	select POWER_RESET
249	select POWER_SUPPLY
250	select HAS_SEPARATE_PREEMPT_RESCHED_BITS
251	select SPARSE_IRQ
252	select SWIOTLB
253	select SYSCTL_EXCEPTION_TRACE
254	select THREAD_INFO_IN_TASK
255	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
256	select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
257	select TRACE_IRQFLAGS_SUPPORT
258	select TRACE_IRQFLAGS_NMI_SUPPORT
259	select HAVE_SOFTIRQ_ON_OWN_STACK
260	select USER_STACKTRACE_SUPPORT
261	select VDSO_GETRANDOM
262	select VMAP_STACK
263	help
264	  ARM 64-bit (AArch64) Linux support.
265
266config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
267	def_bool CC_IS_CLANG
268	# https://github.com/ClangBuiltLinux/linux/issues/1507
269	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
270
271config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
272	def_bool CC_IS_GCC
273	depends on $(cc-option,-fpatchable-function-entry=2)
274
275config 64BIT
276	def_bool y
277
278config MMU
279	def_bool y
280
281config ARM64_CONT_PTE_SHIFT
282	int
283	default 5 if PAGE_SIZE_64KB
284	default 7 if PAGE_SIZE_16KB
285	default 4
286
287config ARM64_CONT_PMD_SHIFT
288	int
289	default 5 if PAGE_SIZE_64KB
290	default 5 if PAGE_SIZE_16KB
291	default 4
292
293config ARCH_MMAP_RND_BITS_MIN
294	default 14 if PAGE_SIZE_64KB
295	default 16 if PAGE_SIZE_16KB
296	default 18
297
298# max bits determined by the following formula:
299#  VA_BITS - PTDESC_TABLE_SHIFT
300config ARCH_MMAP_RND_BITS_MAX
301	default 19 if ARM64_VA_BITS=36
302	default 24 if ARM64_VA_BITS=39
303	default 27 if ARM64_VA_BITS=42
304	default 30 if ARM64_VA_BITS=47
305	default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES
306	default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES
307	default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52)
308	default 14 if ARM64_64K_PAGES
309	default 16 if ARM64_16K_PAGES
310	default 18
311
312# default to 1 TiB (5 bits below ARCH_MMAP_RND_BITS_MAX) on 48-bit and
313# 52-bit VA; smaller VA sizes fall back to ARCH_MMAP_RND_BITS_MIN in
314# arch/Kconfig
315config ARCH_MMAP_RND_BITS
316	default 24 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES
317	default 26 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES
318	default 28 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52)
319
320config ARCH_MMAP_RND_COMPAT_BITS_MIN
321	default 7 if ARM64_64K_PAGES
322	default 9 if ARM64_16K_PAGES
323	default 11
324
325config ARCH_MMAP_RND_COMPAT_BITS_MAX
326	default 16
327
328config NO_IOPORT_MAP
329	def_bool y if !PCI
330
331config STACKTRACE_SUPPORT
332	def_bool y
333
334config ILLEGAL_POINTER_VALUE
335	hex
336	default 0xdead000000000000
337
338config LOCKDEP_SUPPORT
339	def_bool y
340
341config GENERIC_BUG
342	def_bool y
343	depends on BUG
344
345config GENERIC_BUG_RELATIVE_POINTERS
346	def_bool y
347	depends on GENERIC_BUG
348
349config GENERIC_HWEIGHT
350	def_bool y
351
352config GENERIC_CSUM
353	def_bool y
354
355config GENERIC_CALIBRATE_DELAY
356	def_bool y
357
358config SMP
359	def_bool y
360
361config KERNEL_MODE_NEON
362	def_bool y
363
364config FIX_EARLYCON_MEM
365	def_bool y
366
367config PGTABLE_LEVELS
368	int
369	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
370	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
371	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
372	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
373	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
374	default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
375	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
376	default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
377
378config ARCH_SUPPORTS_UPROBES
379	def_bool y
380
381config ARCH_PROC_KCORE_TEXT
382	def_bool y
383
384config BROKEN_GAS_INST
385	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
386
387config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
388	bool
389	# Clang's __builtin_return_address() strips the PAC since 12.0.0
390	# https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
391	default y if CC_IS_CLANG
392	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
393	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
394	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
395	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
396	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
397	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
398	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
399	default n
400
401config KASAN_SHADOW_OFFSET
402	hex
403	depends on KASAN_GENERIC || KASAN_SW_TAGS
404	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
405	default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
406	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
407	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
408	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
409	default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
410	default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
411	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
412	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
413	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
414	default 0xffffffffffffffff
415
416config UNWIND_TABLES
417	bool
418
419source "arch/arm64/Kconfig.platforms"
420
421menu "Kernel Features"
422
423menu "ARM errata workarounds via the alternatives framework"
424
425config AMPERE_ERRATUM_AC03_CPU_38
426        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
427	default y
428	help
429	  This option adds an alternative code sequence to work around Ampere
430	  errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
431
432	  The affected design reports FEAT_HAFDBS as not implemented in
433	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
434	  as required by the architecture. The unadvertised HAFDBS
435	  implementation suffers from an additional erratum where hardware
436	  A/D updates can occur after a PTE has been marked invalid.
437
438	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
439	  which avoids enabling unadvertised hardware Access Flag management
440	  at stage-2.
441
442	  If unsure, say Y.
443
444config AMPERE_ERRATUM_AC04_CPU_23
445        bool "AmpereOne: AC04_CPU_23:  Failure to synchronize writes to HCR_EL2 may corrupt address translations."
446	default y
447	help
448	  This option adds an alternative code sequence to work around Ampere
449	  errata AC04_CPU_23 on AmpereOne.
450
451	  Updates to HCR_EL2 can rarely corrupt simultaneous translations for
452	  data addresses initiated by load/store instructions. Only
453	  instruction initiated translations are vulnerable, not translations
454	  from prefetches for example. A DSB before the store to HCR_EL2 is
455	  sufficient to prevent older instructions from hitting the window
456	  for corruption, and an ISB after is sufficient to prevent younger
457	  instructions from hitting the window for corruption.
458
459	  If unsure, say Y.
460
461config ARM64_WORKAROUND_CLEAN_CACHE
462	bool
463
464config ARM64_ERRATUM_826319
465	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
466	default y
467	select ARM64_WORKAROUND_CLEAN_CACHE
468	help
469	  This option adds an alternative code sequence to work around ARM
470	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
471	  AXI master interface and an L2 cache.
472
473	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
474	  and is unable to accept a certain write via this interface, it will
475	  not progress on read data presented on the read data channel and the
476	  system can deadlock.
477
478	  The workaround promotes data cache clean instructions to
479	  data cache clean-and-invalidate.
480	  Please note that this does not necessarily enable the workaround,
481	  as it depends on the alternative framework, which will only patch
482	  the kernel if an affected CPU is detected.
483
484	  If unsure, say Y.
485
486config ARM64_ERRATUM_827319
487	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
488	default y
489	select ARM64_WORKAROUND_CLEAN_CACHE
490	help
491	  This option adds an alternative code sequence to work around ARM
492	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
493	  master interface and an L2 cache.
494
495	  Under certain conditions this erratum can cause a clean line eviction
496	  to occur at the same time as another transaction to the same address
497	  on the AMBA 5 CHI interface, which can cause data corruption if the
498	  interconnect reorders the two transactions.
499
500	  The workaround promotes data cache clean instructions to
501	  data cache clean-and-invalidate.
502	  Please note that this does not necessarily enable the workaround,
503	  as it depends on the alternative framework, which will only patch
504	  the kernel if an affected CPU is detected.
505
506	  If unsure, say Y.
507
508config ARM64_ERRATUM_824069
509	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
510	default y
511	select ARM64_WORKAROUND_CLEAN_CACHE
512	help
513	  This option adds an alternative code sequence to work around ARM
514	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
515	  to a coherent interconnect.
516
517	  If a Cortex-A53 processor is executing a store or prefetch for
518	  write instruction at the same time as a processor in another
519	  cluster is executing a cache maintenance operation to the same
520	  address, then this erratum might cause a clean cache line to be
521	  incorrectly marked as dirty.
522
523	  The workaround promotes data cache clean instructions to
524	  data cache clean-and-invalidate.
525	  Please note that this option does not necessarily enable the
526	  workaround, as it depends on the alternative framework, which will
527	  only patch the kernel if an affected CPU is detected.
528
529	  If unsure, say Y.
530
531config ARM64_ERRATUM_819472
532	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
533	default y
534	select ARM64_WORKAROUND_CLEAN_CACHE
535	help
536	  This option adds an alternative code sequence to work around ARM
537	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
538	  present when it is connected to a coherent interconnect.
539
540	  If the processor is executing a load and store exclusive sequence at
541	  the same time as a processor in another cluster is executing a cache
542	  maintenance operation to the same address, then this erratum might
543	  cause data corruption.
544
545	  The workaround promotes data cache clean instructions to
546	  data cache clean-and-invalidate.
547	  Please note that this does not necessarily enable the workaround,
548	  as it depends on the alternative framework, which will only patch
549	  the kernel if an affected CPU is detected.
550
551	  If unsure, say Y.
552
553config ARM64_ERRATUM_832075
554	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
555	default y
556	help
557	  This option adds an alternative code sequence to work around ARM
558	  erratum 832075 on Cortex-A57 parts up to r1p2.
559
560	  Affected Cortex-A57 parts might deadlock when exclusive load/store
561	  instructions to Write-Back memory are mixed with Device loads.
562
563	  The workaround is to promote device loads to use Load-Acquire
564	  semantics.
565	  Please note that this does not necessarily enable the workaround,
566	  as it depends on the alternative framework, which will only patch
567	  the kernel if an affected CPU is detected.
568
569	  If unsure, say Y.
570
571config ARM64_ERRATUM_834220
572	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
573	depends on KVM
574	help
575	  This option adds an alternative code sequence to work around ARM
576	  erratum 834220 on Cortex-A57 parts up to r1p2.
