xref: /linux/arch/arm64/Kconfig (revision 2e51c645fee243dbcb5cee3eb063b5713317444c)
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_SHARED_GPIOS
201	select HAVE_BUILDTIME_MCOUNT_SORT
202	select HAVE_EFFICIENT_UNALIGNED_ACCESS
203	select HAVE_GUP_FAST
204	select HAVE_FTRACE_GRAPH_FUNC
205	select HAVE_FUNCTION_TRACER
206	select HAVE_FUNCTION_ERROR_INJECTION
207	select HAVE_FUNCTION_GRAPH_FREGS
208	select HAVE_FUNCTION_GRAPH_TRACER
209	select HAVE_GCC_PLUGINS
210	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
211		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
212	select HAVE_HW_BREAKPOINT if PERF_EVENTS
213	select HAVE_IOREMAP_PROT
214	select HAVE_IRQ_TIME_ACCOUNTING
215	select HAVE_LIVEPATCH
216	select HAVE_MOD_ARCH_SPECIFIC
217	select HAVE_NMI
218	select HAVE_PERF_EVENTS
219	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
220	select HAVE_PERF_REGS
221	select HAVE_PERF_USER_STACK_DUMP
222	select HAVE_REGS_AND_STACK_ACCESS_API
223	select HAVE_RELIABLE_STACKTRACE
224	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
225	select HAVE_FUNCTION_ARG_ACCESS_API
226	select MMU_GATHER_RCU_TABLE_FREE
227	select HAVE_RSEQ
228	select HAVE_RUST
229	select HAVE_STACKPROTECTOR
230	select HAVE_STATIC_CALL if CFI
231	select HAVE_SYSCALL_TRACEPOINTS
232	select HAVE_KPROBES
233	select HAVE_KRETPROBES
234	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
235	select HOTPLUG_SMT if HOTPLUG_CPU
236	select IRQ_DOMAIN
237	select IRQ_FORCED_THREADING
238	select JUMP_LABEL
239	select KASAN_VMALLOC if KASAN
240	select LOCK_MM_AND_FIND_VMA
241	select MODULES_USE_ELF_RELA
242	select NEED_DMA_MAP_STATE
243	select NEED_SG_DMA_LENGTH
244	select OF
245	select OF_EARLY_FLATTREE
246	select PCI_DOMAINS_GENERIC if PCI
247	select PCI_ECAM if (ACPI && PCI)
248	select PCI_SYSCALL if PCI
249	select POWER_RESET
250	select POWER_SUPPLY
251	select HAS_SEPARATE_PREEMPT_RESCHED_BITS
252	select SPARSE_IRQ
253	select SWIOTLB
254	select SYSCTL_EXCEPTION_TRACE
255	select THREAD_INFO_IN_TASK
256	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
257	select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
258	select TRACE_IRQFLAGS_SUPPORT
259	select TRACE_IRQFLAGS_NMI_SUPPORT
260	select HAVE_SOFTIRQ_ON_OWN_STACK
261	select USER_STACKTRACE_SUPPORT
262	select VDSO_GETRANDOM
263	select VMAP_STACK
264	help
265	  ARM 64-bit (AArch64) Linux support.
266
267config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
268	def_bool CC_IS_CLANG
269	# https://github.com/ClangBuiltLinux/linux/issues/1507
270	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
271
272config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
273	def_bool CC_IS_GCC
274	depends on $(cc-option,-fpatchable-function-entry=2)
275
276config 64BIT
277	def_bool y
278
279config MMU
280	def_bool y
281
282config ARM64_CONT_PTE_SHIFT
283	int
284	default 5 if PAGE_SIZE_64KB
285	default 7 if PAGE_SIZE_16KB
286	default 4
287
288config ARM64_CONT_PMD_SHIFT
289	int
290	default 5 if PAGE_SIZE_64KB
291	default 5 if PAGE_SIZE_16KB
292	default 4
293
294config ARCH_MMAP_RND_BITS_MIN
295	default 14 if PAGE_SIZE_64KB
296	default 16 if PAGE_SIZE_16KB
297	default 18
298
299# max bits determined by the following formula:
300#  VA_BITS - PTDESC_TABLE_SHIFT
301config ARCH_MMAP_RND_BITS_MAX
302	default 19 if ARM64_VA_BITS=36
303	default 24 if ARM64_VA_BITS=39
304	default 27 if ARM64_VA_BITS=42
305	default 30 if ARM64_VA_BITS=47
306	default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES
307	default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES
308	default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52)
309	default 14 if ARM64_64K_PAGES
310	default 16 if ARM64_16K_PAGES
311	default 18
312
313# default to 1 TiB (5 bits below ARCH_MMAP_RND_BITS_MAX) on 48-bit and
314# 52-bit VA; smaller VA sizes fall back to ARCH_MMAP_RND_BITS_MIN in
315# arch/Kconfig
316config ARCH_MMAP_RND_BITS
317	default 24 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES
318	default 26 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES
319	default 28 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52)
320
321config ARCH_MMAP_RND_COMPAT_BITS_MIN
322	default 7 if ARM64_64K_PAGES
323	default 9 if ARM64_16K_PAGES
324	default 11
325
326config ARCH_MMAP_RND_COMPAT_BITS_MAX
327	default 16
328
329config NO_IOPORT_MAP
330	def_bool y if !PCI
331
332config STACKTRACE_SUPPORT
333	def_bool y
334
335config ILLEGAL_POINTER_VALUE
336	hex
337	default 0xdead000000000000
338
339config LOCKDEP_SUPPORT
340	def_bool y
341
342config GENERIC_BUG
343	def_bool y
344	depends on BUG
345
346config GENERIC_BUG_RELATIVE_POINTERS
347	def_bool y
348	depends on GENERIC_BUG
349
350config GENERIC_HWEIGHT
351	def_bool y
352
353config GENERIC_CSUM
354	def_bool y
355
356config GENERIC_CALIBRATE_DELAY
357	def_bool y
358
359config SMP
360	def_bool y
361
362config KERNEL_MODE_NEON
363	def_bool y
364
365config FIX_EARLYCON_MEM
366	def_bool y
367
368config PGTABLE_LEVELS
369	int
370	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
371	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
372	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
373	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
374	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
375	default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
376	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
377	default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
378
379config ARCH_SUPPORTS_UPROBES
380	def_bool y
381
382config ARCH_PROC_KCORE_TEXT
383	def_bool y
384
385config BROKEN_GAS_INST
386	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
387
388config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
389	bool
390	# Clang's __builtin_return_address() strips the PAC since 12.0.0
391	# https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
392	default y if CC_IS_CLANG
393	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
394	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
395	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
396	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
397	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
398	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
399	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
400	default n
401
402config KASAN_SHADOW_OFFSET
403	hex
404	depends on KASAN_GENERIC || KASAN_SW_TAGS
405	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
406	default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
407	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
408	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
409	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
410	default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
411	default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
412	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
413	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
414	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
415	default 0xffffffffffffffff
416
417config UNWIND_TABLES
418	bool
419
420source "arch/arm64/Kconfig.platforms"
421
422menu "Kernel Features"
423
424menu "ARM errata workarounds via the alternatives framework"
425
426config AMPERE_ERRATUM_AC03_CPU_38
427        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
428	default y
429	help
430	  This option adds an alternative code sequence to work around Ampere
431	  errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
432
433	  The affected design reports FEAT_HAFDBS as not implemented in
434	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
435	  as required by the architecture. The unadvertised HAFDBS
436	  implementation suffers from an additional erratum where hardware
437	  A/D updates can occur after a PTE has been marked invalid.
438
439	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
440	  which avoids enabling unadvertised hardware Access Flag management
441	  at stage-2.
442
443	  If unsure, say Y.
444
445config AMPERE_ERRATUM_AC04_CPU_23
446        bool "AmpereOne: AC04_CPU_23:  Failure to synchronize writes to HCR_EL2 may corrupt address translations."
447	default y
448	help
449	  This option adds an alternative code sequence to work around Ampere
450	  errata AC04_CPU_23 on AmpereOne.
451
452	  Updates to HCR_EL2 can rarely corrupt simultaneous translations for
453	  data addresses initiated by load/store instructions. Only
454	  instruction initiated translations are vulnerable, not translations
455	  from prefetches for example. A DSB before the store to HCR_EL2 is
456	  sufficient to prevent older instructions from hitting the window
457	  for corruption, and an ISB after is sufficient to prevent younger
458	  instructions from hitting the window for corruption.
459
460	  If unsure, say Y.
461
462config ARM64_WORKAROUND_CLEAN_CACHE
463	bool
464
465config ARM64_ERRATUM_826319
466	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
467	default y
468	select ARM64_WORKAROUND_CLEAN_CACHE
469	help
470	  This option adds an alternative code sequence to work around ARM
471	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
472	  AXI master interface and an L2 cache.
473
474	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
475	  and is unable to accept a certain write via this interface, it will
476	  not progress on read data presented on the read data channel and the
477	  system can deadlock.
478
479	  The workaround promotes data cache clean instructions to
480	  data cache clean-and-invalidate.
481	  Please note that this does not necessarily enable the workaround,
482	  as it depends on the alternative framework, which will only patch
483	  the kernel if an affected CPU is detected.
484
485	  If unsure, say Y.
486
487config ARM64_ERRATUM_827319
488	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
489	default y
490	select ARM64_WORKAROUND_CLEAN_CACHE
491	help
492	  This option adds an alternative code sequence to work around ARM
493	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
494	  master interface and an L2 cache.
495
496	  Under certain conditions this erratum can cause a clean line eviction
497	  to occur at the same time as another transaction to the same address
498	  on the AMBA 5 CHI interface, which can cause data corruption if the
499	  interconnect reorders the two transactions.
500
501	  The workaround promotes data cache clean instructions to
502	  data cache clean-and-invalidate.
503	  Please note that this does not necessarily enable the workaround,
504	  as it depends on the alternative framework, which will only patch
505	  the kernel if an affected CPU is detected.
506
507	  If unsure, say Y.
508
509config ARM64_ERRATUM_824069
510	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
511	default y
512	select ARM64_WORKAROUND_CLEAN_CACHE
513	help
514	  This option adds an alternative code sequence to work around ARM
515	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
516	  to a coherent interconnect.
517
518	  If a Cortex-A53 processor is executing a store or prefetch for
519	  write instruction at the same time as a processor in another
520	  cluster is executing a cache maintenance operation to the same
521	  address, then this erratum might cause a clean cache line to be
522	  incorrectly marked as dirty.
