xref: /linux/arch/arm64/Kconfig (revision 2e973d4882230079bfbdc9f33077006bb50de700)
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 ALTERA_ERRATUM_AGILEX5_2_1_23
1465	bool
1466	help
1467	  The Altera SoCFPGA Agilex5 GIC600 SoC integration has ACE-lite
1468	  addressing limited to the first 32bit of physical address space,
1469	  so the ITS cannot access memory above 4GB.
1470
1471	  Selected by ARCH_INTEL_SOCFPGA, as all Agilex5 devices are affected.
1472
1473config RENESAS_ERRATUM_GEN4GICITS1
1474	bool "Renesas R-Car Gen4: GIC600 can not access physical addresses above 4 GiB"
1475	default y
1476	help
1477	  The Renesas R-Car Gen4 S4/V4H/V4M GIC600 SoC integrations have AXI
1478	  addressing limited to the first 32-bit of physical address space.
1479
1480	  If unsure, say Y.
1481
1482config ROCKCHIP_ERRATUM_3568002
1483	bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB"
1484	default y
1485	help
1486	  The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI
1487	  addressing limited to the first 32bit of physical address space.
1488
1489	  If unsure, say Y.
1490
1491config ROCKCHIP_ERRATUM_3588001
1492	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1493	default y
1494	help
1495	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1496	  This means, that its sharability feature may not be used, even though it
1497	  is supported by the IP itself.
1498
1499	  If unsure, say Y.
1500
1501config NXP_IMX8QM_ERRATUM_ERR050104
1502	bool "NXP iMX8QM/QP ERR050104: broken cache/TLB invalidation broadcast"
1503	default y
1504	help
1505	  On iMX8QM (QuadMax) and iMX8QP (QuadPlus), address bits above bit 35
1506	  in the A53 subsystem ARADDR and ACADDR buses are incorrectly
1507	  connected. This corrupts targeted TLBI and IC broadcasts exchanged
1508	  between the A53 and A72 core clusters.
1509
1510	  Work around this by redirecting targeted TLBI operations to
1511	  broadcast-all variants (VMALLE1IS) in the high-level TLB flush
1512	  functions, upgrading IC IVAU to IC IALLUIS for both kernel and
1513	  user-space, and disabling KVM since correct TLB maintenance
1514	  cannot be guaranteed for guests.
1515
1516	  The user-space IC IVAU is upgraded by trapping it to the kernel
1517	  (SCTLR_EL1.UCI cleared). This also traps the user DC CVAU, DC CVAC,
1518	  DC CVAP, DC CVADP and DC CIVAC instructions, making user cache
1519	  maintenance slower on the affected SoCs.
1520
1521	  If unsure, say Y.
1522
1523config SOCIONEXT_SYNQUACER_PREITS
1524	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1525	default y
1526	help
1527	  Socionext Synquacer SoCs implement a separate h/w block to generate
1528	  MSI doorbell writes with non-zero values for the device ID.
1529
1530	  If unsure, say Y.
1531
1532endmenu # "ARM errata workarounds via the alternatives framework"
1533
1534choice
1535	prompt "Page size"
1536	default ARM64_4K_PAGES
1537	help
1538	  Page size (translation granule) configuration.
1539
1540config ARM64_4K_PAGES
1541	bool "4KB"
1542	select HAVE_PAGE_SIZE_4KB
1543	help
1544	  This feature enables 4KB pages support.
1545
1546config ARM64_16K_PAGES
1547	bool "16KB"
1548	select HAVE_PAGE_SIZE_16KB
1549	help
1550	  The system will use 16KB pages support. AArch32 emulation
1551	  requires applications compiled with 16K (or a multiple of 16K)
1552	  aligned segments.
1553
1554config ARM64_64K_PAGES
1555	bool "64KB"
1556	select HAVE_PAGE_SIZE_64KB
1557	help
1558	  This feature enables 64KB pages support (4KB by default)
1559	  allowing only two levels of page tables and faster TLB
1560	  look-up. AArch32 emulation requires applications compiled
1561	  with 64K aligned segments.
1562
1563endchoice
1564
1565choice
1566	prompt "Virtual address space size"
1567	default ARM64_VA_BITS_52
1568	help
1569	  Allows choosing one of multiple possible virtual address
1570	  space sizes. The level of translation table is determined by
1571	  a combination of page size and virtual address space size.
1572
1573config ARM64_VA_BITS_36
1574	bool "36-bit" if EXPERT
1575	depends on PAGE_SIZE_16KB
1576
1577config ARM64_VA_BITS_39
1578	bool "39-bit"
1579	depends on PAGE_SIZE_4KB
1580
1581config ARM64_VA_BITS_42
1582	bool "42-bit"
1583	depends on PAGE_SIZE_64KB
1584
1585config ARM64_VA_BITS_47
1586	bool "47-bit"
1587	depends on PAGE_SIZE_16KB
1588
1589config ARM64_VA_BITS_48
1590	bool "48-bit"
1591
1592config ARM64_VA_BITS_52
1593	bool "52-bit"
1594	help
1595	  Enable 52-bit virtual addressing for userspace when explicitly
1596	  requested via a hint to mmap(). The kernel will also use 52-bit
1597	  virtual addresses for its own mappings (provided HW support for
1598	  this feature is available, otherwise it reverts to 48-bit).
1599
1600	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1601	  ARMv8.3 Pointer Authentication will result in the PAC being
1602	  reduced from 7 bits to 3 bits, which may have a significant
1603	  impact on its susceptibility to brute-force attacks.