577
578	  Affected Cortex-A57 parts might report a Stage 2 translation
579	  fault as the result of a Stage 1 fault for load crossing a
580	  page boundary when there is a permission or device memory
581	  alignment fault at Stage 1 and a translation fault at Stage 2.
582
583	  The workaround is to verify that the Stage 1 translation
584	  doesn't generate a fault before handling the Stage 2 fault.
585	  Please note that this does not necessarily enable the workaround,
586	  as it depends on the alternative framework, which will only patch
587	  the kernel if an affected CPU is detected.
588
589	  If unsure, say N.
590
591config ARM64_ERRATUM_1742098
592	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
593	depends on COMPAT
594	default y
595	help
596	  This option removes the AES hwcap for aarch32 user-space to
597	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
598
599	  Affected parts may corrupt the AES state if an interrupt is
600	  taken between a pair of AES instructions. These instructions
601	  are only present if the cryptography extensions are present.
602	  All software should have a fallback implementation for CPUs
603	  that don't implement the cryptography extensions.
604
605	  If unsure, say Y.
606
607config ARM64_ERRATUM_845719
608	bool "Cortex-A53: 845719: a load might read incorrect data"
609	depends on COMPAT
610	default y
611	help
612	  This option adds an alternative code sequence to work around ARM
613	  erratum 845719 on Cortex-A53 parts up to r0p4.
614
615	  When running a compat (AArch32) userspace on an affected Cortex-A53
616	  part, a load at EL0 from a virtual address that matches the bottom 32
617	  bits of the virtual address used by a recent load at (AArch64) EL1
618	  might return incorrect data.
619
620	  The workaround is to write the contextidr_el1 register on exception
621	  return to a 32-bit task.
622	  Please note that this does not necessarily enable the workaround,
623	  as it depends on the alternative framework, which will only patch
624	  the kernel if an affected CPU is detected.
625
626	  If unsure, say Y.
627
628config ARM64_ERRATUM_843419
629	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
630	default y
631	help
632	  This option links the kernel with '--fix-cortex-a53-843419' and
633	  enables PLT support to replace certain ADRP instructions, which can
634	  cause subsequent memory accesses to use an incorrect address on
635	  Cortex-A53 parts up to r0p4.
636
637	  If unsure, say Y.
638
639config ARM64_ERRATUM_1024718
640	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
641	default y
642	help
643	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
644
645	  Affected Cortex-A55 cores (all revisions) could cause incorrect
646	  update of the hardware dirty bit when the DBM/AP bits are updated
647	  without a break-before-make. The workaround is to disable the usage
648	  of hardware DBM locally on the affected cores. CPUs not affected by
649	  this erratum will continue to use the feature.
650
651	  If unsure, say Y.
652
653config ARM64_ERRATUM_1418040
654	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
655	default y
656	depends on COMPAT
657	help
658	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
659	  errata 1188873 and 1418040.
660
661	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
662	  cause register corruption when accessing the timer registers
663	  from AArch32 userspace.
664
665	  If unsure, say Y.
666
667config ARM64_WORKAROUND_SPECULATIVE_AT
668	bool
669
670config ARM64_ERRATUM_1165522
671	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
672	default y
673	select ARM64_WORKAROUND_SPECULATIVE_AT
674	help
675	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
676
677	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
678	  corrupted TLBs by speculating an AT instruction during a guest
679	  context switch.
680
681	  If unsure, say Y.
682
683config ARM64_ERRATUM_1319367
684	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
685	default y
686	select ARM64_WORKAROUND_SPECULATIVE_AT
687	help
688	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
689	  and A72 erratum 1319367
690
691	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
692	  speculating an AT instruction during a guest context switch.
693
694	  If unsure, say Y.
695
696config ARM64_ERRATUM_1530923
697	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
698	default y
699	select ARM64_WORKAROUND_SPECULATIVE_AT
700	help
701	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
702
703	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
704	  corrupted TLBs by speculating an AT instruction during a guest
705	  context switch.
706
707	  If unsure, say Y.
708
709config ARM64_WORKAROUND_REPEAT_TLBI_SYNC
710	bool
711	# This workaround is (only) suitable for TLB invalidation errata where
712	# all of the following conditions are true:
713	#
714	# - The effects of the errata are only a loss of ordering/completion
715	#   for explicit memory accesses when the TLBI is completed with a DSB.
716	#   The removal of TLB entries is not affected.
717	#
718	#   Note that architecturally, S2-only invalidation does not remove
719	#   combined S1+S2 entries, and does not complete accesses translated
720	#   via those S1+S2 entries. Consequently, where this condition holds,
721	#   the errata do not affect S2-only invalidation.
722	#
723	# - The errata only affect broadcast TLB invalidation operations (e.g.
724	#   TLBI VMALLE1IS), and do not affect local TLB invalidation
725	#   operations (e.g. TLBI VMALLE1).
726	#
727	# - After any number of affected TLBI operations are completed with a
728	#   DSB, the errata can be mitigated by executing a single arbitrary
729	#   broadcast TLBI (which targets an arbitrary translation regime),
730	#   followed by a DSB.
731	#
732	# For more rationale, see commit a8f78680ee6bf795.
733
734config ARM64_ERRATUM_2441007
735	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
736	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
737	help
738	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
739
740	  Under very rare circumstances, affected Cortex-A55 CPUs
741	  may not handle a race between a break-before-make sequence on one
742	  CPU, and another CPU accessing the same page. This could allow a
743	  store to a page that has been unmapped.
744
745	  Work around this by adding the affected CPUs to the list that needs
746	  TLB sequences to be done twice.
747
748	  If unsure, say N.
749
750config ARM64_ERRATUM_1286807
751	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
752	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
753	help
754	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
755
756	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
757	  address for a cacheable mapping of a location is being
758	  accessed by a core while another core is remapping the virtual
759	  address to a new physical page using the recommended
760	  break-before-make sequence, then under very rare circumstances
761	  TLBI+DSB completes before a read using the translation being
762	  invalidated has been observed by other observers. The
763	  workaround repeats the TLBI+DSB operation.
764
765	  If unsure, say N.
766
767config ARM64_ERRATUM_1463225
768	bool "Cortex-A76: Software Step might prevent interrupt recognition"
769	default y
770	help
771	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
772
773	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
774	  of a system call instruction (SVC) can prevent recognition of
775	  subsequent interrupts when software stepping is disabled in the
776	  exception handler of the system call and either kernel debugging
777	  is enabled or VHE is in use.
778
779	  Work around the erratum by triggering a dummy step exception
780	  when handling a system call from a task that is being stepped
781	  in a VHE configuration of the kernel.
782
783	  If unsure, say Y.
784
785config ARM64_ERRATUM_1542419
786	bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
787	help
788	  This option adds a workaround for ARM Neoverse-N1 erratum
789	  1542419.
790
791	  Affected Neoverse-N1 cores could execute a stale instruction when
792	  modified by another CPU. The workaround depends on a firmware
793	  counterpart.
794
795	  Workaround the issue by hiding the DIC feature from EL0. This
796	  forces user-space to perform cache maintenance.
797
798	  If unsure, say N.
799
800config ARM64_ERRATUM_1508412
801	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
802	default y
803	help
804	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
805
806	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
807	  of a store-exclusive or read of PAR_EL1 and a load with device or
808	  non-cacheable memory attributes. The workaround depends on a firmware
809	  counterpart.
810
811	  KVM guests must also have the workaround implemented or they can
812	  deadlock the system.
813
814	  Work around the issue by inserting DMB SY barriers around PAR_EL1
815	  register reads and warning KVM users. The DMB barrier is sufficient
816	  to prevent a speculative PAR_EL1 read.
817
818	  If unsure, say Y.
819
820config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
821	bool
822
823config ARM64_ERRATUM_2051678
824	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
825	default y
826	help
827	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
828	  Affected Cortex-A510 might not respect the ordering rules for
829	  hardware update of the page table's dirty bit. The workaround
830	  is to not enable the feature on affected CPUs.
831
832	  If unsure, say Y.
833
834config ARM64_ERRATUM_2077057
835	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
836	default y
837	help
838	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
839	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
840	  expected, but a Pointer Authentication trap is taken instead. The
841	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
842	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
843
844	  This can only happen when EL2 is stepping EL1.
845
846	  When these conditions occur, the SPSR_EL2 value is unchanged from the
847	  previous guest entry, and can be restored from the in-memory copy.
848
849	  If unsure, say Y.
850
851config ARM64_ERRATUM_2658417
852	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
853	default y
854	help
855	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
856	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
857	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
858	  A510 CPUs are using shared neon hardware. As the sharing is not
859	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
860	  user-space should not be using these instructions.
861
862	  If unsure, say Y.
863
864config ARM64_ERRATUM_2119858
865	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
866	default y
867	depends on CORESIGHT_TRBE
868	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
869	help
870	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
871
872	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
873	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
874	  the event of a WRAP event.
875
876	  Work around the issue by always making sure we move the TRBPTR_EL1 by
877	  256 bytes before enabling the buffer and filling the first 256 bytes of
878	  the buffer with ETM ignore packets upon disabling.
879
880	  If unsure, say Y.
881
882config ARM64_ERRATUM_2139208
883	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
884	default y
885	depends on CORESIGHT_TRBE
886	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
887	help
888	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
889
890	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
891	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
892	  the event of a WRAP event.
893
894	  Work around the issue by always making sure we move the TRBPTR_EL1 by
895	  256 bytes before enabling the buffer and filling the first 256 bytes of
896	  the buffer with ETM ignore packets upon disabling.
897
898	  If unsure, say Y.
899
900config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
901	bool
902
903config ARM64_ERRATUM_2054223
904	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
905	default y
906	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
907	help
908	  Enable workaround for ARM Cortex-A710 erratum 2054223
909
910	  Affected cores may fail to flush the trace data on a TSB instruction, when
911	  the PE is in trace prohibited state. This will cause losing a few bytes
912	  of the trace cached.
