xref: /linux/arch/arm64/Kconfig (revision 0c65a1331928d0207c385f03fb5eba0cfecce0e6)
1# SPDX-License-Identifier: GPL-2.0-only
2config ARM64
3	def_bool y
4	select ACPI_APMT if ACPI
5	select ACPI_CCA_REQUIRED if ACPI
6	select ACPI_GENERIC_GSI if ACPI
7	select ACPI_GTDT if ACPI
8	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
9	select ACPI_IORT if ACPI
10	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
11	select ACPI_MCFG if (ACPI && PCI)
12	select ACPI_SPCR_TABLE if ACPI
13	select ACPI_PPTT if ACPI
14	select ARCH_HAS_DEBUG_WX
15	select ARCH_BINFMT_ELF_EXTRA_PHDRS
16	select ARCH_BINFMT_ELF_STATE
17	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
18	select ARCH_ENABLE_MEMORY_HOTPLUG
19	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
20	select ARCH_HAS_PMD_SOFTLEAVES if TRANSPARENT_HUGEPAGE
21	select ARCH_HAS_CACHE_LINE_SIZE
22	select ARCH_HAS_CC_PLATFORM
23	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
24	select ARCH_HAS_CURRENT_STACK_POINTER
25	select ARCH_HAS_DEBUG_VIRTUAL
26	select ARCH_HAS_DEBUG_VM_PGTABLE
27	select ARCH_HAS_DMA_OPS if XEN
28	select ARCH_HAS_DMA_PREP_COHERENT
29	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
30	select ARCH_HAS_FAST_MULTIPLIER
31	select ARCH_HAS_FORTIFY_SOURCE
32	select ARCH_HAS_GCOV_PROFILE_ALL
33	select ARCH_HAS_GIGANTIC_PAGE
34	select ARCH_HAS_KCOV
35	select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON
36	select ARCH_HAS_KEEPINITRD
37	select ARCH_HAS_LAZY_MMU_MODE
38	select ARCH_HAS_MEMBARRIER_SYNC_CORE
39	select ARCH_HAS_MEM_ENCRYPT
40	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
41	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
42	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
43	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
44	select ARCH_HAS_PREEMPT_LAZY
45	select ARCH_HAS_PTDUMP
46	select ARCH_HAS_PTE_SPECIAL
47	select ARCH_HAS_HW_PTE_YOUNG
48	select ARCH_HAS_SETUP_DMA_OPS
49	select ARCH_HAS_SET_DIRECT_MAP
50	select ARCH_HAS_SET_MEMORY
51	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
52	select ARCH_STACKWALK
53	select ARCH_HAS_STRICT_KERNEL_RWX
54	select ARCH_HAS_STRICT_MODULE_RWX
55	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
56	select ARCH_HAS_SYNC_DMA_FOR_CPU
57	select ARCH_HAS_BATCHED_DMA_SYNC
58	select ARCH_HAS_SYSCALL_WRAPPER
59	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
60	select ARCH_HAS_ZONE_DMA_SET if EXPERT
61	select ARCH_HAVE_ELF_PROT
62	select ARCH_HAVE_NMI_SAFE_CMPXCHG
63	select ARCH_HAVE_TRACE_MMIO_ACCESS
64	select ARCH_KEEP_MEMBLOCK
65	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
66	select ARCH_USE_CMPXCHG_LOCKREF
67	select ARCH_USE_GNU_PROPERTY
68	select ARCH_USE_MEMTEST
69	select ARCH_USE_QUEUED_RWLOCKS
70	select ARCH_USE_QUEUED_SPINLOCKS
71	select ARCH_USE_SYM_ANNOTATIONS
72	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
73	select ARCH_SUPPORTS_HUGETLBFS
74	select ARCH_SUPPORTS_MEMORY_FAILURE
75	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
76	select ARCH_SUPPORTS_LTO_CLANG 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_HAS_PTE_PROTNONE
82	select ARCH_SUPPORTS_NUMA_BALANCING
83	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
84	select ARCH_SUPPORTS_PER_VMA_LOCK
85	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
86	select ARCH_SUPPORTS_RT
87	select ARCH_SUPPORTS_SCHED_SMT
88	select ARCH_SUPPORTS_SCHED_CLUSTER
89	select ARCH_SUPPORTS_SCHED_MC
90	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
91	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
92	select ARCH_WANT_DEFAULT_BPF_JIT
93	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
94	select ARCH_WANT_FRAME_POINTERS
95	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
96	select ARCH_WANT_LD_ORPHAN_WARN
97	select ARCH_WANTS_EXECMEM_LATE
98	select ARCH_WANTS_NO_INSTR
99	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
100	select ARCH_HAS_UBSAN
101	select ARM_AMBA
102	select ARM_ARCH_TIMER
103	select ARM_GIC
104	select AUDIT_ARCH_COMPAT_GENERIC
105	select ARM_GIC_V2M if PCI
106	select ARM_GIC_V3
107	select ARM_GIC_V3_ITS if PCI
108	select ARM_GIC_V5
109	select ARM_PSCI_FW
110	select BUILDTIME_TABLE_SORT
111	select CLONE_BACKWARDS
112	select COMMON_CLK
113	select CPU_PM if (SUSPEND || CPU_IDLE)
114	select CPUMASK_OFFSTACK if NR_CPUS > 256
115	select DCACHE_WORD_ACCESS
116	select HAVE_EXTRA_IPI_TRACEPOINTS
117	select DYNAMIC_FTRACE if FUNCTION_TRACER
118	select DMA_BOUNCE_UNALIGNED_KMALLOC
119	select DMA_DIRECT_REMAP
120	select EDAC_SUPPORT
121	select FRAME_POINTER
122	select FUNCTION_ALIGNMENT_4B
123	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
124	select GENERIC_ALLOCATOR
125	select GENERIC_ARCH_TOPOLOGY
126	select GENERIC_CLOCKEVENTS_BROADCAST
127	select GENERIC_CPU_AUTOPROBE
128	select GENERIC_CPU_CACHE_MAINTENANCE
129	select GENERIC_CPU_DEVICES
130	select GENERIC_CPU_VULNERABILITIES
131	select GENERIC_EARLY_IOREMAP
132	select GENERIC_IDLE_POLL_SETUP
133	select GENERIC_IOREMAP
134	select GENERIC_IRQ_ENTRY
135	select GENERIC_IRQ_IPI
136	select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
137	select GENERIC_IRQ_PROBE
138	select GENERIC_IRQ_SHOW
139	select GENERIC_IRQ_SHOW_LEVEL
140	select GENERIC_LIB_DEVMEM_IS_ALLOWED
141	select GENERIC_PCI_IOMAP
142	select GENERIC_SCHED_CLOCK
143	select GENERIC_SMP_IDLE_THREAD
144	select GENERIC_GETTIMEOFDAY
145	select HARDIRQS_SW_RESEND
146	select HAS_IOPORT
147	select HAVE_MOVE_PMD
148	select HAVE_MOVE_PUD
149	select HAVE_PCI
150	select HAVE_ACPI_APEI if (ACPI && EFI)
151	select HAVE_ALIGNED_STRUCT_PAGE
152	select HAVE_ARCH_AUDITSYSCALL
153	select HAVE_ARCH_BITREVERSE if BITREVERSE
154	select HAVE_ARCH_COMPILER_H
155	select HAVE_ARCH_HUGE_VMALLOC
156	select HAVE_ARCH_HUGE_VMAP
157	select HAVE_ARCH_JUMP_LABEL
158	select HAVE_ARCH_JUMP_LABEL_RELATIVE
159	select HAVE_ARCH_KASAN
160	select HAVE_ARCH_KASAN_VMALLOC
161	select HAVE_ARCH_KASAN_SW_TAGS
162	select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
163	# Some instrumentation may be unsound, hence EXPERT
164	select HAVE_ARCH_KCSAN if EXPERT
165	select HAVE_ARCH_KFENCE
166	select HAVE_ARCH_KGDB
167	select HAVE_ARCH_KSTACK_ERASE
168	select HAVE_ARCH_MMAP_RND_BITS
169	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
170	select HAVE_ARCH_PREL32_RELOCATIONS
171	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
172	select HAVE_ARCH_SECCOMP_FILTER
173	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
174	select HAVE_ARCH_TRACEHOOK
175	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
176	select HAVE_ARCH_VMAP_STACK
177	select HAVE_ARM_SMCCC
178	select HAVE_ASM_MODVERSIONS
179	select HAVE_EBPF_JIT
180	select HAVE_C_RECORDMCOUNT
181	select HAVE_CMPXCHG_DOUBLE
182	select HAVE_CMPXCHG_LOCAL
183	select HAVE_CONTEXT_TRACKING_USER
184	select HAVE_DEBUG_KMEMLEAK
185	select HAVE_DMA_CONTIGUOUS
186	select HAVE_DYNAMIC_FTRACE
187	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
188		if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
189		    CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
190	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
191		if DYNAMIC_FTRACE_WITH_ARGS
192	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
193		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \
194		    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
195	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
196		if DYNAMIC_FTRACE_WITH_ARGS
197	select HAVE_SAMPLE_FTRACE_DIRECT
198	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
199	select HAVE_BUILDTIME_MCOUNT_SORT
200	select HAVE_EFFICIENT_UNALIGNED_ACCESS
201	select HAVE_GUP_FAST
202	select HAVE_FTRACE_GRAPH_FUNC
203	select HAVE_FUNCTION_TRACER
204	select HAVE_FUNCTION_ERROR_INJECTION
205	select HAVE_FUNCTION_GRAPH_FREGS
206	select HAVE_FUNCTION_GRAPH_TRACER
207	select HAVE_GCC_PLUGINS
208	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
209		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
210	select HAVE_HW_BREAKPOINT if PERF_EVENTS
211	select HAVE_IOREMAP_PROT
212	select HAVE_IRQ_TIME_ACCOUNTING
213	select HAVE_LIVEPATCH
214	select HAVE_MOD_ARCH_SPECIFIC
215	select HAVE_NMI
216	select HAVE_PERF_EVENTS
217	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
218	select HAVE_PERF_REGS
219	select HAVE_PERF_USER_STACK_DUMP
220	select HAVE_PREEMPT_DYNAMIC_KEY
221	select HAVE_REGS_AND_STACK_ACCESS_API
222	select HAVE_RELIABLE_STACKTRACE
223	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
224	select HAVE_FUNCTION_ARG_ACCESS_API
225	select MMU_GATHER_RCU_TABLE_FREE
226	select HAVE_RSEQ
227	select HAVE_RUST if RUSTC_SUPPORTS_ARM64
228	select HAVE_STACKPROTECTOR
229	select HAVE_STATIC_CALL if CFI
230	select HAVE_SYSCALL_TRACEPOINTS
231	select HAVE_KPROBES
232	select HAVE_KRETPROBES
233	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
234	select HOTPLUG_SMT if HOTPLUG_CPU
235	select IRQ_DOMAIN
236	select IRQ_FORCED_THREADING
237	select JUMP_LABEL
238	select KASAN_VMALLOC if KASAN
239	select LOCK_MM_AND_FIND_VMA
240	select MODULES_USE_ELF_RELA
241	select NEED_DMA_MAP_STATE
242	select NEED_SG_DMA_LENGTH
243	select OF
244	select OF_EARLY_FLATTREE
245	select PCI_DOMAINS_GENERIC if PCI
246	select PCI_ECAM if (ACPI && PCI)