523
524	  The workaround promotes data cache clean instructions to
525	  data cache clean-and-invalidate.
526	  Please note that this option does not necessarily enable the
527	  workaround, as it depends on the alternative framework, which will
528	  only patch the kernel if an affected CPU is detected.
529
530	  If unsure, say Y.
531
532config ARM64_ERRATUM_819472
533	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
534	default y
535	select ARM64_WORKAROUND_CLEAN_CACHE
536	help
537	  This option adds an alternative code sequence to work around ARM
538	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
539	  present when it is connected to a coherent interconnect.
540
541	  If the processor is executing a load and store exclusive sequence at
542	  the same time as a processor in another cluster is executing a cache
543	  maintenance operation to the same address, then this erratum might
544	  cause data corruption.
545
546	  The workaround promotes data cache clean instructions to
547	  data cache clean-and-invalidate.
548	  Please note that this does not necessarily enable the workaround,
549	  as it depends on the alternative framework, which will only patch
550	  the kernel if an affected CPU is detected.
551
552	  If unsure, say Y.
553
554config ARM64_ERRATUM_832075
555	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
556	default y
557	help
558	  This option adds an alternative code sequence to work around ARM
559	  erratum 832075 on Cortex-A57 parts up to r1p2.
560
561	  Affected Cortex-A57 parts might deadlock when exclusive load/store
562	  instructions to Write-Back memory are mixed with Device loads.
563
564	  The workaround is to promote device loads to use Load-Acquire
565	  semantics.
566	  Please note that this does not necessarily enable the workaround,
567	  as it depends on the alternative framework, which will only patch
568	  the kernel if an affected CPU is detected.
569
570	  If unsure, say Y.
571
572config ARM64_ERRATUM_834220
573	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
574	depends on KVM
575	help
576	  This option adds an alternative code sequence to work around ARM
577	  erratum 834220 on Cortex-A57 parts up to r1p2.
578
579	  Affected Cortex-A57 parts might report a Stage 2 translation
580	  fault as the result of a Stage 1 fault for load crossing a
581	  page boundary when there is a permission or device memory
582	  alignment fault at Stage 1 and a translation fault at Stage 2.
583
584	  The workaround is to verify that the Stage 1 translation
585	  doesn't generate a fault before handling the Stage 2 fault.
586	  Please note that this does not necessarily enable the workaround,
587	  as it depends on the alternative framework, which will only patch
588	  the kernel if an affected CPU is detected.
589
590	  If unsure, say N.
591
592config ARM64_ERRATUM_1742098
593	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
594	depends on COMPAT
595	default y
596	help
597	  This option removes the AES hwcap for aarch32 user-space to
598	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
599
600	  Affected parts may corrupt the AES state if an interrupt is
601	  taken between a pair of AES instructions. These instructions
602	  are only present if the cryptography extensions are present.
603	  All software should have a fallback implementation for CPUs
604	  that don't implement the cryptography extensions.
605
606	  If unsure, say Y.
607
608config ARM64_ERRATUM_845719
609	bool "Cortex-A53: 845719: a load might read incorrect data"
610	depends on COMPAT
611	default y
612	help
613	  This option adds an alternative code sequence to work around ARM
614	  erratum 845719 on Cortex-A53 parts up to r0p4.
615
616	  When running a compat (AArch32) userspace on an affected Cortex-A53
617	  part, a load at EL0 from a virtual address that matches the bottom 32
618	  bits of the virtual address used by a recent load at (AArch64) EL1
619	  might return incorrect data.
620
621	  The workaround is to write the contextidr_el1 register on exception
622	  return to a 32-bit task.
623	  Please note that this does not necessarily enable the workaround,
624	  as it depends on the alternative framework, which will only patch
625	  the kernel if an affected CPU is detected.
626
627	  If unsure, say Y.
628
629config ARM64_ERRATUM_843419
630	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
631	default y
632	help
633	  This option links the kernel with '--fix-cortex-a53-843419' and
634	  enables PLT support to replace certain ADRP instructions, which can
635	  cause subsequent memory accesses to use an incorrect address on
636	  Cortex-A53 parts up to r0p4.
637
638	  If unsure, say Y.
639
640config ARM64_ERRATUM_1024718
641	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
642	default y
643	help
644	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
645
646	  Affected Cortex-A55 cores (all revisions) could cause incorrect
647	  update of the hardware dirty bit when the DBM/AP bits are updated
648	  without a break-before-make. The workaround is to disable the usage
649	  of hardware DBM locally on the affected cores. CPUs not affected by
650	  this erratum will continue to use the feature.
651
652	  If unsure, say Y.
653
654config ARM64_ERRATUM_1418040
655	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
656	default y
657	depends on COMPAT
658	help
659	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
660	  errata 1188873 and 1418040.
661
662	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
663	  cause register corruption when accessing the timer registers
664	  from AArch32 userspace.
665
666	  If unsure, say Y.
667
668config ARM64_WORKAROUND_SPECULATIVE_AT
669	bool
670
671config ARM64_ERRATUM_1165522
672	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
673	default y
674	select ARM64_WORKAROUND_SPECULATIVE_AT
675	help
676	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
677
678	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
679	  corrupted TLBs by speculating an AT instruction during a guest
680	  context switch.
681
682	  If unsure, say Y.
683
684config ARM64_ERRATUM_1319367
685	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
686	default y
687	select ARM64_WORKAROUND_SPECULATIVE_AT
688	help
689	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
690	  and A72 erratum 1319367
691
692	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
693	  speculating an AT instruction during a guest context switch.
694
695	  If unsure, say Y.
696
697config ARM64_ERRATUM_1530923
698	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
699	default y
700	select ARM64_WORKAROUND_SPECULATIVE_AT
701	help
702	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
703
704	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
705	  corrupted TLBs by speculating an AT instruction during a guest
706	  context switch.
707
708	  If unsure, say Y.
709
710config ARM64_WORKAROUND_REPEAT_TLBI_SYNC
711	bool
712	# This workaround is (only) suitable for TLB invalidation errata where
713	# all of the following conditions are true:
714	#
715	# - The effects of the errata are only a loss of ordering/completion
716	#   for explicit memory accesses when the TLBI is completed with a DSB.
717	#   The removal of TLB entries is not affected.
718	#
719	#   Note that architecturally, S2-only invalidation does not remove
720	#   combined S1+S2 entries, and does not complete accesses translated
721	#   via those S1+S2 entries. Consequently, where this condition holds,
722	#   the errata do not affect S2-only invalidation.
723	#
724	# - The errata only affect broadcast TLB invalidation operations (e.g.
725	#   TLBI VMALLE1IS), and do not affect local TLB invalidation
726	#   operations (e.g. TLBI VMALLE1).
727	#
728	# - After any number of affected TLBI operations are completed with a
729	#   DSB, the errata can be mitigated by executing a single arbitrary
730	#   broadcast TLBI (which targets an arbitrary translation regime),
731	#   followed by a DSB.
732	#
733	# For more rationale, see commit a8f78680ee6bf795.
734
735config ARM64_ERRATUM_2441007
736	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
737	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
738	help
739	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
740
741	  Under very rare circumstances, affected Cortex-A55 CPUs
742	  may not handle a race between a break-before-make sequence on one
743	  CPU, and another CPU accessing the same page. This could allow a
744	  store to a page that has been unmapped.
745
746	  Work around this by adding the affected CPUs to the list that needs
747	  TLB sequences to be done twice.
748
749	  If unsure, say N.
750
751config ARM64_ERRATUM_1286807
752	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
753	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
754	help
755	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
756
757	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
758	  address for a cacheable mapping of a location is being
759	  accessed by a core while another core is remapping the virtual
760	  address to a new physical page using the recommended
761	  break-before-make sequence, then under very rare circumstances
762	  TLBI+DSB completes before a read using the translation being
763	  invalidated has been observed by other observers. The
764	  workaround repeats the TLBI+DSB operation.
765
766	  If unsure, say N.
767
768config ARM64_ERRATUM_1463225
769	bool "Cortex-A76: Software Step might prevent interrupt recognition"
770	default y
771	help
772	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
773
774	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
775	  of a system call instruction (SVC) can prevent recognition of
776	  subsequent interrupts when software stepping is disabled in the
777	  exception handler of the system call and either kernel debugging
778	  is enabled or VHE is in use.
779
780	  Work around the erratum by triggering a dummy step exception
781	  when handling a system call from a task that is being stepped
782	  in a VHE configuration of the kernel.
783
784	  If unsure, say Y.
785
786config ARM64_ERRATUM_1542419
787	bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
788	help
789	  This option adds a workaround for ARM Neoverse-N1 erratum
790	  1542419.
791
792	  Affected Neoverse-N1 cores could execute a stale instruction when
793	  modified by another CPU. The workaround depends on a firmware
794	  counterpart.
795
796	  Workaround the issue by hiding the DIC feature from EL0. This
797	  forces user-space to perform cache maintenance.
798
799	  If unsure, say N.
800
801config ARM64_ERRATUM_1508412
802	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
803	default y
804	help
805	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
806
807	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
808	  of a store-exclusive or read of PAR_EL1 and a load with device or
809	  non-cacheable memory attributes. The workaround depends on a firmware
810	  counterpart.
811
812	  KVM guests must also have the workaround implemented or they can
813	  deadlock the system.
814
815	  Work around the issue by inserting DMB SY barriers around PAR_EL1
816	  register reads and warning KVM users. The DMB barrier is sufficient
817	  to prevent a speculative PAR_EL1 read.
818
819	  If unsure, say Y.
820
821config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
822	bool
823
824config ARM64_ERRATUM_2051678
825	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
826	default y
827	help
828	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
829	  Affected Cortex-A510 might not respect the ordering rules for
830	  hardware update of the page table's dirty bit. The workaround
831	  is to not enable the feature on affected CPUs.
832
833	  If unsure, say Y.
834
835config ARM64_ERRATUM_2077057
836	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
837	default y
838	help
839	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
840	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
841	  expected, but a Pointer Authentication trap is taken instead. The
842	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
843	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
844
845	  This can only happen when EL2 is stepping EL1.
846
847	  When these conditions occur, the SPSR_EL2 value is unchanged from the
848	  previous guest entry, and can be restored from the in-memory copy.