1604
1605	  If unsure, select 48-bit virtual addressing instead.
1606
1607endchoice
1608
1609config ARM64_FORCE_52BIT
1610	bool "Force 52-bit virtual addresses for userspace"
1611	depends on ARM64_VA_BITS_52 && EXPERT
1612	help
1613	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1614	  to maintain compatibility with older software by providing 48-bit VAs
1615	  unless a hint is supplied to mmap.
1616
1617	  This configuration option disables the 48-bit compatibility logic, and
1618	  forces all userspace addresses to be 52-bit on HW that supports it. One
1619	  should only enable this configuration option for stress testing userspace
1620	  memory management code. If unsure say N here.
1621
1622config ARM64_VA_BITS
1623	int
1624	default 36 if ARM64_VA_BITS_36
1625	default 39 if ARM64_VA_BITS_39
1626	default 42 if ARM64_VA_BITS_42
1627	default 47 if ARM64_VA_BITS_47
1628	default 48 if ARM64_VA_BITS_48
1629	default 52 if ARM64_VA_BITS_52
1630
1631choice
1632	prompt "Physical address space size"
1633	default ARM64_PA_BITS_48
1634	help
1635	  Choose the maximum physical address range that the kernel will
1636	  support.
1637
1638config ARM64_PA_BITS_48
1639	bool "48-bit"
1640	depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1641
1642config ARM64_PA_BITS_52
1643	bool "52-bit"
1644	depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1645	help
1646	  Enable support for a 52-bit physical address space, introduced as
1647	  part of the ARMv8.2-LPA extension.
1648
1649	  With this enabled, the kernel will also continue to work on CPUs that
1650	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1651	  minor performance overhead).
1652
1653endchoice
1654
1655config ARM64_PA_BITS
1656	int
1657	default 48 if ARM64_PA_BITS_48
1658	default 52 if ARM64_PA_BITS_52
1659
1660config ARM64_LPA2
1661	def_bool y
1662	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1663
1664config NR_CPUS
1665	int "Maximum number of CPUs (2-4096)"
1666	range 2 4096
1667	default "512"
1668
1669config HOTPLUG_CPU
1670	bool "Support for hot-pluggable CPUs"
1671	select GENERIC_IRQ_MIGRATION
1672	help
1673	  Say Y here to experiment with turning CPUs off and on.  CPUs
1674	  can be controlled through /sys/devices/system/cpu.
1675
1676# Common NUMA Features
1677config NUMA
1678	bool "NUMA Memory Allocation and Scheduler Support"
1679	select GENERIC_ARCH_NUMA
1680	select OF_NUMA
1681	select HAVE_SETUP_PER_CPU_AREA
1682	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1683	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1684	select USE_PERCPU_NUMA_NODE_ID
1685	help
1686	  Enable NUMA (Non-Uniform Memory Access) support.
1687
1688	  The kernel will try to allocate memory used by a CPU on the
1689	  local memory of the CPU and add some more
1690	  NUMA awareness to the kernel.
1691
1692config NODES_SHIFT
1693	int "Maximum NUMA Nodes (as a power of 2)"
1694	range 1 10
1695	default "4"
1696	depends on NUMA
1697	help
1698	  Specify the maximum number of NUMA Nodes available on the target
1699	  system.  Increases memory reserved to accommodate various tables.
1700
1701source "kernel/Kconfig.hz"
1702
1703config ARCH_SPARSEMEM_ENABLE
1704	def_bool y
1705	select SPARSEMEM_VMEMMAP_ENABLE
1706
1707config HW_PERF_EVENTS
1708	def_bool y
1709	depends on ARM_PMU
1710
1711# Supported by clang >= 7.0 or GCC >= 12.0.0
1712config CC_HAVE_SHADOW_CALL_STACK
1713	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1714
1715config PARAVIRT
1716	bool "Enable paravirtualization code"
1717	select HAVE_PV_STEAL_CLOCK_GEN
1718	help
1719	  This changes the kernel so it can modify itself when it is run
1720	  under a hypervisor, potentially improving performance significantly
1721	  over full virtualization.
1722
1723config PARAVIRT_TIME_ACCOUNTING
1724	bool "Paravirtual steal time accounting"
1725	select PARAVIRT
1726	help
1727	  Select this option to enable fine granularity task steal time
1728	  accounting. Time spent executing other tasks in parallel with
1729	  the current vCPU is discounted from the vCPU power. To account for
1730	  that, there can be a small performance impact.