913
914	  Workaround is to issue two TSB consecutively on affected cores.
915
916	  If unsure, say Y.
917
918config ARM64_ERRATUM_2067961
919	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
920	default y
921	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
922	help
923	  Enable workaround for ARM Neoverse-N2 erratum 2067961
924
925	  Affected cores may fail to flush the trace data on a TSB instruction, when
926	  the PE is in trace prohibited state. This will cause losing a few bytes
927	  of the trace cached.
928
929	  Workaround is to issue two TSB consecutively on affected cores.
930
931	  If unsure, say Y.
932
933config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
934	bool
935
936config ARM64_ERRATUM_2253138
937	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
938	depends on CORESIGHT_TRBE
939	default y
940	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
941	help
942	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
943
944	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
945	  for TRBE. Under some conditions, the TRBE might generate a write to the next
946	  virtually addressed page following the last page of the TRBE address space
947	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
948
949	  Work around this in the driver by always making sure that there is a
950	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
951
952	  If unsure, say Y.
953
954config ARM64_ERRATUM_2224489
955	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
956	depends on CORESIGHT_TRBE
957	default y
958	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
959	help
960	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
961
962	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
963	  for TRBE. Under some conditions, the TRBE might generate a write to the next
964	  virtually addressed page following the last page of the TRBE address space
965	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
966
967	  Work around this in the driver by always making sure that there is a
968	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
969
970	  If unsure, say Y.
971
972config ARM64_ERRATUM_2441009
973	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
974	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
975	help
976	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
977
978	  Under very rare circumstances, affected Cortex-A510 CPUs
979	  may not handle a race between a break-before-make sequence on one
980	  CPU, and another CPU accessing the same page. This could allow a
981	  store to a page that has been unmapped.
982
983	  Work around this by adding the affected CPUs to the list that needs
984	  TLB sequences to be done twice.
985
986	  If unsure, say N.
987
988config ARM64_ERRATUM_2064142
989	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
990	depends on CORESIGHT_TRBE
991	default y
992	help
993	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
994
995	  Affected Cortex-A510 core might fail to write into system registers after the
996	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
997	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
998	  and TRBTRG_EL1 will be ignored and will not be effected.
999
1000	  Work around this in the driver by executing TSB CSYNC and DSB after collection
1001	  is stopped and before performing a system register write to one of the affected
1002	  registers.
1003
1004	  If unsure, say Y.
1005
1006config ARM64_ERRATUM_2038923
1007	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
1008	depends on CORESIGHT_TRBE
1009	default y
1010	help
1011	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
1012
1013	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
1014	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
1015	  might be corrupted. This happens after TRBE buffer has been enabled by setting
1016	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
1017	  execution changes from a context, in which trace is prohibited to one where it
1018	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
1019	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
1020	  the trace buffer state might be corrupted.
1021
1022	  Work around this in the driver by preventing an inconsistent view of whether the
1023	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
1024	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
1025	  two ISB instructions if no ERET is to take place.
1026
1027	  If unsure, say Y.
1028
1029config ARM64_ERRATUM_1902691
1030	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1031	depends on CORESIGHT_TRBE
1032	default y
1033	help
1034	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1035
1036	  Affected Cortex-A510 core might cause trace data corruption, when being written
1037	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
1038	  trace data.
1039
1040	  Work around this problem in the driver by just preventing TRBE initialization on
1041	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1042	  on such implementations. This will cover the kernel for any firmware that doesn't
1043	  do this already.
1044
1045	  If unsure, say Y.
1046
1047config ARM64_WORKAROUND_BROKEN_AMU_CONSTCNT
1048	bool
1049	# Targeting errata affecting AMEVCNTR01, the AMU constant counter.
1050	# On affected CPUs the counter may not increment at the expected rate,
1051	# making it unreliable. As a result, AMU users should treat it as
1052	# unavailable rather than relying on misleading counter values.
1053
1054config ARM64_ERRATUM_2457168
1055	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1056	depends on ARM64_AMU_EXTN
1057	select ARM64_WORKAROUND_BROKEN_AMU_CONSTCNT
1058	default y
1059	help
1060	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1061
1062	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1063	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1064	  incorrectly giving a significantly higher output value.
1065
1066	  Work around this problem by returning 0 when reading the affected counter in
1067	  key locations that results in disabling all users of this counter. This effect
1068	  is the same to firmware disabling affected counters.
1069
1070	  If unsure, say Y.
1071
1072config ARM64_ERRATUM_2645198
1073	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1074	default y
1075	help
1076	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1077
1078	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1079	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1080	  next instruction abort caused by permission fault.
1081
1082	  Only user-space does executable to non-executable permission transition via
1083	  mprotect() system call. Workaround the problem by doing a break-before-make
1084	  TLB invalidation, for all changes to executable user space mappings.
1085
1086	  If unsure, say Y.
1087
1088config ARM64_ERRATUM_3821522
1089	bool "Cortex-A725: 3821522: workaround for possible CNT_CYCLES increment error due to WFE/WFI"
1090	depends on ARM64_AMU_EXTN
1091	select ARM64_WORKAROUND_BROKEN_AMU_CONSTCNT
1092	default y
1093	help
1094	  This option adds the workaround for ARM Cortex-A725 erratum 3821522.
1095
1096	  On affected A725 cores, the CNT_CYCLES event may incur a significant
1097	  increment error when entering and subsequently exiting WFx.
1098	  As a result, the CNT_CYCLES may diverge from the system counter
1099	  frequency at which it is expected to increment.
1100	  This renders the AMU counter AMEVCNTR01, that implements CNT_CYCLES,
1101	  being unreliable and unsuitable for use.
1102
1103	  Since there is no hardware workaround, reads of the affected CNT_CYCLES
1104	  counter return 0 in the relevant paths. This causes users of the counter
1105	  to treat it as unavailable and is functionally equivalent to firmware
1106	  disabling the affected counter.
1107
1108	  If unsure, say Y.
1109
1110config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1111	bool
1112
1113config ARM64_ERRATUM_2966298
1114	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1115	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1116	default y
1117	help
1118	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1119
1120	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1121	  load might leak data from a privileged level via a cache side channel.
1122
1123	  Work around this problem by executing a TLBI before returning to EL0.
1124
1125	  If unsure, say Y.
1126
1127config ARM64_ERRATUM_3117295
1128	bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1129	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1130	default y
1131	help
1132	  This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1133
1134	  On an affected Cortex-A510 core, a speculatively executed unprivileged
1135	  load might leak data from a privileged level via a cache side channel.
1136
1137	  Work around this problem by executing a TLBI before returning to EL0.
1138
1139	  If unsure, say Y.
1140
1141config ARM64_ERRATUM_3194386
1142	bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1143	default y
1144	help
1145	  This option adds the workaround for the following errata:
1146
1147	  * ARM Cortex-A76 erratum 3324349
1148	  * ARM Cortex-A77 erratum 3324348
1149	  * ARM Cortex-A78 erratum 3324344
1150	  * ARM Cortex-A78C erratum 3324346
1151	  * ARM Cortex-A78C erratum 3324347
1152	  * ARM Cortex-A710 erratam 3324338
1153	  * ARM Cortex-A715 errartum 3456084
1154	  * ARM Cortex-A720 erratum 3456091
1155	  * ARM Cortex-A725 erratum 3456106
1156	  * ARM Cortex-X1 erratum 3324344
1157	  * ARM Cortex-X1C erratum 3324346
1158	  * ARM Cortex-X2 erratum 3324338
1159	  * ARM Cortex-X3 erratum 3324335
1160	  * ARM Cortex-X4 erratum 3194386
1161	  * ARM Cortex-X925 erratum 3324334
1162	  * ARM Neoverse-N1 erratum 3324349
1163	  * ARM Neoverse N2 erratum 3324339
1164	  * ARM Neoverse-N3 erratum 3456111
1165	  * ARM Neoverse-V1 erratum 3324341
1166	  * ARM Neoverse V2 erratum 3324336
1167	  * ARM Neoverse-V3 erratum 3312417
1168	  * ARM Neoverse-V3AE erratum 3312417
1169
1170	  On affected cores "MSR SSBS, #0" instructions may not affect
1171	  subsequent speculative instructions, which may permit unexepected
1172	  speculative store bypassing.
1173
1174	  Work around this problem by placing a Speculation Barrier (SB) or
1175	  Instruction Synchronization Barrier (ISB) after kernel changes to
1176	  SSBS. The presence of the SSBS special-purpose register is hidden
1177	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1178	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1179
1180	  If unsure, say Y.
1181
1182config ARM64_ERRATUM_4311569
1183	bool "SI L1: 4311569: workaround for premature CMO completion erratum"
1184	default y
1185	help
1186	  This option adds the workaround for ARM SI L1 erratum 4311569.
1187
1188	  The erratum of SI L1 can cause an early response to a combined write
1189	  and cache maintenance operation (WR+CMO) before the operation is fully
1190	  completed to the Point of Serialization (POS).
1191	  This can result in a non-I/O coherent agent observing stale data,
1192	  potentially leading to system instability or incorrect behavior.
1193
1194	  Enabling this option implements a software workaround by inserting a
1195	  second loop of Cache Maintenance Operation (CMO) immediately following the
1196	  end of function to do CMOs. This ensures that the data is correctly serialized
1197	  before the buffer is handed off to a non-coherent agent.
1198
1199	  If unsure, say Y.
1200
1201config ARM64_ERRATUM_4193714
1202	bool "C1-Pro: 4193714: SME DVMSync early acknowledgement"
1203	depends on ARM64_SME
1204	default y
1205	help
1206	  Enable workaround for C1-Pro acknowledging the DVMSync before
1207	  the SME memory accesses are complete. This will cause TLB
1208	  maintenance for processes using SME to also issue an IPI to
1209	  the affected CPUs.