849
850	  If unsure, say Y.
851
852config ARM64_ERRATUM_2658417
853	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
854	default y
855	help
856	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
857	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
858	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
859	  A510 CPUs are using shared neon hardware. As the sharing is not
860	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
861	  user-space should not be using these instructions.
862
863	  If unsure, say Y.
864
865config ARM64_ERRATUM_2119858
866	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
867	default y
868	depends on CORESIGHT_TRBE
869	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
870	help
871	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
872
873	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
874	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
875	  the event of a WRAP event.
876
877	  Work around the issue by always making sure we move the TRBPTR_EL1 by
878	  256 bytes before enabling the buffer and filling the first 256 bytes of
879	  the buffer with ETM ignore packets upon disabling.
880
881	  If unsure, say Y.
882
883config ARM64_ERRATUM_2139208
884	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
885	default y
886	depends on CORESIGHT_TRBE
887	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
888	help
889	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
890
891	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
892	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
893	  the event of a WRAP event.
894
895	  Work around the issue by always making sure we move the TRBPTR_EL1 by
896	  256 bytes before enabling the buffer and filling the first 256 bytes of
897	  the buffer with ETM ignore packets upon disabling.
898
899	  If unsure, say Y.
900
901config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
902	bool
903
904config ARM64_ERRATUM_2054223
905	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
906	default y
907	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
908	help
909	  Enable workaround for ARM Cortex-A710 erratum 2054223
910
911	  Affected cores may fail to flush the trace data on a TSB instruction, when
912	  the PE is in trace prohibited state. This will cause losing a few bytes
913	  of the trace cached.
914
915	  Workaround is to issue two TSB consecutively on affected cores.
916
917	  If unsure, say Y.
918
919config ARM64_ERRATUM_2067961
920	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
921	default y
922	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
923	help
924	  Enable workaround for ARM Neoverse-N2 erratum 2067961
925
926	  Affected cores may fail to flush the trace data on a TSB instruction, when
927	  the PE is in trace prohibited state. This will cause losing a few bytes
928	  of the trace cached.
929
930	  Workaround is to issue two TSB consecutively on affected cores.
931
932	  If unsure, say Y.
933
934config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
935	bool
936
937config ARM64_ERRATUM_2253138
938	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
939	depends on CORESIGHT_TRBE
940	default y
941	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
942	help
943	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
944
945	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
946	  for TRBE. Under some conditions, the TRBE might generate a write to the next
947	  virtually addressed page following the last page of the TRBE address space
948	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
949
950	  Work around this in the driver by always making sure that there is a
951	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
952
953	  If unsure, say Y.
954
955config ARM64_ERRATUM_2224489
956	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
957	depends on CORESIGHT_TRBE
958	default y
959	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
960	help
961	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
962
963	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
964	  for TRBE. Under some conditions, the TRBE might generate a write to the next
965	  virtually addressed page following the last page of the TRBE address space
966	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
967
968	  Work around this in the driver by always making sure that there is a
969	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
970
971	  If unsure, say Y.
972
973config ARM64_ERRATUM_2441009
974	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
975	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
976	help
977	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
978
979	  Under very rare circumstances, affected Cortex-A510 CPUs
980	  may not handle a race between a break-before-make sequence on one
981	  CPU, and another CPU accessing the same page. This could allow a
982	  store to a page that has been unmapped.
983
984	  Work around this by adding the affected CPUs to the list that needs
985	  TLB sequences to be done twice.
986
987	  If unsure, say N.
988
989config ARM64_ERRATUM_2064142
990	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
991	depends on CORESIGHT_TRBE
992	default y
993	help
994	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
995
996	  Affected Cortex-A510 core might fail to write into system registers after the
997	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
998	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
999	  and TRBTRG_EL1 will be ignored and will not be effected.
1000
1001	  Work around this in the driver by executing TSB CSYNC and DSB after collection
1002	  is stopped and before performing a system register write to one of the affected
1003	  registers.
1004
1005	  If unsure, say Y.
1006
1007config ARM64_ERRATUM_2038923
1008	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
1009	depends on CORESIGHT_TRBE
1010	default y
1011	help
1012	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
1013
1014	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
1015	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
1016	  might be corrupted. This happens after TRBE buffer has been enabled by setting
1017	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
1018	  execution changes from a context, in which trace is prohibited to one where it
1019	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
1020	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
1021	  the trace buffer state might be corrupted.
1022
1023	  Work around this in the driver by preventing an inconsistent view of whether the
1024	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
1025	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
1026	  two ISB instructions if no ERET is to take place.
1027
1028	  If unsure, say Y.
1029
1030config ARM64_ERRATUM_1902691
1031	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1032	depends on CORESIGHT_TRBE
1033	default y
1034	help
1035	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1036
1037	  Affected Cortex-A510 core might cause trace data corruption, when being written
1038	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
1039	  trace data.
1040
1041	  Work around this problem in the driver by just preventing TRBE initialization on
1042	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1043	  on such implementations. This will cover the kernel for any firmware that doesn't
1044	  do this already.
1045
1046	  If unsure, say Y.
1047
1048config ARM64_WORKAROUND_BROKEN_AMU_CONSTCNT
1049	bool
1050	# Targeting errata affecting AMEVCNTR01, the AMU constant counter.
1051	# On affected CPUs the counter may not increment at the expected rate,
1052	# making it unreliable. As a result, AMU users should treat it as
1053	# unavailable rather than relying on misleading counter values.
1054
1055config ARM64_ERRATUM_2457168
1056	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1057	depends on ARM64_AMU_EXTN
1058	select ARM64_WORKAROUND_BROKEN_AMU_CONSTCNT
1059	default y
1060	help
1061	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1062
1063	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1064	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1065	  incorrectly giving a significantly higher output value.
1066
1067	  Work around this problem by returning 0 when reading the affected counter in
1068	  key locations that results in disabling all users of this counter. This effect
1069	  is the same to firmware disabling affected counters.
1070
1071	  If unsure, say Y.
1072
1073config ARM64_ERRATUM_2645198
1074	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1075	default y
1076	help
1077	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1078
1079	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1080	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1081	  next instruction abort caused by permission fault.
1082
1083	  Only user-space does executable to non-executable permission transition via
1084	  mprotect() system call. Workaround the problem by doing a break-before-make
1085	  TLB invalidation, for all changes to executable user space mappings.
1086
1087	  If unsure, say Y.
1088
1089config ARM64_ERRATUM_3821522
1090	bool "Cortex-A725: 3821522: workaround for possible CNT_CYCLES increment error due to WFE/WFI"
1091	depends on ARM64_AMU_EXTN
1092	select ARM64_WORKAROUND_BROKEN_AMU_CONSTCNT
1093	default y
1094	help
1095	  This option adds the workaround for ARM Cortex-A725 erratum 3821522.
1096
1097	  On affected A725 cores, the CNT_CYCLES event may incur a significant
1098	  increment error when entering and subsequently exiting WFx.
1099	  As a result, the CNT_CYCLES may diverge from the system counter
1100	  frequency at which it is expected to increment.
1101	  This renders the AMU counter AMEVCNTR01, that implements CNT_CYCLES,
1102	  being unreliable and unsuitable for use.
1103
1104	  Since there is no hardware workaround, reads of the affected CNT_CYCLES
1105	  counter return 0 in the relevant paths. This causes users of the counter
1106	  to treat it as unavailable and is functionally equivalent to firmware
1107	  disabling the affected counter.
1108
1109	  If unsure, say Y.
1110
1111config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1112	bool
1113
1114config ARM64_ERRATUM_2966298
1115	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1116	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1117	default y
1118	help
1119	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1120
1121	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1122	  load might leak data from a privileged level via a cache side channel.
1123
1124	  Work around this problem by executing a TLBI before returning to EL0.
1125
1126	  If unsure, say Y.
1127
1128config ARM64_ERRATUM_3117295
1129	bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1130	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1131	default y
1132	help
1133	  This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1134
1135	  On an affected Cortex-A510 core, a speculatively executed unprivileged
1136	  load might leak data from a privileged level via a cache side channel.
1137
1138	  Work around this problem by executing a TLBI before returning to EL0.
1139
1140	  If unsure, say Y.
1141
1142config ARM64_ERRATUM_3194386
1143	bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1144	default y
1145	help
1146	  This option adds the workaround for the following errata:
1147
1148	  * ARM Cortex-A76 erratum 3324349
1149	  * ARM Cortex-A77 erratum 3324348
1150	  * ARM Cortex-A78 erratum 3324344
1151	  * ARM Cortex-A78C erratum 3324346
1152	  * ARM Cortex-A78C erratum 3324347
1153	  * ARM Cortex-A710 erratam 3324338
1154	  * ARM Cortex-A715 errartum 3456084
1155	  * ARM Cortex-A720 erratum 3456091
1156	  * ARM Cortex-A725 erratum 3456106
1157	  * ARM Cortex-X1 erratum 3324344
1158	  * ARM Cortex-X1C erratum 3324346
1159	  * ARM Cortex-X2 erratum 3324338
1160	  * ARM Cortex-X3 erratum 3324335
1161	  * ARM Cortex-X4 erratum 3194386
1162	  * ARM Cortex-X925 erratum 3324334
1163	  * ARM Neoverse-N1 erratum 3324349
1164	  * ARM Neoverse N2 erratum 3324339
1165	  * ARM Neoverse-N3 erratum 3456111
1166	  * ARM Neoverse-V1 erratum 3324341
1167	  * ARM Neoverse V2 erratum 3324336
1168	  * ARM Neoverse-V3 erratum 3312417
1169	  * ARM Neoverse-V3AE erratum 3312417
1170
1171	  On affected cores "MSR SSBS, #0" instructions may not affect
1172	  subsequent speculative instructions, which may permit unexepected
1173	  speculative store bypassing.
1174
1175	  Work around this problem by placing a Speculation Barrier (SB) or
1176	  Instruction Synchronization Barrier (ISB) after kernel changes to
1177	  SSBS. The presence of the SSBS special-purpose register is hidden
1178	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1179	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1180
1181	  If unsure, say Y.
1182
1183config ARM64_ERRATUM_4311569
1184	bool "SI L1: 4311569: workaround for premature CMO completion erratum"
1185	default y
1186	help
1187	  This option adds the workaround for ARM SI L1 erratum 4311569.
1188
1189	  The erratum of SI L1 can cause an early response to a combined write
1190	  and cache maintenance operation (WR+CMO) before the operation is fully
1191	  completed to the Point of Serialization (POS).