247	select PCI_SYSCALL if PCI
248	select POWER_RESET
249	select POWER_SUPPLY
250	select HAS_SEPARATE_PREEMPT_RESCHED_BITS
251	select SPARSE_IRQ
252	select SWIOTLB
253	select SYSCTL_EXCEPTION_TRACE
254	select THREAD_INFO_IN_TASK
255	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
256	select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
257	select TRACE_IRQFLAGS_SUPPORT
258	select TRACE_IRQFLAGS_NMI_SUPPORT
259	select HAVE_SOFTIRQ_ON_OWN_STACK
260	select USER_STACKTRACE_SUPPORT
261	select VDSO_GETRANDOM
262	select VMAP_STACK
263	help
264	  ARM 64-bit (AArch64) Linux support.
265
266config RUSTC_SUPPORTS_ARM64
267	def_bool y
268	depends on CPU_LITTLE_ENDIAN
269
270config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
271	def_bool CC_IS_CLANG
272	# https://github.com/ClangBuiltLinux/linux/issues/1507
273	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
274
275config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
276	def_bool CC_IS_GCC
277	depends on $(cc-option,-fpatchable-function-entry=2)
278
279config 64BIT
280	def_bool y
281
282config MMU
283	def_bool y
284
285config ARM64_CONT_PTE_SHIFT
286	int
287	default 5 if PAGE_SIZE_64KB
288	default 7 if PAGE_SIZE_16KB
289	default 4
290
291config ARM64_CONT_PMD_SHIFT
292	int
293	default 5 if PAGE_SIZE_64KB
294	default 5 if PAGE_SIZE_16KB
295	default 4
296
297config ARCH_MMAP_RND_BITS_MIN
298	default 14 if PAGE_SIZE_64KB
299	default 16 if PAGE_SIZE_16KB
300	default 18
301
302# max bits determined by the following formula:
303#  VA_BITS - PTDESC_TABLE_SHIFT
304config ARCH_MMAP_RND_BITS_MAX
305	default 19 if ARM64_VA_BITS=36
306	default 24 if ARM64_VA_BITS=39
307	default 27 if ARM64_VA_BITS=42
308	default 30 if ARM64_VA_BITS=47
309	default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES
310	default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES
311	default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52)
312	default 14 if ARM64_64K_PAGES
313	default 16 if ARM64_16K_PAGES
314	default 18
315
316config ARCH_MMAP_RND_COMPAT_BITS_MIN
317	default 7 if ARM64_64K_PAGES
318	default 9 if ARM64_16K_PAGES
319	default 11
320
321config ARCH_MMAP_RND_COMPAT_BITS_MAX
322	default 16
323
324config NO_IOPORT_MAP
325	def_bool y if !PCI
326
327config STACKTRACE_SUPPORT
328	def_bool y
329
330config ILLEGAL_POINTER_VALUE
331	hex
332	default 0xdead000000000000
333
334config LOCKDEP_SUPPORT
335	def_bool y
336
337config GENERIC_BUG
338	def_bool y
339	depends on BUG
340
341config GENERIC_BUG_RELATIVE_POINTERS
342	def_bool y
343	depends on GENERIC_BUG
344
345config GENERIC_HWEIGHT
346	def_bool y
347
348config GENERIC_CSUM
349	def_bool y
350
351config GENERIC_CALIBRATE_DELAY
352	def_bool y
353
354config SMP
355	def_bool y
356
357config KERNEL_MODE_NEON
358	def_bool y
359
360config FIX_EARLYCON_MEM
361	def_bool y
362
363config PGTABLE_LEVELS
364	int
365	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
366	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
367	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
368	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
369	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
370	default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
371	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
372	default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
373
374config ARCH_SUPPORTS_UPROBES
375	def_bool y
376
377config ARCH_PROC_KCORE_TEXT
378	def_bool y
379
380config BROKEN_GAS_INST
381	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
382
383config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
384	bool
385	# Clang's __builtin_return_address() strips the PAC since 12.0.0
386	# https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
387	default y if CC_IS_CLANG
388	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
389	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
390	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
391	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
392	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
393	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
394	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
395	default n
396
397config KASAN_SHADOW_OFFSET
398	hex
399	depends on KASAN_GENERIC || KASAN_SW_TAGS
400	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
401	default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
402	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
403	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
404	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
405	default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
406	default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
407	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
408	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
409	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
410	default 0xffffffffffffffff
411
412config UNWIND_TABLES
413	bool
414
415source "arch/arm64/Kconfig.platforms"
416
417menu "Kernel Features"
418
419menu "ARM errata workarounds via the alternatives framework"
420
421config AMPERE_ERRATUM_AC03_CPU_38
422        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
423	default y
424	help
425	  This option adds an alternative code sequence to work around Ampere
426	  errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
427
428	  The affected design reports FEAT_HAFDBS as not implemented in
429	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
430	  as required by the architecture. The unadvertised HAFDBS
431	  implementation suffers from an additional erratum where hardware
432	  A/D updates can occur after a PTE has been marked invalid.
433
434	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
435	  which avoids enabling unadvertised hardware Access Flag management
436	  at stage-2.
437
438	  If unsure, say Y.
439
440config AMPERE_ERRATUM_AC04_CPU_23
441        bool "AmpereOne: AC04_CPU_23:  Failure to synchronize writes to HCR_EL2 may corrupt address translations."
442	default y
443	help
444	  This option adds an alternative code sequence to work around Ampere
445	  errata AC04_CPU_23 on AmpereOne.
446
447	  Updates to HCR_EL2 can rarely corrupt simultaneous translations for
448	  data addresses initiated by load/store instructions. Only
449	  instruction initiated translations are vulnerable, not translations
450	  from prefetches for example. A DSB before the store to HCR_EL2 is
451	  sufficient to prevent older instructions from hitting the window
452	  for corruption, and an ISB after is sufficient to prevent younger
453	  instructions from hitting the window for corruption.
454
455	  If unsure, say Y.
456
457config ARM64_WORKAROUND_CLEAN_CACHE
458	bool
459
460config ARM64_ERRATUM_826319
461	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
462	default y
463	select ARM64_WORKAROUND_CLEAN_CACHE
464	help
465	  This option adds an alternative code sequence to work around ARM
466	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
467	  AXI master interface and an L2 cache.
468
469	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
470	  and is unable to accept a certain write via this interface, it will
471	  not progress on read data presented on the read data channel and the
472	  system can deadlock.
473
474	  The workaround promotes data cache clean instructions to
475	  data cache clean-and-invalidate.
476	  Please note that this does not necessarily enable the workaround,
477	  as it depends on the alternative framework, which will only patch
478	  the kernel if an affected CPU is detected.
479
480	  If unsure, say Y.
481
482config ARM64_ERRATUM_827319
483	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
484	default y
485	select ARM64_WORKAROUND_CLEAN_CACHE
486	help
487	  This option adds an alternative code sequence to work around ARM
488	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
489	  master interface and an L2 cache.
490
491	  Under certain conditions this erratum can cause a clean line eviction
492	  to occur at the same time as another transaction to the same address
493	  on the AMBA 5 CHI interface, which can cause data corruption if the
494	  interconnect reorders the two transactions.
495
496	  The workaround promotes data cache clean instructions to
497	  data cache clean-and-invalidate.
498	  Please note that this does not necessarily enable the workaround,
499	  as it depends on the alternative framework, which will only patch
500	  the kernel if an affected CPU is detected.
501
502	  If unsure, say Y.
503
504config ARM64_ERRATUM_824069
505	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
506	default y
507	select ARM64_WORKAROUND_CLEAN_CACHE
508	help
509	  This option adds an alternative code sequence to work around ARM
510	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
511	  to a coherent interconnect.
512
513	  If a Cortex-A53 processor is executing a store or prefetch for
514	  write instruction at the same time as a processor in another
515	  cluster is executing a cache maintenance operation to the same
516	  address, then this erratum might cause a clean cache line to be
517	  incorrectly marked as dirty.
518
519	  The workaround promotes data cache clean instructions to
520	  data cache clean-and-invalidate.
521	  Please note that this option does not necessarily enable the
522	  workaround, as it depends on the alternative framework, which will
523	  only patch the kernel if an affected CPU is detected.
524
525	  If unsure, say Y.
526
527config ARM64_ERRATUM_819472
528	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
529	default y
530	select ARM64_WORKAROUND_CLEAN_CACHE
531	help
532	  This option adds an alternative code sequence to work around ARM
533	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
534	  present when it is connected to a coherent interconnect.
535
536	  If the processor is executing a load and store exclusive sequence at
537	  the same time as a processor in another cluster is executing a cache
538	  maintenance operation to the same address, then this erratum might
539	  cause data corruption.
540
541	  The workaround promotes data cache clean instructions to
542	  data cache clean-and-invalidate.
543	  Please note that this does not necessarily enable the workaround,
544	  as it depends on the alternative framework, which will only patch
545	  the kernel if an affected CPU is detected.
546
547	  If unsure, say Y.
548
549config ARM64_ERRATUM_832075
550	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
551	default y
552	help
553	  This option adds an alternative code sequence to work around ARM
554	  erratum 832075 on Cortex-A57 parts up to r1p2.
555
556	  Affected Cortex-A57 parts might deadlock when exclusive load/store
557	  instructions to Write-Back memory are mixed with Device loads.
558
559	  The workaround is to promote device loads to use Load-Acquire
560	  semantics.
561	  Please note that this does not necessarily enable the workaround,
562	  as it depends on the alternative framework, which will only patch
563	  the kernel if an affected CPU is detected.
564
565	  If unsure, say Y.
566
567config ARM64_ERRATUM_834220
568	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
569	depends on KVM
570	help
571	  This option adds an alternative code sequence to work around ARM
572	  erratum 834220 on Cortex-A57 parts up to r1p2.
573
574	  Affected Cortex-A57 parts might report a Stage 2 translation
575	  fault as the result of a Stage 1 fault for load crossing a
576	  page boundary when there is a permission or device memory
577	  alignment fault at Stage 1 and a translation fault at Stage 2.
578
579	  The workaround is to verify that the Stage 1 translation
580	  doesn't generate a fault before handling the Stage 2 fault.
581	  Please note that this does not necessarily enable the workaround,
582	  as it depends on the alternative framework, which will only patch
583	  the kernel if an affected CPU is detected.
584
585	  If unsure, say N.
586
587config ARM64_ERRATUM_1742098
588	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
589	depends on COMPAT
590	default y
591	help
592	  This option removes the AES hwcap for aarch32 user-space to
593	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
594
595	  Affected parts may corrupt the AES state if an interrupt is
596	  taken between a pair of AES instructions. These instructions
597	  are only present if the cryptography extensions are present.
598	  All software should have a fallback implementation for CPUs
599	  that don't implement the cryptography extensions.
600
601	  If unsure, say Y.
602
603config ARM64_ERRATUM_845719
604	bool "Cortex-A53: 845719: a load might read incorrect data"
605	depends on COMPAT
606	default y
607	help
608	  This option adds an alternative code sequence to work around ARM
609	  erratum 845719 on Cortex-A53 parts up to r0p4.