1210
1211	  If unsure, say Y.
1212
1213config ARM64_ERRATUM_4118414
1214	bool "Various: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
1215	default y
1216	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
1217	help
1218	  This option adds a workaround for the following errata:
1219
1220	  * ARM C1-Premium erratum 4193780
1221	  * ARM C1-Ultra erratum 4193780
1222	  * ARM Cortex-A76 erratum 4193800
1223	  * ARM Cortex-A76AE erratum 4193801
1224	  * ARM Cortex-A77 erratum 4193798
1225	  * ARM Cortex-A78 erratum 4193791
1226	  * ARM Cortex-A78AE erratum 4193793
1227	  * ARM Cortex-A78C erratum 4193794
1228	  * ARM Cortex-A710 erratum 4193788
1229	  * ARM Cortex-X1 erratum 4193791
1230	  * ARM Cortex-X1C erratum 4193792
1231	  * ARM Cortex-X2 erratum 4193788
1232	  * ARM Cortex-X3 erratum 4193786
1233	  * ARM Cortex-X4 erratum 4118414
1234	  * ARM Cortex-X925 erratum 4193781
1235	  * ARM Neoverse-N1 erratum 4193800
1236	  * ARM Neoverse-N2 erratum 4193789
1237	  * ARM Neoverse-V1 erratum 4193790
1238	  * ARM Neoverse-V2 erratum 4193787
1239	  * ARM Neoverse-V3 erratum 4193784
1240	  * ARM Neoverse-V3AE erratum 4193784
1241	  * Microsoft Azure Cobalt 100 4193789
1242	  * NVIDIA Olympus erratum T410-OLY-1029
1243
1244	  On affected cores, some memory accesses might not be completed by
1245	  broadcast TLB invalidation.
1246
1247	  This issue is also known as CVE-2025-10263.
1248
1249	  If unsure, say Y.
1250
1251config CAVIUM_ERRATUM_22375
1252	bool "Cavium erratum 22375, 24313"
1253	default y
1254	help
1255	  Enable workaround for errata 22375 and 24313.
1256
1257	  This implements two gicv3-its errata workarounds for ThunderX. Both
1258	  with a small impact affecting only ITS table allocation.
1259
1260	    erratum 22375: only alloc 8MB table size
1261	    erratum 24313: ignore memory access type
1262
1263	  The fixes are in ITS initialization and basically ignore memory access
1264	  type and table size provided by the TYPER and BASER registers.
1265
1266	  If unsure, say Y.
1267
1268config CAVIUM_ERRATUM_23144
1269	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1270	depends on NUMA
1271	default y
1272	help
1273	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1274
1275	  If unsure, say Y.
1276
1277config CAVIUM_ERRATUM_23154
1278	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1279	default y
1280	help
1281	  The ThunderX GICv3 implementation requires a modified version for
1282	  reading the IAR status to ensure data synchronization
1283	  (access to icc_iar1_el1 is not sync'ed before and after).
1284
1285	  It also suffers from erratum 38545 (also present on Marvell's
1286	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1287	  spuriously presented to the CPU interface.
1288
1289	  If unsure, say Y.
1290
1291config CAVIUM_ERRATUM_27456
1292	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1293	default y
1294	help
1295	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1296	  instructions may cause the icache to become corrupted if it
1297	  contains data for a non-current ASID.  The fix is to
1298	  invalidate the icache when changing the mm context.
1299
1300	  If unsure, say Y.
1301
1302config CAVIUM_ERRATUM_30115
1303	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1304	default y
1305	help
1306	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1307	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1308	  interrupts in host. Trapping both GICv3 group-0 and group-1
1309	  accesses sidesteps the issue.
1310
1311	  If unsure, say Y.
1312
1313config CAVIUM_TX2_ERRATUM_219
1314	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1315	default y
1316	help
1317	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1318	  TTBR update and the corresponding context synchronizing operation can
1319	  cause a spurious Data Abort to be delivered to any hardware thread in
1320	  the CPU core.
1321
1322	  Work around the issue by avoiding the problematic code sequence and
1323	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1324	  trap handler performs the corresponding register access, skips the
1325	  instruction and ensures context synchronization by virtue of the
1326	  exception return.
1327
1328	  If unsure, say Y.
1329
1330config FUJITSU_ERRATUM_010001
1331	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1332	default y
1333	help
1334	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1335	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1336	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1337	  This fault occurs under a specific hardware condition when a
1338	  load/store instruction performs an address translation using:
1339	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1340	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1341	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1342	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1343
1344	  The workaround is to ensure these bits are clear in TCR_ELx.
1345	  The workaround only affects the Fujitsu-A64FX.
1346
1347	  If unsure, say Y.
1348
1349config HISILICON_ERRATUM_161600802
1350	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1351	default y
1352	help
1353	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1354	  when issued ITS commands such as VMOVP and VMAPP, and requires
1355	  a 128kB offset to be applied to the target address in this commands.
1356
1357	  If unsure, say Y.
1358
1359config HISILICON_ERRATUM_162100801
1360	bool "Hip09 162100801 erratum support"
1361	default y
1362	help
1363	  When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches
1364	  during unmapping operation, which will cause some vSGIs lost.
1365	  To fix the issue, invalidate related vPE cache through GICR_INVALLR
1366	  after VMOVP.
1367
1368	  If unsure, say Y.
1369
1370config HISILICON_ERRATUM_162100125
1371	bool "Hisilicon erratum 162100125"
1372	default y
1373	select ARM64_WORKAROUND_DISABLE_CNP
1374	help
1375	  On HiSilicon HIP09, TLB entry matching behavior when CNP
1376	  (TTBRx.CNP=1) is enabled differs from the ARM architecture
1377	  specification.
1378
1379	  TLB entries may be incorrectly shared between CPUs, potentially
1380	  causing TLB conflicts and stale mappings.
1381
1382	  Disable CNP support for affected HiSilicon HIP09 cores.
1383
1384	  If unsure, say Y.
1385
1386config QCOM_FALKOR_ERRATUM_1003
1387	bool "Falkor E1003: Incorrect translation due to ASID change"
1388	default y
1389	help
1390	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1391	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1392	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1393	  then only for entries in the walk cache, since the leaf translation
1394	  is unchanged. Work around the erratum by invalidating the walk cache
1395	  entries for the trampoline before entering the kernel proper.
1396
1397config QCOM_FALKOR_ERRATUM_1009
1398	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1399	default y
1400	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
1401	help
1402	  On Falkor v1, the CPU may prematurely complete a DSB following a
1403	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1404	  one more time to fix the issue.
1405
1406	  If unsure, say Y.
1407
1408config QCOM_QDF2400_ERRATUM_0065
1409	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1410	default y
1411	help
1412	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1413	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1414	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1415
1416	  If unsure, say Y.
1417
1418config QCOM_FALKOR_ERRATUM_E1041
1419	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1420	default y
1421	help
1422	  Falkor CPU may speculatively fetch instructions from an improper
1423	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1424	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1425
1426	  If unsure, say Y.
1427
1428config ARM64_WORKAROUND_DISABLE_CNP
1429	bool
1430
1431config NVIDIA_CARMEL_CNP_ERRATUM
1432	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1433	default y
1434	select ARM64_WORKAROUND_DISABLE_CNP
1435	help
1436	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1437	  invalidate shared TLB entries installed by a different core, as it would
1438	  on standard ARM cores.
1439
1440	  If unsure, say Y.
1441
1442config NVIDIA_OLYMPUS_1027_ERRATUM
1443	bool "NVIDIA Olympus: device store/load ordering erratum"
1444	default y
1445	help
1446	  This option adds an alternative code sequence to work around an
1447	  NVIDIA Olympus core erratum where a Device-nGnR* store can be
1448	  observed by a peripheral after a younger Device-nGnR* load to the
1449	  same peripheral. This breaks the program order that drivers rely
1450	  on for MMIO and can leave a device in an incorrect state.
1451
1452	  The workaround inserts a DMB OSH immediately before raw MMIO loads.
1453	  The erratum cannot occur when a DMB that orders loads appears
1454	  between the store and load, preventing the younger load from being
1455	  observed before the older store.
1456
1457	  The alternatives framework patches in DMB OSH only when an affected
1458	  CPU is detected. Other CPUs execute a NOP in its place. Disabling
1459	  this option leaves the original MMIO read instruction stream
1460	  unchanged.
1461
1462	  If unsure, say Y.
1463
1464config RENESAS_ERRATUM_GEN4GICITS1
1465	bool "Renesas R-Car Gen4: GIC600 can not access physical addresses above 4 GiB"
1466	default y
1467	help
1468	  The Renesas R-Car Gen4 S4/V4H/V4M GIC600 SoC integrations have AXI
1469	  addressing limited to the first 32-bit of physical address space.
1470
1471	  If unsure, say Y.
1472
1473config ROCKCHIP_ERRATUM_3568002
1474	bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB"
1475	default y
1476	help
1477	  The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI
1478	  addressing limited to the first 32bit of physical address space.
1479
1480	  If unsure, say Y.
1481
1482config ROCKCHIP_ERRATUM_3588001
1483	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1484	default y
1485	help
1486	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1487	  This means, that its sharability feature may not be used, even though it
1488	  is supported by the IP itself.
1489
1490	  If unsure, say Y.
1491
1492config NXP_IMX8QM_ERRATUM_ERR050104
1493	bool "NXP iMX8QM/QP ERR050104: broken cache/TLB invalidation broadcast"
1494	default y
1495	help
1496	  On iMX8QM (QuadMax) and iMX8QP (QuadPlus), address bits above bit 35
1497	  in the A53 subsystem ARADDR and ACADDR buses are incorrectly
1498	  connected. This corrupts targeted TLBI and IC broadcasts exchanged
1499	  between the A53 and A72 core clusters.
1500
1501	  Work around this by redirecting targeted TLBI operations to
1502	  broadcast-all variants (VMALLE1IS) in the high-level TLB flush
1503	  functions, upgrading IC IVAU to IC IALLUIS for both kernel and
1504	  user-space, and disabling KVM since correct TLB maintenance
1505	  cannot be guaranteed for guests.
1506
1507	  The user-space IC IVAU is upgraded by trapping it to the kernel
1508	  (SCTLR_EL1.UCI cleared). This also traps the user DC CVAU, DC CVAC,
1509	  DC CVAP, DC CVADP and DC CIVAC instructions, making user cache
1510	  maintenance slower on the affected SoCs.