1192	  This can result in a non-I/O coherent agent observing stale data,
1193	  potentially leading to system instability or incorrect behavior.
1194
1195	  Enabling this option implements a software workaround by inserting a
1196	  second loop of Cache Maintenance Operation (CMO) immediately following the
1197	  end of function to do CMOs. This ensures that the data is correctly serialized
1198	  before the buffer is handed off to a non-coherent agent.
1199
1200	  If unsure, say Y.
1201
1202config ARM64_ERRATUM_4193714
1203	bool "C1-Pro: 4193714: SME DVMSync early acknowledgement"
1204	depends on ARM64_SME
1205	default y
1206	help
1207	  Enable workaround for C1-Pro acknowledging the DVMSync before
1208	  the SME memory accesses are complete. This will cause TLB
1209	  maintenance for processes using SME to also issue an IPI to
1210	  the affected CPUs.
1211
1212	  If unsure, say Y.
1213
1214config ARM64_ERRATUM_4118414
1215	bool "Various: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
1216	default y
1217	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
1218	help
1219	  This option adds a workaround for the following errata:
1220
1221	  * ARM C1-Premium erratum 4193780
1222	  * ARM C1-Ultra erratum 4193780
1223	  * ARM Cortex-A76 erratum 4193800
1224	  * ARM Cortex-A76AE erratum 4193801
1225	  * ARM Cortex-A77 erratum 4193798
1226	  * ARM Cortex-A78 erratum 4193791
1227	  * ARM Cortex-A78AE erratum 4193793
1228	  * ARM Cortex-A78C erratum 4193794
1229	  * ARM Cortex-A710 erratum 4193788
1230	  * ARM Cortex-X1 erratum 4193791
1231	  * ARM Cortex-X1C erratum 4193792
1232	  * ARM Cortex-X2 erratum 4193788
1233	  * ARM Cortex-X3 erratum 4193786
1234	  * ARM Cortex-X4 erratum 4118414
1235	  * ARM Cortex-X925 erratum 4193781
1236	  * ARM Neoverse-N1 erratum 4193800
1237	  * ARM Neoverse-N2 erratum 4193789
1238	  * ARM Neoverse-V1 erratum 4193790
1239	  * ARM Neoverse-V2 erratum 4193787
1240	  * ARM Neoverse-V3 erratum 4193784
1241	  * ARM Neoverse-V3AE erratum 4193784
1242	  * Microsoft Azure Cobalt 100 4193789
1243	  * NVIDIA Olympus erratum T410-OLY-1029
1244
1245	  On affected cores, some memory accesses might not be completed by
1246	  broadcast TLB invalidation.
1247
1248	  This issue is also known as CVE-2025-10263.
1249
1250	  If unsure, say Y.
1251
1252config CAVIUM_ERRATUM_22375
1253	bool "Cavium erratum 22375, 24313"
1254	default y
1255	help
1256	  Enable workaround for errata 22375 and 24313.
1257
1258	  This implements two gicv3-its errata workarounds for ThunderX. Both
1259	  with a small impact affecting only ITS table allocation.
1260
1261	    erratum 22375: only alloc 8MB table size
1262	    erratum 24313: ignore memory access type
1263
1264	  The fixes are in ITS initialization and basically ignore memory access
1265	  type and table size provided by the TYPER and BASER registers.
1266
1267	  If unsure, say Y.
1268
1269config CAVIUM_ERRATUM_23144
1270	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1271	depends on NUMA
1272	default y
1273	help
1274	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1275
1276	  If unsure, say Y.
1277
1278config CAVIUM_ERRATUM_23154
1279	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1280	default y
1281	help
1282	  The ThunderX GICv3 implementation requires a modified version for
1283	  reading the IAR status to ensure data synchronization
1284	  (access to icc_iar1_el1 is not sync'ed before and after).
1285
1286	  It also suffers from erratum 38545 (also present on Marvell's
1287	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1288	  spuriously presented to the CPU interface.
1289
1290	  If unsure, say Y.
1291
1292config CAVIUM_ERRATUM_27456
1293	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1294	default y
1295	help
1296	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1297	  instructions may cause the icache to become corrupted if it
1298	  contains data for a non-current ASID.  The fix is to
1299	  invalidate the icache when changing the mm context.
1300
1301	  If unsure, say Y.
1302
1303config CAVIUM_ERRATUM_30115
1304	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1305	default y
1306	help
1307	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1308	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1309	  interrupts in host. Trapping both GICv3 group-0 and group-1
1310	  accesses sidesteps the issue.
1311
1312	  If unsure, say Y.
1313
1314config CAVIUM_TX2_ERRATUM_219
1315	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1316	default y
1317	help
1318	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1319	  TTBR update and the corresponding context synchronizing operation can
1320	  cause a spurious Data Abort to be delivered to any hardware thread in
1321	  the CPU core.
1322
1323	  Work around the issue by avoiding the problematic code sequence and
1324	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1325	  trap handler performs the corresponding register access, skips the
1326	  instruction and ensures context synchronization by virtue of the
1327	  exception return.
1328
1329	  If unsure, say Y.
1330
1331config FUJITSU_ERRATUM_010001
1332	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1333	default y
1334	help
1335	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1336	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1337	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1338	  This fault occurs under a specific hardware condition when a
1339	  load/store instruction performs an address translation using:
1340	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1341	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1342	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1343	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1344
1345	  The workaround is to ensure these bits are clear in TCR_ELx.
1346	  The workaround only affects the Fujitsu-A64FX.
1347
1348	  If unsure, say Y.
1349
1350config HISILICON_ERRATUM_161600802
1351	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1352	default y
1353	help
1354	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1355	  when issued ITS commands such as VMOVP and VMAPP, and requires
1356	  a 128kB offset to be applied to the target address in this commands.
1357
1358	  If unsure, say Y.
1359
1360config HISILICON_ERRATUM_162100801
1361	bool "Hip09 162100801 erratum support"
1362	default y
1363	help
1364	  When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches
1365	  during unmapping operation, which will cause some vSGIs lost.
1366	  To fix the issue, invalidate related vPE cache through GICR_INVALLR
1367	  after VMOVP.
1368
1369	  If unsure, say Y.
1370
1371config HISILICON_ERRATUM_162100125
1372	bool "Hisilicon erratum 162100125"
1373	default y
1374	select ARM64_WORKAROUND_DISABLE_CNP
1375	help
1376	  On HiSilicon HIP09, TLB entry matching behavior when CNP
1377	  (TTBRx.CNP=1) is enabled differs from the ARM architecture
1378	  specification.
1379
1380	  TLB entries may be incorrectly shared between CPUs, potentially
1381	  causing TLB conflicts and stale mappings.
1382
1383	  Disable CNP support for affected HiSilicon HIP09 cores.
1384
1385	  If unsure, say Y.
1386
1387config QCOM_FALKOR_ERRATUM_1003
1388	bool "Falkor E1003: Incorrect translation due to ASID change"
1389	default y
1390	help
1391	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1392	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1393	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1394	  then only for entries in the walk cache, since the leaf translation
1395	  is unchanged. Work around the erratum by invalidating the walk cache
1396	  entries for the trampoline before entering the kernel proper.
1397
1398config QCOM_FALKOR_ERRATUM_1009
1399	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1400	default y
1401	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
1402	help
1403	  On Falkor v1, the CPU may prematurely complete a DSB following a
1404	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1405	  one more time to fix the issue.
1406
1407	  If unsure, say Y.
1408
1409config QCOM_QDF2400_ERRATUM_0065
1410	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1411	default y
1412	help
1413	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1414	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1415	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1416
1417	  If unsure, say Y.
1418
1419config QCOM_FALKOR_ERRATUM_E1041
1420	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1421	default y
1422	help
1423	  Falkor CPU may speculatively fetch instructions from an improper
1424	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1425	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1426
1427	  If unsure, say Y.
1428
1429config ARM64_WORKAROUND_DISABLE_CNP
1430	bool
1431
1432config NVIDIA_CARMEL_CNP_ERRATUM
1433	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1434	default y
1435	select ARM64_WORKAROUND_DISABLE_CNP
1436	help
1437	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1438	  invalidate shared TLB entries installed by a different core, as it would
1439	  on standard ARM cores.
1440
1441	  If unsure, say Y.
1442
1443config NVIDIA_OLYMPUS_1027_ERRATUM
1444	bool "NVIDIA Olympus: device store/load ordering erratum"
1445	default y
1446	help
1447	  This option adds an alternative code sequence to work around an
1448	  NVIDIA Olympus core erratum where a Device-nGnR* store can be
1449	  observed by a peripheral after a younger Device-nGnR* load to the
1450	  same peripheral. This breaks the program order that drivers rely
1451	  on for MMIO and can leave a device in an incorrect state.
1452
1453	  The workaround inserts a DMB OSH immediately before raw MMIO loads.
1454	  The erratum cannot occur when a DMB that orders loads appears
1455	  between the store and load, preventing the younger load from being
1456	  observed before the older store.
1457
1458	  The alternatives framework patches in DMB OSH only when an affected
1459	  CPU is detected. Other CPUs execute a NOP in its place. Disabling
1460	  this option leaves the original MMIO read instruction stream
1461	  unchanged.
1462
1463	  If unsure, say Y.
1464
1465config ALTERA_ERRATUM_AGILEX5_2_1_23
1466	bool
1467	help
1468	  The Altera SoCFPGA Agilex5 GIC600 SoC integration has ACE-lite
1469	  addressing limited to the first 32bit of physical address space,
1470	  so the ITS cannot access memory above 4GB.
1471
1472	  Selected by ARCH_INTEL_SOCFPGA, as all Agilex5 devices are affected.
1473
1474config RENESAS_ERRATUM_GEN4GICITS1
1475	bool "Renesas R-Car Gen4: GIC600 can not access physical addresses above 4 GiB"
1476	default y
1477	help
1478	  The Renesas R-Car Gen4 S4/V4H/V4M GIC600 SoC integrations have AXI
1479	  addressing limited to the first 32-bit of physical address space.
1480
1481	  If unsure, say Y.
1482
1483config ROCKCHIP_ERRATUM_3568002
1484	bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB"
1485	default y
1486	help
1487	  The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI
1488	  addressing limited to the first 32bit of physical address space.
1489
1490	  If unsure, say Y.
1491
1492config ROCKCHIP_ERRATUM_3588001
1493	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1494	default y
1495	help
1496	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1497	  This means, that its sharability feature may not be used, even though it
1498	  is supported by the IP itself.
