xref: /linux/arch/arm64/Kconfig (revision 80476f22b8b7e193b26f285a7c9f9e4b63abca16)
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_ENABLE_THP_MIGRATION 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 if CPU_LITTLE_ENDIAN
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_SUPPORTS_NUMA_BALANCING
82	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
83	select ARCH_SUPPORTS_PER_VMA_LOCK
84	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
85	select ARCH_SUPPORTS_RT
86	select ARCH_SUPPORTS_SCHED_SMT
87	select ARCH_SUPPORTS_SCHED_CLUSTER
88	select ARCH_SUPPORTS_SCHED_MC
89	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
90	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
91	select ARCH_WANT_DEFAULT_BPF_JIT
92	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
93	select ARCH_WANT_FRAME_POINTERS
94	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
95	select ARCH_WANT_LD_ORPHAN_WARN
96	select ARCH_WANTS_EXECMEM_LATE
97	select ARCH_WANTS_NO_INSTR
98	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
99	select ARCH_HAS_UBSAN
100	select ARM_AMBA
101	select ARM_ARCH_TIMER
102	select ARM_GIC
103	select AUDIT_ARCH_COMPAT_GENERIC
104	select ARM_GIC_V2M if PCI
105	select ARM_GIC_V3
106	select ARM_GIC_V3_ITS if PCI
107	select ARM_GIC_V5
108	select ARM_PSCI_FW
109	select BUILDTIME_TABLE_SORT
110	select CLONE_BACKWARDS
111	select COMMON_CLK
112	select CPU_PM if (SUSPEND || CPU_IDLE)
113	select CPUMASK_OFFSTACK if NR_CPUS > 256
114	select DCACHE_WORD_ACCESS
115	select HAVE_EXTRA_IPI_TRACEPOINTS
116	select DYNAMIC_FTRACE if FUNCTION_TRACER
117	select DMA_BOUNCE_UNALIGNED_KMALLOC
118	select DMA_DIRECT_REMAP
119	select EDAC_SUPPORT
120	select FRAME_POINTER
121	select FUNCTION_ALIGNMENT_4B
122	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
123	select GENERIC_ALLOCATOR
124	select GENERIC_ARCH_TOPOLOGY
125	select GENERIC_CLOCKEVENTS_BROADCAST
126	select GENERIC_CPU_AUTOPROBE
127	select GENERIC_CPU_CACHE_MAINTENANCE
128	select GENERIC_CPU_DEVICES
129	select GENERIC_CPU_VULNERABILITIES
130	select GENERIC_EARLY_IOREMAP
131	select GENERIC_IDLE_POLL_SETUP
132	select GENERIC_IOREMAP
133	select GENERIC_IRQ_ENTRY
134	select GENERIC_IRQ_IPI
135	select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
136	select GENERIC_IRQ_PROBE
137	select GENERIC_IRQ_SHOW
138	select GENERIC_IRQ_SHOW_LEVEL
139	select GENERIC_LIB_DEVMEM_IS_ALLOWED
140	select GENERIC_PCI_IOMAP
141	select GENERIC_SCHED_CLOCK
142	select GENERIC_SMP_IDLE_THREAD
143	select GENERIC_GETTIMEOFDAY
144	select HARDIRQS_SW_RESEND
145	select HAS_IOPORT
146	select HAVE_MOVE_PMD
147	select HAVE_MOVE_PUD
148	select HAVE_PCI
149	select HAVE_ACPI_APEI if (ACPI && EFI)
150	select HAVE_ALIGNED_STRUCT_PAGE
151	select HAVE_ARCH_AUDITSYSCALL
152	select HAVE_ARCH_BITREVERSE
153	select HAVE_ARCH_COMPILER_H
154	select HAVE_ARCH_HUGE_VMALLOC
155	select HAVE_ARCH_HUGE_VMAP
156	select HAVE_ARCH_JUMP_LABEL
157	select HAVE_ARCH_JUMP_LABEL_RELATIVE
158	select HAVE_ARCH_KASAN
159	select HAVE_ARCH_KASAN_VMALLOC
160	select HAVE_ARCH_KASAN_SW_TAGS
161	select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
162	# Some instrumentation may be unsound, hence EXPERT
163	select HAVE_ARCH_KCSAN if EXPERT
164	select HAVE_ARCH_KFENCE
165	select HAVE_ARCH_KGDB
166	select HAVE_ARCH_KSTACK_ERASE
167	select HAVE_ARCH_MMAP_RND_BITS
168	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
169	select HAVE_ARCH_PREL32_RELOCATIONS
170	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
171	select HAVE_ARCH_SECCOMP_FILTER
172	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
173	select HAVE_ARCH_TRACEHOOK
174	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
175	select HAVE_ARCH_VMAP_STACK
176	select HAVE_ARM_SMCCC
177	select HAVE_ASM_MODVERSIONS
178	select HAVE_EBPF_JIT
179	select HAVE_C_RECORDMCOUNT
180	select HAVE_CMPXCHG_DOUBLE
181	select HAVE_CMPXCHG_LOCAL
182	select HAVE_CONTEXT_TRACKING_USER
183	select HAVE_DEBUG_KMEMLEAK
184	select HAVE_DMA_CONTIGUOUS
185	select HAVE_DYNAMIC_FTRACE
186	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
187		if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
188		    CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
189	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
190		if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
191	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
192		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \
193		    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
194	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
195		if DYNAMIC_FTRACE_WITH_ARGS
196	select HAVE_SAMPLE_FTRACE_DIRECT
197	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
198	select HAVE_BUILDTIME_MCOUNT_SORT
199	select HAVE_EFFICIENT_UNALIGNED_ACCESS
200	select HAVE_GUP_FAST
201	select HAVE_FTRACE_GRAPH_FUNC
202	select HAVE_FUNCTION_TRACER
203	select HAVE_FUNCTION_ERROR_INJECTION
204	select HAVE_FUNCTION_GRAPH_FREGS
205	select HAVE_FUNCTION_GRAPH_TRACER
206	select HAVE_GCC_PLUGINS
207	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
208		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
209	select HAVE_HW_BREAKPOINT if PERF_EVENTS
210	select HAVE_IOREMAP_PROT
211	select HAVE_IRQ_TIME_ACCOUNTING
212	select HAVE_LIVEPATCH
213	select HAVE_MOD_ARCH_SPECIFIC
214	select HAVE_NMI
215	select HAVE_PERF_EVENTS
216	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
217	select HAVE_PERF_REGS
218	select HAVE_PERF_USER_STACK_DUMP
219	select HAVE_PREEMPT_DYNAMIC_KEY
220	select HAVE_REGS_AND_STACK_ACCESS_API
221	select HAVE_RELIABLE_STACKTRACE
222	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
223	select HAVE_FUNCTION_ARG_ACCESS_API
224	select MMU_GATHER_RCU_TABLE_FREE
225	select HAVE_RSEQ
226	select HAVE_RUST if RUSTC_SUPPORTS_ARM64
227	select HAVE_STACKPROTECTOR
228	select HAVE_STATIC_CALL if CFI
229	select HAVE_SYSCALL_TRACEPOINTS
230	select HAVE_KPROBES
231	select HAVE_KRETPROBES
232	select HAVE_GENERIC_VDSO
233	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
234	select HOTPLUG_SMT if HOTPLUG_CPU
235	select IRQ_DOMAIN
236	select IRQ_FORCED_THREADING
237	select JUMP_LABEL
238	select KASAN_VMALLOC if KASAN
239	select LOCK_MM_AND_FIND_VMA
240	select MODULES_USE_ELF_RELA
241	select NEED_DMA_MAP_STATE
242	select NEED_SG_DMA_LENGTH
243	select OF
244	select OF_EARLY_FLATTREE
245	select PCI_DOMAINS_GENERIC if PCI
246	select PCI_ECAM if (ACPI && PCI)