610
611	  When running a compat (AArch32) userspace on an affected Cortex-A53
612	  part, a load at EL0 from a virtual address that matches the bottom 32
613	  bits of the virtual address used by a recent load at (AArch64) EL1
614	  might return incorrect data.
615
616	  The workaround is to write the contextidr_el1 register on exception
617	  return to a 32-bit task.
618	  Please note that this does not necessarily enable the workaround,
619	  as it depends on the alternative framework, which will only patch
620	  the kernel if an affected CPU is detected.
621
622	  If unsure, say Y.
623
624config ARM64_ERRATUM_843419
625	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
626	default y
627	help
628	  This option links the kernel with '--fix-cortex-a53-843419' and
629	  enables PLT support to replace certain ADRP instructions, which can
630	  cause subsequent memory accesses to use an incorrect address on
631	  Cortex-A53 parts up to r0p4.
632
633	  If unsure, say Y.
634
635config ARM64_ERRATUM_1024718
636	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
637	default y
638	help
639	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
640
641	  Affected Cortex-A55 cores (all revisions) could cause incorrect
642	  update of the hardware dirty bit when the DBM/AP bits are updated
643	  without a break-before-make. The workaround is to disable the usage
644	  of hardware DBM locally on the affected cores. CPUs not affected by
645	  this erratum will continue to use the feature.
646
647	  If unsure, say Y.
648
649config ARM64_ERRATUM_1418040
650	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
651	default y
652	depends on COMPAT
653	help
654	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
655	  errata 1188873 and 1418040.
656
657	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
658	  cause register corruption when accessing the timer registers
659	  from AArch32 userspace.
660
661	  If unsure, say Y.
662
663config ARM64_WORKAROUND_SPECULATIVE_AT
664	bool
665
666config ARM64_ERRATUM_1165522
667	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
668	default y
669	select ARM64_WORKAROUND_SPECULATIVE_AT
670	help
671	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
672
673	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
674	  corrupted TLBs by speculating an AT instruction during a guest
675	  context switch.
676
677	  If unsure, say Y.
678
679config ARM64_ERRATUM_1319367
680	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
681	default y
682	select ARM64_WORKAROUND_SPECULATIVE_AT
683	help
684	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
685	  and A72 erratum 1319367
686
687	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
688	  speculating an AT instruction during a guest context switch.
689
690	  If unsure, say Y.
691
692config ARM64_ERRATUM_1530923
693	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
694	default y
695	select ARM64_WORKAROUND_SPECULATIVE_AT
696	help
697	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
698
699	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
700	  corrupted TLBs by speculating an AT instruction during a guest
701	  context switch.
702
703	  If unsure, say Y.
704
705config ARM64_WORKAROUND_REPEAT_TLBI_SYNC
706	bool
707	# This workaround is (only) suitable for TLB invalidation errata where
708	# all of the following conditions are true:
709	#
710	# - The effects of the errata are only a loss of ordering/completion
711	#   for explicit memory accesses when the TLBI is completed with a DSB.
712	#   The removal of TLB entries is not affected.
713	#
714	#   Note that architecturally, S2-only invalidation does not remove
715	#   combined S1+S2 entries, and does not complete accesses translated
716	#   via those S1+S2 entries. Consequently, where this condition holds,
717	#   the errata do not affect S2-only invalidation.
718	#
719	# - The errata only affect broadcast TLB invalidation operations (e.g.
720	#   TLBI VMALLE1IS), and do not affect local TLB invalidation
721	#   operations (e.g. TLBI VMALLE1).
722	#
723	# - After any number of affected TLBI operations are completed with a
724	#   DSB, the errata can be mitigated by executing a single arbitrary
725	#   broadcast TLBI (which targets an arbitrary translation regime),
726	#   followed by a DSB.
727	#
728	# For more rationale, see commit a8f78680ee6bf795.
729
730config ARM64_ERRATUM_2441007
731	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
732	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
733	help
734	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
735
736	  Under very rare circumstances, affected Cortex-A55 CPUs
737	  may not handle a race between a break-before-make sequence on one
738	  CPU, and another CPU accessing the same page. This could allow a
739	  store to a page that has been unmapped.
740
741	  Work around this by adding the affected CPUs to the list that needs
742	  TLB sequences to be done twice.
743
744	  If unsure, say N.
745
746config ARM64_ERRATUM_1286807
747	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
748	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
749	help
750	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
751
752	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
753	  address for a cacheable mapping of a location is being
754	  accessed by a core while another core is remapping the virtual
755	  address to a new physical page using the recommended
756	  break-before-make sequence, then under very rare circumstances
757	  TLBI+DSB completes before a read using the translation being
758	  invalidated has been observed by other observers. The
759	  workaround repeats the TLBI+DSB operation.
760
761	  If unsure, say N.
762
763config ARM64_ERRATUM_1463225
764	bool "Cortex-A76: Software Step might prevent interrupt recognition"
765	default y
766	help
767	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
768
769	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
770	  of a system call instruction (SVC) can prevent recognition of
771	  subsequent interrupts when software stepping is disabled in the
772	  exception handler of the system call and either kernel debugging
773	  is enabled or VHE is in use.
774
775	  Work around the erratum by triggering a dummy step exception
776	  when handling a system call from a task that is being stepped
777	  in a VHE configuration of the kernel.
778
779	  If unsure, say Y.
780
781config ARM64_ERRATUM_1542419
782	bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
783	help
784	  This option adds a workaround for ARM Neoverse-N1 erratum
785	  1542419.
786
787	  Affected Neoverse-N1 cores could execute a stale instruction when
788	  modified by another CPU. The workaround depends on a firmware
789	  counterpart.
790
791	  Workaround the issue by hiding the DIC feature from EL0. This
792	  forces user-space to perform cache maintenance.
793
794	  If unsure, say N.
795
796config ARM64_ERRATUM_1508412
797	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
798	default y
799	help
800	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
801
802	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
803	  of a store-exclusive or read of PAR_EL1 and a load with device or
804	  non-cacheable memory attributes. The workaround depends on a firmware
805	  counterpart.
806
807	  KVM guests must also have the workaround implemented or they can
808	  deadlock the system.
809
810	  Work around the issue by inserting DMB SY barriers around PAR_EL1
811	  register reads and warning KVM users. The DMB barrier is sufficient
812	  to prevent a speculative PAR_EL1 read.
813
814	  If unsure, say Y.
815
816config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
817	bool
818
819config ARM64_ERRATUM_2051678
820	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
821	default y
822	help
823	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
824	  Affected Cortex-A510 might not respect the ordering rules for
825	  hardware update of the page table's dirty bit. The workaround
826	  is to not enable the feature on affected CPUs.
827
828	  If unsure, say Y.
829
830config ARM64_ERRATUM_2077057
831	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
832	default y
833	help
834	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
835	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
836	  expected, but a Pointer Authentication trap is taken instead. The
837	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
838	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
839
840	  This can only happen when EL2 is stepping EL1.
841
842	  When these conditions occur, the SPSR_EL2 value is unchanged from the
843	  previous guest entry, and can be restored from the in-memory copy.
844
845	  If unsure, say Y.
846
847config ARM64_ERRATUM_2658417
848	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
849	default y
850	help
851	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
852	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
853	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
854	  A510 CPUs are using shared neon hardware. As the sharing is not
855	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
856	  user-space should not be using these instructions.
857
858	  If unsure, say Y.
859
860config ARM64_ERRATUM_2119858
861	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
862	default y
863	depends on CORESIGHT_TRBE
864	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
865	help
866	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
867
868	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
869	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
870	  the event of a WRAP event.
871
872	  Work around the issue by always making sure we move the TRBPTR_EL1 by
873	  256 bytes before enabling the buffer and filling the first 256 bytes of
874	  the buffer with ETM ignore packets upon disabling.
875
876	  If unsure, say Y.
877
878config ARM64_ERRATUM_2139208
879	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
880	default y
881	depends on CORESIGHT_TRBE
882	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
883	help
884	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
885
886	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
887	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
888	  the event of a WRAP event.
889
890	  Work around the issue by always making sure we move the TRBPTR_EL1 by
891	  256 bytes before enabling the buffer and filling the first 256 bytes of
892	  the buffer with ETM ignore packets upon disabling.
893
894	  If unsure, say Y.
895
896config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
897	bool
898
899config ARM64_ERRATUM_2054223
900	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
901	default y
902	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
903	help
904	  Enable workaround for ARM Cortex-A710 erratum 2054223
905
906	  Affected cores may fail to flush the trace data on a TSB instruction, when
907	  the PE is in trace prohibited state. This will cause losing a few bytes
908	  of the trace cached.
909
910	  Workaround is to issue two TSB consecutively on affected cores.
911
912	  If unsure, say Y.
913
914config ARM64_ERRATUM_2067961
915	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
916	default y
917	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
918	help
919	  Enable workaround for ARM Neoverse-N2 erratum 2067961
920
921	  Affected cores may fail to flush the trace data on a TSB instruction, when
922	  the PE is in trace prohibited state. This will cause losing a few bytes
923	  of the trace cached.
924
925	  Workaround is to issue two TSB consecutively on affected cores.
926
927	  If unsure, say Y.
928
929config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
930	bool
931
932config ARM64_ERRATUM_2253138
933	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
934	depends on CORESIGHT_TRBE
935	default y
936	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
937	help
938	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
939
940	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
941	  for TRBE. Under some conditions, the TRBE might generate a write to the next
942	  virtually addressed page following the last page of the TRBE address space
943	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
944
945	  Work around this in the driver by always making sure that there is a
946	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
947
948	  If unsure, say Y.
949
950config ARM64_ERRATUM_2224489
951	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
952	depends on CORESIGHT_TRBE
953	default y
954	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
955	help
956	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
957
958	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
959	  for TRBE. Under some conditions, the TRBE might generate a write to the next
960	  virtually addressed page following the last page of the TRBE address space
961	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
962
963	  Work around this in the driver by always making sure that there is a
964	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
965
966	  If unsure, say Y.
967
968config ARM64_ERRATUM_2441009
969	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
970	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
971	help
972	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
973
974	  Under very rare circumstances, affected Cortex-A510 CPUs
975	  may not handle a race between a break-before-make sequence on one
976	  CPU, and another CPU accessing the same page. This could allow a
977	  store to a page that has been unmapped.
978
979	  Work around this by adding the affected CPUs to the list that needs
980	  TLB sequences to be done twice.
981
982	  If unsure, say N.
983
984config ARM64_ERRATUM_2064142
985	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
986	depends on CORESIGHT_TRBE
987	default y
988	help
989	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
990
991	  Affected Cortex-A510 core might fail to write into system registers after the
992	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
993	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
994	  and TRBTRG_EL1 will be ignored and will not be effected.
995
996	  Work around this in the driver by executing TSB CSYNC and DSB after collection
997	  is stopped and before performing a system register write to one of the affected
998	  registers.
999
1000	  If unsure, say Y.
1001
1002config ARM64_ERRATUM_2038923
1003	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
1004	depends on CORESIGHT_TRBE
1005	default y
1006	help
1007	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
1008
1009	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
1010	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
1011	  might be corrupted. This happens after TRBE buffer has been enabled by setting
1012	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
1013	  execution changes from a context, in which trace is prohibited to one where it
1014	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
1015	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
1016	  the trace buffer state might be corrupted.