1499
1500	  If unsure, say Y.
1501
1502config NXP_IMX8QM_ERRATUM_ERR050104
1503	bool "NXP iMX8QM/QP ERR050104: broken cache/TLB invalidation broadcast"
1504	default y
1505	help
1506	  On iMX8QM (QuadMax) and iMX8QP (QuadPlus), address bits above bit 35
1507	  in the A53 subsystem ARADDR and ACADDR buses are incorrectly
1508	  connected. This corrupts targeted TLBI and IC broadcasts exchanged
1509	  between the A53 and A72 core clusters.
1510
1511	  Work around this by redirecting targeted TLBI operations to
1512	  broadcast-all variants (VMALLE1IS) in the high-level TLB flush
1513	  functions, upgrading IC IVAU to IC IALLUIS for both kernel and
1514	  user-space, and disabling KVM since correct TLB maintenance
1515	  cannot be guaranteed for guests.
1516
1517	  The user-space IC IVAU is upgraded by trapping it to the kernel
1518	  (SCTLR_EL1.UCI cleared). This also traps the user DC CVAU, DC CVAC,
1519	  DC CVAP, DC CVADP and DC CIVAC instructions, making user cache
1520	  maintenance slower on the affected SoCs.
1521
1522	  If unsure, say Y.
1523
1524config SOCIONEXT_SYNQUACER_PREITS
1525	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1526	default y
1527	help
1528	  Socionext Synquacer SoCs implement a separate h/w block to generate
1529	  MSI doorbell writes with non-zero values for the device ID.
1530
1531	  If unsure, say Y.
1532
1533endmenu # "ARM errata workarounds via the alternatives framework"
1534
1535choice
1536	prompt "Page size"
1537	default ARM64_4K_PAGES
1538	help
1539	  Page size (translation granule) configuration.
1540
1541config ARM64_4K_PAGES
1542	bool "4KB"
1543	select HAVE_PAGE_SIZE_4KB
1544	help
1545	  This feature enables 4KB pages support.
1546
1547config ARM64_16K_PAGES
1548	bool "16KB"
1549	select HAVE_PAGE_SIZE_16KB
1550	help
1551	  The system will use 16KB pages support. AArch32 emulation
1552	  requires applications compiled with 16K (or a multiple of 16K)
1553	  aligned segments.
1554
1555config ARM64_64K_PAGES
1556	bool "64KB"
1557	select HAVE_PAGE_SIZE_64KB
1558	help
1559	  This feature enables 64KB pages support (4KB by default)
1560	  allowing only two levels of page tables and faster TLB
1561	  look-up. AArch32 emulation requires applications compiled
1562	  with 64K aligned segments.
1563
1564endchoice
1565
1566choice
1567	prompt "Virtual address space size"
1568	default ARM64_VA_BITS_52
1569	help
1570	  Allows choosing one of multiple possible virtual address
1571	  space sizes. The level of translation table is determined by
1572	  a combination of page size and virtual address space size.
1573
1574config ARM64_VA_BITS_36
1575	bool "36-bit" if EXPERT
1576	depends on PAGE_SIZE_16KB
1577
1578config ARM64_VA_BITS_39
1579	bool "39-bit"
1580	depends on PAGE_SIZE_4KB
1581
1582config ARM64_VA_BITS_42
1583	bool "42-bit"
1584	depends on PAGE_SIZE_64KB
1585
1586config ARM64_VA_BITS_47
1587	bool "47-bit"
1588	depends on PAGE_SIZE_16KB
1589
1590config ARM64_VA_BITS_48
1591	bool "48-bit"
1592
1593config ARM64_VA_BITS_52
1594	bool "52-bit"
1595	help
1596	  Enable 52-bit virtual addressing for userspace when explicitly
1597	  requested via a hint to mmap(). The kernel will also use 52-bit
1598	  virtual addresses for its own mappings (provided HW support for
1599	  this feature is available, otherwise it reverts to 48-bit).
1600
1601	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1602	  ARMv8.3 Pointer Authentication will result in the PAC being
1603	  reduced from 7 bits to 3 bits, which may have a significant
1604	  impact on its susceptibility to brute-force attacks.
1605
1606	  If unsure, select 48-bit virtual addressing instead.
1607
1608endchoice
1609
1610config ARM64_FORCE_52BIT
1611	bool "Force 52-bit virtual addresses for userspace"
1612	depends on ARM64_VA_BITS_52 && EXPERT
1613	help
1614	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1615	  to maintain compatibility with older software by providing 48-bit VAs
1616	  unless a hint is supplied to mmap.
1617
1618	  This configuration option disables the 48-bit compatibility logic, and
1619	  forces all userspace addresses to be 52-bit on HW that supports it. One
1620	  should only enable this configuration option for stress testing userspace
1621	  memory management code. If unsure say N here.
1622
1623config ARM64_VA_BITS
1624	int
1625	default 36 if ARM64_VA_BITS_36
1626	default 39 if ARM64_VA_BITS_39
1627	default 42 if ARM64_VA_BITS_42
1628	default 47 if ARM64_VA_BITS_47
1629	default 48 if ARM64_VA_BITS_48
1630	default 52 if ARM64_VA_BITS_52
1631
1632choice
1633	prompt "Physical address space size"
1634	default ARM64_PA_BITS_48
1635	help
1636	  Choose the maximum physical address range that the kernel will
1637	  support.
1638
1639config ARM64_PA_BITS_48
1640	bool "48-bit"
1641	depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1642
1643config ARM64_PA_BITS_52
1644	bool "52-bit"
1645	depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1646	help
1647	  Enable support for a 52-bit physical address space, introduced as
1648	  part of the ARMv8.2-LPA extension.
1649
1650	  With this enabled, the kernel will also continue to work on CPUs that
1651	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1652	  minor performance overhead).
1653
1654endchoice
1655
1656config ARM64_PA_BITS
1657	int
1658	default 48 if ARM64_PA_BITS_48
1659	default 52 if ARM64_PA_BITS_52
1660
1661config ARM64_LPA2
1662	def_bool y
1663	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1664
1665config NR_CPUS
1666	int "Maximum number of CPUs (2-4096)"
1667	range 2 4096
1668	default "512"
1669
1670config HOTPLUG_CPU
1671	bool "Support for hot-pluggable CPUs"
1672	select GENERIC_IRQ_MIGRATION
1673	help
1674	  Say Y here to experiment with turning CPUs off and on.  CPUs
1675	  can be controlled through /sys/devices/system/cpu.
1676
1677# Common NUMA Features
1678config NUMA
1679	bool "NUMA Memory Allocation and Scheduler Support"
1680	select GENERIC_ARCH_NUMA
1681	select OF_NUMA
1682	select HAVE_SETUP_PER_CPU_AREA
1683	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1684	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1685	select USE_PERCPU_NUMA_NODE_ID
1686	help
1687	  Enable NUMA (Non-Uniform Memory Access) support.
1688
1689	  The kernel will try to allocate memory used by a CPU on the
1690	  local memory of the CPU and add some more
1691	  NUMA awareness to the kernel.
1692
1693config NODES_SHIFT
1694	int "Maximum NUMA Nodes (as a power of 2)"
1695	range 1 10
1696	default "4"
1697	depends on NUMA
1698	help
1699	  Specify the maximum number of NUMA Nodes available on the target
1700	  system.  Increases memory reserved to accommodate various tables.
1701
1702source "kernel/Kconfig.hz"
1703
1704config ARCH_SPARSEMEM_ENABLE
1705	def_bool y
1706	select SPARSEMEM_VMEMMAP_ENABLE
1707
1708config HW_PERF_EVENTS
1709	def_bool y
1710	depends on ARM_PMU
1711
1712# Supported by clang >= 7.0 or GCC >= 12.0.0
1713config CC_HAVE_SHADOW_CALL_STACK
1714	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1715
1716config PARAVIRT
1717	bool "Enable paravirtualization code"
1718	select HAVE_PV_STEAL_CLOCK_GEN
1719	help
1720	  This changes the kernel so it can modify itself when it is run
1721	  under a hypervisor, potentially improving performance significantly
1722	  over full virtualization.
1723
1724config PARAVIRT_TIME_ACCOUNTING
1725	bool "Paravirtual steal time accounting"
1726	select PARAVIRT
1727	help
1728	  Select this option to enable fine granularity task steal time
1729	  accounting. Time spent executing other tasks in parallel with
1730	  the current vCPU is discounted from the vCPU power. To account for
1731	  that, there can be a small performance impact.
1732
1733	  If in doubt, say N here.
1734
1735config ARCH_SUPPORTS_KEXEC
1736	def_bool PM_SLEEP_SMP
1737
1738config ARCH_SUPPORTS_KEXEC_FILE
1739	def_bool y
1740
1741config ARCH_SELECTS_KEXEC_FILE
1742	def_bool y
1743	depends on KEXEC_FILE
1744	select HAVE_IMA_KEXEC if IMA
1745
1746config ARCH_SUPPORTS_KEXEC_SIG
1747	def_bool y
1748
1749config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1750	def_bool y
1751
1752config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1753	def_bool y
1754
1755config ARCH_SUPPORTS_KEXEC_HANDOVER
1756	def_bool y
1757
1758config ARCH_SUPPORTS_CRASH_DUMP
1759	def_bool y
1760
1761config ARCH_DEFAULT_CRASH_DUMP
1762	def_bool y
1763
1764config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1765	def_bool CRASH_RESERVE
1766
1767config TRANS_TABLE
1768	def_bool y
1769	depends on HIBERNATION || KEXEC_CORE
1770
1771config XEN_DOM0
1772	def_bool y
1773	depends on XEN
1774
1775config XEN
1776	bool "Xen guest support on ARM64"
1777	depends on ARM64 && OF
1778	select SWIOTLB_XEN
1779	select PARAVIRT
1780	help
1781	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1782
1783# include/linux/mmzone.h requires the following to be true:
1784#
1785#   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1786#
1787# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1788#
1789#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1790# ----+-------------------+--------------+----------------------+-------------------------+
1791# 4K  |       27          |      12      |       15             |         10              |
1792# 16K |       27          |      14      |       13             |         11              |
1793# 64K |       29          |      16      |       13             |         13              |
1794config ARCH_FORCE_MAX_ORDER
1795	int
1796	default "13" if ARM64_64K_PAGES
1797	default "11" if ARM64_16K_PAGES
1798	default "10"
1799	help
1800	  The kernel page allocator limits the size of maximal physically
1801	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1802	  defines the maximal power of two of number of pages that can be
1803	  allocated as a single contiguous block. This option allows
1804	  overriding the default setting when ability to allocate very
1805	  large blocks of physically contiguous memory is required.