1731
1732	  If in doubt, say N here.
1733
1734config ARCH_SUPPORTS_KEXEC
1735	def_bool PM_SLEEP_SMP
1736
1737config ARCH_SUPPORTS_KEXEC_FILE
1738	def_bool y
1739
1740config ARCH_SELECTS_KEXEC_FILE
1741	def_bool y
1742	depends on KEXEC_FILE
1743	select HAVE_IMA_KEXEC if IMA
1744
1745config ARCH_SUPPORTS_KEXEC_SIG
1746	def_bool y
1747
1748config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1749	def_bool y
1750
1751config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1752	def_bool y
1753
1754config ARCH_SUPPORTS_KEXEC_HANDOVER
1755	def_bool y
1756
1757config ARCH_SUPPORTS_CRASH_DUMP
1758	def_bool y
1759
1760config ARCH_DEFAULT_CRASH_DUMP
1761	def_bool y
1762
1763config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1764	def_bool CRASH_RESERVE
1765
1766config TRANS_TABLE
1767	def_bool y
1768	depends on HIBERNATION || KEXEC_CORE
1769
1770config XEN_DOM0
1771	def_bool y
1772	depends on XEN
1773
1774config XEN
1775	bool "Xen guest support on ARM64"
1776	depends on ARM64 && OF
1777	select SWIOTLB_XEN
1778	select PARAVIRT
1779	help
1780	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1781
1782# include/linux/mmzone.h requires the following to be true:
1783#
1784#   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1785#
1786# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1787#
1788#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1789# ----+-------------------+--------------+----------------------+-------------------------+
1790# 4K  |       27          |      12      |       15             |         10              |
1791# 16K |       27          |      14      |       13             |         11              |
1792# 64K |       29          |      16      |       13             |         13              |
1793config ARCH_FORCE_MAX_ORDER
1794	int
1795	default "13" if ARM64_64K_PAGES
1796	default "11" if ARM64_16K_PAGES
1797	default "10"
1798	help
1799	  The kernel page allocator limits the size of maximal physically
1800	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1801	  defines the maximal power of two of number of pages that can be
1802	  allocated as a single contiguous block. This option allows
1803	  overriding the default setting when ability to allocate very
1804	  large blocks of physically contiguous memory is required.
1805
1806	  The maximal size of allocation cannot exceed the size of the
1807	  section, so the value of MAX_PAGE_ORDER should satisfy
1808
1809	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1810
1811	  Don't change if unsure.
1812
1813config UNMAP_KERNEL_AT_EL0
1814	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1815	default y
1816	help
1817	  Speculation attacks against some high-performance processors can
1818	  be used to bypass MMU permission checks and leak kernel data to
1819	  userspace. This can be defended against by unmapping the kernel
1820	  when running in userspace, mapping it back in on exception entry
1821	  via a trampoline page in the vector table.
1822
1823	  If unsure, say Y.
1824
1825config MITIGATE_SPECTRE_BRANCH_HISTORY
1826	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1827	default y
1828	help
1829	  Speculation attacks against some high-performance processors can
1830	  make use of branch history to influence future speculation.
1831	  When taking an exception from user-space, a sequence of branches
1832	  or a firmware call overwrites the branch history.
1833
1834config ARM64_SW_TTBR0_PAN
1835	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1836	depends on !KCSAN
1837	help
1838	  Enabling this option prevents the kernel from accessing
1839	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1840	  zeroed area and reserved ASID. The user access routines
1841	  restore the valid TTBR0_EL1 temporarily.
1842
1843config ARM64_TAGGED_ADDR_ABI
1844	bool "Enable the tagged user addresses syscall ABI"
1845	default y
1846	help
1847	  When this option is enabled, user applications can opt in to a
1848	  relaxed ABI via prctl() allowing tagged addresses to be passed
1849	  to system calls as pointer arguments. For details, see
1850	  Documentation/arch/arm64/tagged-address-abi.rst.
1851
1852menuconfig COMPAT
1853	bool "Kernel support for 32-bit EL0"
1854	depends on ARM64_4K_PAGES || EXPERT
1855	select HAVE_UID16
1856	select OLD_SIGSUSPEND3
1857	select COMPAT_OLD_SIGACTION
1858	help
1859	  This option enables support for a 32-bit EL0 running under a 64-bit
1860	  kernel at EL1. AArch32-specific components such as system calls,
1861	  the user helper functions, VFP support and the ptrace interface are
1862	  handled appropriately by the kernel.
1863
1864	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1865	  that you will only be able to execute AArch32 binaries that were compiled
1866	  with page size aligned segments.
1867
1868	  If you want to execute 32-bit userspace applications, say Y.
1869
1870if COMPAT
1871
1872config KUSER_HELPERS
1873	bool "Enable kuser helpers page for 32-bit applications"
1874	default y
1875	help
1876	  Warning: disabling this option may break 32-bit user programs.
1877
1878	  Provide kuser helpers to compat tasks. The kernel provides
1879	  helper code to userspace in read only form at a fixed location
1880	  to allow userspace to be independent of the CPU type fitted to
1881	  the system. This permits binaries to be run on ARMv4 through
1882	  to ARMv8 without modification.
1883
1884	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1885
1886	  However, the fixed address nature of these helpers can be used
1887	  by ROP (return orientated programming) authors when creating
1888	  exploits.
1889
1890	  If all of the binaries and libraries which run on your platform
1891	  are built specifically for your platform, and make no use of
1892	  these helpers, then you can turn this option off to hinder
1893	  such exploits. However, in that case, if a binary or library
1894	  relying on those helpers is run, it will not function correctly.
1895
1896	  Say N here only if you are absolutely certain that you do not
1897	  need these helpers; otherwise, the safe option is to say Y.
1898
1899config COMPAT_VDSO
1900	bool "Enable vDSO for 32-bit applications"
1901	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1902	default y
1903	help
1904	  Place in the process address space of 32-bit applications an
1905	  ELF shared object providing fast implementations of gettimeofday
1906	  and clock_gettime.
1907
1908	  You must have a 32-bit build of glibc 2.22 or later for programs
1909	  to seamlessly take advantage of this.
1910
1911config THUMB2_COMPAT_VDSO
1912	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1913	depends on COMPAT_VDSO
1914	default y
1915	help
1916	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1917	  otherwise with '-marm'.