1017
1018	  Work around this in the driver by preventing an inconsistent view of whether the
1019	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
1020	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
1021	  two ISB instructions if no ERET is to take place.
1022
1023	  If unsure, say Y.
1024
1025config ARM64_ERRATUM_1902691
1026	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1027	depends on CORESIGHT_TRBE
1028	default y
1029	help
1030	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1031
1032	  Affected Cortex-A510 core might cause trace data corruption, when being written
1033	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
1034	  trace data.
1035
1036	  Work around this problem in the driver by just preventing TRBE initialization on
1037	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1038	  on such implementations. This will cover the kernel for any firmware that doesn't
1039	  do this already.
1040
1041	  If unsure, say Y.
1042
1043config ARM64_ERRATUM_2457168
1044	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1045	depends on ARM64_AMU_EXTN
1046	default y
1047	help
1048	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1049
1050	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1051	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1052	  incorrectly giving a significantly higher output value.
1053
1054	  Work around this problem by returning 0 when reading the affected counter in
1055	  key locations that results in disabling all users of this counter. This effect
1056	  is the same to firmware disabling affected counters.
1057
1058	  If unsure, say Y.
1059
1060config ARM64_ERRATUM_2645198
1061	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1062	default y
1063	help
1064	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1065
1066	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1067	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1068	  next instruction abort caused by permission fault.
1069
1070	  Only user-space does executable to non-executable permission transition via
1071	  mprotect() system call. Workaround the problem by doing a break-before-make
1072	  TLB invalidation, for all changes to executable user space mappings.
1073
1074	  If unsure, say Y.
1075
1076config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1077	bool
1078
1079config ARM64_ERRATUM_2966298
1080	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1081	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1082	default y
1083	help
1084	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1085
1086	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1087	  load might leak data from a privileged level via a cache side channel.
1088
1089	  Work around this problem by executing a TLBI before returning to EL0.
1090
1091	  If unsure, say Y.
1092
1093config ARM64_ERRATUM_3117295
1094	bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1095	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1096	default y
1097	help
1098	  This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1099
1100	  On an affected Cortex-A510 core, a speculatively executed unprivileged
1101	  load might leak data from a privileged level via a cache side channel.
1102
1103	  Work around this problem by executing a TLBI before returning to EL0.
1104
1105	  If unsure, say Y.
1106
1107config ARM64_ERRATUM_3194386
1108	bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1109	default y
1110	help
1111	  This option adds the workaround for the following errata:
1112
1113	  * ARM Cortex-A76 erratum 3324349
1114	  * ARM Cortex-A77 erratum 3324348
1115	  * ARM Cortex-A78 erratum 3324344
1116	  * ARM Cortex-A78C erratum 3324346
1117	  * ARM Cortex-A78C erratum 3324347
1118	  * ARM Cortex-A710 erratam 3324338
1119	  * ARM Cortex-A715 errartum 3456084
1120	  * ARM Cortex-A720 erratum 3456091
1121	  * ARM Cortex-A725 erratum 3456106
1122	  * ARM Cortex-X1 erratum 3324344
1123	  * ARM Cortex-X1C erratum 3324346
1124	  * ARM Cortex-X2 erratum 3324338
1125	  * ARM Cortex-X3 erratum 3324335
1126	  * ARM Cortex-X4 erratum 3194386
1127	  * ARM Cortex-X925 erratum 3324334
1128	  * ARM Neoverse-N1 erratum 3324349
1129	  * ARM Neoverse N2 erratum 3324339
1130	  * ARM Neoverse-N3 erratum 3456111
1131	  * ARM Neoverse-V1 erratum 3324341
1132	  * ARM Neoverse V2 erratum 3324336
1133	  * ARM Neoverse-V3 erratum 3312417
1134	  * ARM Neoverse-V3AE erratum 3312417
1135
1136	  On affected cores "MSR SSBS, #0" instructions may not affect
1137	  subsequent speculative instructions, which may permit unexepected
1138	  speculative store bypassing.
1139
1140	  Work around this problem by placing a Speculation Barrier (SB) or
1141	  Instruction Synchronization Barrier (ISB) after kernel changes to
1142	  SSBS. The presence of the SSBS special-purpose register is hidden
1143	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1144	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1145
1146	  If unsure, say Y.
1147
1148config ARM64_ERRATUM_4311569
1149	bool "SI L1: 4311569: workaround for premature CMO completion erratum"
1150	default y
1151	help
1152	  This option adds the workaround for ARM SI L1 erratum 4311569.
1153
1154	  The erratum of SI L1 can cause an early response to a combined write
1155	  and cache maintenance operation (WR+CMO) before the operation is fully
1156	  completed to the Point of Serialization (POS).
1157	  This can result in a non-I/O coherent agent observing stale data,
1158	  potentially leading to system instability or incorrect behavior.
1159
1160	  Enabling this option implements a software workaround by inserting a
1161	  second loop of Cache Maintenance Operation (CMO) immediately following the
1162	  end of function to do CMOs. This ensures that the data is correctly serialized
1163	  before the buffer is handed off to a non-coherent agent.
1164
1165	  If unsure, say Y.
1166
1167config ARM64_ERRATUM_4193714
1168	bool "C1-Pro: 4193714: SME DVMSync early acknowledgement"
1169	depends on ARM64_SME
1170	default y
1171	help
1172	  Enable workaround for C1-Pro acknowledging the DVMSync before
1173	  the SME memory accesses are complete. This will cause TLB
1174	  maintenance for processes using SME to also issue an IPI to
1175	  the affected CPUs.
1176
1177	  If unsure, say Y.
1178
1179config ARM64_ERRATUM_4118414
1180	bool "Various: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
1181	default y
1182	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
1183	help
1184	  This option adds a workaround for the following errata:
1185
1186	  * ARM C1-Premium erratum 4193780
1187	  * ARM C1-Ultra erratum 4193780
1188	  * ARM Cortex-A76 erratum 4193800
1189	  * ARM Cortex-A76AE erratum 4193801
1190	  * ARM Cortex-A77 erratum 4193798
1191	  * ARM Cortex-A78 erratum 4193791
1192	  * ARM Cortex-A78AE erratum 4193793
1193	  * ARM Cortex-A78C erratum 4193794
1194	  * ARM Cortex-A710 erratum 4193788
1195	  * ARM Cortex-X1 erratum 4193791
1196	  * ARM Cortex-X1C erratum 4193792
1197	  * ARM Cortex-X2 erratum 4193788
1198	  * ARM Cortex-X3 erratum 4193786
1199	  * ARM Cortex-X4 erratum 4118414
1200	  * ARM Cortex-X925 erratum 4193781
1201	  * ARM Neoverse-N1 erratum 4193800
1202	  * ARM Neoverse-N2 erratum 4193789
1203	  * ARM Neoverse-V1 erratum 4193790
1204	  * ARM Neoverse-V2 erratum 4193787
1205	  * ARM Neoverse-V3 erratum 4193784
1206	  * ARM Neoverse-V3AE erratum 4193784
1207	  * Microsoft Azure Cobalt 100 4193789
1208	  * NVIDIA Olympus erratum T410-OLY-1029
1209
1210	  On affected cores, some memory accesses might not be completed by
1211	  broadcast TLB invalidation.
1212
1213	  This issue is also known as CVE-2025-10263.
1214
1215	  If unsure, say Y.
1216
1217config CAVIUM_ERRATUM_22375
1218	bool "Cavium erratum 22375, 24313"
1219	default y
1220	help
1221	  Enable workaround for errata 22375 and 24313.
1222
1223	  This implements two gicv3-its errata workarounds for ThunderX. Both
1224	  with a small impact affecting only ITS table allocation.
1225
1226	    erratum 22375: only alloc 8MB table size
1227	    erratum 24313: ignore memory access type
1228
1229	  The fixes are in ITS initialization and basically ignore memory access
1230	  type and table size provided by the TYPER and BASER registers.
1231
1232	  If unsure, say Y.
1233
1234config CAVIUM_ERRATUM_23144
1235	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1236	depends on NUMA
1237	default y
1238	help
1239	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1240
1241	  If unsure, say Y.
1242
1243config CAVIUM_ERRATUM_23154
1244	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1245	default y
1246	help
1247	  The ThunderX GICv3 implementation requires a modified version for
1248	  reading the IAR status to ensure data synchronization
1249	  (access to icc_iar1_el1 is not sync'ed before and after).
1250
1251	  It also suffers from erratum 38545 (also present on Marvell's
1252	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1253	  spuriously presented to the CPU interface.
1254
1255	  If unsure, say Y.
1256
1257config CAVIUM_ERRATUM_27456
1258	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1259	default y
1260	help
1261	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1262	  instructions may cause the icache to become corrupted if it
1263	  contains data for a non-current ASID.  The fix is to
1264	  invalidate the icache when changing the mm context.
1265
1266	  If unsure, say Y.
1267
1268config CAVIUM_ERRATUM_30115
1269	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1270	default y
1271	help
1272	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1273	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1274	  interrupts in host. Trapping both GICv3 group-0 and group-1
1275	  accesses sidesteps the issue.
1276
1277	  If unsure, say Y.
1278
1279config CAVIUM_TX2_ERRATUM_219
1280	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1281	default y
1282	help
1283	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1284	  TTBR update and the corresponding context synchronizing operation can
1285	  cause a spurious Data Abort to be delivered to any hardware thread in
1286	  the CPU core.
1287
1288	  Work around the issue by avoiding the problematic code sequence and
1289	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1290	  trap handler performs the corresponding register access, skips the
1291	  instruction and ensures context synchronization by virtue of the
1292	  exception return.
1293
1294	  If unsure, say Y.
1295
1296config FUJITSU_ERRATUM_010001
1297	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1298	default y
1299	help
1300	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1301	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1302	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1303	  This fault occurs under a specific hardware condition when a
1304	  load/store instruction performs an address translation using:
1305	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1306	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1307	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1308	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1309
1310	  The workaround is to ensure these bits are clear in TCR_ELx.
1311	  The workaround only affects the Fujitsu-A64FX.
1312
1313	  If unsure, say Y.
1314
1315config HISILICON_ERRATUM_161600802
1316	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1317	default y
1318	help
1319	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1320	  when issued ITS commands such as VMOVP and VMAPP, and requires
1321	  a 128kB offset to be applied to the target address in this commands.
1322
1323	  If unsure, say Y.
1324
1325config HISILICON_ERRATUM_162100801
1326	bool "Hip09 162100801 erratum support"
1327	default y
1328	help
1329	  When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches
1330	  during unmapping operation, which will cause some vSGIs lost.
1331	  To fix the issue, invalidate related vPE cache through GICR_INVALLR
1332	  after VMOVP.
1333
1334	  If unsure, say Y.
1335
1336config HISILICON_ERRATUM_162100125
1337	bool "Hisilicon erratum 162100125"
1338	default y
1339	select ARM64_WORKAROUND_DISABLE_CNP
1340	help
1341	  On HiSilicon HIP09, TLB entry matching behavior when CNP
1342	  (TTBRx.CNP=1) is enabled differs from the ARM architecture
1343	  specification.
1344
1345	  TLB entries may be incorrectly shared between CPUs, potentially
1346	  causing TLB conflicts and stale mappings.