247	select PCI_SYSCALL if PCI
248	select POWER_RESET
249	select POWER_SUPPLY
250	select SPARSE_IRQ
251	select SWIOTLB
252	select SYSCTL_EXCEPTION_TRACE
253	select THREAD_INFO_IN_TASK
254	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
255	select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
256	select TRACE_IRQFLAGS_SUPPORT
257	select TRACE_IRQFLAGS_NMI_SUPPORT
258	select HAVE_SOFTIRQ_ON_OWN_STACK
259	select USER_STACKTRACE_SUPPORT
260	select VDSO_GETRANDOM
261	select VMAP_STACK
262	help
263	  ARM 64-bit (AArch64) Linux support.
264
265config RUSTC_SUPPORTS_ARM64
266	def_bool y
267	depends on CPU_LITTLE_ENDIAN
268
269config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
270	def_bool CC_IS_CLANG
271	# https://github.com/ClangBuiltLinux/linux/issues/1507
272	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
273
274config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
275	def_bool CC_IS_GCC
276	depends on $(cc-option,-fpatchable-function-entry=2)
277
278config 64BIT
279	def_bool y
280
281config MMU
282	def_bool y
283
284config ARM64_CONT_PTE_SHIFT
285	int
286	default 5 if PAGE_SIZE_64KB
287	default 7 if PAGE_SIZE_16KB
288	default 4
289
290config ARM64_CONT_PMD_SHIFT
291	int
292	default 5 if PAGE_SIZE_64KB
293	default 5 if PAGE_SIZE_16KB
294	default 4
295
296config ARCH_MMAP_RND_BITS_MIN
297	default 14 if PAGE_SIZE_64KB
298	default 16 if PAGE_SIZE_16KB
299	default 18
300
301# max bits determined by the following formula:
302#  VA_BITS - PTDESC_TABLE_SHIFT
303config ARCH_MMAP_RND_BITS_MAX
304	default 19 if ARM64_VA_BITS=36
305	default 24 if ARM64_VA_BITS=39
306	default 27 if ARM64_VA_BITS=42
307	default 30 if ARM64_VA_BITS=47
308	default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES
309	default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES
310	default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52)
311	default 14 if ARM64_64K_PAGES
312	default 16 if ARM64_16K_PAGES
313	default 18
314
315config ARCH_MMAP_RND_COMPAT_BITS_MIN
316	default 7 if ARM64_64K_PAGES
317	default 9 if ARM64_16K_PAGES
318	default 11
319
320config ARCH_MMAP_RND_COMPAT_BITS_MAX
321	default 16
322
323config NO_IOPORT_MAP
324	def_bool y if !PCI
325
326config STACKTRACE_SUPPORT
327	def_bool y
328
329config ILLEGAL_POINTER_VALUE
330	hex
331	default 0xdead000000000000
332
333config LOCKDEP_SUPPORT
334	def_bool y
335
336config GENERIC_BUG
337	def_bool y
338	depends on BUG
339
340config GENERIC_BUG_RELATIVE_POINTERS
341	def_bool y
342	depends on GENERIC_BUG
343
344config GENERIC_HWEIGHT
345	def_bool y
346
347config GENERIC_CSUM
348	def_bool y
349
350config GENERIC_CALIBRATE_DELAY
351	def_bool y
352
353config SMP
354	def_bool y
355
356config KERNEL_MODE_NEON
357	def_bool y
358
359config FIX_EARLYCON_MEM
360	def_bool y
361
362config PGTABLE_LEVELS
363	int
364	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
365	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
366	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
367	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
368	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
369	default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
370	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
371	default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
372
373config ARCH_SUPPORTS_UPROBES
374	def_bool y
375
376config ARCH_PROC_KCORE_TEXT
377	def_bool y
378
379config BROKEN_GAS_INST
380	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
381
382config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
383	bool
384	# Clang's __builtin_return_address() strips the PAC since 12.0.0
385	# https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
386	default y if CC_IS_CLANG
387	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
388	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
389	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
390	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
391	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
392	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
393	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
394	default n
395
396config KASAN_SHADOW_OFFSET
397	hex
398	depends on KASAN_GENERIC || KASAN_SW_TAGS
399	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
400	default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
401	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
402	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
403	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
404	default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
405	default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
406	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
407	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
408	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
409	default 0xffffffffffffffff
410
411config UNWIND_TABLES
412	bool
413
414source "arch/arm64/Kconfig.platforms"
415
416menu "Kernel Features"
417
418menu "ARM errata workarounds via the alternatives framework"
419
420config AMPERE_ERRATUM_AC03_CPU_38
421        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
422	default y
423	help
424	  This option adds an alternative code sequence to work around Ampere
425	  errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
426
427	  The affected design reports FEAT_HAFDBS as not implemented in
428	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
429	  as required by the architecture. The unadvertised HAFDBS
430	  implementation suffers from an additional erratum where hardware
431	  A/D updates can occur after a PTE has been marked invalid.
432
433	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
434	  which avoids enabling unadvertised hardware Access Flag management
435	  at stage-2.
436
437	  If unsure, say Y.
438
439config AMPERE_ERRATUM_AC04_CPU_23
440        bool "AmpereOne: AC04_CPU_23:  Failure to synchronize writes to HCR_EL2 may corrupt address translations."
441	default y
442	help
443	  This option adds an alternative code sequence to work around Ampere
444	  errata AC04_CPU_23 on AmpereOne.
445
446	  Updates to HCR_EL2 can rarely corrupt simultaneous translations for
447	  data addresses initiated by load/store instructions. Only
448	  instruction initiated translations are vulnerable, not translations
449	  from prefetches for example. A DSB before the store to HCR_EL2 is
450	  sufficient to prevent older instructions from hitting the window
451	  for corruption, and an ISB after is sufficient to prevent younger
452	  instructions from hitting the window for corruption.
453
454	  If unsure, say Y.
455
456config ARM64_WORKAROUND_CLEAN_CACHE
457	bool
458
459config ARM64_ERRATUM_826319
460	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
461	default y
462	select ARM64_WORKAROUND_CLEAN_CACHE
463	help
464	  This option adds an alternative code sequence to work around ARM
465	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
466	  AXI master interface and an L2 cache.
467
468	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
469	  and is unable to accept a certain write via this interface, it will
470	  not progress on read data presented on the read data channel and the
471	  system can deadlock.
472
473	  The workaround promotes data cache clean instructions to
474	  data cache clean-and-invalidate.
475	  Please note that this does not necessarily enable the workaround,
476	  as it depends on the alternative framework, which will only patch
477	  the kernel if an affected CPU is detected.
478
479	  If unsure, say Y.
480
481config ARM64_ERRATUM_827319
482	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
483	default y
484	select ARM64_WORKAROUND_CLEAN_CACHE
485	help
486	  This option adds an alternative code sequence to work around ARM
487	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
488	  master interface and an L2 cache.
489
490	  Under certain conditions this erratum can cause a clean line eviction
491	  to occur at the same time as another transaction to the same address
492	  on the AMBA 5 CHI interface, which can cause data corruption if the
493	  interconnect reorders the two transactions.
494
495	  The workaround promotes data cache clean instructions to
496	  data cache clean-and-invalidate.
497	  Please note that this does not necessarily enable the workaround,
498	  as it depends on the alternative framework, which will only patch
499	  the kernel if an affected CPU is detected.
500
501	  If unsure, say Y.
502
503config ARM64_ERRATUM_824069
504	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
505	default y
506	select ARM64_WORKAROUND_CLEAN_CACHE
507	help
508	  This option adds an alternative code sequence to work around ARM
509	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
510	  to a coherent interconnect.
511
512	  If a Cortex-A53 processor is executing a store or prefetch for
513	  write instruction at the same time as a processor in another
514	  cluster is executing a cache maintenance operation to the same
515	  address, then this erratum might cause a clean cache line to be
516	  incorrectly marked as dirty.
517
518	  The workaround promotes data cache clean instructions to
519	  data cache clean-and-invalidate.
520	  Please note that this option does not necessarily enable the
521	  workaround, as it depends on the alternative framework, which will
522	  only patch the kernel if an affected CPU is detected.
523
524	  If unsure, say Y.
525
526config ARM64_ERRATUM_819472
527	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
528	default y
529	select ARM64_WORKAROUND_CLEAN_CACHE
530	help
531	  This option adds an alternative code sequence to work around ARM
532	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
533	  present when it is connected to a coherent interconnect.
534
535	  If the processor is executing a load and store exclusive sequence at
536	  the same time as a processor in another cluster is executing a cache
537	  maintenance operation to the same address, then this erratum might
538	  cause data corruption.
539
540	  The workaround promotes data cache clean instructions to
541	  data cache clean-and-invalidate.
542	  Please note that this does not necessarily enable the workaround,
543	  as it depends on the alternative framework, which will only patch
544	  the kernel if an affected CPU is detected.
545
546	  If unsure, say Y.
547
548config ARM64_ERRATUM_832075
549	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
550	default y
551	help
552	  This option adds an alternative code sequence to work around ARM
553	  erratum 832075 on Cortex-A57 parts up to r1p2.
554
555	  Affected Cortex-A57 parts might deadlock when exclusive load/store
556	  instructions to Write-Back memory are mixed with Device loads.
557
558	  The workaround is to promote device loads to use Load-Acquire
559	  semantics.
560	  Please note that this does not necessarily enable the workaround,
561	  as it depends on the alternative framework, which will only patch
562	  the kernel if an affected CPU is detected.
563
564	  If unsure, say Y.
565
566config ARM64_ERRATUM_834220
567	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
568	depends on KVM
569	help
570	  This option adds an alternative code sequence to work around ARM
571	  erratum 834220 on Cortex-A57 parts up to r1p2.
572
573	  Affected Cortex-A57 parts might report a Stage 2 translation
574	  fault as the result of a Stage 1 fault for load crossing a
575	  page boundary when there is a permission or device memory
576	  alignment fault at Stage 1 and a translation fault at Stage 2.
577
578	  The workaround is to verify that the Stage 1 translation
579	  doesn't generate a fault before handling the Stage 2 fault.
580	  Please note that this does not necessarily enable the workaround,
581	  as it depends on the alternative framework, which will only patch
582	  the kernel if an affected CPU is detected.
583
584	  If unsure, say N.
585
586config ARM64_ERRATUM_1742098
587	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
588	depends on COMPAT
589	default y
590	help
591	  This option removes the AES hwcap for aarch32 user-space to
592	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
593
594	  Affected parts may corrupt the AES state if an interrupt is
595	  taken between a pair of AES instructions. These instructions
596	  are only present if the cryptography extensions are present.
597	  All software should have a fallback implementation for CPUs
598	  that don't implement the cryptography extensions.
599
600	  If unsure, say Y.
601
602config ARM64_ERRATUM_845719
603	bool "Cortex-A53: 845719: a load might read incorrect data"
604	depends on COMPAT
605	default y
606	help
607	  This option adds an alternative code sequence to work around ARM
608	  erratum 845719 on Cortex-A53 parts up to r0p4.
609
610	  When running a compat (AArch32) userspace on an affected Cortex-A53
611	  part, a load at EL0 from a virtual address that matches the bottom 32
612	  bits of the virtual address used by a recent load at (AArch64) EL1
613	  might return incorrect data.
614
615	  The workaround is to write the contextidr_el1 register on exception
616	  return to a 32-bit task.
617	  Please note that this does not necessarily enable the workaround,
618	  as it depends on the alternative framework, which will only patch
619	  the kernel if an affected CPU is detected.
620
621	  If unsure, say Y.
622
623config ARM64_ERRATUM_843419
624	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
625	default y
626	help
627	  This option links the kernel with '--fix-cortex-a53-843419' and
628	  enables PLT support to replace certain ADRP instructions, which can
629	  cause subsequent memory accesses to use an incorrect address on
630	  Cortex-A53 parts up to r0p4.
631
632	  If unsure, say Y.
633
634config ARM64_ERRATUM_1024718
635	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
636	default y
637	help
638	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
639
640	  Affected Cortex-A55 cores (all revisions) could cause incorrect
641	  update of the hardware dirty bit when the DBM/AP bits are updated
642	  without a break-before-make. The workaround is to disable the usage
643	  of hardware DBM locally on the affected cores. CPUs not affected by
644	  this erratum will continue to use the feature.
645
646	  If unsure, say Y.
647
648config ARM64_ERRATUM_1418040
649	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
650	default y
651	depends on COMPAT
652	help
653	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
654	  errata 1188873 and 1418040.
655
656	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
657	  cause register corruption when accessing the timer registers
658	  from AArch32 userspace.
659
660	  If unsure, say Y.
661
662config ARM64_WORKAROUND_SPECULATIVE_AT
663	bool
664
665config ARM64_ERRATUM_1165522
666	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
667	default y
668	select ARM64_WORKAROUND_SPECULATIVE_AT
669	help
670	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
671
672	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
673	  corrupted TLBs by speculating an AT instruction during a guest
674	  context switch.