1918
1919config COMPAT_ALIGNMENT_FIXUPS
1920	bool "Fix up misaligned multi-word loads and stores in user space"
1921
1922menuconfig ARMV8_DEPRECATED
1923	bool "Emulate deprecated/obsolete ARMv8 instructions"
1924	depends on SYSCTL
1925	help
1926	  Legacy software support may require certain instructions
1927	  that have been deprecated or obsoleted in the architecture.
1928
1929	  Enable this config to enable selective emulation of these
1930	  features.
1931
1932	  If unsure, say Y
1933
1934if ARMV8_DEPRECATED
1935
1936config SWP_EMULATION
1937	bool "Emulate SWP/SWPB instructions"
1938	help
1939	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1940	  they are always undefined. Say Y here to enable software
1941	  emulation of these instructions for userspace using LDXR/STXR.
1942	  This feature can be controlled at runtime with the abi.swp
1943	  sysctl which is disabled by default.
1944
1945	  In some older versions of glibc [<=2.8] SWP is used during futex
1946	  trylock() operations with the assumption that the code will not
1947	  be preempted. This invalid assumption may be more likely to fail
1948	  with SWP emulation enabled, leading to deadlock of the user
1949	  application.
1950
1951	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1952	  on an external transaction monitoring block called a global
1953	  monitor to maintain update atomicity. If your system does not
1954	  implement a global monitor, this option can cause programs that
1955	  perform SWP operations to uncached memory to deadlock.
1956
1957	  If unsure, say Y
1958
1959config CP15_BARRIER_EMULATION
1960	bool "Emulate CP15 Barrier instructions"
1961	help
1962	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1963	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1964	  strongly recommended to use the ISB, DSB, and DMB
1965	  instructions instead.
1966
1967	  Say Y here to enable software emulation of these
1968	  instructions for AArch32 userspace code. When this option is
1969	  enabled, CP15 barrier usage is traced which can help
1970	  identify software that needs updating. This feature can be
1971	  controlled at runtime with the abi.cp15_barrier sysctl.
1972
1973	  If unsure, say Y
1974
1975config SETEND_EMULATION
1976	bool "Emulate SETEND instruction"
1977	help
1978	  The SETEND instruction alters the data-endianness of the
1979	  AArch32 EL0, and is deprecated in ARMv8.
1980
1981	  Say Y here to enable software emulation of the instruction
1982	  for AArch32 userspace code. This feature can be controlled
1983	  at runtime with the abi.setend sysctl.
1984
1985	  Note: All the cpus on the system must have mixed endian support at EL0
1986	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1987	  endian - is hotplugged in after this feature has been enabled, there could
1988	  be unexpected results in the applications.
1989
1990	  If unsure, say Y
1991endif # ARMV8_DEPRECATED
1992
1993endif # COMPAT
1994
1995menu "ARMv8.1 architectural features"
1996
1997config ARM64_HW_AFDBM
1998	bool "Support for hardware updates of the Access and Dirty page flags"
1999	default y
2000	help
2001	  The ARMv8.1 architecture extensions introduce support for
2002	  hardware updates of the access and dirty information in page
2003	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
2004	  capable processors, accesses to pages with PTE_AF cleared will
2005	  set this bit instead of raising an access flag fault.
2006	  Similarly, writes to read-only pages with the DBM bit set will
2007	  clear the read-only bit (AP[2]) instead of raising a
2008	  permission fault.
2009
2010	  Kernels built with this configuration option enabled continue
2011	  to work on pre-ARMv8.1 hardware and the performance impact is
2012	  minimal. If unsure, say Y.
2013
2014endmenu # "ARMv8.1 architectural features"
2015
2016menu "ARMv8.2 architectural features"
2017
2018config ARM64_PMEM
2019	bool "Enable support for persistent memory"
2020	select ARCH_HAS_PMEM_API
2021	select ARCH_HAS_UACCESS_FLUSHCACHE
2022	help
2023	  Say Y to enable support for the persistent memory API based on the
2024	  ARMv8.2 DCPoP feature.
2025
2026	  The feature is detected at runtime, and the kernel will use DC CVAC
2027	  operations if DC CVAP is not supported (following the behaviour of
2028	  DC CVAP itself if the system does not define a point of persistence).
2029
2030config ARM64_RAS_EXTN
2031	bool "Enable support for RAS CPU Extensions"
2032	default y
2033	help
2034	  CPUs that support the Reliability, Availability and Serviceability
2035	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
2036	  errors, classify them and report them to software.
2037
2038	  On CPUs with these extensions system software can use additional
2039	  barriers to determine if faults are pending and read the
2040	  classification from a new set of registers.
2041
2042	  Selecting this feature will allow the kernel to use these barriers
2043	  and access the new registers if the system supports the extension.
2044	  Platform RAS features may additionally depend on firmware support.
2045
2046config ARM64_CNP
2047	bool "Enable support for Common Not Private (CNP) translations"
2048	default y
2049	help
2050	  Common Not Private (CNP) allows translation table entries to
2051	  be shared between different PEs in the same inner shareable
2052	  domain, so the hardware can use this fact to optimise the
2053	  caching of such entries in the TLB.
2054
2055	  Selecting this option allows the CNP feature to be detected
2056	  at runtime, and does not affect PEs that do not implement
2057	  this feature.