1806
1807	  The maximal size of allocation cannot exceed the size of the
1808	  section, so the value of MAX_PAGE_ORDER should satisfy
1809
1810	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1811
1812	  Don't change if unsure.
1813
1814config UNMAP_KERNEL_AT_EL0
1815	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1816	default y
1817	help
1818	  Speculation attacks against some high-performance processors can
1819	  be used to bypass MMU permission checks and leak kernel data to
1820	  userspace. This can be defended against by unmapping the kernel
1821	  when running in userspace, mapping it back in on exception entry
1822	  via a trampoline page in the vector table.
1823
1824	  If unsure, say Y.
1825
1826config MITIGATE_SPECTRE_BRANCH_HISTORY
1827	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1828	default y
1829	help
1830	  Speculation attacks against some high-performance processors can
1831	  make use of branch history to influence future speculation.
1832	  When taking an exception from user-space, a sequence of branches
1833	  or a firmware call overwrites the branch history.
1834
1835config ARM64_SW_TTBR0_PAN
1836	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1837	depends on !KCSAN
1838	help
1839	  Enabling this option prevents the kernel from accessing
1840	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1841	  zeroed area and reserved ASID. The user access routines
1842	  restore the valid TTBR0_EL1 temporarily.
1843
1844config ARM64_TAGGED_ADDR_ABI
1845	bool "Enable the tagged user addresses syscall ABI"
1846	default y
1847	help
1848	  When this option is enabled, user applications can opt in to a
1849	  relaxed ABI via prctl() allowing tagged addresses to be passed
1850	  to system calls as pointer arguments. For details, see
1851	  Documentation/arch/arm64/tagged-address-abi.rst.
1852
1853menuconfig COMPAT
1854	bool "Kernel support for 32-bit EL0"
1855	depends on ARM64_4K_PAGES || EXPERT
1856	select HAVE_UID16
1857	select OLD_SIGSUSPEND3
1858	select COMPAT_OLD_SIGACTION
1859	help
1860	  This option enables support for a 32-bit EL0 running under a 64-bit
1861	  kernel at EL1. AArch32-specific components such as system calls,
1862	  the user helper functions, VFP support and the ptrace interface are
1863	  handled appropriately by the kernel.
1864
1865	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1866	  that you will only be able to execute AArch32 binaries that were compiled
1867	  with page size aligned segments.
1868
1869	  If you want to execute 32-bit userspace applications, say Y.
1870
1871if COMPAT
1872
1873config KUSER_HELPERS
1874	bool "Enable kuser helpers page for 32-bit applications"
1875	default y
1876	help
1877	  Warning: disabling this option may break 32-bit user programs.
1878
1879	  Provide kuser helpers to compat tasks. The kernel provides
1880	  helper code to userspace in read only form at a fixed location
1881	  to allow userspace to be independent of the CPU type fitted to
1882	  the system. This permits binaries to be run on ARMv4 through
1883	  to ARMv8 without modification.
1884
1885	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1886
1887	  However, the fixed address nature of these helpers can be used
1888	  by ROP (return orientated programming) authors when creating
1889	  exploits.
1890
1891	  If all of the binaries and libraries which run on your platform
1892	  are built specifically for your platform, and make no use of
1893	  these helpers, then you can turn this option off to hinder
1894	  such exploits. However, in that case, if a binary or library
1895	  relying on those helpers is run, it will not function correctly.
1896
1897	  Say N here only if you are absolutely certain that you do not
1898	  need these helpers; otherwise, the safe option is to say Y.
1899
1900config COMPAT_VDSO
1901	bool "Enable vDSO for 32-bit applications"
1902	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1903	default y
1904	help
1905	  Place in the process address space of 32-bit applications an
1906	  ELF shared object providing fast implementations of gettimeofday
1907	  and clock_gettime.
1908
1909	  You must have a 32-bit build of glibc 2.22 or later for programs
1910	  to seamlessly take advantage of this.
1911
1912config THUMB2_COMPAT_VDSO
1913	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1914	depends on COMPAT_VDSO
1915	default y
1916	help
1917	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1918	  otherwise with '-marm'.
1919
1920config COMPAT_ALIGNMENT_FIXUPS
1921	bool "Fix up misaligned multi-word loads and stores in user space"
1922
1923menuconfig ARMV8_DEPRECATED
1924	bool "Emulate deprecated/obsolete ARMv8 instructions"
1925	depends on SYSCTL
1926	help
1927	  Legacy software support may require certain instructions
1928	  that have been deprecated or obsoleted in the architecture.
1929
1930	  Enable this config to enable selective emulation of these
1931	  features.
1932
1933	  If unsure, say Y
1934
1935if ARMV8_DEPRECATED
1936
1937config SWP_EMULATION
1938	bool "Emulate SWP/SWPB instructions"
1939	help
1940	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1941	  they are always undefined. Say Y here to enable software
1942	  emulation of these instructions for userspace using LDXR/STXR.
1943	  This feature can be controlled at runtime with the abi.swp
1944	  sysctl which is disabled by default.
1945
1946	  In some older versions of glibc [<=2.8] SWP is used during futex
1947	  trylock() operations with the assumption that the code will not
1948	  be preempted. This invalid assumption may be more likely to fail
1949	  with SWP emulation enabled, leading to deadlock of the user
1950	  application.
1951
1952	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1953	  on an external transaction monitoring block called a global
1954	  monitor to maintain update atomicity. If your system does not
1955	  implement a global monitor, this option can cause programs that
1956	  perform SWP operations to uncached memory to deadlock.
1957
1958	  If unsure, say Y
1959
1960config CP15_BARRIER_EMULATION
1961	bool "Emulate CP15 Barrier instructions"
1962	help
1963	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1964	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1965	  strongly recommended to use the ISB, DSB, and DMB
1966	  instructions instead.
1967
1968	  Say Y here to enable software emulation of these
1969	  instructions for AArch32 userspace code. When this option is
1970	  enabled, CP15 barrier usage is traced which can help
1971	  identify software that needs updating. This feature can be
1972	  controlled at runtime with the abi.cp15_barrier sysctl.
1973
1974	  If unsure, say Y
1975
1976config SETEND_EMULATION
1977	bool "Emulate SETEND instruction"
1978	help
1979	  The SETEND instruction alters the data-endianness of the
1980	  AArch32 EL0, and is deprecated in ARMv8.
1981
1982	  Say Y here to enable software emulation of the instruction
1983	  for AArch32 userspace code. This feature can be controlled
1984	  at runtime with the abi.setend sysctl.
1985
1986	  Note: All the cpus on the system must have mixed endian support at EL0
1987	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1988	  endian - is hotplugged in after this feature has been enabled, there could
1989	  be unexpected results in the applications.
1990
1991	  If unsure, say Y
1992endif # ARMV8_DEPRECATED
1993
1994endif # COMPAT
1995
1996menu "ARMv8.1 architectural features"
1997
1998config ARM64_HW_AFDBM
1999	bool "Support for hardware updates of the Access and Dirty page flags"
2000	default y
2001	help
2002	  The ARMv8.1 architecture extensions introduce support for
2003	  hardware updates of the access and dirty information in page
2004	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
2005	  capable processors, accesses to pages with PTE_AF cleared will
2006	  set this bit instead of raising an access flag fault.
2007	  Similarly, writes to read-only pages with the DBM bit set will
2008	  clear the read-only bit (AP[2]) instead of raising a
2009	  permission fault.
2010
2011	  Kernels built with this configuration option enabled continue
2012	  to work on pre-ARMv8.1 hardware and the performance impact is
2013	  minimal. If unsure, say Y.
2014
2015endmenu # "ARMv8.1 architectural features"
2016
2017menu "ARMv8.2 architectural features"
2018
2019config ARM64_PMEM
2020	bool "Enable support for persistent memory"
2021	select ARCH_HAS_PMEM_API
2022	select ARCH_HAS_UACCESS_FLUSHCACHE
2023	help
2024	  Say Y to enable support for the persistent memory API based on the
2025	  ARMv8.2 DCPoP feature.
2026
2027	  The feature is detected at runtime, and the kernel will use DC CVAC
2028	  operations if DC CVAP is not supported (following the behaviour of
2029	  DC CVAP itself if the system does not define a point of persistence).
2030
2031config ARM64_RAS_EXTN
2032	bool "Enable support for RAS CPU Extensions"
2033	default y
2034	help
2035	  CPUs that support the Reliability, Availability and Serviceability
2036	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
2037	  errors, classify them and report them to software.
2038
2039	  On CPUs with these extensions system software can use additional
2040	  barriers to determine if faults are pending and read the
2041	  classification from a new set of registers.
2042
2043	  Selecting this feature will allow the kernel to use these barriers
2044	  and access the new registers if the system supports the extension.
2045	  Platform RAS features may additionally depend on firmware support.
2046
2047config ARM64_CNP
2048	bool "Enable support for Common Not Private (CNP) translations"
2049	default y
2050	help
2051	  Common Not Private (CNP) allows translation table entries to
2052	  be shared between different PEs in the same inner shareable
2053	  domain, so the hardware can use this fact to optimise the
2054	  caching of such entries in the TLB.
2055
2056	  Selecting this option allows the CNP feature to be detected
2057	  at runtime, and does not affect PEs that do not implement
2058	  this feature.
2059
2060endmenu # "ARMv8.2 architectural features"
2061
2062menu "ARMv8.3 architectural features"
2063
2064config ARM64_PTR_AUTH
2065	bool "Enable support for pointer authentication"
2066	default y
2067	help
2068	  Pointer authentication (part of the ARMv8.3 Extensions) provides
2069	  instructions for signing and authenticating pointers against secret
2070	  keys, which can be used to mitigate Return Oriented Programming (ROP)
2071	  and other attacks.
2072
2073	  This option enables these instructions at EL0 (i.e. for userspace).
2074	  Choosing this option will cause the kernel to initialise secret keys
2075	  for each process at exec() time, with these keys being
2076	  context-switched along with the process.
2077
2078	  The feature is detected at runtime. If the feature is not present in
2079	  hardware it will not be advertised to userspace/KVM guest nor will it
2080	  be enabled.