675
676	  If unsure, say Y.
677
678config ARM64_ERRATUM_1319367
679	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
680	default y
681	select ARM64_WORKAROUND_SPECULATIVE_AT
682	help
683	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
684	  and A72 erratum 1319367
685
686	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
687	  speculating an AT instruction during a guest context switch.
688
689	  If unsure, say Y.
690
691config ARM64_ERRATUM_1530923
692	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
693	default y
694	select ARM64_WORKAROUND_SPECULATIVE_AT
695	help
696	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
697
698	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
699	  corrupted TLBs by speculating an AT instruction during a guest
700	  context switch.
701
702	  If unsure, say Y.
703
704config ARM64_WORKAROUND_REPEAT_TLBI
705	bool
706
707config ARM64_ERRATUM_2441007
708	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
709	select ARM64_WORKAROUND_REPEAT_TLBI
710	help
711	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
712
713	  Under very rare circumstances, affected Cortex-A55 CPUs
714	  may not handle a race between a break-before-make sequence on one
715	  CPU, and another CPU accessing the same page. This could allow a
716	  store to a page that has been unmapped.
717
718	  Work around this by adding the affected CPUs to the list that needs
719	  TLB sequences to be done twice.
720
721	  If unsure, say N.
722
723config ARM64_ERRATUM_1286807
724	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
725	select ARM64_WORKAROUND_REPEAT_TLBI
726	help
727	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
728
729	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
730	  address for a cacheable mapping of a location is being
731	  accessed by a core while another core is remapping the virtual
732	  address to a new physical page using the recommended
733	  break-before-make sequence, then under very rare circumstances
734	  TLBI+DSB completes before a read using the translation being
735	  invalidated has been observed by other observers. The
736	  workaround repeats the TLBI+DSB operation.
737
738	  If unsure, say N.
739
740config ARM64_ERRATUM_1463225
741	bool "Cortex-A76: Software Step might prevent interrupt recognition"
742	default y
743	help
744	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
745
746	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
747	  of a system call instruction (SVC) can prevent recognition of
748	  subsequent interrupts when software stepping is disabled in the
749	  exception handler of the system call and either kernel debugging
750	  is enabled or VHE is in use.
751
752	  Work around the erratum by triggering a dummy step exception
753	  when handling a system call from a task that is being stepped
754	  in a VHE configuration of the kernel.
755
756	  If unsure, say Y.
757
758config ARM64_ERRATUM_1542419
759	bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
760	help
761	  This option adds a workaround for ARM Neoverse-N1 erratum
762	  1542419.
763
764	  Affected Neoverse-N1 cores could execute a stale instruction when
765	  modified by another CPU. The workaround depends on a firmware
766	  counterpart.
767
768	  Workaround the issue by hiding the DIC feature from EL0. This
769	  forces user-space to perform cache maintenance.
770
771	  If unsure, say N.
772
773config ARM64_ERRATUM_1508412
774	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
775	default y
776	help
777	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
778
779	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
780	  of a store-exclusive or read of PAR_EL1 and a load with device or
781	  non-cacheable memory attributes. The workaround depends on a firmware
782	  counterpart.
783
784	  KVM guests must also have the workaround implemented or they can
785	  deadlock the system.
786
787	  Work around the issue by inserting DMB SY barriers around PAR_EL1
788	  register reads and warning KVM users. The DMB barrier is sufficient
789	  to prevent a speculative PAR_EL1 read.
790
791	  If unsure, say Y.
792
793config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
794	bool
795
796config ARM64_ERRATUM_2051678
797	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
798	default y
799	help
800	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
801	  Affected Cortex-A510 might not respect the ordering rules for
802	  hardware update of the page table's dirty bit. The workaround
803	  is to not enable the feature on affected CPUs.
804
805	  If unsure, say Y.
806
807config ARM64_ERRATUM_2077057
808	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
809	default y
810	help
811	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
812	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
813	  expected, but a Pointer Authentication trap is taken instead. The
814	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
815	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
816
817	  This can only happen when EL2 is stepping EL1.
818
819	  When these conditions occur, the SPSR_EL2 value is unchanged from the
820	  previous guest entry, and can be restored from the in-memory copy.
821
822	  If unsure, say Y.
823
824config ARM64_ERRATUM_2658417
825	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
826	default y
827	help
828	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
829	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
830	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
831	  A510 CPUs are using shared neon hardware. As the sharing is not
832	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
833	  user-space should not be using these instructions.
834
835	  If unsure, say Y.
836
837config ARM64_ERRATUM_2119858
838	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
839	default y
840	depends on CORESIGHT_TRBE
841	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
842	help
843	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
844
845	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
846	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
847	  the event of a WRAP event.
848
849	  Work around the issue by always making sure we move the TRBPTR_EL1 by
850	  256 bytes before enabling the buffer and filling the first 256 bytes of
851	  the buffer with ETM ignore packets upon disabling.
852
853	  If unsure, say Y.
854
855config ARM64_ERRATUM_2139208
856	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
857	default y
858	depends on CORESIGHT_TRBE
859	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
860	help
861	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
862
863	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
864	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
865	  the event of a WRAP event.
866
867	  Work around the issue by always making sure we move the TRBPTR_EL1 by
868	  256 bytes before enabling the buffer and filling the first 256 bytes of
869	  the buffer with ETM ignore packets upon disabling.
870
871	  If unsure, say Y.
872
873config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
874	bool
875
876config ARM64_ERRATUM_2054223
877	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
878	default y
879	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
880	help
881	  Enable workaround for ARM Cortex-A710 erratum 2054223
882
883	  Affected cores may fail to flush the trace data on a TSB instruction, when
884	  the PE is in trace prohibited state. This will cause losing a few bytes
885	  of the trace cached.
886
887	  Workaround is to issue two TSB consecutively on affected cores.
888
889	  If unsure, say Y.
890
891config ARM64_ERRATUM_2067961
892	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
893	default y
894	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
895	help
896	  Enable workaround for ARM Neoverse-N2 erratum 2067961
897
898	  Affected cores may fail to flush the trace data on a TSB instruction, when
899	  the PE is in trace prohibited state. This will cause losing a few bytes
900	  of the trace cached.
901
902	  Workaround is to issue two TSB consecutively on affected cores.
903
904	  If unsure, say Y.
905
906config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
907	bool
908
909config ARM64_ERRATUM_2253138
910	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
911	depends on CORESIGHT_TRBE
912	default y
913	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
914	help
915	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
916
917	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
918	  for TRBE. Under some conditions, the TRBE might generate a write to the next
919	  virtually addressed page following the last page of the TRBE address space
920	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
921
922	  Work around this in the driver by always making sure that there is a
923	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
924
925	  If unsure, say Y.
926
927config ARM64_ERRATUM_2224489
928	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
929	depends on CORESIGHT_TRBE
930	default y
931	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
932	help
933	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
934
935	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
936	  for TRBE. Under some conditions, the TRBE might generate a write to the next
937	  virtually addressed page following the last page of the TRBE address space
938	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
939
940	  Work around this in the driver by always making sure that there is a
941	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
942
943	  If unsure, say Y.
944
945config ARM64_ERRATUM_2441009
946	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
947	select ARM64_WORKAROUND_REPEAT_TLBI
948	help
949	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
950
951	  Under very rare circumstances, affected Cortex-A510 CPUs
952	  may not handle a race between a break-before-make sequence on one
953	  CPU, and another CPU accessing the same page. This could allow a
954	  store to a page that has been unmapped.
955
956	  Work around this by adding the affected CPUs to the list that needs
957	  TLB sequences to be done twice.
958
959	  If unsure, say N.
960
961config ARM64_ERRATUM_2064142
962	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
963	depends on CORESIGHT_TRBE
964	default y
965	help
966	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
967
968	  Affected Cortex-A510 core might fail to write into system registers after the
969	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
970	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
971	  and TRBTRG_EL1 will be ignored and will not be effected.
972
973	  Work around this in the driver by executing TSB CSYNC and DSB after collection
974	  is stopped and before performing a system register write to one of the affected
975	  registers.
976
977	  If unsure, say Y.
978
979config ARM64_ERRATUM_2038923
980	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
981	depends on CORESIGHT_TRBE
982	default y
983	help
984	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
985
986	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
987	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
988	  might be corrupted. This happens after TRBE buffer has been enabled by setting
989	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
990	  execution changes from a context, in which trace is prohibited to one where it
991	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
992	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
993	  the trace buffer state might be corrupted.
994
995	  Work around this in the driver by preventing an inconsistent view of whether the
996	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
997	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
998	  two ISB instructions if no ERET is to take place.
999
1000	  If unsure, say Y.
1001
1002config ARM64_ERRATUM_1902691
1003	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1004	depends on CORESIGHT_TRBE
1005	default y
1006	help
1007	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1008
1009	  Affected Cortex-A510 core might cause trace data corruption, when being written
1010	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
1011	  trace data.
1012
1013	  Work around this problem in the driver by just preventing TRBE initialization on
1014	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1015	  on such implementations. This will cover the kernel for any firmware that doesn't
1016	  do this already.
1017
1018	  If unsure, say Y.
1019
1020config ARM64_ERRATUM_2457168
1021	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1022	depends on ARM64_AMU_EXTN
1023	default y
1024	help
1025	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1026
1027	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1028	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1029	  incorrectly giving a significantly higher output value.
1030
1031	  Work around this problem by returning 0 when reading the affected counter in
1032	  key locations that results in disabling all users of this counter. This effect
1033	  is the same to firmware disabling affected counters.
1034
1035	  If unsure, say Y.
1036
1037config ARM64_ERRATUM_2645198
1038	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1039	default y
1040	help
1041	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1042
1043	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1044	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1045	  next instruction abort caused by permission fault.
1046
1047	  Only user-space does executable to non-executable permission transition via
1048	  mprotect() system call. Workaround the problem by doing a break-before-make
1049	  TLB invalidation, for all changes to executable user space mappings.
1050
1051	  If unsure, say Y.
1052
1053config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1054	bool
1055
1056config ARM64_ERRATUM_2966298
1057	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1058	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1059	default y
1060	help
1061	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1062
1063	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1064	  load might leak data from a privileged level via a cache side channel.
1065
1066	  Work around this problem by executing a TLBI before returning to EL0.
1067
1068	  If unsure, say Y.
1069
1070config ARM64_ERRATUM_3117295
1071	bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1072	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1073	default y
1074	help
1075	  This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1076
1077	  On an affected Cortex-A510 core, a speculatively executed unprivileged
1078	  load might leak data from a privileged level via a cache side channel.