1347
1348	  Disable CNP support for affected HiSilicon HIP09 cores.
1349
1350	  If unsure, say Y.
1351
1352config QCOM_FALKOR_ERRATUM_1003
1353	bool "Falkor E1003: Incorrect translation due to ASID change"
1354	default y
1355	help
1356	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1357	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1358	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1359	  then only for entries in the walk cache, since the leaf translation
1360	  is unchanged. Work around the erratum by invalidating the walk cache
1361	  entries for the trampoline before entering the kernel proper.
1362
1363config QCOM_FALKOR_ERRATUM_1009
1364	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1365	default y
1366	select ARM64_WORKAROUND_REPEAT_TLBI_SYNC
1367	help
1368	  On Falkor v1, the CPU may prematurely complete a DSB following a
1369	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1370	  one more time to fix the issue.
1371
1372	  If unsure, say Y.
1373
1374config QCOM_QDF2400_ERRATUM_0065
1375	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1376	default y
1377	help
1378	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1379	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1380	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1381
1382	  If unsure, say Y.
1383
1384config QCOM_FALKOR_ERRATUM_E1041
1385	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1386	default y
1387	help
1388	  Falkor CPU may speculatively fetch instructions from an improper
1389	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1390	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1391
1392	  If unsure, say Y.
1393
1394config ARM64_WORKAROUND_DISABLE_CNP
1395	bool
1396
1397config NVIDIA_CARMEL_CNP_ERRATUM
1398	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1399	default y
1400	select ARM64_WORKAROUND_DISABLE_CNP
1401	help
1402	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1403	  invalidate shared TLB entries installed by a different core, as it would
1404	  on standard ARM cores.
1405
1406	  If unsure, say Y.
1407
1408config NVIDIA_OLYMPUS_1027_ERRATUM
1409	bool "NVIDIA Olympus: device store/load ordering erratum"
1410	default y
1411	help
1412	  This option adds an alternative code sequence to work around an
1413	  NVIDIA Olympus core erratum where a Device-nGnR* store can be
1414	  observed by a peripheral after a younger Device-nGnR* load to the
1415	  same peripheral. This breaks the program order that drivers rely
1416	  on for MMIO and can leave a device in an incorrect state.
1417
1418	  The workaround inserts a DMB OSH immediately before raw MMIO loads.
1419	  The erratum cannot occur when a DMB that orders loads appears
1420	  between the store and load, preventing the younger load from being
1421	  observed before the older store.
1422
1423	  The alternatives framework patches in DMB OSH only when an affected
1424	  CPU is detected. Other CPUs execute a NOP in its place. Disabling
1425	  this option leaves the original MMIO read instruction stream
1426	  unchanged.
1427
1428	  If unsure, say Y.
1429
1430config ALTERA_ERRATUM_AGILEX5_2_1_23
1431	bool
1432	help
1433	  The Altera SoCFPGA Agilex5 GIC600 SoC integration has ACE-lite
1434	  addressing limited to the first 32bit of physical address space,
1435	  so the ITS cannot access memory above 4GB.
1436
1437	  Selected by ARCH_INTEL_SOCFPGA, as all Agilex5 devices are affected.
1438
1439config RENESAS_ERRATUM_GEN4GICITS1
1440	bool "Renesas R-Car Gen4: GIC600 can not access physical addresses above 4 GiB"
1441	default y
1442	help
1443	  The Renesas R-Car Gen4 S4/V4H/V4M GIC600 SoC integrations have AXI
1444	  addressing limited to the first 32-bit of physical address space.
1445
1446	  If unsure, say Y.
1447
1448config ROCKCHIP_ERRATUM_3568002
1449	bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB"
1450	default y
1451	help
1452	  The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI
1453	  addressing limited to the first 32bit of physical address space.
1454
1455	  If unsure, say Y.
1456
1457config ROCKCHIP_ERRATUM_3588001
1458	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1459	default y
1460	help
1461	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1462	  This means, that its sharability feature may not be used, even though it
1463	  is supported by the IP itself.
1464
1465	  If unsure, say Y.
1466
1467config SOCIONEXT_SYNQUACER_PREITS
1468	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1469	default y
1470	help
1471	  Socionext Synquacer SoCs implement a separate h/w block to generate
1472	  MSI doorbell writes with non-zero values for the device ID.
1473
1474	  If unsure, say Y.
1475
1476endmenu # "ARM errata workarounds via the alternatives framework"
1477
1478choice
1479	prompt "Page size"
1480	default ARM64_4K_PAGES
1481	help
1482	  Page size (translation granule) configuration.
1483
1484config ARM64_4K_PAGES
1485	bool "4KB"
1486	select HAVE_PAGE_SIZE_4KB
1487	help
1488	  This feature enables 4KB pages support.
1489
1490config ARM64_16K_PAGES
1491	bool "16KB"
1492	select HAVE_PAGE_SIZE_16KB
1493	help
1494	  The system will use 16KB pages support. AArch32 emulation
1495	  requires applications compiled with 16K (or a multiple of 16K)
1496	  aligned segments.
1497
1498config ARM64_64K_PAGES
1499	bool "64KB"
1500	select HAVE_PAGE_SIZE_64KB
1501	help
1502	  This feature enables 64KB pages support (4KB by default)
1503	  allowing only two levels of page tables and faster TLB
1504	  look-up. AArch32 emulation requires applications compiled
1505	  with 64K aligned segments.
1506
1507endchoice
1508
1509choice
1510	prompt "Virtual address space size"
1511	default ARM64_VA_BITS_52
1512	help
1513	  Allows choosing one of multiple possible virtual address
1514	  space sizes. The level of translation table is determined by
1515	  a combination of page size and virtual address space size.
1516
1517config ARM64_VA_BITS_36
1518	bool "36-bit" if EXPERT
1519	depends on PAGE_SIZE_16KB
1520
1521config ARM64_VA_BITS_39
1522	bool "39-bit"
1523	depends on PAGE_SIZE_4KB
1524
1525config ARM64_VA_BITS_42
1526	bool "42-bit"
1527	depends on PAGE_SIZE_64KB
1528
1529config ARM64_VA_BITS_47
1530	bool "47-bit"
1531	depends on PAGE_SIZE_16KB
1532
1533config ARM64_VA_BITS_48
1534	bool "48-bit"
1535
1536config ARM64_VA_BITS_52
1537	bool "52-bit"
1538	help
1539	  Enable 52-bit virtual addressing for userspace when explicitly
1540	  requested via a hint to mmap(). The kernel will also use 52-bit
1541	  virtual addresses for its own mappings (provided HW support for
1542	  this feature is available, otherwise it reverts to 48-bit).
1543
1544	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1545	  ARMv8.3 Pointer Authentication will result in the PAC being
1546	  reduced from 7 bits to 3 bits, which may have a significant
1547	  impact on its susceptibility to brute-force attacks.
1548
1549	  If unsure, select 48-bit virtual addressing instead.
1550
1551endchoice
1552
1553config ARM64_FORCE_52BIT
1554	bool "Force 52-bit virtual addresses for userspace"
1555	depends on ARM64_VA_BITS_52 && EXPERT
1556	help
1557	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1558	  to maintain compatibility with older software by providing 48-bit VAs
1559	  unless a hint is supplied to mmap.
1560
1561	  This configuration option disables the 48-bit compatibility logic, and
1562	  forces all userspace addresses to be 52-bit on HW that supports it. One
1563	  should only enable this configuration option for stress testing userspace
1564	  memory management code. If unsure say N here.
1565
1566config ARM64_VA_BITS
1567	int
1568	default 36 if ARM64_VA_BITS_36
1569	default 39 if ARM64_VA_BITS_39
1570	default 42 if ARM64_VA_BITS_42
1571	default 47 if ARM64_VA_BITS_47
1572	default 48 if ARM64_VA_BITS_48
1573	default 52 if ARM64_VA_BITS_52
1574
1575choice
1576	prompt "Physical address space size"
1577	default ARM64_PA_BITS_48
1578	help
1579	  Choose the maximum physical address range that the kernel will
1580	  support.
1581
1582config ARM64_PA_BITS_48
1583	bool "48-bit"
1584	depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1585
1586config ARM64_PA_BITS_52
1587	bool "52-bit"
1588	depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1589	help
1590	  Enable support for a 52-bit physical address space, introduced as
1591	  part of the ARMv8.2-LPA extension.
1592
1593	  With this enabled, the kernel will also continue to work on CPUs that
1594	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1595	  minor performance overhead).
1596
1597endchoice
1598
1599config ARM64_PA_BITS
1600	int
1601	default 48 if ARM64_PA_BITS_48
1602	default 52 if ARM64_PA_BITS_52
1603
1604config ARM64_LPA2
1605	def_bool y
1606	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1607
1608choice
1609	prompt "Endianness"
1610	default CPU_LITTLE_ENDIAN
1611	help
1612	  Select the endianness of data accesses performed by the CPU. Userspace
1613	  applications will need to be compiled and linked for the endianness
1614	  that is selected here.
1615
1616config CPU_BIG_ENDIAN
1617	bool "Build big-endian kernel"
1618	depends on BROKEN
1619	help
1620	  Say Y if you plan on running a kernel with a big-endian userspace.
1621
1622config CPU_LITTLE_ENDIAN
1623	bool "Build little-endian kernel"
1624	help
1625	  Say Y if you plan on running a kernel with a little-endian userspace.
1626	  This is usually the case for distributions targeting arm64.
1627
1628endchoice
1629
1630config NR_CPUS
1631	int "Maximum number of CPUs (2-4096)"
1632	range 2 4096
1633	default "512"
1634
1635config HOTPLUG_CPU
1636	bool "Support for hot-pluggable CPUs"
1637	select GENERIC_IRQ_MIGRATION
1638	help
1639	  Say Y here to experiment with turning CPUs off and on.  CPUs
1640	  can be controlled through /sys/devices/system/cpu.
1641
1642# Common NUMA Features
1643config NUMA
1644	bool "NUMA Memory Allocation and Scheduler Support"
1645	select GENERIC_ARCH_NUMA
1646	select OF_NUMA
1647	select HAVE_SETUP_PER_CPU_AREA
1648	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1649	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1650	select USE_PERCPU_NUMA_NODE_ID
1651	help
1652	  Enable NUMA (Non-Uniform Memory Access) support.
1653
1654	  The kernel will try to allocate memory used by a CPU on the
1655	  local memory of the CPU and add some more
1656	  NUMA awareness to the kernel.
1657
1658config NODES_SHIFT
1659	int "Maximum NUMA Nodes (as a power of 2)"
1660	range 1 10
1661	default "4"
1662	depends on NUMA
1663	help
1664	  Specify the maximum number of NUMA Nodes available on the target
1665	  system.  Increases memory reserved to accommodate various tables.
1666
1667source "kernel/Kconfig.hz"
1668
1669config ARCH_SPARSEMEM_ENABLE
1670	def_bool y
1671	select SPARSEMEM_VMEMMAP_ENABLE
1672
1673config HW_PERF_EVENTS
1674	def_bool y
1675	depends on ARM_PMU
1676
1677# Supported by clang >= 7.0 or GCC >= 12.0.0
1678config CC_HAVE_SHADOW_CALL_STACK
1679	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1680
1681config PARAVIRT
1682	bool "Enable paravirtualization code"
1683	select HAVE_PV_STEAL_CLOCK_GEN
1684	help
1685	  This changes the kernel so it can modify itself when it is run
1686	  under a hypervisor, potentially improving performance significantly
1687	  over full virtualization.