2058
2059endmenu # "ARMv8.2 architectural features"
2060
2061menu "ARMv8.3 architectural features"
2062
2063config ARM64_PTR_AUTH
2064	bool "Enable support for pointer authentication"
2065	default y
2066	help
2067	  Pointer authentication (part of the ARMv8.3 Extensions) provides
2068	  instructions for signing and authenticating pointers against secret
2069	  keys, which can be used to mitigate Return Oriented Programming (ROP)
2070	  and other attacks.
2071
2072	  This option enables these instructions at EL0 (i.e. for userspace).
2073	  Choosing this option will cause the kernel to initialise secret keys
2074	  for each process at exec() time, with these keys being
2075	  context-switched along with the process.
2076
2077	  The feature is detected at runtime. If the feature is not present in
2078	  hardware it will not be advertised to userspace/KVM guest nor will it
2079	  be enabled.
2080
2081	  If the feature is present on the boot CPU but not on a late CPU, then
2082	  the late CPU will be parked. Also, if the boot CPU does not have
2083	  address auth and the late CPU has then the late CPU will still boot
2084	  but with the feature disabled. On such a system, this option should
2085	  not be selected.
2086
2087config ARM64_PTR_AUTH_KERNEL
2088	bool "Use pointer authentication for kernel"
2089	default y
2090	depends on ARM64_PTR_AUTH
2091	# Modern compilers insert a .note.gnu.property section note for PAC
2092	# which is only understood by binutils starting with version 2.33.1.
2093	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
2094	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
2095	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2096	help
2097	  If the compiler supports the -mbranch-protection or
2098	  -msign-return-address flag (e.g. GCC 7 or later), then this option
2099	  will cause the kernel itself to be compiled with return address
2100	  protection. In this case, and if the target hardware is known to
2101	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
2102	  disabled with minimal loss of protection.
2103
2104	  This feature works with FUNCTION_GRAPH_TRACER option only if
2105	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
2106
2107config CC_HAS_BRANCH_PROT_PAC_RET
2108	# GCC 9 or later, clang 8 or later
2109	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
2110
2111config AS_HAS_CFI_NEGATE_RA_STATE
2112	# binutils 2.34+
2113	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
2114
2115endmenu # "ARMv8.3 architectural features"
2116
2117menu "ARMv8.4 architectural features"
2118
2119config ARM64_AMU_EXTN
2120	bool "Enable support for the Activity Monitors Unit CPU extension"
2121	default y
2122	help
2123	  The activity monitors extension is an optional extension introduced
2124	  by the ARMv8.4 CPU architecture. This enables support for version 1
2125	  of the activity monitors architecture, AMUv1.
2126
2127	  To enable the use of this extension on CPUs that implement it, say Y.
2128
2129	  Note that for architectural reasons, firmware _must_ implement AMU
2130	  support when running on CPUs that present the activity monitors
2131	  extension. The required support is present in:
2132	    * Version 1.5 and later of the ARM Trusted Firmware
2133
2134	  For kernels that have this configuration enabled but boot with broken
2135	  firmware, you may need to say N here until the firmware is fixed.
2136	  Otherwise you may experience firmware panics or lockups when
2137	  accessing the counter registers. Even if you are not observing these
2138	  symptoms, the values returned by the register reads might not
2139	  correctly reflect reality. Most commonly, the value read will be 0,
2140	  indicating that the counter is not enabled.
2141
2142config ARM64_TLB_RANGE
2143	bool "Enable support for tlbi range feature"
2144	default y
2145	help
2146	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2147	  range of input addresses.
2148
2149config ARM64_MPAM
2150	bool "Enable support for MPAM"
2151	select ARM64_MPAM_DRIVER
2152	select ARCH_HAS_CPU_RESCTRL
2153	help
2154	  Memory System Resource Partitioning and Monitoring (MPAM) is an
2155	  optional extension to the Arm architecture that allows each
2156	  transaction issued to the memory system to be labelled with a
2157	  Partition identifier (PARTID) and Performance Monitoring Group
2158	  identifier (PMG).
2159
2160	  Memory system components, such as the caches, can be configured with
2161	  policies to control how much of various physical resources (such as
2162	  memory bandwidth or cache memory) the transactions labelled with each
2163	  PARTID can consume.  Depending on the capabilities of the hardware,
2164	  the PARTID and PMG can also be used as filtering criteria to measure
2165	  the memory system resource consumption of different parts of a
2166	  workload.
2167
2168	  Use of this extension requires CPU support, support in the
2169	  Memory System Components (MSC), and a description from firmware
2170	  of where the MSCs are in the address space.
2171
2172	  MPAM is exposed to user-space via the resctrl pseudo filesystem.
2173
2174	  This option enables the extra context switch code.
2175
2176endmenu # "ARMv8.4 architectural features"
2177
2178menu "ARMv8.5 architectural features"
2179
2180config AS_HAS_ARMV8_5
2181	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2182
2183config ARM64_BTI
2184	bool "Branch Target Identification support"
2185	default y
2186	help
2187	  Branch Target Identification (part of the ARMv8.5 Extensions)
2188	  provides a mechanism to limit the set of locations to which computed
2189	  branch instructions such as BR or BLR can jump.
2190
2191	  To make use of BTI on CPUs that support it, say Y.
2192
2193	  BTI is intended to provide complementary protection to other control
2194	  flow integrity protection mechanisms, such as the Pointer
2195	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2196	  For this reason, it does not make sense to enable this option without
2197	  also enabling support for pointer authentication.  Thus, when
2198	  enabling this option you should also select ARM64_PTR_AUTH=y.