1511
1512	  If unsure, say Y.
1513
1514config SOCIONEXT_SYNQUACER_PREITS
1515	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1516	default y
1517	help
1518	  Socionext Synquacer SoCs implement a separate h/w block to generate
1519	  MSI doorbell writes with non-zero values for the device ID.
1520
1521	  If unsure, say Y.
1522
1523endmenu # "ARM errata workarounds via the alternatives framework"
1524
1525choice
1526	prompt "Page size"
1527	default ARM64_4K_PAGES
1528	help
1529	  Page size (translation granule) configuration.
1530
1531config ARM64_4K_PAGES
1532	bool "4KB"
1533	select HAVE_PAGE_SIZE_4KB
1534	help
1535	  This feature enables 4KB pages support.
1536
1537config ARM64_16K_PAGES
1538	bool "16KB"
1539	select HAVE_PAGE_SIZE_16KB
1540	help
1541	  The system will use 16KB pages support. AArch32 emulation
1542	  requires applications compiled with 16K (or a multiple of 16K)
1543	  aligned segments.
1544
1545config ARM64_64K_PAGES
1546	bool "64KB"
1547	select HAVE_PAGE_SIZE_64KB
1548	help
1549	  This feature enables 64KB pages support (4KB by default)
1550	  allowing only two levels of page tables and faster TLB
1551	  look-up. AArch32 emulation requires applications compiled
1552	  with 64K aligned segments.
1553
1554endchoice
1555
1556choice
1557	prompt "Virtual address space size"
1558	default ARM64_VA_BITS_52
1559	help
1560	  Allows choosing one of multiple possible virtual address
1561	  space sizes. The level of translation table is determined by
1562	  a combination of page size and virtual address space size.
1563
1564config ARM64_VA_BITS_36
1565	bool "36-bit" if EXPERT
1566	depends on PAGE_SIZE_16KB
1567
1568config ARM64_VA_BITS_39
1569	bool "39-bit"
1570	depends on PAGE_SIZE_4KB
1571
1572config ARM64_VA_BITS_42
1573	bool "42-bit"
1574	depends on PAGE_SIZE_64KB
1575
1576config ARM64_VA_BITS_47
1577	bool "47-bit"
1578	depends on PAGE_SIZE_16KB
1579
1580config ARM64_VA_BITS_48
1581	bool "48-bit"
1582
1583config ARM64_VA_BITS_52
1584	bool "52-bit"
1585	help
1586	  Enable 52-bit virtual addressing for userspace when explicitly
1587	  requested via a hint to mmap(). The kernel will also use 52-bit
1588	  virtual addresses for its own mappings (provided HW support for
1589	  this feature is available, otherwise it reverts to 48-bit).
1590
1591	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1592	  ARMv8.3 Pointer Authentication will result in the PAC being
1593	  reduced from 7 bits to 3 bits, which may have a significant
1594	  impact on its susceptibility to brute-force attacks.
1595
1596	  If unsure, select 48-bit virtual addressing instead.
1597
1598endchoice
1599
1600config ARM64_FORCE_52BIT
1601	bool "Force 52-bit virtual addresses for userspace"
1602	depends on ARM64_VA_BITS_52 && EXPERT
1603	help
1604	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1605	  to maintain compatibility with older software by providing 48-bit VAs
1606	  unless a hint is supplied to mmap.
1607
1608	  This configuration option disables the 48-bit compatibility logic, and
1609	  forces all userspace addresses to be 52-bit on HW that supports it. One
1610	  should only enable this configuration option for stress testing userspace
1611	  memory management code. If unsure say N here.
1612
1613config ARM64_VA_BITS
1614	int
1615	default 36 if ARM64_VA_BITS_36
1616	default 39 if ARM64_VA_BITS_39
1617	default 42 if ARM64_VA_BITS_42
1618	default 47 if ARM64_VA_BITS_47
1619	default 48 if ARM64_VA_BITS_48
1620	default 52 if ARM64_VA_BITS_52
1621
1622choice
1623	prompt "Physical address space size"
1624	default ARM64_PA_BITS_48
1625	help
1626	  Choose the maximum physical address range that the kernel will
1627	  support.
1628
1629config ARM64_PA_BITS_48
1630	bool "48-bit"
1631	depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1632
1633config ARM64_PA_BITS_52
1634	bool "52-bit"
1635	depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1636	help
1637	  Enable support for a 52-bit physical address space, introduced as
1638	  part of the ARMv8.2-LPA extension.
1639
1640	  With this enabled, the kernel will also continue to work on CPUs that
1641	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1642	  minor performance overhead).
1643
1644endchoice
1645
1646config ARM64_PA_BITS
1647	int
1648	default 48 if ARM64_PA_BITS_48
1649	default 52 if ARM64_PA_BITS_52
1650
1651config ARM64_LPA2
1652	def_bool y
1653	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1654
1655config NR_CPUS
1656	int "Maximum number of CPUs (2-4096)"
1657	range 2 4096
1658	default "512"
1659
1660config HOTPLUG_CPU
1661	bool "Support for hot-pluggable CPUs"
1662	select GENERIC_IRQ_MIGRATION
1663	help
1664	  Say Y here to experiment with turning CPUs off and on.  CPUs
1665	  can be controlled through /sys/devices/system/cpu.
1666
1667# Common NUMA Features
1668config NUMA
1669	bool "NUMA Memory Allocation and Scheduler Support"
1670	select GENERIC_ARCH_NUMA
1671	select OF_NUMA
1672	select HAVE_SETUP_PER_CPU_AREA
1673	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1674	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1675	select USE_PERCPU_NUMA_NODE_ID
1676	help
1677	  Enable NUMA (Non-Uniform Memory Access) support.
1678
1679	  The kernel will try to allocate memory used by a CPU on the
1680	  local memory of the CPU and add some more
1681	  NUMA awareness to the kernel.
1682
1683config NODES_SHIFT
1684	int "Maximum NUMA Nodes (as a power of 2)"
1685	range 1 10
1686	default "4"
1687	depends on NUMA
1688	help
1689	  Specify the maximum number of NUMA Nodes available on the target
1690	  system.  Increases memory reserved to accommodate various tables.
1691
1692source "kernel/Kconfig.hz"
1693
1694config ARCH_SPARSEMEM_ENABLE
1695	def_bool y
1696	select SPARSEMEM_VMEMMAP_ENABLE
1697
1698config HW_PERF_EVENTS
1699	def_bool y
1700	depends on ARM_PMU
1701
1702# Supported by clang >= 7.0 or GCC >= 12.0.0
1703config CC_HAVE_SHADOW_CALL_STACK
1704	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1705
1706config PARAVIRT
1707	bool "Enable paravirtualization code"
1708	select HAVE_PV_STEAL_CLOCK_GEN
1709	help
1710	  This changes the kernel so it can modify itself when it is run
1711	  under a hypervisor, potentially improving performance significantly
1712	  over full virtualization.
1713
1714config PARAVIRT_TIME_ACCOUNTING
1715	bool "Paravirtual steal time accounting"
1716	select PARAVIRT
1717	help
1718	  Select this option to enable fine granularity task steal time
1719	  accounting. Time spent executing other tasks in parallel with
1720	  the current vCPU is discounted from the vCPU power. To account for
1721	  that, there can be a small performance impact.
1722
1723	  If in doubt, say N here.
1724
1725config ARCH_SUPPORTS_KEXEC
1726	def_bool PM_SLEEP_SMP
1727
1728config ARCH_SUPPORTS_KEXEC_FILE
1729	def_bool y
1730
1731config ARCH_SELECTS_KEXEC_FILE
1732	def_bool y
1733	depends on KEXEC_FILE
1734	select HAVE_IMA_KEXEC if IMA
1735
1736config ARCH_SUPPORTS_KEXEC_SIG
1737	def_bool y
1738
1739config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1740	def_bool y
1741
1742config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1743	def_bool y
1744
1745config ARCH_SUPPORTS_KEXEC_HANDOVER
1746	def_bool y
1747
1748config ARCH_SUPPORTS_CRASH_DUMP
1749	def_bool y
1750
1751config ARCH_DEFAULT_CRASH_DUMP
1752	def_bool y
1753
1754config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1755	def_bool CRASH_RESERVE
1756
1757config TRANS_TABLE
1758	def_bool y
1759	depends on HIBERNATION || KEXEC_CORE
1760
1761config XEN_DOM0
1762	def_bool y
1763	depends on XEN
1764
1765config XEN
1766	bool "Xen guest support on ARM64"
1767	depends on ARM64 && OF
1768	select SWIOTLB_XEN
1769	select PARAVIRT
1770	help
1771	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1772
1773# include/linux/mmzone.h requires the following to be true:
1774#
1775#   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1776#
1777# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1778#
1779#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1780# ----+-------------------+--------------+----------------------+-------------------------+
1781# 4K  |       27          |      12      |       15             |         10              |
1782# 16K |       27          |      14      |       13             |         11              |
1783# 64K |       29          |      16      |       13             |         13              |
1784config ARCH_FORCE_MAX_ORDER
1785	int
1786	default "13" if ARM64_64K_PAGES
1787	default "11" if ARM64_16K_PAGES
1788	default "10"
1789	help
1790	  The kernel page allocator limits the size of maximal physically
1791	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1792	  defines the maximal power of two of number of pages that can be
1793	  allocated as a single contiguous block. This option allows
1794	  overriding the default setting when ability to allocate very
1795	  large blocks of physically contiguous memory is required.
1796
1797	  The maximal size of allocation cannot exceed the size of the
1798	  section, so the value of MAX_PAGE_ORDER should satisfy
1799
1800	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1801
1802	  Don't change if unsure.
1803
1804config UNMAP_KERNEL_AT_EL0
1805	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1806	default y
1807	help
1808	  Speculation attacks against some high-performance processors can
1809	  be used to bypass MMU permission checks and leak kernel data to
1810	  userspace. This can be defended against by unmapping the kernel
1811	  when running in userspace, mapping it back in on exception entry
1812	  via a trampoline page in the vector table.