1688
1689config PARAVIRT_TIME_ACCOUNTING
1690	bool "Paravirtual steal time accounting"
1691	select PARAVIRT
1692	help
1693	  Select this option to enable fine granularity task steal time
1694	  accounting. Time spent executing other tasks in parallel with
1695	  the current vCPU is discounted from the vCPU power. To account for
1696	  that, there can be a small performance impact.
1697
1698	  If in doubt, say N here.
1699
1700config ARCH_SUPPORTS_KEXEC
1701	def_bool PM_SLEEP_SMP
1702
1703config ARCH_SUPPORTS_KEXEC_FILE
1704	def_bool y
1705
1706config ARCH_SELECTS_KEXEC_FILE
1707	def_bool y
1708	depends on KEXEC_FILE
1709	select HAVE_IMA_KEXEC if IMA
1710
1711config ARCH_SUPPORTS_KEXEC_SIG
1712	def_bool y
1713
1714config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1715	def_bool y
1716
1717config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1718	def_bool y
1719
1720config ARCH_SUPPORTS_KEXEC_HANDOVER
1721	def_bool y
1722
1723config ARCH_SUPPORTS_CRASH_DUMP
1724	def_bool y
1725
1726config ARCH_DEFAULT_CRASH_DUMP
1727	def_bool y
1728
1729config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1730	def_bool CRASH_RESERVE
1731
1732config TRANS_TABLE
1733	def_bool y
1734	depends on HIBERNATION || KEXEC_CORE
1735
1736config XEN_DOM0
1737	def_bool y
1738	depends on XEN
1739
1740config XEN
1741	bool "Xen guest support on ARM64"
1742	depends on ARM64 && OF
1743	select SWIOTLB_XEN
1744	select PARAVIRT
1745	help
1746	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1747
1748# include/linux/mmzone.h requires the following to be true:
1749#
1750#   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1751#
1752# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1753#
1754#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1755# ----+-------------------+--------------+----------------------+-------------------------+
1756# 4K  |       27          |      12      |       15             |         10              |
1757# 16K |       27          |      14      |       13             |         11              |
1758# 64K |       29          |      16      |       13             |         13              |
1759config ARCH_FORCE_MAX_ORDER
1760	int
1761	default "13" if ARM64_64K_PAGES
1762	default "11" if ARM64_16K_PAGES
1763	default "10"
1764	help
1765	  The kernel page allocator limits the size of maximal physically
1766	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1767	  defines the maximal power of two of number of pages that can be
1768	  allocated as a single contiguous block. This option allows
1769	  overriding the default setting when ability to allocate very
1770	  large blocks of physically contiguous memory is required.
1771
1772	  The maximal size of allocation cannot exceed the size of the
1773	  section, so the value of MAX_PAGE_ORDER should satisfy
1774
1775	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1776
1777	  Don't change if unsure.
1778
1779config UNMAP_KERNEL_AT_EL0
1780	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1781	default y
1782	help
1783	  Speculation attacks against some high-performance processors can
1784	  be used to bypass MMU permission checks and leak kernel data to
1785	  userspace. This can be defended against by unmapping the kernel
1786	  when running in userspace, mapping it back in on exception entry
1787	  via a trampoline page in the vector table.
1788
1789	  If unsure, say Y.
1790
1791config MITIGATE_SPECTRE_BRANCH_HISTORY
1792	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1793	default y
1794	help
1795	  Speculation attacks against some high-performance processors can
1796	  make use of branch history to influence future speculation.
1797	  When taking an exception from user-space, a sequence of branches
1798	  or a firmware call overwrites the branch history.
1799
1800config ARM64_SW_TTBR0_PAN
1801	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1802	depends on !KCSAN
1803	help
1804	  Enabling this option prevents the kernel from accessing
1805	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1806	  zeroed area and reserved ASID. The user access routines
1807	  restore the valid TTBR0_EL1 temporarily.
1808
1809config ARM64_TAGGED_ADDR_ABI
1810	bool "Enable the tagged user addresses syscall ABI"
1811	default y
1812	help
1813	  When this option is enabled, user applications can opt in to a
1814	  relaxed ABI via prctl() allowing tagged addresses to be passed
1815	  to system calls as pointer arguments. For details, see
1816	  Documentation/arch/arm64/tagged-address-abi.rst.
1817
1818menuconfig COMPAT
1819	bool "Kernel support for 32-bit EL0"
1820	depends on ARM64_4K_PAGES || EXPERT
1821	select HAVE_UID16
1822	select OLD_SIGSUSPEND3
1823	select COMPAT_OLD_SIGACTION
1824	help
1825	  This option enables support for a 32-bit EL0 running under a 64-bit
1826	  kernel at EL1. AArch32-specific components such as system calls,
1827	  the user helper functions, VFP support and the ptrace interface are
1828	  handled appropriately by the kernel.
1829
1830	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1831	  that you will only be able to execute AArch32 binaries that were compiled
1832	  with page size aligned segments.
1833
1834	  If you want to execute 32-bit userspace applications, say Y.
1835
1836if COMPAT
1837
1838config KUSER_HELPERS
1839	bool "Enable kuser helpers page for 32-bit applications"
1840	default y
1841	help
1842	  Warning: disabling this option may break 32-bit user programs.
1843
1844	  Provide kuser helpers to compat tasks. The kernel provides
1845	  helper code to userspace in read only form at a fixed location
1846	  to allow userspace to be independent of the CPU type fitted to
1847	  the system. This permits binaries to be run on ARMv4 through
1848	  to ARMv8 without modification.
1849
1850	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1851
1852	  However, the fixed address nature of these helpers can be used
1853	  by ROP (return orientated programming) authors when creating
1854	  exploits.
1855
1856	  If all of the binaries and libraries which run on your platform
1857	  are built specifically for your platform, and make no use of
1858	  these helpers, then you can turn this option off to hinder
1859	  such exploits. However, in that case, if a binary or library
1860	  relying on those helpers is run, it will not function correctly.
1861
1862	  Say N here only if you are absolutely certain that you do not
1863	  need these helpers; otherwise, the safe option is to say Y.
1864
1865config COMPAT_VDSO
1866	bool "Enable vDSO for 32-bit applications"
1867	depends on !CPU_BIG_ENDIAN
1868	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1869	default y
1870	help
1871	  Place in the process address space of 32-bit applications an
1872	  ELF shared object providing fast implementations of gettimeofday
1873	  and clock_gettime.
1874
1875	  You must have a 32-bit build of glibc 2.22 or later for programs
1876	  to seamlessly take advantage of this.
1877
1878config THUMB2_COMPAT_VDSO
1879	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1880	depends on COMPAT_VDSO
1881	default y
1882	help
1883	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1884	  otherwise with '-marm'.
1885
1886config COMPAT_ALIGNMENT_FIXUPS
1887	bool "Fix up misaligned multi-word loads and stores in user space"
1888
1889menuconfig ARMV8_DEPRECATED
1890	bool "Emulate deprecated/obsolete ARMv8 instructions"
1891	depends on SYSCTL
1892	help
1893	  Legacy software support may require certain instructions
1894	  that have been deprecated or obsoleted in the architecture.
1895
1896	  Enable this config to enable selective emulation of these
1897	  features.
1898
1899	  If unsure, say Y
1900
1901if ARMV8_DEPRECATED
1902
1903config SWP_EMULATION
1904	bool "Emulate SWP/SWPB instructions"
1905	help
1906	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1907	  they are always undefined. Say Y here to enable software
1908	  emulation of these instructions for userspace using LDXR/STXR.
1909	  This feature can be controlled at runtime with the abi.swp
1910	  sysctl which is disabled by default.
1911
1912	  In some older versions of glibc [<=2.8] SWP is used during futex
1913	  trylock() operations with the assumption that the code will not
1914	  be preempted. This invalid assumption may be more likely to fail
1915	  with SWP emulation enabled, leading to deadlock of the user
1916	  application.
1917
1918	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1919	  on an external transaction monitoring block called a global
1920	  monitor to maintain update atomicity. If your system does not
1921	  implement a global monitor, this option can cause programs that
1922	  perform SWP operations to uncached memory to deadlock.
1923
1924	  If unsure, say Y
1925
1926config CP15_BARRIER_EMULATION
1927	bool "Emulate CP15 Barrier instructions"
1928	help
1929	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1930	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1931	  strongly recommended to use the ISB, DSB, and DMB
1932	  instructions instead.
1933
1934	  Say Y here to enable software emulation of these
1935	  instructions for AArch32 userspace code. When this option is
1936	  enabled, CP15 barrier usage is traced which can help
1937	  identify software that needs updating. This feature can be
1938	  controlled at runtime with the abi.cp15_barrier sysctl.
1939
1940	  If unsure, say Y
1941
1942config SETEND_EMULATION
1943	bool "Emulate SETEND instruction"
1944	help
1945	  The SETEND instruction alters the data-endianness of the
1946	  AArch32 EL0, and is deprecated in ARMv8.
1947
1948	  Say Y here to enable software emulation of the instruction
1949	  for AArch32 userspace code. This feature can be controlled
1950	  at runtime with the abi.setend sysctl.
1951
1952	  Note: All the cpus on the system must have mixed endian support at EL0
1953	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1954	  endian - is hotplugged in after this feature has been enabled, there could
1955	  be unexpected results in the applications.
1956
1957	  If unsure, say Y
1958endif # ARMV8_DEPRECATED
1959
1960endif # COMPAT
1961
1962menu "ARMv8.1 architectural features"
1963
1964config ARM64_HW_AFDBM
1965	bool "Support for hardware updates of the Access and Dirty page flags"
1966	default y
1967	help
1968	  The ARMv8.1 architecture extensions introduce support for
1969	  hardware updates of the access and dirty information in page
1970	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1971	  capable processors, accesses to pages with PTE_AF cleared will
1972	  set this bit instead of raising an access flag fault.
1973	  Similarly, writes to read-only pages with the DBM bit set will
1974	  clear the read-only bit (AP[2]) instead of raising a
1975	  permission fault.
1976
1977	  Kernels built with this configuration option enabled continue
1978	  to work on pre-ARMv8.1 hardware and the performance impact is
1979	  minimal. If unsure, say Y.
1980
1981endmenu # "ARMv8.1 architectural features"
1982
1983menu "ARMv8.2 architectural features"
1984
1985config ARM64_PMEM
1986	bool "Enable support for persistent memory"
1987	select ARCH_HAS_PMEM_API
1988	select ARCH_HAS_UACCESS_FLUSHCACHE
1989	help
1990	  Say Y to enable support for the persistent memory API based on the
1991	  ARMv8.2 DCPoP feature.
1992
1993	  The feature is detected at runtime, and the kernel will use DC CVAC
1994	  operations if DC CVAP is not supported (following the behaviour of
1995	  DC CVAP itself if the system does not define a point of persistence).
1996
1997config ARM64_RAS_EXTN
1998	bool "Enable support for RAS CPU Extensions"
1999	default y
2000	help
2001	  CPUs that support the Reliability, Availability and Serviceability
2002	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
2003	  errors, classify them and report them to software.