1079
1080	  Work around this problem by executing a TLBI before returning to EL0.
1081
1082	  If unsure, say Y.
1083
1084config ARM64_ERRATUM_3194386
1085	bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1086	default y
1087	help
1088	  This option adds the workaround for the following errata:
1089
1090	  * ARM Cortex-A76 erratum 3324349
1091	  * ARM Cortex-A77 erratum 3324348
1092	  * ARM Cortex-A78 erratum 3324344
1093	  * ARM Cortex-A78C erratum 3324346
1094	  * ARM Cortex-A78C erratum 3324347
1095	  * ARM Cortex-A710 erratam 3324338
1096	  * ARM Cortex-A715 errartum 3456084
1097	  * ARM Cortex-A720 erratum 3456091
1098	  * ARM Cortex-A725 erratum 3456106
1099	  * ARM Cortex-X1 erratum 3324344
1100	  * ARM Cortex-X1C erratum 3324346
1101	  * ARM Cortex-X2 erratum 3324338
1102	  * ARM Cortex-X3 erratum 3324335
1103	  * ARM Cortex-X4 erratum 3194386
1104	  * ARM Cortex-X925 erratum 3324334
1105	  * ARM Neoverse-N1 erratum 3324349
1106	  * ARM Neoverse N2 erratum 3324339
1107	  * ARM Neoverse-N3 erratum 3456111
1108	  * ARM Neoverse-V1 erratum 3324341
1109	  * ARM Neoverse V2 erratum 3324336
1110	  * ARM Neoverse-V3 erratum 3312417
1111	  * ARM Neoverse-V3AE erratum 3312417
1112
1113	  On affected cores "MSR SSBS, #0" instructions may not affect
1114	  subsequent speculative instructions, which may permit unexepected
1115	  speculative store bypassing.
1116
1117	  Work around this problem by placing a Speculation Barrier (SB) or
1118	  Instruction Synchronization Barrier (ISB) after kernel changes to
1119	  SSBS. The presence of the SSBS special-purpose register is hidden
1120	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1121	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1122
1123	  If unsure, say Y.
1124
1125config ARM64_ERRATUM_4311569
1126	bool "SI L1: 4311569: workaround for premature CMO completion erratum"
1127	default y
1128	help
1129	  This option adds the workaround for ARM SI L1 erratum 4311569.
1130
1131	  The erratum of SI L1 can cause an early response to a combined write
1132	  and cache maintenance operation (WR+CMO) before the operation is fully
1133	  completed to the Point of Serialization (POS).
1134	  This can result in a non-I/O coherent agent observing stale data,
1135	  potentially leading to system instability or incorrect behavior.
1136
1137	  Enabling this option implements a software workaround by inserting a
1138	  second loop of Cache Maintenance Operation (CMO) immediately following the
1139	  end of function to do CMOs. This ensures that the data is correctly serialized
1140	  before the buffer is handed off to a non-coherent agent.
1141
1142	  If unsure, say Y.
1143
1144config ARM64_ERRATUM_4193714
1145	bool "C1-Pro: 4193714: SME DVMSync early acknowledgement"
1146	depends on ARM64_SME
1147	default y
1148	help
1149	  Enable workaround for C1-Pro acknowledging the DVMSync before
1150	  the SME memory accesses are complete. This will cause TLB
1151	  maintenance for processes using SME to also issue an IPI to
1152	  the affected CPUs.
1153
1154	  If unsure, say Y.
1155
1156config ARM64_ERRATUM_4118414
1157	bool "Various: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
1158	default y
1159	select ARM64_WORKAROUND_REPEAT_TLBI
1160	help
1161	  This option adds a workaround for the following errata:
1162
1163	  * ARM C1-Premium erratum 4193780
1164	  * ARM C1-Ultra erratum 4193780
1165	  * ARM Cortex-A76 erratum 4193800
1166	  * ARM Cortex-A76AE erratum 4193801
1167	  * ARM Cortex-A77 erratum 4193798
1168	  * ARM Cortex-A78 erratum 4193791
1169	  * ARM Cortex-A78AE erratum 4193793
1170	  * ARM Cortex-A78C erratum 4193794
1171	  * ARM Cortex-A710 erratum 4193788
1172	  * ARM Cortex-X1 erratum 4193791
1173	  * ARM Cortex-X1C erratum 4193792
1174	  * ARM Cortex-X2 erratum 4193788
1175	  * ARM Cortex-X3 erratum 4193786
1176	  * ARM Cortex-X4 erratum 4118414
1177	  * ARM Cortex-X925 erratum 4193781
1178	  * ARM Neoverse-N1 erratum 4193800
1179	  * ARM Neoverse-N2 erratum 4193789
1180	  * ARM Neoverse-V1 erratum 4193790
1181	  * ARM Neoverse-V2 erratum 4193787
1182	  * ARM Neoverse-V3 erratum 4193784
1183	  * ARM Neoverse-V3AE erratum 4193784
1184	  * Microsoft Azure Cobalt 100 4193789
1185	  * NVIDIA Olympus erratum T410-OLY-1029
1186
1187	  On affected cores, some memory accesses might not be completed by
1188	  broadcast TLB invalidation.
1189
1190	  This issue is also known as CVE-2025-10263.
1191
1192	  If unsure, say Y.
1193
1194config CAVIUM_ERRATUM_22375
1195	bool "Cavium erratum 22375, 24313"
1196	default y
1197	help
1198	  Enable workaround for errata 22375 and 24313.
1199
1200	  This implements two gicv3-its errata workarounds for ThunderX. Both
1201	  with a small impact affecting only ITS table allocation.
1202
1203	    erratum 22375: only alloc 8MB table size
1204	    erratum 24313: ignore memory access type
1205
1206	  The fixes are in ITS initialization and basically ignore memory access
1207	  type and table size provided by the TYPER and BASER registers.
1208
1209	  If unsure, say Y.
1210
1211config CAVIUM_ERRATUM_23144
1212	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1213	depends on NUMA
1214	default y
1215	help
1216	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1217
1218	  If unsure, say Y.
1219
1220config CAVIUM_ERRATUM_23154
1221	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1222	default y
1223	help
1224	  The ThunderX GICv3 implementation requires a modified version for
1225	  reading the IAR status to ensure data synchronization
1226	  (access to icc_iar1_el1 is not sync'ed before and after).
1227
1228	  It also suffers from erratum 38545 (also present on Marvell's
1229	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1230	  spuriously presented to the CPU interface.
1231
1232	  If unsure, say Y.
1233
1234config CAVIUM_ERRATUM_27456
1235	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1236	default y
1237	help
1238	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1239	  instructions may cause the icache to become corrupted if it
1240	  contains data for a non-current ASID.  The fix is to
1241	  invalidate the icache when changing the mm context.
1242
1243	  If unsure, say Y.
1244
1245config CAVIUM_ERRATUM_30115
1246	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1247	default y
1248	help
1249	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1250	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1251	  interrupts in host. Trapping both GICv3 group-0 and group-1
1252	  accesses sidesteps the issue.
1253
1254	  If unsure, say Y.
1255
1256config CAVIUM_TX2_ERRATUM_219
1257	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1258	default y
1259	help
1260	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1261	  TTBR update and the corresponding context synchronizing operation can
1262	  cause a spurious Data Abort to be delivered to any hardware thread in
1263	  the CPU core.
1264
1265	  Work around the issue by avoiding the problematic code sequence and
1266	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1267	  trap handler performs the corresponding register access, skips the
1268	  instruction and ensures context synchronization by virtue of the
1269	  exception return.
1270
1271	  If unsure, say Y.
1272
1273config FUJITSU_ERRATUM_010001
1274	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1275	default y
1276	help
1277	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1278	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1279	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1280	  This fault occurs under a specific hardware condition when a
1281	  load/store instruction performs an address translation using:
1282	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1283	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1284	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1285	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1286
1287	  The workaround is to ensure these bits are clear in TCR_ELx.
1288	  The workaround only affects the Fujitsu-A64FX.
1289
1290	  If unsure, say Y.
1291
1292config HISILICON_ERRATUM_161600802
1293	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1294	default y
1295	help
1296	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1297	  when issued ITS commands such as VMOVP and VMAPP, and requires
1298	  a 128kB offset to be applied to the target address in this commands.
1299
1300	  If unsure, say Y.
1301
1302config HISILICON_ERRATUM_162100801
1303	bool "Hip09 162100801 erratum support"
1304	default y
1305	help
1306	  When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches
1307	  during unmapping operation, which will cause some vSGIs lost.
1308	  To fix the issue, invalidate related vPE cache through GICR_INVALLR
1309	  after VMOVP.
1310
1311	  If unsure, say Y.
1312
1313config HISILICON_ERRATUM_162100125
1314	bool "Hisilicon erratum 162100125"
1315	default y
1316	select ARM64_WORKAROUND_DISABLE_CNP
1317	help
1318	  On HiSilicon HIP09, TLB entry matching behavior when CNP
1319	  (TTBRx.CNP=1) is enabled differs from the ARM architecture
1320	  specification.
1321
1322	  TLB entries may be incorrectly shared between CPUs, potentially
1323	  causing TLB conflicts and stale mappings.
1324
1325	  Disable CNP support for affected HiSilicon HIP09 cores.
1326
1327	  If unsure, say Y.
1328
1329config QCOM_FALKOR_ERRATUM_1003
1330	bool "Falkor E1003: Incorrect translation due to ASID change"
1331	default y
1332	help
1333	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1334	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1335	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1336	  then only for entries in the walk cache, since the leaf translation
1337	  is unchanged. Work around the erratum by invalidating the walk cache
1338	  entries for the trampoline before entering the kernel proper.
1339
1340config QCOM_FALKOR_ERRATUM_1009
1341	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1342	default y
1343	select ARM64_WORKAROUND_REPEAT_TLBI
1344	help
1345	  On Falkor v1, the CPU may prematurely complete a DSB following a
1346	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1347	  one more time to fix the issue.
1348
1349	  If unsure, say Y.
1350
1351config QCOM_QDF2400_ERRATUM_0065
1352	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1353	default y
1354	help
1355	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1356	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1357	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1358
1359	  If unsure, say Y.
1360
1361config QCOM_FALKOR_ERRATUM_E1041
1362	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1363	default y
1364	help
1365	  Falkor CPU may speculatively fetch instructions from an improper
1366	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1367	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1368
1369	  If unsure, say Y.
1370
1371config ARM64_WORKAROUND_DISABLE_CNP
1372	bool
1373
1374config NVIDIA_CARMEL_CNP_ERRATUM
1375	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1376	default y
1377	select ARM64_WORKAROUND_DISABLE_CNP
1378	help
1379	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1380	  invalidate shared TLB entries installed by a different core, as it would
1381	  on standard ARM cores.