1813
1814	  If unsure, say Y.
1815
1816config MITIGATE_SPECTRE_BRANCH_HISTORY
1817	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1818	default y
1819	help
1820	  Speculation attacks against some high-performance processors can
1821	  make use of branch history to influence future speculation.
1822	  When taking an exception from user-space, a sequence of branches
1823	  or a firmware call overwrites the branch history.
1824
1825config ARM64_SW_TTBR0_PAN
1826	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1827	depends on !KCSAN
1828	help
1829	  Enabling this option prevents the kernel from accessing
1830	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1831	  zeroed area and reserved ASID. The user access routines
1832	  restore the valid TTBR0_EL1 temporarily.
1833
1834config ARM64_TAGGED_ADDR_ABI
1835	bool "Enable the tagged user addresses syscall ABI"
1836	default y
1837	help
1838	  When this option is enabled, user applications can opt in to a
1839	  relaxed ABI via prctl() allowing tagged addresses to be passed
1840	  to system calls as pointer arguments. For details, see
1841	  Documentation/arch/arm64/tagged-address-abi.rst.
1842
1843menuconfig COMPAT
1844	bool "Kernel support for 32-bit EL0"
1845	depends on ARM64_4K_PAGES || EXPERT
1846	select HAVE_UID16
1847	select OLD_SIGSUSPEND3
1848	select COMPAT_OLD_SIGACTION
1849	help
1850	  This option enables support for a 32-bit EL0 running under a 64-bit
1851	  kernel at EL1. AArch32-specific components such as system calls,
1852	  the user helper functions, VFP support and the ptrace interface are
1853	  handled appropriately by the kernel.
1854
1855	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1856	  that you will only be able to execute AArch32 binaries that were compiled
1857	  with page size aligned segments.
1858
1859	  If you want to execute 32-bit userspace applications, say Y.
1860
1861if COMPAT
1862
1863config KUSER_HELPERS
1864	bool "Enable kuser helpers page for 32-bit applications"
1865	default y
1866	help
1867	  Warning: disabling this option may break 32-bit user programs.
1868
1869	  Provide kuser helpers to compat tasks. The kernel provides
1870	  helper code to userspace in read only form at a fixed location
1871	  to allow userspace to be independent of the CPU type fitted to
1872	  the system. This permits binaries to be run on ARMv4 through
1873	  to ARMv8 without modification.
1874
1875	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1876
1877	  However, the fixed address nature of these helpers can be used
1878	  by ROP (return orientated programming) authors when creating
1879	  exploits.
1880
1881	  If all of the binaries and libraries which run on your platform
1882	  are built specifically for your platform, and make no use of
1883	  these helpers, then you can turn this option off to hinder
1884	  such exploits. However, in that case, if a binary or library
1885	  relying on those helpers is run, it will not function correctly.
1886
1887	  Say N here only if you are absolutely certain that you do not
1888	  need these helpers; otherwise, the safe option is to say Y.
1889
1890config COMPAT_VDSO
1891	bool "Enable vDSO for 32-bit applications"
1892	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1893	default y
1894	help
1895	  Place in the process address space of 32-bit applications an
1896	  ELF shared object providing fast implementations of gettimeofday
1897	  and clock_gettime.
1898
1899	  You must have a 32-bit build of glibc 2.22 or later for programs
1900	  to seamlessly take advantage of this.
1901
1902config THUMB2_COMPAT_VDSO
1903	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1904	depends on COMPAT_VDSO
1905	default y
1906	help
1907	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1908	  otherwise with '-marm'.
1909
1910config COMPAT_ALIGNMENT_FIXUPS
1911	bool "Fix up misaligned multi-word loads and stores in user space"
1912
1913menuconfig ARMV8_DEPRECATED
1914	bool "Emulate deprecated/obsolete ARMv8 instructions"
1915	depends on SYSCTL
1916	help
1917	  Legacy software support may require certain instructions
1918	  that have been deprecated or obsoleted in the architecture.
1919
1920	  Enable this config to enable selective emulation of these
1921	  features.
1922
1923	  If unsure, say Y
1924
1925if ARMV8_DEPRECATED
1926
1927config SWP_EMULATION
1928	bool "Emulate SWP/SWPB instructions"
1929	help
1930	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1931	  they are always undefined. Say Y here to enable software
1932	  emulation of these instructions for userspace using LDXR/STXR.
1933	  This feature can be controlled at runtime with the abi.swp
1934	  sysctl which is disabled by default.
1935
1936	  In some older versions of glibc [<=2.8] SWP is used during futex
1937	  trylock() operations with the assumption that the code will not
1938	  be preempted. This invalid assumption may be more likely to fail
1939	  with SWP emulation enabled, leading to deadlock of the user
1940	  application.
1941
1942	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1943	  on an external transaction monitoring block called a global
1944	  monitor to maintain update atomicity. If your system does not
1945	  implement a global monitor, this option can cause programs that
1946	  perform SWP operations to uncached memory to deadlock.
1947
1948	  If unsure, say Y
1949
1950config CP15_BARRIER_EMULATION
1951	bool "Emulate CP15 Barrier instructions"
1952	help
1953	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1954	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1955	  strongly recommended to use the ISB, DSB, and DMB
1956	  instructions instead.
1957
1958	  Say Y here to enable software emulation of these
1959	  instructions for AArch32 userspace code. When this option is
1960	  enabled, CP15 barrier usage is traced which can help
1961	  identify software that needs updating. This feature can be
1962	  controlled at runtime with the abi.cp15_barrier sysctl.
1963
1964	  If unsure, say Y
1965
1966config SETEND_EMULATION
1967	bool "Emulate SETEND instruction"
1968	help
1969	  The SETEND instruction alters the data-endianness of the
1970	  AArch32 EL0, and is deprecated in ARMv8.
1971
1972	  Say Y here to enable software emulation of the instruction
1973	  for AArch32 userspace code. This feature can be controlled
1974	  at runtime with the abi.setend sysctl.
1975
1976	  Note: All the cpus on the system must have mixed endian support at EL0
1977	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1978	  endian - is hotplugged in after this feature has been enabled, there could
1979	  be unexpected results in the applications.
1980
1981	  If unsure, say Y
1982endif # ARMV8_DEPRECATED
1983
1984endif # COMPAT
1985
1986menu "ARMv8.1 architectural features"
1987
1988config ARM64_HW_AFDBM
1989	bool "Support for hardware updates of the Access and Dirty page flags"
1990	default y
1991	help
1992	  The ARMv8.1 architecture extensions introduce support for
1993	  hardware updates of the access and dirty information in page
1994	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1995	  capable processors, accesses to pages with PTE_AF cleared will
1996	  set this bit instead of raising an access flag fault.
1997	  Similarly, writes to read-only pages with the DBM bit set will
1998	  clear the read-only bit (AP[2]) instead of raising a
1999	  permission fault.
2000
2001	  Kernels built with this configuration option enabled continue
2002	  to work on pre-ARMv8.1 hardware and the performance impact is
2003	  minimal. If unsure, say Y.
2004
2005endmenu # "ARMv8.1 architectural features"
2006
2007menu "ARMv8.2 architectural features"
2008
2009config ARM64_PMEM
2010	bool "Enable support for persistent memory"
2011	select ARCH_HAS_PMEM_API
2012	select ARCH_HAS_UACCESS_FLUSHCACHE
2013	help
2014	  Say Y to enable support for the persistent memory API based on the
2015	  ARMv8.2 DCPoP feature.
2016
2017	  The feature is detected at runtime, and the kernel will use DC CVAC
2018	  operations if DC CVAP is not supported (following the behaviour of
2019	  DC CVAP itself if the system does not define a point of persistence).
2020
2021config ARM64_RAS_EXTN
2022	bool "Enable support for RAS CPU Extensions"
2023	default y
2024	help
2025	  CPUs that support the Reliability, Availability and Serviceability
2026	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
2027	  errors, classify them and report them to software.
2028
2029	  On CPUs with these extensions system software can use additional
2030	  barriers to determine if faults are pending and read the
2031	  classification from a new set of registers.
2032
2033	  Selecting this feature will allow the kernel to use these barriers
2034	  and access the new registers if the system supports the extension.
2035	  Platform RAS features may additionally depend on firmware support.
2036
2037config ARM64_CNP
2038	bool "Enable support for Common Not Private (CNP) translations"
2039	default y
2040	help
2041	  Common Not Private (CNP) allows translation table entries to
2042	  be shared between different PEs in the same inner shareable
2043	  domain, so the hardware can use this fact to optimise the
2044	  caching of such entries in the TLB.
2045
2046	  Selecting this option allows the CNP feature to be detected
2047	  at runtime, and does not affect PEs that do not implement
2048	  this feature.
2049
2050endmenu # "ARMv8.2 architectural features"
2051
2052menu "ARMv8.3 architectural features"
2053
2054config ARM64_PTR_AUTH
2055	bool "Enable support for pointer authentication"
2056	default y
2057	help
2058	  Pointer authentication (part of the ARMv8.3 Extensions) provides
2059	  instructions for signing and authenticating pointers against secret
2060	  keys, which can be used to mitigate Return Oriented Programming (ROP)
2061	  and other attacks.
2062
2063	  This option enables these instructions at EL0 (i.e. for userspace).
2064	  Choosing this option will cause the kernel to initialise secret keys
2065	  for each process at exec() time, with these keys being
2066	  context-switched along with the process.
2067
2068	  The feature is detected at runtime. If the feature is not present in
2069	  hardware it will not be advertised to userspace/KVM guest nor will it
2070	  be enabled.
2071
2072	  If the feature is present on the boot CPU but not on a late CPU, then
2073	  the late CPU will be parked. Also, if the boot CPU does not have
2074	  address auth and the late CPU has then the late CPU will still boot
2075	  but with the feature disabled. On such a system, this option should
2076	  not be selected.
2077
2078config ARM64_PTR_AUTH_KERNEL
2079	bool "Use pointer authentication for kernel"
2080	default y
2081	depends on ARM64_PTR_AUTH
2082	# Modern compilers insert a .note.gnu.property section note for PAC
2083	# which is only understood by binutils starting with version 2.33.1.