2004
2005	  On CPUs with these extensions system software can use additional
2006	  barriers to determine if faults are pending and read the
2007	  classification from a new set of registers.
2008
2009	  Selecting this feature will allow the kernel to use these barriers
2010	  and access the new registers if the system supports the extension.
2011	  Platform RAS features may additionally depend on firmware support.
2012
2013config ARM64_CNP
2014	bool "Enable support for Common Not Private (CNP) translations"
2015	default y
2016	help
2017	  Common Not Private (CNP) allows translation table entries to
2018	  be shared between different PEs in the same inner shareable
2019	  domain, so the hardware can use this fact to optimise the
2020	  caching of such entries in the TLB.
2021
2022	  Selecting this option allows the CNP feature to be detected
2023	  at runtime, and does not affect PEs that do not implement
2024	  this feature.
2025
2026endmenu # "ARMv8.2 architectural features"
2027
2028menu "ARMv8.3 architectural features"
2029
2030config ARM64_PTR_AUTH
2031	bool "Enable support for pointer authentication"
2032	default y
2033	help
2034	  Pointer authentication (part of the ARMv8.3 Extensions) provides
2035	  instructions for signing and authenticating pointers against secret
2036	  keys, which can be used to mitigate Return Oriented Programming (ROP)
2037	  and other attacks.
2038
2039	  This option enables these instructions at EL0 (i.e. for userspace).
2040	  Choosing this option will cause the kernel to initialise secret keys
2041	  for each process at exec() time, with these keys being
2042	  context-switched along with the process.
2043
2044	  The feature is detected at runtime. If the feature is not present in
2045	  hardware it will not be advertised to userspace/KVM guest nor will it
2046	  be enabled.
2047
2048	  If the feature is present on the boot CPU but not on a late CPU, then
2049	  the late CPU will be parked. Also, if the boot CPU does not have
2050	  address auth and the late CPU has then the late CPU will still boot
2051	  but with the feature disabled. On such a system, this option should
2052	  not be selected.
2053
2054config ARM64_PTR_AUTH_KERNEL
2055	bool "Use pointer authentication for kernel"
2056	default y
2057	depends on ARM64_PTR_AUTH
2058	# Modern compilers insert a .note.gnu.property section note for PAC
2059	# which is only understood by binutils starting with version 2.33.1.
2060	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
2061	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
2062	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2063	help
2064	  If the compiler supports the -mbranch-protection or
2065	  -msign-return-address flag (e.g. GCC 7 or later), then this option
2066	  will cause the kernel itself to be compiled with return address
2067	  protection. In this case, and if the target hardware is known to
2068	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
2069	  disabled with minimal loss of protection.
2070
2071	  This feature works with FUNCTION_GRAPH_TRACER option only if
2072	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
2073
2074config CC_HAS_BRANCH_PROT_PAC_RET
2075	# GCC 9 or later, clang 8 or later
2076	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
2077
2078config AS_HAS_CFI_NEGATE_RA_STATE
2079	# binutils 2.34+
2080	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
2081
2082endmenu # "ARMv8.3 architectural features"
2083
2084menu "ARMv8.4 architectural features"
2085
2086config ARM64_AMU_EXTN
2087	bool "Enable support for the Activity Monitors Unit CPU extension"
2088	default y
2089	help
2090	  The activity monitors extension is an optional extension introduced
2091	  by the ARMv8.4 CPU architecture. This enables support for version 1
2092	  of the activity monitors architecture, AMUv1.
2093
2094	  To enable the use of this extension on CPUs that implement it, say Y.
2095
2096	  Note that for architectural reasons, firmware _must_ implement AMU
2097	  support when running on CPUs that present the activity monitors
2098	  extension. The required support is present in:
2099	    * Version 1.5 and later of the ARM Trusted Firmware
2100
2101	  For kernels that have this configuration enabled but boot with broken
2102	  firmware, you may need to say N here until the firmware is fixed.
2103	  Otherwise you may experience firmware panics or lockups when
2104	  accessing the counter registers. Even if you are not observing these
2105	  symptoms, the values returned by the register reads might not
2106	  correctly reflect reality. Most commonly, the value read will be 0,
2107	  indicating that the counter is not enabled.
2108
2109config ARM64_TLB_RANGE
2110	bool "Enable support for tlbi range feature"
2111	default y
2112	help
2113	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2114	  range of input addresses.
2115
2116config ARM64_MPAM
2117	bool "Enable support for MPAM"
2118	select ARM64_MPAM_DRIVER
2119	select ARCH_HAS_CPU_RESCTRL
2120	help
2121	  Memory System Resource Partitioning and Monitoring (MPAM) is an
2122	  optional extension to the Arm architecture that allows each
2123	  transaction issued to the memory system to be labelled with a
2124	  Partition identifier (PARTID) and Performance Monitoring Group
2125	  identifier (PMG).
2126
2127	  Memory system components, such as the caches, can be configured with
2128	  policies to control how much of various physical resources (such as
2129	  memory bandwidth or cache memory) the transactions labelled with each
2130	  PARTID can consume.  Depending on the capabilities of the hardware,
2131	  the PARTID and PMG can also be used as filtering criteria to measure
2132	  the memory system resource consumption of different parts of a
2133	  workload.
2134
2135	  Use of this extension requires CPU support, support in the
2136	  Memory System Components (MSC), and a description from firmware
2137	  of where the MSCs are in the address space.
2138
2139	  MPAM is exposed to user-space via the resctrl pseudo filesystem.
2140
2141	  This option enables the extra context switch code.
2142
2143endmenu # "ARMv8.4 architectural features"
2144
2145menu "ARMv8.5 architectural features"
2146
2147config AS_HAS_ARMV8_5
2148	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2149
2150config ARM64_BTI
2151	bool "Branch Target Identification support"
2152	default y
2153	help
2154	  Branch Target Identification (part of the ARMv8.5 Extensions)
2155	  provides a mechanism to limit the set of locations to which computed
2156	  branch instructions such as BR or BLR can jump.
2157
2158	  To make use of BTI on CPUs that support it, say Y.
2159
2160	  BTI is intended to provide complementary protection to other control
2161	  flow integrity protection mechanisms, such as the Pointer
2162	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2163	  For this reason, it does not make sense to enable this option without
2164	  also enabling support for pointer authentication.  Thus, when
2165	  enabling this option you should also select ARM64_PTR_AUTH=y.
2166
2167	  Userspace binaries must also be specifically compiled to make use of
2168	  this mechanism.  If you say N here or the hardware does not support
2169	  BTI, such binaries can still run, but you get no additional
2170	  enforcement of branch destinations.
2171
2172config ARM64_BTI_KERNEL
2173	bool "Use Branch Target Identification for kernel"
2174	default y
2175	depends on ARM64_BTI
2176	depends on ARM64_PTR_AUTH_KERNEL
2177	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2178	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2179	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2180	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2181	depends on !CC_IS_GCC
2182	# https://github.com/llvm/llvm-project/issues/215547
2183	depends on !CC_IS_CLANG || CLANG_VERSION < 210000
2184	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2185	help
2186	  Build the kernel with Branch Target Identification annotations
2187	  and enable enforcement of this for kernel code. When this option
2188	  is enabled and the system supports BTI all kernel code including
2189	  modular code must have BTI enabled.
2190
2191config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2192	# GCC 9 or later, clang 8 or later
2193	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2194
2195config ARM64_E0PD
2196	bool "Enable support for E0PD"
2197	default y
2198	help
2199	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2200	  that EL0 accesses made via TTBR1 always fault in constant time,
2201	  providing similar benefits to KASLR as those provided by KPTI, but
2202	  with lower overhead and without disrupting legitimate access to
2203	  kernel memory such as SPE.
2204
2205	  This option enables E0PD for TTBR1 where available.
2206
2207config ARM64_AS_HAS_MTE
2208	# Initial support for MTE went in binutils 2.32.0, checked with
2209	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2210	# as a late addition to the final architecture spec (LDGM/STGM)
2211	# is only supported in the newer 2.32.x and 2.33 binutils
2212	# versions, hence the extra "stgm" instruction check below.
2213	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2214
2215config ARM64_MTE
2216	bool "Memory Tagging Extension support"
2217	default y
2218	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2219	depends on AS_HAS_ARMV8_5
2220	# Required for tag checking in the uaccess routines
2221	select ARCH_HAS_SUBPAGE_FAULTS
2222	select ARCH_USES_HIGH_VMA_FLAGS
2223	select ARCH_USES_PG_ARCH_2
2224	select ARCH_USES_PG_ARCH_3
2225	help
2226	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2227	  architectural support for run-time, always-on detection of
2228	  various classes of memory error to aid with software debugging
2229	  to eliminate vulnerabilities arising from memory-unsafe
2230	  languages.
2231
2232	  This option enables the support for the Memory Tagging
2233	  Extension at EL0 (i.e. for userspace).
2234
2235	  Selecting this option allows the feature to be detected at
2236	  runtime. Any secondary CPU not implementing this feature will
2237	  not be allowed a late bring-up.
2238
2239	  Userspace binaries that want to use this feature must
2240	  explicitly opt in. The mechanism for the userspace is
2241	  described in:
2242
2243	  Documentation/arch/arm64/memory-tagging-extension.rst.
2244
2245endmenu # "ARMv8.5 architectural features"
2246
2247menu "ARMv8.7 architectural features"
2248
2249config ARM64_EPAN
2250	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2251	default y
2252	help
2253	  Enhanced Privileged Access Never (EPAN) allows Privileged
2254	  Access Never to be used with Execute-only mappings.
2255
2256	  The feature is detected at runtime, and will remain disabled
2257	  if the cpu does not implement the feature.
2258endmenu # "ARMv8.7 architectural features"
2259
2260config AS_HAS_MOPS
2261	def_bool $(as-instr,.arch_extension mops)
2262
2263menu "ARMv8.9 architectural features"
2264
2265config ARM64_POE
2266	prompt "Permission Overlay Extension"
2267	def_bool y
2268	select ARCH_USES_HIGH_VMA_FLAGS
2269	select ARCH_HAS_PKEYS
2270	help
2271	  The Permission Overlay Extension is used to implement Memory
2272	  Protection Keys. Memory Protection Keys provides a mechanism for
2273	  enforcing page-based protections, but without requiring modification
2274	  of the page tables when an application changes protection domains.
2275
2276	  For details, see Documentation/core-api/protection-keys.rst
2277
2278	  If unsure, say y.
2279
2280config ARCH_PKEY_BITS
2281	int
2282	default 3
2283
2284config ARM64_HAFT
2285	bool "Support for Hardware managed Access Flag for Table Descriptors"
2286	depends on ARM64_HW_AFDBM
2287	default y
2288	help
2289	  The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access
2290	  Flag for Table descriptors. When enabled an architectural executed
2291	  memory access will update the Access Flag in each Table descriptor
2292	  which is accessed during the translation table walk and for which
2293	  the Access Flag is 0. The Access Flag of the Table descriptor use
2294	  the same bit of PTE_AF.
2295
2296	  The feature will only be enabled if all the CPUs in the system
2297	  support this feature. If unsure, say Y.