1382
1383	  If unsure, say Y.
1384
1385config ROCKCHIP_ERRATUM_3568002
1386	bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB"
1387	default y
1388	help
1389	  The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI
1390	  addressing limited to the first 32bit of physical address space.
1391
1392	  If unsure, say Y.
1393
1394config ROCKCHIP_ERRATUM_3588001
1395	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1396	default y
1397	help
1398	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1399	  This means, that its sharability feature may not be used, even though it
1400	  is supported by the IP itself.
1401
1402	  If unsure, say Y.
1403
1404config SOCIONEXT_SYNQUACER_PREITS
1405	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1406	default y
1407	help
1408	  Socionext Synquacer SoCs implement a separate h/w block to generate
1409	  MSI doorbell writes with non-zero values for the device ID.
1410
1411	  If unsure, say Y.
1412
1413endmenu # "ARM errata workarounds via the alternatives framework"
1414
1415choice
1416	prompt "Page size"
1417	default ARM64_4K_PAGES
1418	help
1419	  Page size (translation granule) configuration.
1420
1421config ARM64_4K_PAGES
1422	bool "4KB"
1423	select HAVE_PAGE_SIZE_4KB
1424	help
1425	  This feature enables 4KB pages support.
1426
1427config ARM64_16K_PAGES
1428	bool "16KB"
1429	select HAVE_PAGE_SIZE_16KB
1430	help
1431	  The system will use 16KB pages support. AArch32 emulation
1432	  requires applications compiled with 16K (or a multiple of 16K)
1433	  aligned segments.
1434
1435config ARM64_64K_PAGES
1436	bool "64KB"
1437	select HAVE_PAGE_SIZE_64KB
1438	help
1439	  This feature enables 64KB pages support (4KB by default)
1440	  allowing only two levels of page tables and faster TLB
1441	  look-up. AArch32 emulation requires applications compiled
1442	  with 64K aligned segments.
1443
1444endchoice
1445
1446choice
1447	prompt "Virtual address space size"
1448	default ARM64_VA_BITS_52
1449	help
1450	  Allows choosing one of multiple possible virtual address
1451	  space sizes. The level of translation table is determined by
1452	  a combination of page size and virtual address space size.
1453
1454config ARM64_VA_BITS_36
1455	bool "36-bit" if EXPERT
1456	depends on PAGE_SIZE_16KB
1457
1458config ARM64_VA_BITS_39
1459	bool "39-bit"
1460	depends on PAGE_SIZE_4KB
1461
1462config ARM64_VA_BITS_42
1463	bool "42-bit"
1464	depends on PAGE_SIZE_64KB
1465
1466config ARM64_VA_BITS_47
1467	bool "47-bit"
1468	depends on PAGE_SIZE_16KB
1469
1470config ARM64_VA_BITS_48
1471	bool "48-bit"
1472
1473config ARM64_VA_BITS_52
1474	bool "52-bit"
1475	help
1476	  Enable 52-bit virtual addressing for userspace when explicitly
1477	  requested via a hint to mmap(). The kernel will also use 52-bit
1478	  virtual addresses for its own mappings (provided HW support for
1479	  this feature is available, otherwise it reverts to 48-bit).
1480
1481	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1482	  ARMv8.3 Pointer Authentication will result in the PAC being
1483	  reduced from 7 bits to 3 bits, which may have a significant
1484	  impact on its susceptibility to brute-force attacks.
1485
1486	  If unsure, select 48-bit virtual addressing instead.
1487
1488endchoice
1489
1490config ARM64_FORCE_52BIT
1491	bool "Force 52-bit virtual addresses for userspace"
1492	depends on ARM64_VA_BITS_52 && EXPERT
1493	help
1494	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1495	  to maintain compatibility with older software by providing 48-bit VAs
1496	  unless a hint is supplied to mmap.
1497
1498	  This configuration option disables the 48-bit compatibility logic, and
1499	  forces all userspace addresses to be 52-bit on HW that supports it. One
1500	  should only enable this configuration option for stress testing userspace
1501	  memory management code. If unsure say N here.
1502
1503config ARM64_VA_BITS
1504	int
1505	default 36 if ARM64_VA_BITS_36
1506	default 39 if ARM64_VA_BITS_39
1507	default 42 if ARM64_VA_BITS_42
1508	default 47 if ARM64_VA_BITS_47
1509	default 48 if ARM64_VA_BITS_48
1510	default 52 if ARM64_VA_BITS_52
1511
1512choice
1513	prompt "Physical address space size"
1514	default ARM64_PA_BITS_48
1515	help
1516	  Choose the maximum physical address range that the kernel will
1517	  support.
1518
1519config ARM64_PA_BITS_48
1520	bool "48-bit"
1521	depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1522
1523config ARM64_PA_BITS_52
1524	bool "52-bit"
1525	depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1526	help
1527	  Enable support for a 52-bit physical address space, introduced as
1528	  part of the ARMv8.2-LPA extension.
1529
1530	  With this enabled, the kernel will also continue to work on CPUs that
1531	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1532	  minor performance overhead).
1533
1534endchoice
1535
1536config ARM64_PA_BITS
1537	int
1538	default 48 if ARM64_PA_BITS_48
1539	default 52 if ARM64_PA_BITS_52
1540
1541config ARM64_LPA2
1542	def_bool y
1543	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1544
1545choice
1546	prompt "Endianness"
1547	default CPU_LITTLE_ENDIAN
1548	help
1549	  Select the endianness of data accesses performed by the CPU. Userspace
1550	  applications will need to be compiled and linked for the endianness
1551	  that is selected here.
1552
1553config CPU_BIG_ENDIAN
1554	bool "Build big-endian kernel"
1555	depends on BROKEN
1556	help
1557	  Say Y if you plan on running a kernel with a big-endian userspace.
1558
1559config CPU_LITTLE_ENDIAN
1560	bool "Build little-endian kernel"
1561	help
1562	  Say Y if you plan on running a kernel with a little-endian userspace.
1563	  This is usually the case for distributions targeting arm64.
1564
1565endchoice
1566
1567config NR_CPUS
1568	int "Maximum number of CPUs (2-4096)"
1569	range 2 4096
1570	default "512"
1571
1572config HOTPLUG_CPU
1573	bool "Support for hot-pluggable CPUs"
1574	select GENERIC_IRQ_MIGRATION
1575	help
1576	  Say Y here to experiment with turning CPUs off and on.  CPUs
1577	  can be controlled through /sys/devices/system/cpu.
1578
1579# Common NUMA Features
1580config NUMA
1581	bool "NUMA Memory Allocation and Scheduler Support"
1582	select GENERIC_ARCH_NUMA
1583	select OF_NUMA
1584	select HAVE_SETUP_PER_CPU_AREA
1585	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1586	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1587	select USE_PERCPU_NUMA_NODE_ID
1588	help
1589	  Enable NUMA (Non-Uniform Memory Access) support.
1590
1591	  The kernel will try to allocate memory used by a CPU on the
1592	  local memory of the CPU and add some more
1593	  NUMA awareness to the kernel.
1594
1595config NODES_SHIFT
1596	int "Maximum NUMA Nodes (as a power of 2)"
1597	range 1 10
1598	default "4"
1599	depends on NUMA
1600	help
1601	  Specify the maximum number of NUMA Nodes available on the target
1602	  system.  Increases memory reserved to accommodate various tables.
1603
1604source "kernel/Kconfig.hz"
1605
1606config ARCH_SPARSEMEM_ENABLE
1607	def_bool y
1608	select SPARSEMEM_VMEMMAP_ENABLE
1609
1610config HW_PERF_EVENTS
1611	def_bool y
1612	depends on ARM_PMU
1613
1614# Supported by clang >= 7.0 or GCC >= 12.0.0
1615config CC_HAVE_SHADOW_CALL_STACK
1616	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1617
1618config PARAVIRT
1619	bool "Enable paravirtualization code"
1620	select HAVE_PV_STEAL_CLOCK_GEN
1621	help
1622	  This changes the kernel so it can modify itself when it is run
1623	  under a hypervisor, potentially improving performance significantly
1624	  over full virtualization.
1625
1626config PARAVIRT_TIME_ACCOUNTING
1627	bool "Paravirtual steal time accounting"
1628	select PARAVIRT
1629	help
1630	  Select this option to enable fine granularity task steal time
1631	  accounting. Time spent executing other tasks in parallel with
1632	  the current vCPU is discounted from the vCPU power. To account for
1633	  that, there can be a small performance impact.
1634
1635	  If in doubt, say N here.
1636
1637config ARCH_SUPPORTS_KEXEC
1638	def_bool PM_SLEEP_SMP
1639
1640config ARCH_SUPPORTS_KEXEC_FILE
1641	def_bool y
1642
1643config ARCH_SELECTS_KEXEC_FILE
1644	def_bool y
1645	depends on KEXEC_FILE
1646	select HAVE_IMA_KEXEC if IMA
1647
1648config ARCH_SUPPORTS_KEXEC_SIG
1649	def_bool y
1650
1651config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1652	def_bool y
1653
1654config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1655	def_bool y
1656
1657config ARCH_SUPPORTS_KEXEC_HANDOVER
1658	def_bool y
1659
1660config ARCH_SUPPORTS_CRASH_DUMP
1661	def_bool y
1662
1663config ARCH_DEFAULT_CRASH_DUMP
1664	def_bool y
1665
1666config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1667	def_bool CRASH_RESERVE
1668
1669config TRANS_TABLE
1670	def_bool y
1671	depends on HIBERNATION || KEXEC_CORE
1672
1673config XEN_DOM0
1674	def_bool y
1675	depends on XEN
1676
1677config XEN
1678	bool "Xen guest support on ARM64"
1679	depends on ARM64 && OF
1680	select SWIOTLB_XEN
1681	select PARAVIRT
1682	help
1683	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1684
1685# include/linux/mmzone.h requires the following to be true:
1686#
1687#   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1688#
1689# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1690#
1691#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1692# ----+-------------------+--------------+----------------------+-------------------------+
1693# 4K  |       27          |      12      |       15             |         10              |
1694# 16K |       27          |      14      |       13             |         11              |
1695# 64K |       29          |      16      |       13             |         13              |
1696config ARCH_FORCE_MAX_ORDER
1697	int
1698	default "13" if ARM64_64K_PAGES
1699	default "11" if ARM64_16K_PAGES
1700	default "10"
1701	help
1702	  The kernel page allocator limits the size of maximal physically
1703	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1704	  defines the maximal power of two of number of pages that can be
1705	  allocated as a single contiguous block. This option allows
1706	  overriding the default setting when ability to allocate very
1707	  large blocks of physically contiguous memory is required.