2081
2082	  If the feature is present on the boot CPU but not on a late CPU, then
2083	  the late CPU will be parked. Also, if the boot CPU does not have
2084	  address auth and the late CPU has then the late CPU will still boot
2085	  but with the feature disabled. On such a system, this option should
2086	  not be selected.
2087
2088config ARM64_PTR_AUTH_KERNEL
2089	bool "Use pointer authentication for kernel"
2090	default y
2091	depends on ARM64_PTR_AUTH
2092	# Modern compilers insert a .note.gnu.property section note for PAC
2093	# which is only understood by binutils starting with version 2.33.1.
2094	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
2095	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
2096	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2097	help
2098	  If the compiler supports the -mbranch-protection or
2099	  -msign-return-address flag (e.g. GCC 7 or later), then this option
2100	  will cause the kernel itself to be compiled with return address
2101	  protection. In this case, and if the target hardware is known to
2102	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
2103	  disabled with minimal loss of protection.
2104
2105	  This feature works with FUNCTION_GRAPH_TRACER option only if
2106	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
2107
2108config CC_HAS_BRANCH_PROT_PAC_RET
2109	# GCC 9 or later, clang 8 or later
2110	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
2111
2112config AS_HAS_CFI_NEGATE_RA_STATE
2113	# binutils 2.34+
2114	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
2115
2116endmenu # "ARMv8.3 architectural features"
2117
2118menu "ARMv8.4 architectural features"
2119
2120config ARM64_AMU_EXTN
2121	bool "Enable support for the Activity Monitors Unit CPU extension"
2122	default y
2123	help
2124	  The activity monitors extension is an optional extension introduced
2125	  by the ARMv8.4 CPU architecture. This enables support for version 1
2126	  of the activity monitors architecture, AMUv1.
2127
2128	  To enable the use of this extension on CPUs that implement it, say Y.
2129
2130	  Note that for architectural reasons, firmware _must_ implement AMU
2131	  support when running on CPUs that present the activity monitors
2132	  extension. The required support is present in:
2133	    * Version 1.5 and later of the ARM Trusted Firmware
2134
2135	  For kernels that have this configuration enabled but boot with broken
2136	  firmware, you may need to say N here until the firmware is fixed.
2137	  Otherwise you may experience firmware panics or lockups when
2138	  accessing the counter registers. Even if you are not observing these
2139	  symptoms, the values returned by the register reads might not
2140	  correctly reflect reality. Most commonly, the value read will be 0,
2141	  indicating that the counter is not enabled.
2142
2143config ARM64_TLB_RANGE
2144	bool "Enable support for tlbi range feature"
2145	default y
2146	help
2147	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2148	  range of input addresses.
2149
2150config ARM64_MPAM
2151	bool "Enable support for MPAM"
2152	select ARM64_MPAM_DRIVER
2153	select ARCH_HAS_CPU_RESCTRL
2154	help
2155	  Memory System Resource Partitioning and Monitoring (MPAM) is an
2156	  optional extension to the Arm architecture that allows each
2157	  transaction issued to the memory system to be labelled with a
2158	  Partition identifier (PARTID) and Performance Monitoring Group
2159	  identifier (PMG).
2160
2161	  Memory system components, such as the caches, can be configured with
2162	  policies to control how much of various physical resources (such as
2163	  memory bandwidth or cache memory) the transactions labelled with each
2164	  PARTID can consume.  Depending on the capabilities of the hardware,
2165	  the PARTID and PMG can also be used as filtering criteria to measure
2166	  the memory system resource consumption of different parts of a
2167	  workload.
2168
2169	  Use of this extension requires CPU support, support in the
2170	  Memory System Components (MSC), and a description from firmware
2171	  of where the MSCs are in the address space.
2172
2173	  MPAM is exposed to user-space via the resctrl pseudo filesystem.
2174
2175	  This option enables the extra context switch code.
2176
2177endmenu # "ARMv8.4 architectural features"
2178
2179menu "ARMv8.5 architectural features"
2180
2181config AS_HAS_ARMV8_5
2182	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2183
2184config ARM64_BTI
2185	bool "Branch Target Identification support"
2186	default y
2187	help
2188	  Branch Target Identification (part of the ARMv8.5 Extensions)
2189	  provides a mechanism to limit the set of locations to which computed
2190	  branch instructions such as BR or BLR can jump.
2191
2192	  To make use of BTI on CPUs that support it, say Y.
2193
2194	  BTI is intended to provide complementary protection to other control
2195	  flow integrity protection mechanisms, such as the Pointer
2196	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2197	  For this reason, it does not make sense to enable this option without
2198	  also enabling support for pointer authentication.  Thus, when
2199	  enabling this option you should also select ARM64_PTR_AUTH=y.
2200
2201	  Userspace binaries must also be specifically compiled to make use of
2202	  this mechanism.  If you say N here or the hardware does not support
2203	  BTI, such binaries can still run, but you get no additional
2204	  enforcement of branch destinations.
2205
2206config ARM64_BTI_KERNEL
2207	bool "Use Branch Target Identification for kernel"
2208	default y
2209	depends on ARM64_BTI
2210	depends on ARM64_PTR_AUTH_KERNEL
2211	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2212	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2213	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2214	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2215	depends on !CC_IS_GCC
2216	# https://github.com/llvm/llvm-project/issues/215547
2217	depends on !CC_IS_CLANG || CLANG_VERSION < 210000
2218	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2219	help
2220	  Build the kernel with Branch Target Identification annotations
2221	  and enable enforcement of this for kernel code. When this option
2222	  is enabled and the system supports BTI all kernel code including
2223	  modular code must have BTI enabled.
2224
2225config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2226	# GCC 9 or later, clang 8 or later
2227	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2228
2229config ARM64_E0PD
2230	bool "Enable support for E0PD"
2231	default y
2232	help
2233	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2234	  that EL0 accesses made via TTBR1 always fault in constant time,
2235	  providing similar benefits to KASLR as those provided by KPTI, but
2236	  with lower overhead and without disrupting legitimate access to
2237	  kernel memory such as SPE.
2238
2239	  This option enables E0PD for TTBR1 where available.
2240
2241config ARM64_AS_HAS_MTE
2242	# Initial support for MTE went in binutils 2.32.0, checked with
2243	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2244	# as a late addition to the final architecture spec (LDGM/STGM)
2245	# is only supported in the newer 2.32.x and 2.33 binutils
2246	# versions, hence the extra "stgm" instruction check below.
2247	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2248
2249config ARM64_MTE
2250	bool "Memory Tagging Extension support"
2251	default y
2252	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2253	depends on AS_HAS_ARMV8_5
2254	# Required for tag checking in the uaccess routines
2255	select ARCH_HAS_SUBPAGE_FAULTS
2256	select ARCH_USES_HIGH_VMA_FLAGS
2257	select ARCH_USES_PG_ARCH_2
2258	select ARCH_USES_PG_ARCH_3
2259	help
2260	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2261	  architectural support for run-time, always-on detection of
2262	  various classes of memory error to aid with software debugging
2263	  to eliminate vulnerabilities arising from memory-unsafe
2264	  languages.
2265
2266	  This option enables the support for the Memory Tagging
2267	  Extension at EL0 (i.e. for userspace).
2268
2269	  Selecting this option allows the feature to be detected at
2270	  runtime. Any secondary CPU not implementing this feature will
2271	  not be allowed a late bring-up.
2272
2273	  Userspace binaries that want to use this feature must
2274	  explicitly opt in. The mechanism for the userspace is
2275	  described in:
2276
2277	  Documentation/arch/arm64/memory-tagging-extension.rst.
2278
2279endmenu # "ARMv8.5 architectural features"
2280
2281menu "ARMv8.7 architectural features"
2282
2283config ARM64_EPAN
2284	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2285	default y
2286	help
2287	  Enhanced Privileged Access Never (EPAN) allows Privileged
2288	  Access Never to be used with Execute-only mappings.
2289
2290	  The feature is detected at runtime, and will remain disabled
2291	  if the cpu does not implement the feature.
2292endmenu # "ARMv8.7 architectural features"
2293
2294config AS_HAS_MOPS
2295	def_bool $(as-instr,.arch_extension mops)
2296
2297menu "ARMv8.9 architectural features"
2298
2299config ARM64_POE
2300	prompt "Permission Overlay Extension"
2301	def_bool y
2302	select ARCH_USES_HIGH_VMA_FLAGS
2303	select ARCH_HAS_PKEYS
2304	help
2305	  The Permission Overlay Extension is used to implement Memory
2306	  Protection Keys. Memory Protection Keys provides a mechanism for
2307	  enforcing page-based protections, but without requiring modification
2308	  of the page tables when an application changes protection domains.
2309
2310	  For details, see Documentation/core-api/protection-keys.rst
2311
2312	  If unsure, say y.
2313
2314config ARCH_PKEY_BITS
2315	int
2316	default 3
2317
2318config ARM64_HAFT
2319	bool "Support for Hardware managed Access Flag for Table Descriptors"
2320	depends on ARM64_HW_AFDBM
2321	default y
2322	help
2323	  The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access
2324	  Flag for Table descriptors. When enabled an architectural executed
2325	  memory access will update the Access Flag in each Table descriptor
2326	  which is accessed during the translation table walk and for which
2327	  the Access Flag is 0. The Access Flag of the Table descriptor use
2328	  the same bit of PTE_AF.
2329
2330	  The feature will only be enabled if all the CPUs in the system
2331	  support this feature. If unsure, say Y.
2332
2333endmenu # "ARMv8.9 architectural features"
2334
2335menu "ARMv9.4 architectural features"
2336
2337config ARM64_GCS
2338	bool "Enable support for Guarded Control Stack (GCS)"
2339	default y
2340	select ARCH_HAS_USER_SHADOW_STACK
2341	select ARCH_USES_HIGH_VMA_FLAGS
2342	help
2343	  Guarded Control Stack (GCS) provides support for a separate
2344	  stack with restricted access which contains only return
2345	  addresses.  This can be used to harden against some attacks
2346	  by comparing return address used by the program with what is
2347	  stored in the GCS, and may also be used to efficiently obtain
2348	  the call stack for applications such as profiling.
2349
2350	  The feature is detected at runtime, and will remain disabled
2351	  if the system does not implement the feature.