2298
2299endmenu # "ARMv8.9 architectural features"
2300
2301menu "ARMv9.4 architectural features"
2302
2303config ARM64_GCS
2304	bool "Enable support for Guarded Control Stack (GCS)"
2305	default y
2306	select ARCH_HAS_USER_SHADOW_STACK
2307	select ARCH_USES_HIGH_VMA_FLAGS
2308	help
2309	  Guarded Control Stack (GCS) provides support for a separate
2310	  stack with restricted access which contains only return
2311	  addresses.  This can be used to harden against some attacks
2312	  by comparing return address used by the program with what is
2313	  stored in the GCS, and may also be used to efficiently obtain
2314	  the call stack for applications such as profiling.
2315
2316	  The feature is detected at runtime, and will remain disabled
2317	  if the system does not implement the feature.
2318
2319endmenu # "ARMv9.4 architectural features"
2320
2321config AS_HAS_LSUI
2322	def_bool $(as-instr,.arch_extension lsui)
2323	help
2324	  Supported by LLVM 20+ and binutils 2.45+.
2325
2326menu "ARMv9.6 architectural features"
2327
2328config ARM64_LSUI
2329	bool "Support Unprivileged Load Store Instructions (LSUI)"
2330	default y
2331	depends on AS_HAS_LSUI && !CPU_BIG_ENDIAN
2332	help
2333	  The Unprivileged Load Store Instructions (LSUI) provides
2334	  variants load/store instructions that access user-space memory
2335	  from the kernel without clearing PSTATE.PAN bit.
2336
2337	  This feature is supported by LLVM 20+ and binutils 2.45+.
2338
2339endmenu # "ARMv9.6 architectural feature"
2340
2341config ARM64_SVE
2342	bool "ARM Scalable Vector Extension support"
2343	default y
2344	help
2345	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2346	  execution state which complements and extends the SIMD functionality
2347	  of the base architecture to support much larger vectors and to enable
2348	  additional vectorisation opportunities.
2349
2350	  To enable use of this extension on CPUs that implement it, say Y.
2351
2352	  On CPUs that support the SVE2 extensions, this option will enable
2353	  those too.
2354
2355	  Note that for architectural reasons, firmware _must_ implement SVE
2356	  support when running on SVE capable hardware.  The required support
2357	  is present in:
2358
2359	    * version 1.5 and later of the ARM Trusted Firmware
2360	    * the AArch64 boot wrapper since commit 5e1261e08abf
2361	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2362
2363	  For other firmware implementations, consult the firmware documentation
2364	  or vendor.
2365
2366	  If you need the kernel to boot on SVE-capable hardware with broken
2367	  firmware, you may need to say N here until you get your firmware
2368	  fixed.  Otherwise, you may experience firmware panics or lockups when
2369	  booting the kernel.  If unsure and you are not observing these
2370	  symptoms, you should assume that it is safe to say Y.
2371
2372config AS_HAS_SME
2373	# Supported by LLVM 13+ and binutils 2.38+
2374	def_bool $(as-instr,.arch_extension sme)
2375
2376config ARM64_SME
2377	bool "ARM Scalable Matrix Extension support"
2378	default y
2379	depends on ARM64_SVE
2380	depends on AS_HAS_SME
2381	help
2382	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2383	  execution state which utilises a substantial subset of the SVE
2384	  instruction set, together with the addition of new architectural
2385	  register state capable of holding two dimensional matrix tiles to
2386	  enable various matrix operations.
2387
2388config ARM64_PSEUDO_NMI
2389	bool "Support for NMI-like interrupts"
2390	select ARM_GIC_V3
2391	help
2392	  Adds support for mimicking Non-Maskable Interrupts through the use of
2393	  GIC interrupt priority. This support requires version 3 or later of
2394	  ARM GIC.
2395
2396	  This high priority configuration for interrupts needs to be
2397	  explicitly enabled by setting the kernel parameter
2398	  "irqchip.gicv3_pseudo_nmi" to 1.
2399
2400	  If unsure, say N
2401
2402if ARM64_PSEUDO_NMI
2403config ARM64_DEBUG_PRIORITY_MASKING
2404	bool "Debug interrupt priority masking"
2405	help
2406	  This adds runtime checks to functions enabling/disabling
2407	  interrupts when using priority masking. The additional checks verify
2408	  the validity of ICC_PMR_EL1 when calling concerned functions.
2409
2410	  If unsure, say N
2411endif # ARM64_PSEUDO_NMI
2412
2413config RELOCATABLE
2414	bool "Build a relocatable kernel image" if EXPERT
2415	select ARCH_HAS_RELR
2416	default y
2417	help
2418	  This builds the kernel as a Position Independent Executable (PIE),
2419	  which retains all relocation metadata required to relocate the
2420	  kernel binary at runtime to a different virtual address than the
2421	  address it was linked at.
2422	  Since AArch64 uses the RELA relocation format, this requires a
2423	  relocation pass at runtime even if the kernel is loaded at the
2424	  same address it was linked at.
2425
2426config RANDOMIZE_BASE
2427	bool "Randomize the address of the kernel image"
2428	select RELOCATABLE
2429	help
2430	  Randomizes the virtual address at which the kernel image is
2431	  loaded, as a security feature that deters exploit attempts
2432	  relying on knowledge of the location of kernel internals.
2433
2434	  It is the bootloader's job to provide entropy, by passing a
2435	  random u64 value in /chosen/kaslr-seed at kernel entry.
2436
2437	  When booting via the UEFI stub, it will invoke the firmware's
2438	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2439	  to the kernel proper. In addition, it will randomise the physical
2440	  location of the kernel Image as well.
2441
2442	  If unsure, say N.
2443
2444config RANDOMIZE_MODULE_REGION_FULL
2445	bool "Randomize the module region over a 2 GB range"
2446	depends on RANDOMIZE_BASE
2447	default y
2448	help
2449	  Randomizes the location of the module region inside a 2 GB window
2450	  covering the core kernel. This way, it is less likely for modules
2451	  to leak information about the location of core kernel data structures
2452	  but it does imply that function calls between modules and the core
2453	  kernel will need to be resolved via veneers in the module PLT.
2454
2455	  When this option is not set, the module region will be randomized over
2456	  a limited range that contains the [_stext, _etext] interval of the
2457	  core kernel, so branch relocations are almost always in range unless
2458	  the region is exhausted. In this particular case of region
2459	  exhaustion, modules might be able to fall back to a larger 2GB area.
2460
2461config CC_HAVE_STACKPROTECTOR_SYSREG
2462	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2463
2464config STACKPROTECTOR_PER_TASK
2465	def_bool y
2466	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2467
2468config UNWIND_PATCH_PAC_INTO_SCS
2469	bool "Enable shadow call stack dynamically using code patching"
2470	depends on CC_IS_CLANG
2471	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2472	depends on SHADOW_CALL_STACK
2473	select UNWIND_TABLES
2474	select DYNAMIC_SCS
2475
2476config ARM64_CONTPTE
2477	bool "Contiguous PTE mappings for user memory" if EXPERT
2478	depends on TRANSPARENT_HUGEPAGE
2479	default y
2480	help
2481	  When enabled, user mappings are configured using the PTE contiguous
2482	  bit, for any mappings that meet the size and alignment requirements.
2483	  This reduces TLB pressure and improves performance.
2484
2485endmenu # "Kernel Features"
2486
2487menu "Boot options"
2488
2489config ARM64_ACPI_PARKING_PROTOCOL
2490	bool "Enable support for the ARM64 ACPI parking protocol"
2491	depends on ACPI
2492	help
2493	  Enable support for the ARM64 ACPI parking protocol. If disabled
2494	  the kernel will not allow booting through the ARM64 ACPI parking
2495	  protocol even if the corresponding data is present in the ACPI
2496	  MADT table.
2497
2498config CMDLINE
2499	string "Default kernel command string"
2500	default ""
2501	help
2502	  Provide a set of default command-line options at build time by
2503	  entering them here. As a minimum, you should specify the
2504	  root device (e.g. root=/dev/nfs).
2505
2506choice
2507	prompt "Kernel command line type"
2508	depends on CMDLINE != ""
2509	default CMDLINE_FROM_BOOTLOADER
2510	help
2511	  Choose how the kernel will handle the provided default kernel
2512	  command line string.
2513
2514config CMDLINE_FROM_BOOTLOADER
2515	bool "Use bootloader kernel arguments if available"
2516	help
2517	  Uses the command-line options passed by the boot loader. If
2518	  the boot loader doesn't provide any, the default kernel command
2519	  string provided in CMDLINE will be used.
2520
2521config CMDLINE_FORCE
2522	bool "Always use the default kernel command string"
2523	help
2524	  Always use the default kernel command string, even if the boot
2525	  loader passes other arguments to the kernel.
2526	  This is useful if you cannot or don't want to change the
2527	  command-line options your boot loader passes to the kernel.
2528
2529endchoice
2530
2531config EFI_STUB
2532	bool
2533
2534config EFI
2535	bool "UEFI runtime support"
2536	depends on OF && !CPU_BIG_ENDIAN
2537	depends on KERNEL_MODE_NEON
2538	select ARCH_SUPPORTS_ACPI
2539	select LIBFDT
2540	select UCS2_STRING
2541	select EFI_PARAMS_FROM_FDT
2542	select EFI_RUNTIME_WRAPPERS
2543	select EFI_STUB
2544	select EFI_GENERIC_STUB
2545	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2546	default y
2547	help
2548	  This option provides support for runtime services provided
2549	  by UEFI firmware (such as non-volatile variables, realtime
2550	  clock, and platform reset). A UEFI stub is also provided to
2551	  allow the kernel to be booted as an EFI application. This
2552	  is only useful on systems that have UEFI firmware.
2553
2554config COMPRESSED_INSTALL
2555	bool "Install compressed image by default"
2556	help
2557	  This makes the regular "make install" install the compressed
2558	  image we built, not the legacy uncompressed one.
2559
2560	  You can check that a compressed image works for you by doing
2561	  "make zinstall" first, and verifying that everything is fine
2562	  in your environment before making "make install" do this for
2563	  you.
2564
2565config DMI
2566	bool "Enable support for SMBIOS (DMI) tables"
2567	depends on EFI
2568	default y
2569	help
2570	  This enables SMBIOS/DMI feature for systems.
2571
2572	  This option is only useful on systems that have UEFI firmware.
2573	  However, even with this option, the resultant kernel should
2574	  continue to boot on existing non-UEFI platforms.
2575
2576endmenu # "Boot options"
2577
2578menu "Power management options"
2579
2580source "kernel/power/Kconfig"
2581
2582config ARCH_HIBERNATION_POSSIBLE
2583	def_bool y
2584	depends on CPU_PM
2585
2586config ARCH_HIBERNATION_HEADER
2587	def_bool y
2588	depends on HIBERNATION
2589
2590config ARCH_SUSPEND_POSSIBLE
2591	def_bool y
2592
2593endmenu # "Power management options"
2594
2595menu "CPU Power Management"
2596
2597source "drivers/cpuidle/Kconfig"
2598
2599source "drivers/cpufreq/Kconfig"
2600
2601endmenu # "CPU Power Management"
2602
2603source "drivers/acpi/Kconfig"
2604
2605source "arch/arm64/kvm/Kconfig"
2606
2607source "kernel/livepatch/Kconfig"
2608