1708
1709	  The maximal size of allocation cannot exceed the size of the
1710	  section, so the value of MAX_PAGE_ORDER should satisfy
1711
1712	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1713
1714	  Don't change if unsure.
1715
1716config UNMAP_KERNEL_AT_EL0
1717	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1718	default y
1719	help
1720	  Speculation attacks against some high-performance processors can
1721	  be used to bypass MMU permission checks and leak kernel data to
1722	  userspace. This can be defended against by unmapping the kernel
1723	  when running in userspace, mapping it back in on exception entry
1724	  via a trampoline page in the vector table.
1725
1726	  If unsure, say Y.
1727
1728config MITIGATE_SPECTRE_BRANCH_HISTORY
1729	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1730	default y
1731	help
1732	  Speculation attacks against some high-performance processors can
1733	  make use of branch history to influence future speculation.
1734	  When taking an exception from user-space, a sequence of branches
1735	  or a firmware call overwrites the branch history.
1736
1737config ARM64_SW_TTBR0_PAN
1738	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1739	depends on !KCSAN
1740	help
1741	  Enabling this option prevents the kernel from accessing
1742	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1743	  zeroed area and reserved ASID. The user access routines
1744	  restore the valid TTBR0_EL1 temporarily.
1745
1746config ARM64_TAGGED_ADDR_ABI
1747	bool "Enable the tagged user addresses syscall ABI"
1748	default y
1749	help
1750	  When this option is enabled, user applications can opt in to a
1751	  relaxed ABI via prctl() allowing tagged addresses to be passed
1752	  to system calls as pointer arguments. For details, see
1753	  Documentation/arch/arm64/tagged-address-abi.rst.
1754
1755menuconfig COMPAT
1756	bool "Kernel support for 32-bit EL0"
1757	depends on ARM64_4K_PAGES || EXPERT
1758	select HAVE_UID16
1759	select OLD_SIGSUSPEND3
1760	select COMPAT_OLD_SIGACTION
1761	help
1762	  This option enables support for a 32-bit EL0 running under a 64-bit
1763	  kernel at EL1. AArch32-specific components such as system calls,
1764	  the user helper functions, VFP support and the ptrace interface are
1765	  handled appropriately by the kernel.
1766
1767	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1768	  that you will only be able to execute AArch32 binaries that were compiled
1769	  with page size aligned segments.
1770
1771	  If you want to execute 32-bit userspace applications, say Y.
1772
1773if COMPAT
1774
1775config KUSER_HELPERS
1776	bool "Enable kuser helpers page for 32-bit applications"
1777	default y
1778	help
1779	  Warning: disabling this option may break 32-bit user programs.
1780
1781	  Provide kuser helpers to compat tasks. The kernel provides
1782	  helper code to userspace in read only form at a fixed location
1783	  to allow userspace to be independent of the CPU type fitted to
1784	  the system. This permits binaries to be run on ARMv4 through
1785	  to ARMv8 without modification.
1786
1787	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1788
1789	  However, the fixed address nature of these helpers can be used
1790	  by ROP (return orientated programming) authors when creating
1791	  exploits.
1792
1793	  If all of the binaries and libraries which run on your platform
1794	  are built specifically for your platform, and make no use of
1795	  these helpers, then you can turn this option off to hinder
1796	  such exploits. However, in that case, if a binary or library
1797	  relying on those helpers is run, it will not function correctly.
1798
1799	  Say N here only if you are absolutely certain that you do not
1800	  need these helpers; otherwise, the safe option is to say Y.
1801
1802config COMPAT_VDSO
1803	bool "Enable vDSO for 32-bit applications"
1804	depends on !CPU_BIG_ENDIAN
1805	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1806	default y
1807	help
1808	  Place in the process address space of 32-bit applications an
1809	  ELF shared object providing fast implementations of gettimeofday
1810	  and clock_gettime.
1811
1812	  You must have a 32-bit build of glibc 2.22 or later for programs
1813	  to seamlessly take advantage of this.
1814
1815config THUMB2_COMPAT_VDSO
1816	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1817	depends on COMPAT_VDSO
1818	default y
1819	help
1820	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1821	  otherwise with '-marm'.
1822
1823config COMPAT_ALIGNMENT_FIXUPS
1824	bool "Fix up misaligned multi-word loads and stores in user space"
1825
1826menuconfig ARMV8_DEPRECATED
1827	bool "Emulate deprecated/obsolete ARMv8 instructions"
1828	depends on SYSCTL
1829	help
1830	  Legacy software support may require certain instructions
1831	  that have been deprecated or obsoleted in the architecture.
1832
1833	  Enable this config to enable selective emulation of these
1834	  features.
1835
1836	  If unsure, say Y
1837
1838if ARMV8_DEPRECATED
1839
1840config SWP_EMULATION
1841	bool "Emulate SWP/SWPB instructions"
1842	help
1843	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1844	  they are always undefined. Say Y here to enable software
1845	  emulation of these instructions for userspace using LDXR/STXR.
1846	  This feature can be controlled at runtime with the abi.swp
1847	  sysctl which is disabled by default.
1848
1849	  In some older versions of glibc [<=2.8] SWP is used during futex
1850	  trylock() operations with the assumption that the code will not
1851	  be preempted. This invalid assumption may be more likely to fail
1852	  with SWP emulation enabled, leading to deadlock of the user
1853	  application.
1854
1855	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1856	  on an external transaction monitoring block called a global
1857	  monitor to maintain update atomicity. If your system does not
1858	  implement a global monitor, this option can cause programs that
1859	  perform SWP operations to uncached memory to deadlock.
1860
1861	  If unsure, say Y
1862
1863config CP15_BARRIER_EMULATION
1864	bool "Emulate CP15 Barrier instructions"
1865	help
1866	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1867	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1868	  strongly recommended to use the ISB, DSB, and DMB
1869	  instructions instead.
1870
1871	  Say Y here to enable software emulation of these
1872	  instructions for AArch32 userspace code. When this option is
1873	  enabled, CP15 barrier usage is traced which can help
1874	  identify software that needs updating. This feature can be
1875	  controlled at runtime with the abi.cp15_barrier sysctl.
1876
1877	  If unsure, say Y
1878
1879config SETEND_EMULATION
1880	bool "Emulate SETEND instruction"
1881	help
1882	  The SETEND instruction alters the data-endianness of the
1883	  AArch32 EL0, and is deprecated in ARMv8.
1884
1885	  Say Y here to enable software emulation of the instruction
1886	  for AArch32 userspace code. This feature can be controlled
1887	  at runtime with the abi.setend sysctl.
1888
1889	  Note: All the cpus on the system must have mixed endian support at EL0
1890	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1891	  endian - is hotplugged in after this feature has been enabled, there could
1892	  be unexpected results in the applications.
1893
1894	  If unsure, say Y
1895endif # ARMV8_DEPRECATED
1896
1897endif # COMPAT
1898
1899menu "ARMv8.1 architectural features"
1900
1901config ARM64_HW_AFDBM
1902	bool "Support for hardware updates of the Access and Dirty page flags"
1903	default y
1904	help
1905	  The ARMv8.1 architecture extensions introduce support for
1906	  hardware updates of the access and dirty information in page
1907	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1908	  capable processors, accesses to pages with PTE_AF cleared will
1909	  set this bit instead of raising an access flag fault.
1910	  Similarly, writes to read-only pages with the DBM bit set will
1911	  clear the read-only bit (AP[2]) instead of raising a
1912	  permission fault.
1913
1914	  Kernels built with this configuration option enabled continue
1915	  to work on pre-ARMv8.1 hardware and the performance impact is
1916	  minimal. If unsure, say Y.
1917
1918endmenu # "ARMv8.1 architectural features"
1919
1920menu "ARMv8.2 architectural features"
1921
1922config ARM64_PMEM
1923	bool "Enable support for persistent memory"
1924	select ARCH_HAS_PMEM_API
1925	select ARCH_HAS_UACCESS_FLUSHCACHE
1926	help
1927	  Say Y to enable support for the persistent memory API based on the
1928	  ARMv8.2 DCPoP feature.
1929
1930	  The feature is detected at runtime, and the kernel will use DC CVAC
1931	  operations if DC CVAP is not supported (following the behaviour of
1932	  DC CVAP itself if the system does not define a point of persistence).
1933
1934config ARM64_RAS_EXTN
1935	bool "Enable support for RAS CPU Extensions"
1936	default y
1937	help
1938	  CPUs that support the Reliability, Availability and Serviceability
1939	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1940	  errors, classify them and report them to software.
1941
1942	  On CPUs with these extensions system software can use additional
1943	  barriers to determine if faults are pending and read the
1944	  classification from a new set of registers.
1945
1946	  Selecting this feature will allow the kernel to use these barriers
1947	  and access the new registers if the system supports the extension.
1948	  Platform RAS features may additionally depend on firmware support.
1949
1950config ARM64_CNP
1951	bool "Enable support for Common Not Private (CNP) translations"
1952	default y
1953	help
1954	  Common Not Private (CNP) allows translation table entries to
1955	  be shared between different PEs in the same inner shareable
1956	  domain, so the hardware can use this fact to optimise the
1957	  caching of such entries in the TLB.
1958
1959	  Selecting this option allows the CNP feature to be detected
1960	  at runtime, and does not affect PEs that do not implement
1961	  this feature.
1962
1963endmenu # "ARMv8.2 architectural features"
1964
1965menu "ARMv8.3 architectural features"
1966
1967config ARM64_PTR_AUTH
1968	bool "Enable support for pointer authentication"
1969	default y
1970	help
1971	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1972	  instructions for signing and authenticating pointers against secret
1973	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1974	  and other attacks.
1975
1976	  This option enables these instructions at EL0 (i.e. for userspace).
1977	  Choosing this option will cause the kernel to initialise secret keys
1978	  for each process at exec() time, with these keys being
1979	  context-switched along with the process.