2084	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
2085	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
2086	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2087	help
2088	  If the compiler supports the -mbranch-protection or
2089	  -msign-return-address flag (e.g. GCC 7 or later), then this option
2090	  will cause the kernel itself to be compiled with return address
2091	  protection. In this case, and if the target hardware is known to
2092	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
2093	  disabled with minimal loss of protection.
2094
2095	  This feature works with FUNCTION_GRAPH_TRACER option only if
2096	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
2097
2098config CC_HAS_BRANCH_PROT_PAC_RET
2099	# GCC 9 or later, clang 8 or later
2100	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
2101
2102config AS_HAS_CFI_NEGATE_RA_STATE
2103	# binutils 2.34+
2104	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
2105
2106endmenu # "ARMv8.3 architectural features"
2107
2108menu "ARMv8.4 architectural features"
2109
2110config ARM64_AMU_EXTN
2111	bool "Enable support for the Activity Monitors Unit CPU extension"
2112	default y
2113	help
2114	  The activity monitors extension is an optional extension introduced
2115	  by the ARMv8.4 CPU architecture. This enables support for version 1
2116	  of the activity monitors architecture, AMUv1.
2117
2118	  To enable the use of this extension on CPUs that implement it, say Y.
2119
2120	  Note that for architectural reasons, firmware _must_ implement AMU
2121	  support when running on CPUs that present the activity monitors
2122	  extension. The required support is present in:
2123	    * Version 1.5 and later of the ARM Trusted Firmware
2124
2125	  For kernels that have this configuration enabled but boot with broken
2126	  firmware, you may need to say N here until the firmware is fixed.
2127	  Otherwise you may experience firmware panics or lockups when
2128	  accessing the counter registers. Even if you are not observing these
2129	  symptoms, the values returned by the register reads might not
2130	  correctly reflect reality. Most commonly, the value read will be 0,
2131	  indicating that the counter is not enabled.
2132
2133config ARM64_TLB_RANGE
2134	bool "Enable support for tlbi range feature"
2135	default y
2136	help
2137	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2138	  range of input addresses.
2139
2140config ARM64_MPAM
2141	bool "Enable support for MPAM"
2142	select ARM64_MPAM_DRIVER
2143	select ARCH_HAS_CPU_RESCTRL
2144	help
2145	  Memory System Resource Partitioning and Monitoring (MPAM) is an
2146	  optional extension to the Arm architecture that allows each
2147	  transaction issued to the memory system to be labelled with a
2148	  Partition identifier (PARTID) and Performance Monitoring Group
2149	  identifier (PMG).
2150
2151	  Memory system components, such as the caches, can be configured with
2152	  policies to control how much of various physical resources (such as
2153	  memory bandwidth or cache memory) the transactions labelled with each
2154	  PARTID can consume.  Depending on the capabilities of the hardware,
2155	  the PARTID and PMG can also be used as filtering criteria to measure
2156	  the memory system resource consumption of different parts of a
2157	  workload.
2158
2159	  Use of this extension requires CPU support, support in the
2160	  Memory System Components (MSC), and a description from firmware
2161	  of where the MSCs are in the address space.
2162
2163	  MPAM is exposed to user-space via the resctrl pseudo filesystem.
2164
2165	  This option enables the extra context switch code.
2166
2167endmenu # "ARMv8.4 architectural features"
2168
2169menu "ARMv8.5 architectural features"
2170
2171config AS_HAS_ARMV8_5
2172	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2173
2174config ARM64_BTI
2175	bool "Branch Target Identification support"
2176	default y
2177	help
2178	  Branch Target Identification (part of the ARMv8.5 Extensions)
2179	  provides a mechanism to limit the set of locations to which computed
2180	  branch instructions such as BR or BLR can jump.
2181
2182	  To make use of BTI on CPUs that support it, say Y.
2183
2184	  BTI is intended to provide complementary protection to other control
2185	  flow integrity protection mechanisms, such as the Pointer
2186	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2187	  For this reason, it does not make sense to enable this option without
2188	  also enabling support for pointer authentication.  Thus, when
2189	  enabling this option you should also select ARM64_PTR_AUTH=y.
2190
2191	  Userspace binaries must also be specifically compiled to make use of
2192	  this mechanism.  If you say N here or the hardware does not support
2193	  BTI, such binaries can still run, but you get no additional
2194	  enforcement of branch destinations.
2195
2196config ARM64_BTI_KERNEL
2197	bool "Use Branch Target Identification for kernel"
2198	default y
2199	depends on ARM64_BTI
2200	depends on ARM64_PTR_AUTH_KERNEL
2201	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2202	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2203	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2204	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2205	depends on !CC_IS_GCC
2206	# https://github.com/llvm/llvm-project/issues/215547
2207	depends on !CC_IS_CLANG || CLANG_VERSION < 210000
2208	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2209	help
2210	  Build the kernel with Branch Target Identification annotations
2211	  and enable enforcement of this for kernel code. When this option
2212	  is enabled and the system supports BTI all kernel code including
2213	  modular code must have BTI enabled.
2214
2215config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2216	# GCC 9 or later, clang 8 or later
2217	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2218
2219config ARM64_E0PD
2220	bool "Enable support for E0PD"
2221	default y
2222	help
2223	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2224	  that EL0 accesses made via TTBR1 always fault in constant time,
2225	  providing similar benefits to KASLR as those provided by KPTI, but
2226	  with lower overhead and without disrupting legitimate access to
2227	  kernel memory such as SPE.
2228
2229	  This option enables E0PD for TTBR1 where available.
2230
2231config ARM64_AS_HAS_MTE
2232	# Initial support for MTE went in binutils 2.32.0, checked with
2233	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2234	# as a late addition to the final architecture spec (LDGM/STGM)
2235	# is only supported in the newer 2.32.x and 2.33 binutils
2236	# versions, hence the extra "stgm" instruction check below.
2237	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2238
2239config ARM64_MTE
2240	bool "Memory Tagging Extension support"
2241	default y
2242	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2243	depends on AS_HAS_ARMV8_5
2244	# Required for tag checking in the uaccess routines
2245	select ARCH_HAS_SUBPAGE_FAULTS
2246	select ARCH_USES_HIGH_VMA_FLAGS
2247	select ARCH_USES_PG_ARCH_2
2248	select ARCH_USES_PG_ARCH_3
2249	help
2250	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2251	  architectural support for run-time, always-on detection of
2252	  various classes of memory error to aid with software debugging
2253	  to eliminate vulnerabilities arising from memory-unsafe
2254	  languages.
2255
2256	  This option enables the support for the Memory Tagging
2257	  Extension at EL0 (i.e. for userspace).
2258
2259	  Selecting this option allows the feature to be detected at
2260	  runtime. Any secondary CPU not implementing this feature will
2261	  not be allowed a late bring-up.
2262
2263	  Userspace binaries that want to use this feature must
2264	  explicitly opt in. The mechanism for the userspace is
2265	  described in:
2266
2267	  Documentation/arch/arm64/memory-tagging-extension.rst.
2268
2269endmenu # "ARMv8.5 architectural features"
2270
2271menu "ARMv8.7 architectural features"
2272
2273config ARM64_EPAN
2274	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2275	default y
2276	help
2277	  Enhanced Privileged Access Never (EPAN) allows Privileged
2278	  Access Never to be used with Execute-only mappings.
2279
2280	  The feature is detected at runtime, and will remain disabled
2281	  if the cpu does not implement the feature.
2282endmenu # "ARMv8.7 architectural features"
2283
2284config AS_HAS_MOPS
2285	def_bool $(as-instr,.arch_extension mops)
2286
2287menu "ARMv8.9 architectural features"
2288
2289config ARM64_POE
2290	prompt "Permission Overlay Extension"
2291	def_bool y
2292	select ARCH_USES_HIGH_VMA_FLAGS
2293	select ARCH_HAS_PKEYS
2294	help
2295	  The Permission Overlay Extension is used to implement Memory
2296	  Protection Keys. Memory Protection Keys provides a mechanism for
2297	  enforcing page-based protections, but without requiring modification
2298	  of the page tables when an application changes protection domains.
2299
2300	  For details, see Documentation/core-api/protection-keys.rst
2301
2302	  If unsure, say y.
2303
2304config ARCH_PKEY_BITS
2305	int
2306	default 3
2307
2308config ARM64_HAFT
2309	bool "Support for Hardware managed Access Flag for Table Descriptors"
2310	depends on ARM64_HW_AFDBM
2311	default y
2312	help
2313	  The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access
2314	  Flag for Table descriptors. When enabled an architectural executed
2315	  memory access will update the Access Flag in each Table descriptor
2316	  which is accessed during the translation table walk and for which
2317	  the Access Flag is 0. The Access Flag of the Table descriptor use
2318	  the same bit of PTE_AF.
2319
2320	  The feature will only be enabled if all the CPUs in the system
2321	  support this feature. If unsure, say Y.
2322
2323endmenu # "ARMv8.9 architectural features"
2324
2325menu "ARMv9.4 architectural features"
2326
2327config ARM64_GCS
2328	bool "Enable support for Guarded Control Stack (GCS)"
2329	default y
2330	select ARCH_HAS_USER_SHADOW_STACK
2331	select ARCH_USES_HIGH_VMA_FLAGS
2332	help
2333	  Guarded Control Stack (GCS) provides support for a separate
2334	  stack with restricted access which contains only return
2335	  addresses.  This can be used to harden against some attacks
2336	  by comparing return address used by the program with what is
2337	  stored in the GCS, and may also be used to efficiently obtain
2338	  the call stack for applications such as profiling.
2339
2340	  The feature is detected at runtime, and will remain disabled
2341	  if the system does not implement the feature.
2342
2343endmenu # "ARMv9.4 architectural features"
2344
2345config AS_HAS_LSUI
2346	def_bool $(as-instr,.arch_extension lsui)
2347	help
2348	  Supported by LLVM 20+ and binutils 2.45+.
2349
2350menu "ARMv9.6 architectural features"
2351
2352config ARM64_LSUI
2353	bool "Support Unprivileged Load Store Instructions (LSUI)"
2354	default y
2355	depends on AS_HAS_LSUI
2356	help
2357	  The Unprivileged Load Store Instructions (LSUI) provides
2358	  variants load/store instructions that access user-space memory
2359	  from the kernel without clearing PSTATE.PAN bit.