2199
2200	  Userspace binaries must also be specifically compiled to make use of
2201	  this mechanism.  If you say N here or the hardware does not support
2202	  BTI, such binaries can still run, but you get no additional
2203	  enforcement of branch destinations.
2204
2205config ARM64_BTI_KERNEL
2206	bool "Use Branch Target Identification for kernel"
2207	default y
2208	depends on ARM64_BTI
2209	depends on ARM64_PTR_AUTH_KERNEL
2210	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2211	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2212	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2213	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2214	depends on !CC_IS_GCC
2215	# https://github.com/llvm/llvm-project/issues/215547
2216	depends on !CC_IS_CLANG || CLANG_VERSION < 210000
2217	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2218	help
2219	  Build the kernel with Branch Target Identification annotations
2220	  and enable enforcement of this for kernel code. When this option
2221	  is enabled and the system supports BTI all kernel code including
2222	  modular code must have BTI enabled.
2223
2224config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2225	# GCC 9 or later, clang 8 or later
2226	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2227
2228config ARM64_E0PD
2229	bool "Enable support for E0PD"
2230	default y
2231	help
2232	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2233	  that EL0 accesses made via TTBR1 always fault in constant time,
2234	  providing similar benefits to KASLR as those provided by KPTI, but
2235	  with lower overhead and without disrupting legitimate access to
2236	  kernel memory such as SPE.
2237
2238	  This option enables E0PD for TTBR1 where available.
2239
2240config ARM64_AS_HAS_MTE
2241	# Initial support for MTE went in binutils 2.32.0, checked with
2242	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2243	# as a late addition to the final architecture spec (LDGM/STGM)
2244	# is only supported in the newer 2.32.x and 2.33 binutils
2245	# versions, hence the extra "stgm" instruction check below.
2246	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2247
2248config ARM64_MTE
2249	bool "Memory Tagging Extension support"
2250	default y
2251	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2252	depends on AS_HAS_ARMV8_5
2253	# Required for tag checking in the uaccess routines
2254	select ARCH_HAS_SUBPAGE_FAULTS
2255	select ARCH_USES_HIGH_VMA_FLAGS
2256	select ARCH_USES_PG_ARCH_2
2257	select ARCH_USES_PG_ARCH_3
2258	help
2259	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2260	  architectural support for run-time, always-on detection of
2261	  various classes of memory error to aid with software debugging
2262	  to eliminate vulnerabilities arising from memory-unsafe
2263	  languages.
2264
2265	  This option enables the support for the Memory Tagging
2266	  Extension at EL0 (i.e. for userspace).
2267
2268	  Selecting this option allows the feature to be detected at
2269	  runtime. Any secondary CPU not implementing this feature will
2270	  not be allowed a late bring-up.
2271
2272	  Userspace binaries that want to use this feature must
2273	  explicitly opt in. The mechanism for the userspace is
2274	  described in:
2275
2276	  Documentation/arch/arm64/memory-tagging-extension.rst.
2277
2278endmenu # "ARMv8.5 architectural features"
2279
2280menu "ARMv8.7 architectural features"
2281
2282config ARM64_EPAN
2283	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2284	default y
2285	help
2286	  Enhanced Privileged Access Never (EPAN) allows Privileged
2287	  Access Never to be used with Execute-only mappings.
2288
2289	  The feature is detected at runtime, and will remain disabled
2290	  if the cpu does not implement the feature.
2291endmenu # "ARMv8.7 architectural features"
2292
2293config AS_HAS_MOPS
2294	def_bool $(as-instr,.arch_extension mops)
2295
2296menu "ARMv8.9 architectural features"
2297
2298config ARM64_POE
2299	prompt "Permission Overlay Extension"
2300	def_bool y
2301	select ARCH_USES_HIGH_VMA_FLAGS
2302	select ARCH_HAS_PKEYS
2303	help
2304	  The Permission Overlay Extension is used to implement Memory
2305	  Protection Keys. Memory Protection Keys provides a mechanism for
2306	  enforcing page-based protections, but without requiring modification
2307	  of the page tables when an application changes protection domains.
2308
2309	  For details, see Documentation/core-api/protection-keys.rst
2310
2311	  If unsure, say y.
2312
2313config ARCH_PKEY_BITS
2314	int
2315	default 3
2316
2317config ARM64_HAFT
2318	bool "Support for Hardware managed Access Flag for Table Descriptors"
2319	depends on ARM64_HW_AFDBM
2320	default y
2321	help
2322	  The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access
2323	  Flag for Table descriptors. When enabled an architectural executed
2324	  memory access will update the Access Flag in each Table descriptor
2325	  which is accessed during the translation table walk and for which
2326	  the Access Flag is 0. The Access Flag of the Table descriptor use
2327	  the same bit of PTE_AF.
2328
2329	  The feature will only be enabled if all the CPUs in the system
2330	  support this feature. If unsure, say Y.
2331
2332endmenu # "ARMv8.9 architectural features"
2333
2334menu "ARMv9.4 architectural features"
2335
2336config ARM64_GCS
2337	bool "Enable support for Guarded Control Stack (GCS)"
2338	default y
2339	select ARCH_HAS_USER_SHADOW_STACK
2340	select ARCH_USES_HIGH_VMA_FLAGS
2341	help
2342	  Guarded Control Stack (GCS) provides support for a separate
2343	  stack with restricted access which contains only return
2344	  addresses.  This can be used to harden against some attacks
2345	  by comparing return address used by the program with what is
2346	  stored in the GCS, and may also be used to efficiently obtain
2347	  the call stack for applications such as profiling.