1980
1981	  The feature is detected at runtime. If the feature is not present in
1982	  hardware it will not be advertised to userspace/KVM guest nor will it
1983	  be enabled.
1984
1985	  If the feature is present on the boot CPU but not on a late CPU, then
1986	  the late CPU will be parked. Also, if the boot CPU does not have
1987	  address auth and the late CPU has then the late CPU will still boot
1988	  but with the feature disabled. On such a system, this option should
1989	  not be selected.
1990
1991config ARM64_PTR_AUTH_KERNEL
1992	bool "Use pointer authentication for kernel"
1993	default y
1994	depends on ARM64_PTR_AUTH
1995	# Modern compilers insert a .note.gnu.property section note for PAC
1996	# which is only understood by binutils starting with version 2.33.1.
1997	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1998	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1999	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2000	help
2001	  If the compiler supports the -mbranch-protection or
2002	  -msign-return-address flag (e.g. GCC 7 or later), then this option
2003	  will cause the kernel itself to be compiled with return address
2004	  protection. In this case, and if the target hardware is known to
2005	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
2006	  disabled with minimal loss of protection.
2007
2008	  This feature works with FUNCTION_GRAPH_TRACER option only if
2009	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
2010
2011config CC_HAS_BRANCH_PROT_PAC_RET
2012	# GCC 9 or later, clang 8 or later
2013	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
2014
2015config AS_HAS_CFI_NEGATE_RA_STATE
2016	# binutils 2.34+
2017	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
2018
2019endmenu # "ARMv8.3 architectural features"
2020
2021menu "ARMv8.4 architectural features"
2022
2023config ARM64_AMU_EXTN
2024	bool "Enable support for the Activity Monitors Unit CPU extension"
2025	default y
2026	help
2027	  The activity monitors extension is an optional extension introduced
2028	  by the ARMv8.4 CPU architecture. This enables support for version 1
2029	  of the activity monitors architecture, AMUv1.
2030
2031	  To enable the use of this extension on CPUs that implement it, say Y.
2032
2033	  Note that for architectural reasons, firmware _must_ implement AMU
2034	  support when running on CPUs that present the activity monitors
2035	  extension. The required support is present in:
2036	    * Version 1.5 and later of the ARM Trusted Firmware
2037
2038	  For kernels that have this configuration enabled but boot with broken
2039	  firmware, you may need to say N here until the firmware is fixed.
2040	  Otherwise you may experience firmware panics or lockups when
2041	  accessing the counter registers. Even if you are not observing these
2042	  symptoms, the values returned by the register reads might not
2043	  correctly reflect reality. Most commonly, the value read will be 0,
2044	  indicating that the counter is not enabled.
2045
2046config ARM64_TLB_RANGE
2047	bool "Enable support for tlbi range feature"
2048	default y
2049	help
2050	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2051	  range of input addresses.
2052
2053config ARM64_MPAM
2054	bool "Enable support for MPAM"
2055	select ARM64_MPAM_DRIVER
2056	select ARCH_HAS_CPU_RESCTRL
2057	help
2058	  Memory System Resource Partitioning and Monitoring (MPAM) is an
2059	  optional extension to the Arm architecture that allows each
2060	  transaction issued to the memory system to be labelled with a
2061	  Partition identifier (PARTID) and Performance Monitoring Group
2062	  identifier (PMG).
2063
2064	  Memory system components, such as the caches, can be configured with
2065	  policies to control how much of various physical resources (such as
2066	  memory bandwidth or cache memory) the transactions labelled with each
2067	  PARTID can consume.  Depending on the capabilities of the hardware,
2068	  the PARTID and PMG can also be used as filtering criteria to measure
2069	  the memory system resource consumption of different parts of a
2070	  workload.
2071
2072	  Use of this extension requires CPU support, support in the
2073	  Memory System Components (MSC), and a description from firmware
2074	  of where the MSCs are in the address space.
2075
2076	  MPAM is exposed to user-space via the resctrl pseudo filesystem.
2077
2078	  This option enables the extra context switch code.
2079
2080endmenu # "ARMv8.4 architectural features"
2081
2082menu "ARMv8.5 architectural features"
2083
2084config AS_HAS_ARMV8_5
2085	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2086
2087config ARM64_BTI
2088	bool "Branch Target Identification support"
2089	default y
2090	help
2091	  Branch Target Identification (part of the ARMv8.5 Extensions)
2092	  provides a mechanism to limit the set of locations to which computed
2093	  branch instructions such as BR or BLR can jump.
2094
2095	  To make use of BTI on CPUs that support it, say Y.
2096
2097	  BTI is intended to provide complementary protection to other control
2098	  flow integrity protection mechanisms, such as the Pointer
2099	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2100	  For this reason, it does not make sense to enable this option without
2101	  also enabling support for pointer authentication.  Thus, when
2102	  enabling this option you should also select ARM64_PTR_AUTH=y.
2103
2104	  Userspace binaries must also be specifically compiled to make use of
2105	  this mechanism.  If you say N here or the hardware does not support
2106	  BTI, such binaries can still run, but you get no additional
2107	  enforcement of branch destinations.
2108
2109config ARM64_BTI_KERNEL
2110	bool "Use Branch Target Identification for kernel"
2111	default y
2112	depends on ARM64_BTI
2113	depends on ARM64_PTR_AUTH_KERNEL
2114	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2115	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2116	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2117	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2118	depends on !CC_IS_GCC
2119	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2120	help
2121	  Build the kernel with Branch Target Identification annotations
2122	  and enable enforcement of this for kernel code. When this option
2123	  is enabled and the system supports BTI all kernel code including
2124	  modular code must have BTI enabled.
2125
2126config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2127	# GCC 9 or later, clang 8 or later
2128	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2129
2130config ARM64_E0PD
2131	bool "Enable support for E0PD"
2132	default y
2133	help
2134	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2135	  that EL0 accesses made via TTBR1 always fault in constant time,
2136	  providing similar benefits to KASLR as those provided by KPTI, but
2137	  with lower overhead and without disrupting legitimate access to
2138	  kernel memory such as SPE.
2139
2140	  This option enables E0PD for TTBR1 where available.
2141
2142config ARM64_AS_HAS_MTE
2143	# Initial support for MTE went in binutils 2.32.0, checked with
2144	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2145	# as a late addition to the final architecture spec (LDGM/STGM)
2146	# is only supported in the newer 2.32.x and 2.33 binutils
2147	# versions, hence the extra "stgm" instruction check below.
2148	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2149
2150config ARM64_MTE
2151	bool "Memory Tagging Extension support"
2152	default y
2153	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2154	depends on AS_HAS_ARMV8_5
2155	# Required for tag checking in the uaccess routines
2156	select ARCH_HAS_SUBPAGE_FAULTS
2157	select ARCH_USES_HIGH_VMA_FLAGS
2158	select ARCH_USES_PG_ARCH_2
2159	select ARCH_USES_PG_ARCH_3
2160	help
2161	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2162	  architectural support for run-time, always-on detection of
2163	  various classes of memory error to aid with software debugging
2164	  to eliminate vulnerabilities arising from memory-unsafe
2165	  languages.
2166
2167	  This option enables the support for the Memory Tagging
2168	  Extension at EL0 (i.e. for userspace).
2169
2170	  Selecting this option allows the feature to be detected at
2171	  runtime. Any secondary CPU not implementing this feature will
2172	  not be allowed a late bring-up.
2173
2174	  Userspace binaries that want to use this feature must
2175	  explicitly opt in. The mechanism for the userspace is
2176	  described in:
2177
2178	  Documentation/arch/arm64/memory-tagging-extension.rst.
2179
2180endmenu # "ARMv8.5 architectural features"
2181
2182menu "ARMv8.7 architectural features"
2183
2184config ARM64_EPAN
2185	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2186	default y
2187	help
2188	  Enhanced Privileged Access Never (EPAN) allows Privileged
2189	  Access Never to be used with Execute-only mappings.
2190
2191	  The feature is detected at runtime, and will remain disabled
2192	  if the cpu does not implement the feature.
2193endmenu # "ARMv8.7 architectural features"
2194
2195config AS_HAS_MOPS
2196	def_bool $(as-instr,.arch_extension mops)
2197
2198menu "ARMv8.9 architectural features"
2199
2200config ARM64_POE
2201	prompt "Permission Overlay Extension"
2202	def_bool y
2203	select ARCH_USES_HIGH_VMA_FLAGS
2204	select ARCH_HAS_PKEYS
2205	help
2206	  The Permission Overlay Extension is used to implement Memory
2207	  Protection Keys. Memory Protection Keys provides a mechanism for
2208	  enforcing page-based protections, but without requiring modification
2209	  of the page tables when an application changes protection domains.
2210
2211	  For details, see Documentation/core-api/protection-keys.rst
2212
2213	  If unsure, say y.
2214
2215config ARCH_PKEY_BITS
2216	int
2217	default 3
2218
2219config ARM64_HAFT
2220	bool "Support for Hardware managed Access Flag for Table Descriptors"
2221	depends on ARM64_HW_AFDBM
2222	default y
2223	help
2224	  The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access
2225	  Flag for Table descriptors. When enabled an architectural executed
2226	  memory access will update the Access Flag in each Table descriptor
2227	  which is accessed during the translation table walk and for which
2228	  the Access Flag is 0. The Access Flag of the Table descriptor use
2229	  the same bit of PTE_AF.
2230
2231	  The feature will only be enabled if all the CPUs in the system
2232	  support this feature. If unsure, say Y.
2233
2234endmenu # "ARMv8.9 architectural features"
2235
2236menu "ARMv9.4 architectural features"
2237
2238config ARM64_GCS
2239	bool "Enable support for Guarded Control Stack (GCS)"
2240	default y
2241	select ARCH_HAS_USER_SHADOW_STACK
2242	select ARCH_USES_HIGH_VMA_FLAGS
2243	help
2244	  Guarded Control Stack (GCS) provides support for a separate
2245	  stack with restricted access which contains only return
2246	  addresses.  This can be used to harden against some attacks
2247	  by comparing return address used by the program with what is
2248	  stored in the GCS, and may also be used to efficiently obtain
2249	  the call stack for applications such as profiling.
2250
2251	  The feature is detected at runtime, and will remain disabled
2252	  if the system does not implement the feature.