2360
2361	  This feature is supported by LLVM 20+ and binutils 2.45+.
2362
2363endmenu # "ARMv9.6 architectural feature"
2364
2365config ARM64_SVE
2366	bool "ARM Scalable Vector Extension support"
2367	default y
2368	help
2369	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2370	  execution state which complements and extends the SIMD functionality
2371	  of the base architecture to support much larger vectors and to enable
2372	  additional vectorisation opportunities.
2373
2374	  To enable use of this extension on CPUs that implement it, say Y.
2375
2376	  On CPUs that support the SVE2 extensions, this option will enable
2377	  those too.
2378
2379	  Note that for architectural reasons, firmware _must_ implement SVE
2380	  support when running on SVE capable hardware.  The required support
2381	  is present in:
2382
2383	    * version 1.5 and later of the ARM Trusted Firmware
2384	    * the AArch64 boot wrapper since commit 5e1261e08abf
2385	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2386
2387	  For other firmware implementations, consult the firmware documentation
2388	  or vendor.
2389
2390	  If you need the kernel to boot on SVE-capable hardware with broken
2391	  firmware, you may need to say N here until you get your firmware
2392	  fixed.  Otherwise, you may experience firmware panics or lockups when
2393	  booting the kernel.  If unsure and you are not observing these
2394	  symptoms, you should assume that it is safe to say Y.
2395
2396config AS_HAS_SME
2397	# Supported by LLVM 13+ and binutils 2.38+
2398	def_bool $(as-instr,.arch_extension sme)
2399
2400config ARM64_SME
2401	bool "ARM Scalable Matrix Extension support"
2402	default y
2403	depends on ARM64_SVE
2404	depends on AS_HAS_SME
2405	help
2406	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2407	  execution state which utilises a substantial subset of the SVE
2408	  instruction set, together with the addition of new architectural
2409	  register state capable of holding two dimensional matrix tiles to
2410	  enable various matrix operations.
2411
2412config ARM64_PSEUDO_NMI
2413	bool "Support for NMI-like interrupts"
2414	select ARM_GIC_V3
2415	help
2416	  Adds support for mimicking Non-Maskable Interrupts through the use of
2417	  GIC interrupt priority. This support requires version 3 or later of
2418	  ARM GIC.
2419
2420	  This high priority configuration for interrupts needs to be
2421	  explicitly enabled by setting the kernel parameter
2422	  "irqchip.gicv3_pseudo_nmi" to 1.
2423
2424	  If unsure, say N
2425
2426if ARM64_PSEUDO_NMI
2427config ARM64_DEBUG_PRIORITY_MASKING
2428	bool "Debug interrupt priority masking"
2429	help
2430	  This adds runtime checks to functions enabling/disabling
2431	  interrupts when using priority masking. The additional checks verify
2432	  the validity of ICC_PMR_EL1 when calling concerned functions.
2433
2434	  If unsure, say N
2435endif # ARM64_PSEUDO_NMI
2436
2437config RELOCATABLE
2438	bool "Build a relocatable kernel image" if EXPERT
2439	select ARCH_HAS_RELR
2440	default y
2441	help
2442	  This builds the kernel as a Position Independent Executable (PIE),
2443	  which retains all relocation metadata required to relocate the
2444	  kernel binary at runtime to a different virtual address than the
2445	  address it was linked at.
2446	  Since AArch64 uses the RELA relocation format, this requires a
2447	  relocation pass at runtime even if the kernel is loaded at the
2448	  same address it was linked at.
2449
2450config RANDOMIZE_BASE
2451	bool "Randomize the address of the kernel image"
2452	select RELOCATABLE
2453	help
2454	  Randomizes the virtual address at which the kernel image is
2455	  loaded, as a security feature that deters exploit attempts
2456	  relying on knowledge of the location of kernel internals.
2457
2458	  It is the bootloader's job to provide entropy, by passing a
2459	  random u64 value in /chosen/kaslr-seed at kernel entry.
2460
2461	  When booting via the UEFI stub, it will invoke the firmware's
2462	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2463	  to the kernel proper. In addition, it will randomise the physical
2464	  location of the kernel Image as well.
2465
2466	  If unsure, say N.
2467
2468config RANDOMIZE_MODULE_REGION_FULL
2469	bool "Randomize the module region over a 2 GB range"
2470	depends on RANDOMIZE_BASE
2471	default y
2472	help
2473	  Randomizes the location of the module region inside a 2 GB window
2474	  covering the core kernel. This way, it is less likely for modules
2475	  to leak information about the location of core kernel data structures
2476	  but it does imply that function calls between modules and the core
2477	  kernel will need to be resolved via veneers in the module PLT.
2478
2479	  When this option is not set, the module region will be randomized over
2480	  a limited range that contains the [_stext, _etext] interval of the
2481	  core kernel, so branch relocations are almost always in range unless
2482	  the region is exhausted. In this particular case of region
2483	  exhaustion, modules might be able to fall back to a larger 2GB area.
2484
2485config CC_HAVE_STACKPROTECTOR_SYSREG
2486	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2487
2488config STACKPROTECTOR_PER_TASK
2489	def_bool y
2490	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2491
2492config UNWIND_PATCH_PAC_INTO_SCS
2493	bool "Enable shadow call stack dynamically using code patching"
2494	depends on CC_IS_CLANG
2495	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2496	depends on SHADOW_CALL_STACK
2497	select UNWIND_TABLES
2498	select DYNAMIC_SCS
2499
2500config ARM64_CONTPTE
2501	bool "Contiguous PTE mappings for user memory" if EXPERT
2502	depends on TRANSPARENT_HUGEPAGE
2503	default y
2504	help
2505	  When enabled, user mappings are configured using the PTE contiguous
2506	  bit, for any mappings that meet the size and alignment requirements.
2507	  This reduces TLB pressure and improves performance.
2508
2509endmenu # "Kernel Features"
2510
2511menu "Boot options"
2512
2513config ARM64_ACPI_PARKING_PROTOCOL
2514	bool "Enable support for the ARM64 ACPI parking protocol"
2515	depends on ACPI
2516	help
2517	  Enable support for the ARM64 ACPI parking protocol. If disabled
2518	  the kernel will not allow booting through the ARM64 ACPI parking
2519	  protocol even if the corresponding data is present in the ACPI
2520	  MADT table.
2521
2522config CMDLINE
2523	string "Default kernel command string"
2524	default ""
2525	help
2526	  Provide a set of default command-line options at build time by
2527	  entering them here. As a minimum, you should specify the
2528	  root device (e.g. root=/dev/nfs).
2529
2530choice
2531	prompt "Kernel command line type"
2532	depends on CMDLINE != ""
2533	default CMDLINE_FROM_BOOTLOADER
2534	help
2535	  Choose how the kernel will handle the provided default kernel
2536	  command line string.
2537
2538config CMDLINE_FROM_BOOTLOADER
2539	bool "Use bootloader kernel arguments if available"
2540	help
2541	  Uses the command-line options passed by the boot loader. If
2542	  the boot loader doesn't provide any, the default kernel command
2543	  string provided in CMDLINE will be used.
2544
2545config CMDLINE_FORCE
2546	bool "Always use the default kernel command string"
2547	help
2548	  Always use the default kernel command string, even if the boot
2549	  loader passes other arguments to the kernel.
2550	  This is useful if you cannot or don't want to change the
2551	  command-line options your boot loader passes to the kernel.
2552
2553endchoice
2554
2555config EFI_STUB
2556	bool
2557
2558config EFI
2559	bool "UEFI runtime support"
2560	depends on OF
2561	depends on KERNEL_MODE_NEON
2562	select ARCH_SUPPORTS_ACPI
2563	select LIBFDT
2564	select UCS2_STRING
2565	select EFI_PARAMS_FROM_FDT
2566	select EFI_RUNTIME_WRAPPERS
2567	select EFI_STUB
2568	select EFI_GENERIC_STUB
2569	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2570	default y
2571	help
2572	  This option provides support for runtime services provided
2573	  by UEFI firmware (such as non-volatile variables, realtime
2574	  clock, and platform reset). A UEFI stub is also provided to
2575	  allow the kernel to be booted as an EFI application. This
2576	  is only useful on systems that have UEFI firmware.
2577
2578config COMPRESSED_INSTALL
2579	bool "Install compressed image by default"
2580	help
2581	  This makes the regular "make install" install the compressed
2582	  image we built, not the legacy uncompressed one.
2583
2584	  You can check that a compressed image works for you by doing
2585	  "make zinstall" first, and verifying that everything is fine
2586	  in your environment before making "make install" do this for
2587	  you.
2588
2589config DMI
2590	bool "Enable support for SMBIOS (DMI) tables"
2591	depends on EFI
2592	default y
2593	help
2594	  This enables SMBIOS/DMI feature for systems.
2595
2596	  This option is only useful on systems that have UEFI firmware.
2597	  However, even with this option, the resultant kernel should
2598	  continue to boot on existing non-UEFI platforms.
2599
2600endmenu # "Boot options"
2601
2602menu "Power management options"
2603
2604source "kernel/power/Kconfig"
2605
2606config ARCH_HIBERNATION_POSSIBLE
2607	def_bool y
2608	depends on CPU_PM
2609
2610config ARCH_HIBERNATION_HEADER
2611	def_bool y
2612	depends on HIBERNATION
2613
2614config ARCH_SUSPEND_POSSIBLE
2615	def_bool y
2616
2617endmenu # "Power management options"
2618
2619menu "CPU Power Management"
2620
2621source "drivers/cpuidle/Kconfig"
2622
2623source "drivers/cpufreq/Kconfig"
2624
2625endmenu # "CPU Power Management"
2626
2627source "drivers/acpi/Kconfig"
2628
2629source "arch/arm64/kvm/Kconfig"
2630
2631source "kernel/livepatch/Kconfig"
2632