2348
2349	  The feature is detected at runtime, and will remain disabled
2350	  if the system does not implement the feature.
2351
2352endmenu # "ARMv9.4 architectural features"
2353
2354config AS_HAS_LSUI
2355	def_bool $(as-instr,.arch_extension lsui)
2356	help
2357	  Supported by LLVM 20+ and binutils 2.45+.
2358
2359menu "ARMv9.6 architectural features"
2360
2361config ARM64_LSUI
2362	bool "Support Unprivileged Load Store Instructions (LSUI)"
2363	default y
2364	depends on AS_HAS_LSUI
2365	help
2366	  The Unprivileged Load Store Instructions (LSUI) provides
2367	  variants load/store instructions that access user-space memory
2368	  from the kernel without clearing PSTATE.PAN bit.
2369
2370	  This feature is supported by LLVM 20+ and binutils 2.45+.
2371
2372endmenu # "ARMv9.6 architectural feature"
2373
2374config ARM64_SVE
2375	bool "ARM Scalable Vector Extension support"
2376	default y
2377	help
2378	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2379	  execution state which complements and extends the SIMD functionality
2380	  of the base architecture to support much larger vectors and to enable
2381	  additional vectorisation opportunities.
2382
2383	  To enable use of this extension on CPUs that implement it, say Y.
2384
2385	  On CPUs that support the SVE2 extensions, this option will enable
2386	  those too.
2387
2388	  Note that for architectural reasons, firmware _must_ implement SVE
2389	  support when running on SVE capable hardware.  The required support
2390	  is present in:
2391
2392	    * version 1.5 and later of the ARM Trusted Firmware
2393	    * the AArch64 boot wrapper since commit 5e1261e08abf
2394	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2395
2396	  For other firmware implementations, consult the firmware documentation
2397	  or vendor.
2398
2399	  If you need the kernel to boot on SVE-capable hardware with broken
2400	  firmware, you may need to say N here until you get your firmware
2401	  fixed.  Otherwise, you may experience firmware panics or lockups when
2402	  booting the kernel.  If unsure and you are not observing these
2403	  symptoms, you should assume that it is safe to say Y.
2404
2405config AS_HAS_SME
2406	# Supported by LLVM 13+ and binutils 2.38+
2407	def_bool $(as-instr,.arch_extension sme)
2408
2409config ARM64_SME
2410	bool "ARM Scalable Matrix Extension support"
2411	default y
2412	depends on ARM64_SVE
2413	depends on AS_HAS_SME
2414	help
2415	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2416	  execution state which utilises a substantial subset of the SVE
2417	  instruction set, together with the addition of new architectural
2418	  register state capable of holding two dimensional matrix tiles to
2419	  enable various matrix operations.
2420
2421config ARM64_PSEUDO_NMI
2422	bool "Support for NMI-like interrupts"
2423	select ARM_GIC_V3
2424	help
2425	  Adds support for mimicking Non-Maskable Interrupts through the use of
2426	  GIC interrupt priority. This support requires version 3 or later of
2427	  ARM GIC.
2428
2429	  This high priority configuration for interrupts needs to be
2430	  explicitly enabled by setting the kernel parameter
2431	  "irqchip.gicv3_pseudo_nmi" to 1.
2432
2433	  If unsure, say N
2434
2435if ARM64_PSEUDO_NMI
2436config ARM64_DEBUG_PRIORITY_MASKING
2437	bool "Debug interrupt priority masking"
2438	help
2439	  This adds runtime checks to functions enabling/disabling
2440	  interrupts when using priority masking. The additional checks verify
2441	  the validity of ICC_PMR_EL1 when calling concerned functions.
2442
2443	  If unsure, say N
2444endif # ARM64_PSEUDO_NMI
2445
2446config RELOCATABLE
2447	bool "Build a relocatable kernel image" if EXPERT
2448	select ARCH_HAS_RELR
2449	default y
2450	help
2451	  This builds the kernel as a Position Independent Executable (PIE),
2452	  which retains all relocation metadata required to relocate the
2453	  kernel binary at runtime to a different virtual address than the
2454	  address it was linked at.
2455	  Since AArch64 uses the RELA relocation format, this requires a
2456	  relocation pass at runtime even if the kernel is loaded at the
2457	  same address it was linked at.
2458
2459config RANDOMIZE_BASE
2460	bool "Randomize the address of the kernel image"
2461	select RELOCATABLE
2462	help
2463	  Randomizes the virtual address at which the kernel image is
2464	  loaded, as a security feature that deters exploit attempts
2465	  relying on knowledge of the location of kernel internals.
2466
2467	  It is the bootloader's job to provide entropy, by passing a
2468	  random u64 value in /chosen/kaslr-seed at kernel entry.
2469
2470	  When booting via the UEFI stub, it will invoke the firmware's
2471	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2472	  to the kernel proper. In addition, it will randomise the physical
2473	  location of the kernel Image as well.
2474
2475	  If unsure, say N.
2476
2477config RANDOMIZE_MODULE_REGION_FULL
2478	bool "Randomize the module region over a 2 GB range"
2479	depends on RANDOMIZE_BASE
2480	default y
2481	help
2482	  Randomizes the location of the module region inside a 2 GB window
2483	  covering the core kernel. This way, it is less likely for modules
2484	  to leak information about the location of core kernel data structures
2485	  but it does imply that function calls between modules and the core
2486	  kernel will need to be resolved via veneers in the module PLT.