2253
2254endmenu # "ARMv9.4 architectural features"
2255
2256config AS_HAS_LSUI
2257	def_bool $(as-instr,.arch_extension lsui)
2258	help
2259	  Supported by LLVM 20+ and binutils 2.45+.
2260
2261menu "ARMv9.6 architectural features"
2262
2263config ARM64_LSUI
2264	bool "Support Unprivileged Load Store Instructions (LSUI)"
2265	default y
2266	depends on AS_HAS_LSUI && !CPU_BIG_ENDIAN
2267	help
2268	  The Unprivileged Load Store Instructions (LSUI) provides
2269	  variants load/store instructions that access user-space memory
2270	  from the kernel without clearing PSTATE.PAN bit.
2271
2272	  This feature is supported by LLVM 20+ and binutils 2.45+.
2273
2274endmenu # "ARMv9.6 architectural feature"
2275
2276config ARM64_SVE
2277	bool "ARM Scalable Vector Extension support"
2278	default y
2279	help
2280	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2281	  execution state which complements and extends the SIMD functionality
2282	  of the base architecture to support much larger vectors and to enable
2283	  additional vectorisation opportunities.
2284
2285	  To enable use of this extension on CPUs that implement it, say Y.
2286
2287	  On CPUs that support the SVE2 extensions, this option will enable
2288	  those too.
2289
2290	  Note that for architectural reasons, firmware _must_ implement SVE
2291	  support when running on SVE capable hardware.  The required support
2292	  is present in:
2293
2294	    * version 1.5 and later of the ARM Trusted Firmware
2295	    * the AArch64 boot wrapper since commit 5e1261e08abf
2296	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2297
2298	  For other firmware implementations, consult the firmware documentation
2299	  or vendor.
2300
2301	  If you need the kernel to boot on SVE-capable hardware with broken
2302	  firmware, you may need to say N here until you get your firmware
2303	  fixed.  Otherwise, you may experience firmware panics or lockups when
2304	  booting the kernel.  If unsure and you are not observing these
2305	  symptoms, you should assume that it is safe to say Y.
2306
2307config AS_HAS_SME
2308	# Supported by LLVM 13+ and binutils 2.38+
2309	def_bool $(as-instr,.arch_extension sme)
2310
2311config ARM64_SME
2312	bool "ARM Scalable Matrix Extension support"
2313	default y
2314	depends on ARM64_SVE
2315	depends on AS_HAS_SME
2316	help
2317	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2318	  execution state which utilises a substantial subset of the SVE
2319	  instruction set, together with the addition of new architectural
2320	  register state capable of holding two dimensional matrix tiles to
2321	  enable various matrix operations.
2322
2323config ARM64_PSEUDO_NMI
2324	bool "Support for NMI-like interrupts"
2325	select ARM_GIC_V3
2326	help
2327	  Adds support for mimicking Non-Maskable Interrupts through the use of
2328	  GIC interrupt priority. This support requires version 3 or later of
2329	  ARM GIC.
2330
2331	  This high priority configuration for interrupts needs to be
2332	  explicitly enabled by setting the kernel parameter
2333	  "irqchip.gicv3_pseudo_nmi" to 1.
2334
2335	  If unsure, say N
2336
2337if ARM64_PSEUDO_NMI
2338config ARM64_DEBUG_PRIORITY_MASKING
2339	bool "Debug interrupt priority masking"
2340	help
2341	  This adds runtime checks to functions enabling/disabling
2342	  interrupts when using priority masking. The additional checks verify
2343	  the validity of ICC_PMR_EL1 when calling concerned functions.
2344
2345	  If unsure, say N
2346endif # ARM64_PSEUDO_NMI
2347
2348config RELOCATABLE
2349	bool "Build a relocatable kernel image" if EXPERT
2350	select ARCH_HAS_RELR
2351	default y
2352	help
2353	  This builds the kernel as a Position Independent Executable (PIE),
2354	  which retains all relocation metadata required to relocate the
2355	  kernel binary at runtime to a different virtual address than the
2356	  address it was linked at.
2357	  Since AArch64 uses the RELA relocation format, this requires a
2358	  relocation pass at runtime even if the kernel is loaded at the
2359	  same address it was linked at.
2360
2361config RANDOMIZE_BASE
2362	bool "Randomize the address of the kernel image"
2363	select RELOCATABLE
2364	help
2365	  Randomizes the virtual address at which the kernel image is
2366	  loaded, as a security feature that deters exploit attempts
2367	  relying on knowledge of the location of kernel internals.
2368
2369	  It is the bootloader's job to provide entropy, by passing a
2370	  random u64 value in /chosen/kaslr-seed at kernel entry.
2371
2372	  When booting via the UEFI stub, it will invoke the firmware's
2373	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2374	  to the kernel proper. In addition, it will randomise the physical
2375	  location of the kernel Image as well.
2376
2377	  If unsure, say N.
2378
2379config RANDOMIZE_MODULE_REGION_FULL
2380	bool "Randomize the module region over a 2 GB range"
2381	depends on RANDOMIZE_BASE
2382	default y
2383	help
2384	  Randomizes the location of the module region inside a 2 GB window
2385	  covering the core kernel. This way, it is less likely for modules
2386	  to leak information about the location of core kernel data structures
2387	  but it does imply that function calls between modules and the core
2388	  kernel will need to be resolved via veneers in the module PLT.
2389
2390	  When this option is not set, the module region will be randomized over
2391	  a limited range that contains the [_stext, _etext] interval of the
2392	  core kernel, so branch relocations are almost always in range unless
2393	  the region is exhausted. In this particular case of region
2394	  exhaustion, modules might be able to fall back to a larger 2GB area.
2395
2396config CC_HAVE_STACKPROTECTOR_SYSREG
2397	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2398
2399config STACKPROTECTOR_PER_TASK
2400	def_bool y
2401	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2402
2403config UNWIND_PATCH_PAC_INTO_SCS
2404	bool "Enable shadow call stack dynamically using code patching"
2405	depends on CC_IS_CLANG
2406	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2407	depends on SHADOW_CALL_STACK
2408	select UNWIND_TABLES
2409	select DYNAMIC_SCS
2410
2411config ARM64_CONTPTE
2412	bool "Contiguous PTE mappings for user memory" if EXPERT
2413	depends on TRANSPARENT_HUGEPAGE
2414	default y
2415	help
2416	  When enabled, user mappings are configured using the PTE contiguous
2417	  bit, for any mappings that meet the size and alignment requirements.
2418	  This reduces TLB pressure and improves performance.
2419
2420endmenu # "Kernel Features"
2421
2422menu "Boot options"
2423
2424config ARM64_ACPI_PARKING_PROTOCOL
2425	bool "Enable support for the ARM64 ACPI parking protocol"
2426	depends on ACPI
2427	help
2428	  Enable support for the ARM64 ACPI parking protocol. If disabled
2429	  the kernel will not allow booting through the ARM64 ACPI parking
2430	  protocol even if the corresponding data is present in the ACPI
2431	  MADT table.
2432
2433config CMDLINE
2434	string "Default kernel command string"
2435	default ""
2436	help
2437	  Provide a set of default command-line options at build time by
2438	  entering them here. As a minimum, you should specify the
2439	  root device (e.g. root=/dev/nfs).
2440
2441choice
2442	prompt "Kernel command line type"
2443	depends on CMDLINE != ""
2444	default CMDLINE_FROM_BOOTLOADER
2445	help
2446	  Choose how the kernel will handle the provided default kernel
2447	  command line string.
2448
2449config CMDLINE_FROM_BOOTLOADER
2450	bool "Use bootloader kernel arguments if available"
2451	help
2452	  Uses the command-line options passed by the boot loader. If
2453	  the boot loader doesn't provide any, the default kernel command
2454	  string provided in CMDLINE will be used.
2455
2456config CMDLINE_FORCE
2457	bool "Always use the default kernel command string"
2458	help
2459	  Always use the default kernel command string, even if the boot
2460	  loader passes other arguments to the kernel.
2461	  This is useful if you cannot or don't want to change the
2462	  command-line options your boot loader passes to the kernel.
2463
2464endchoice
2465
2466config EFI_STUB
2467	bool
2468
2469config EFI
2470	bool "UEFI runtime support"
2471	depends on OF && !CPU_BIG_ENDIAN
2472	depends on KERNEL_MODE_NEON
2473	select ARCH_SUPPORTS_ACPI
2474	select LIBFDT
2475	select UCS2_STRING
2476	select EFI_PARAMS_FROM_FDT
2477	select EFI_RUNTIME_WRAPPERS
2478	select EFI_STUB
2479	select EFI_GENERIC_STUB
2480	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2481	default y
2482	help
2483	  This option provides support for runtime services provided
2484	  by UEFI firmware (such as non-volatile variables, realtime
2485	  clock, and platform reset). A UEFI stub is also provided to
2486	  allow the kernel to be booted as an EFI application. This
2487	  is only useful on systems that have UEFI firmware.
2488
2489config COMPRESSED_INSTALL
2490	bool "Install compressed image by default"
2491	help
2492	  This makes the regular "make install" install the compressed
2493	  image we built, not the legacy uncompressed one.
2494
2495	  You can check that a compressed image works for you by doing
2496	  "make zinstall" first, and verifying that everything is fine
2497	  in your environment before making "make install" do this for
2498	  you.
2499
2500config DMI
2501	bool "Enable support for SMBIOS (DMI) tables"
2502	depends on EFI
2503	default y
2504	help
2505	  This enables SMBIOS/DMI feature for systems.
2506
2507	  This option is only useful on systems that have UEFI firmware.
2508	  However, even with this option, the resultant kernel should
2509	  continue to boot on existing non-UEFI platforms.
2510
2511endmenu # "Boot options"
2512
2513menu "Power management options"
2514
2515source "kernel/power/Kconfig"
2516
2517config ARCH_HIBERNATION_POSSIBLE
2518	def_bool y
2519	depends on CPU_PM
2520
2521config ARCH_HIBERNATION_HEADER
2522	def_bool y
2523	depends on HIBERNATION
2524
2525config ARCH_SUSPEND_POSSIBLE
2526	def_bool y
2527
2528endmenu # "Power management options"
2529
2530menu "CPU Power Management"
2531
2532source "drivers/cpuidle/Kconfig"
2533
2534source "drivers/cpufreq/Kconfig"
2535
2536endmenu # "CPU Power Management"
2537
2538source "drivers/acpi/Kconfig"
2539
2540source "arch/arm64/kvm/Kconfig"
2541
2542source "kernel/livepatch/Kconfig"
2543