2352
2353endmenu # "ARMv9.4 architectural features"
2354
2355config AS_HAS_LSUI
2356	def_bool $(as-instr,.arch_extension lsui)
2357	help
2358	  Supported by LLVM 20+ and binutils 2.45+.
2359
2360menu "ARMv9.6 architectural features"
2361
2362config ARM64_LSUI
2363	bool "Support Unprivileged Load Store Instructions (LSUI)"
2364	default y
2365	depends on AS_HAS_LSUI
2366	help
2367	  The Unprivileged Load Store Instructions (LSUI) provides
2368	  variants load/store instructions that access user-space memory
2369	  from the kernel without clearing PSTATE.PAN bit.
2370
2371	  This feature is supported by LLVM 20+ and binutils 2.45+.
2372
2373endmenu # "ARMv9.6 architectural feature"
2374
2375config ARM64_SVE
2376	bool "ARM Scalable Vector Extension support"
2377	default y
2378	help
2379	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2380	  execution state which complements and extends the SIMD functionality
2381	  of the base architecture to support much larger vectors and to enable
2382	  additional vectorisation opportunities.
2383
2384	  To enable use of this extension on CPUs that implement it, say Y.
2385
2386	  On CPUs that support the SVE2 extensions, this option will enable
2387	  those too.
2388
2389	  Note that for architectural reasons, firmware _must_ implement SVE
2390	  support when running on SVE capable hardware.  The required support
2391	  is present in:
2392
2393	    * version 1.5 and later of the ARM Trusted Firmware
2394	    * the AArch64 boot wrapper since commit 5e1261e08abf
2395	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2396
2397	  For other firmware implementations, consult the firmware documentation
2398	  or vendor.
2399
2400	  If you need the kernel to boot on SVE-capable hardware with broken
2401	  firmware, you may need to say N here until you get your firmware
2402	  fixed.  Otherwise, you may experience firmware panics or lockups when
2403	  booting the kernel.  If unsure and you are not observing these
2404	  symptoms, you should assume that it is safe to say Y.
2405
2406config AS_HAS_SME
2407	# Supported by LLVM 13+ and binutils 2.38+
2408	def_bool $(as-instr,.arch_extension sme)
2409
2410config ARM64_SME
2411	bool "ARM Scalable Matrix Extension support"
2412	default y
2413	depends on ARM64_SVE
2414	depends on AS_HAS_SME
2415	help
2416	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2417	  execution state which utilises a substantial subset of the SVE
2418	  instruction set, together with the addition of new architectural
2419	  register state capable of holding two dimensional matrix tiles to
2420	  enable various matrix operations.
2421
2422config ARM64_PSEUDO_NMI
2423	bool "Support for NMI-like interrupts"
2424	select ARM_GIC_V3
2425	help
2426	  Adds support for mimicking Non-Maskable Interrupts through the use of
2427	  GIC interrupt priority. This support requires version 3 or later of
2428	  ARM GIC.
2429
2430	  This high priority configuration for interrupts needs to be
2431	  explicitly enabled by setting the kernel parameter
2432	  "irqchip.gicv3_pseudo_nmi" to 1.
2433
2434	  If unsure, say N
2435
2436if ARM64_PSEUDO_NMI
2437config ARM64_DEBUG_PRIORITY_MASKING
2438	bool "Debug interrupt priority masking"
2439	help
2440	  This adds runtime checks to functions enabling/disabling
2441	  interrupts when using priority masking. The additional checks verify
2442	  the validity of ICC_PMR_EL1 when calling concerned functions.
2443
2444	  If unsure, say N
2445endif # ARM64_PSEUDO_NMI
2446
2447config RELOCATABLE
2448	bool "Build a relocatable kernel image" if EXPERT
2449	select ARCH_HAS_RELR
2450	default y
2451	help
2452	  This builds the kernel as a Position Independent Executable (PIE),
2453	  which retains all relocation metadata required to relocate the
2454	  kernel binary at runtime to a different virtual address than the
2455	  address it was linked at.
2456	  Since AArch64 uses the RELA relocation format, this requires a
2457	  relocation pass at runtime even if the kernel is loaded at the
2458	  same address it was linked at.
2459
2460config RANDOMIZE_BASE
2461	bool "Randomize the address of the kernel image"
2462	select RELOCATABLE
2463	help
2464	  Randomizes the virtual address at which the kernel image is
2465	  loaded, as a security feature that deters exploit attempts
2466	  relying on knowledge of the location of kernel internals.
2467
2468	  It is the bootloader's job to provide entropy, by passing a
2469	  random u64 value in /chosen/kaslr-seed at kernel entry.
2470
2471	  When booting via the UEFI stub, it will invoke the firmware's
2472	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2473	  to the kernel proper. In addition, it will randomise the physical
2474	  location of the kernel Image as well.
2475
2476	  If unsure, say N.
2477
2478config RANDOMIZE_MODULE_REGION_FULL
2479	bool "Randomize the module region over a 2 GB range"
2480	depends on RANDOMIZE_BASE
2481	default y
2482	help
2483	  Randomizes the location of the module region inside a 2 GB window
2484	  covering the core kernel. This way, it is less likely for modules
2485	  to leak information about the location of core kernel data structures
2486	  but it does imply that function calls between modules and the core
2487	  kernel will need to be resolved via veneers in the module PLT.
2488
2489	  When this option is not set, the module region will be randomized over
2490	  a limited range that contains the [_stext, _etext] interval of the
2491	  core kernel, so branch relocations are almost always in range unless
2492	  the region is exhausted. In this particular case of region
2493	  exhaustion, modules might be able to fall back to a larger 2GB area.
2494
2495config CC_HAVE_STACKPROTECTOR_SYSREG
2496	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2497
2498config STACKPROTECTOR_PER_TASK
2499	def_bool y
2500	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2501
2502config UNWIND_PATCH_PAC_INTO_SCS
2503	bool "Enable shadow call stack dynamically using code patching"
2504	depends on CC_IS_CLANG
2505	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2506	depends on SHADOW_CALL_STACK
2507	select UNWIND_TABLES
2508	select DYNAMIC_SCS
2509
2510config ARM64_CONTPTE
2511	bool "Contiguous PTE mappings for user memory" if EXPERT
2512	depends on TRANSPARENT_HUGEPAGE
2513	default y
2514	help
2515	  When enabled, user mappings are configured using the PTE contiguous
2516	  bit, for any mappings that meet the size and alignment requirements.
2517	  This reduces TLB pressure and improves performance.
2518
2519endmenu # "Kernel Features"
2520
2521menu "Boot options"
2522
2523config ARM64_ACPI_PARKING_PROTOCOL
2524	bool "Enable support for the ARM64 ACPI parking protocol"
2525	depends on ACPI
2526	help
2527	  Enable support for the ARM64 ACPI parking protocol. If disabled
2528	  the kernel will not allow booting through the ARM64 ACPI parking
2529	  protocol even if the corresponding data is present in the ACPI
2530	  MADT table.
2531
2532config CMDLINE
2533	string "Default kernel command string"
2534	default ""
2535	help
2536	  Provide a set of default command-line options at build time by
2537	  entering them here. As a minimum, you should specify the
2538	  root device (e.g. root=/dev/nfs).
2539
2540choice
2541	prompt "Kernel command line type"
2542	depends on CMDLINE != ""
2543	default CMDLINE_FROM_BOOTLOADER
2544	help
2545	  Choose how the kernel will handle the provided default kernel
2546	  command line string.
2547
2548config CMDLINE_FROM_BOOTLOADER
2549	bool "Use bootloader kernel arguments if available"
2550	help
2551	  Uses the command-line options passed by the boot loader. If
2552	  the boot loader doesn't provide any, the default kernel command
2553	  string provided in CMDLINE will be used.
2554
2555config CMDLINE_FORCE
2556	bool "Always use the default kernel command string"
2557	help
2558	  Always use the default kernel command string, even if the boot
2559	  loader passes other arguments to the kernel.
2560	  This is useful if you cannot or don't want to change the
2561	  command-line options your boot loader passes to the kernel.
2562
2563endchoice
2564
2565config EFI_STUB
2566	bool
2567
2568config EFI
2569	bool "UEFI runtime support"
2570	depends on OF
2571	depends on KERNEL_MODE_NEON
2572	select ARCH_SUPPORTS_ACPI
2573	select LIBFDT
2574	select UCS2_STRING
2575	select EFI_PARAMS_FROM_FDT
2576	select EFI_RUNTIME_WRAPPERS
2577	select EFI_STUB
2578	select EFI_GENERIC_STUB
2579	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2580	default y
2581	help
2582	  This option provides support for runtime services provided
2583	  by UEFI firmware (such as non-volatile variables, realtime
2584	  clock, and platform reset). A UEFI stub is also provided to
2585	  allow the kernel to be booted as an EFI application. This
2586	  is only useful on systems that have UEFI firmware.
2587
2588config COMPRESSED_INSTALL
2589	bool "Install compressed image by default"
2590	help
2591	  This makes the regular "make install" install the compressed
2592	  image we built, not the legacy uncompressed one.
2593
2594	  You can check that a compressed image works for you by doing
2595	  "make zinstall" first, and verifying that everything is fine
2596	  in your environment before making "make install" do this for
2597	  you.
2598
2599config DMI
2600	bool "Enable support for SMBIOS (DMI) tables"
2601	depends on EFI
2602	default y
2603	help
2604	  This enables SMBIOS/DMI feature for systems.
2605
2606	  This option is only useful on systems that have UEFI firmware.
2607	  However, even with this option, the resultant kernel should
2608	  continue to boot on existing non-UEFI platforms.
2609
2610endmenu # "Boot options"
2611
2612menu "Power management options"
2613
2614source "kernel/power/Kconfig"
2615
2616config ARCH_HIBERNATION_POSSIBLE
2617	def_bool y
2618	depends on CPU_PM
2619
2620config ARCH_HIBERNATION_HEADER
2621	def_bool y
2622	depends on HIBERNATION
2623
2624config ARCH_SUSPEND_POSSIBLE
2625	def_bool y
2626
2627endmenu # "Power management options"
2628
2629menu "CPU Power Management"
2630
2631source "drivers/cpuidle/Kconfig"
2632
2633source "drivers/cpufreq/Kconfig"
2634
2635endmenu # "CPU Power Management"
2636
2637source "drivers/acpi/Kconfig"
2638
2639source "arch/arm64/kvm/Kconfig"
2640
2641source "kernel/livepatch/Kconfig"
2642