2487
2488	  When this option is not set, the module region will be randomized over
2489	  a limited range that contains the [_stext, _etext] interval of the
2490	  core kernel, so branch relocations are almost always in range unless
2491	  the region is exhausted. In this particular case of region
2492	  exhaustion, modules might be able to fall back to a larger 2GB area.
2493
2494config CC_HAVE_STACKPROTECTOR_SYSREG
2495	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2496
2497config STACKPROTECTOR_PER_TASK
2498	def_bool y
2499	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2500
2501config UNWIND_PATCH_PAC_INTO_SCS
2502	bool "Enable shadow call stack dynamically using code patching"
2503	depends on CC_IS_CLANG
2504	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2505	depends on SHADOW_CALL_STACK
2506	select UNWIND_TABLES
2507	select DYNAMIC_SCS
2508
2509config ARM64_CONTPTE
2510	bool "Contiguous PTE mappings for user memory" if EXPERT
2511	depends on TRANSPARENT_HUGEPAGE
2512	default y
2513	help
2514	  When enabled, user mappings are configured using the PTE contiguous
2515	  bit, for any mappings that meet the size and alignment requirements.
2516	  This reduces TLB pressure and improves performance.
2517
2518endmenu # "Kernel Features"
2519
2520menu "Boot options"
2521
2522config ARM64_ACPI_PARKING_PROTOCOL
2523	bool "Enable support for the ARM64 ACPI parking protocol"
2524	depends on ACPI
2525	help
2526	  Enable support for the ARM64 ACPI parking protocol. If disabled
2527	  the kernel will not allow booting through the ARM64 ACPI parking
2528	  protocol even if the corresponding data is present in the ACPI
2529	  MADT table.
2530
2531config CMDLINE
2532	string "Default kernel command string"
2533	default ""
2534	help
2535	  Provide a set of default command-line options at build time by
2536	  entering them here. As a minimum, you should specify the
2537	  root device (e.g. root=/dev/nfs).
2538
2539choice
2540	prompt "Kernel command line type"
2541	depends on CMDLINE != ""
2542	default CMDLINE_FROM_BOOTLOADER
2543	help
2544	  Choose how the kernel will handle the provided default kernel
2545	  command line string.
2546
2547config CMDLINE_FROM_BOOTLOADER
2548	bool "Use bootloader kernel arguments if available"
2549	help
2550	  Uses the command-line options passed by the boot loader. If
2551	  the boot loader doesn't provide any, the default kernel command
2552	  string provided in CMDLINE will be used.
2553
2554config CMDLINE_FORCE
2555	bool "Always use the default kernel command string"
2556	help
2557	  Always use the default kernel command string, even if the boot
2558	  loader passes other arguments to the kernel.
2559	  This is useful if you cannot or don't want to change the
2560	  command-line options your boot loader passes to the kernel.
2561
2562endchoice
2563
2564config EFI_STUB
2565	bool
2566
2567config EFI
2568	bool "UEFI runtime support"
2569	depends on OF
2570	depends on KERNEL_MODE_NEON
2571	select ARCH_SUPPORTS_ACPI
2572	select LIBFDT
2573	select UCS2_STRING
2574	select EFI_PARAMS_FROM_FDT
2575	select EFI_RUNTIME_WRAPPERS
2576	select EFI_STUB
2577	select EFI_GENERIC_STUB
2578	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2579	default y
2580	help
2581	  This option provides support for runtime services provided
2582	  by UEFI firmware (such as non-volatile variables, realtime
2583	  clock, and platform reset). A UEFI stub is also provided to
2584	  allow the kernel to be booted as an EFI application. This
2585	  is only useful on systems that have UEFI firmware.
2586
2587config COMPRESSED_INSTALL
2588	bool "Install compressed image by default"
2589	help
2590	  This makes the regular "make install" install the compressed
2591	  image we built, not the legacy uncompressed one.
2592
2593	  You can check that a compressed image works for you by doing
2594	  "make zinstall" first, and verifying that everything is fine
2595	  in your environment before making "make install" do this for
2596	  you.
2597
2598config DMI
2599	bool "Enable support for SMBIOS (DMI) tables"
2600	depends on EFI
2601	default y
2602	help
2603	  This enables SMBIOS/DMI feature for systems.
2604
2605	  This option is only useful on systems that have UEFI firmware.
2606	  However, even with this option, the resultant kernel should
2607	  continue to boot on existing non-UEFI platforms.
2608
2609endmenu # "Boot options"
2610
2611menu "Power management options"
2612
2613source "kernel/power/Kconfig"
2614
2615config ARCH_HIBERNATION_POSSIBLE
2616	def_bool y
2617	depends on CPU_PM
2618
2619config ARCH_HIBERNATION_HEADER
2620	def_bool y
2621	depends on HIBERNATION
2622
2623config ARCH_SUSPEND_POSSIBLE
2624	def_bool y
2625
2626endmenu # "Power management options"
2627
2628menu "CPU Power Management"
2629
2630source "drivers/cpuidle/Kconfig"
2631
2632source "drivers/cpufreq/Kconfig"
2633
2634endmenu # "CPU Power Management"
2635
2636source "drivers/acpi/Kconfig"
2637
2638source "arch/arm64/kvm/Kconfig"
2639
2640source "kernel/livepatch/Kconfig"
2641