xref: /linux/arch/arm64/Kconfig (revision ecacc9c8d3ed0f63065f4a1e94bfd8bf65a3ffaf)
1# SPDX-License-Identifier: GPL-2.0-only
2config ARM64
3	def_bool y
4	select ACPI_APMT if ACPI
5	select ACPI_CCA_REQUIRED if ACPI
6	select ACPI_GENERIC_GSI if ACPI
7	select ACPI_GTDT if ACPI
8	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
9	select ACPI_IORT if ACPI
10	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
11	select ACPI_MCFG if (ACPI && PCI)
12	select ACPI_SPCR_TABLE if ACPI
13	select ACPI_PPTT if ACPI
14	select ARCH_HAS_DEBUG_WX
15	select ARCH_BINFMT_ELF_EXTRA_PHDRS
16	select ARCH_BINFMT_ELF_STATE
17	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
18	select ARCH_ENABLE_MEMORY_HOTPLUG
19	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
20	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
21	select ARCH_HAS_CACHE_LINE_SIZE
22	select ARCH_HAS_CC_PLATFORM
23	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
24	select ARCH_HAS_CURRENT_STACK_POINTER
25	select ARCH_HAS_DEBUG_VIRTUAL
26	select ARCH_HAS_DEBUG_VM_PGTABLE
27	select ARCH_HAS_DMA_OPS if XEN
28	select ARCH_HAS_DMA_PREP_COHERENT
29	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
30	select ARCH_HAS_FAST_MULTIPLIER
31	select ARCH_HAS_FORTIFY_SOURCE
32	select ARCH_HAS_GCOV_PROFILE_ALL
33	select ARCH_HAS_GIGANTIC_PAGE
34	select ARCH_HAS_KCOV
35	select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON
36	select ARCH_HAS_KEEPINITRD
37	select ARCH_HAS_LAZY_MMU_MODE
38	select ARCH_HAS_MEMBARRIER_SYNC_CORE
39	select ARCH_HAS_MEM_ENCRYPT
40	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
41	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
42	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
43	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
44	select ARCH_HAS_PREEMPT_LAZY
45	select ARCH_HAS_PTDUMP
46	select ARCH_HAS_PTE_SPECIAL
47	select ARCH_HAS_HW_PTE_YOUNG
48	select ARCH_HAS_SETUP_DMA_OPS
49	select ARCH_HAS_SET_DIRECT_MAP
50	select ARCH_HAS_SET_MEMORY
51	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
52	select ARCH_STACKWALK
53	select ARCH_HAS_STRICT_KERNEL_RWX
54	select ARCH_HAS_STRICT_MODULE_RWX
55	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
56	select ARCH_HAS_SYNC_DMA_FOR_CPU
57	select ARCH_HAS_BATCHED_DMA_SYNC
58	select ARCH_HAS_SYSCALL_WRAPPER
59	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
60	select ARCH_HAS_ZONE_DMA_SET if EXPERT
61	select ARCH_HAVE_ELF_PROT
62	select ARCH_HAVE_NMI_SAFE_CMPXCHG
63	select ARCH_HAVE_TRACE_MMIO_ACCESS
64	select ARCH_KEEP_MEMBLOCK
65	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
66	select ARCH_USE_CMPXCHG_LOCKREF
67	select ARCH_USE_GNU_PROPERTY
68	select ARCH_USE_MEMTEST
69	select ARCH_USE_QUEUED_RWLOCKS
70	select ARCH_USE_QUEUED_SPINLOCKS
71	select ARCH_USE_SYM_ANNOTATIONS
72	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
73	select ARCH_SUPPORTS_HUGETLBFS
74	select ARCH_SUPPORTS_MEMORY_FAILURE
75	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
76	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
77	select ARCH_SUPPORTS_LTO_CLANG_THIN
78	select ARCH_SUPPORTS_CFI
79	select ARCH_SUPPORTS_ATOMIC_RMW
80	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
81	select ARCH_SUPPORTS_NUMA_BALANCING
82	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
83	select ARCH_SUPPORTS_PER_VMA_LOCK
84	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
85	select ARCH_SUPPORTS_RT
86	select ARCH_SUPPORTS_SCHED_SMT
87	select ARCH_SUPPORTS_SCHED_CLUSTER
88	select ARCH_SUPPORTS_SCHED_MC
89	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
90	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
91	select ARCH_WANT_DEFAULT_BPF_JIT
92	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
93	select ARCH_WANT_FRAME_POINTERS
94	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
95	select ARCH_WANT_LD_ORPHAN_WARN
96	select ARCH_WANTS_EXECMEM_LATE
97	select ARCH_WANTS_NO_INSTR
98	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
99	select ARCH_HAS_UBSAN
100	select ARM_AMBA
101	select ARM_ARCH_TIMER
102	select ARM_GIC
103	select AUDIT_ARCH_COMPAT_GENERIC
104	select ARM_GIC_V2M if PCI
105	select ARM_GIC_V3
106	select ARM_GIC_V3_ITS if PCI
107	select ARM_GIC_V5
108	select ARM_PSCI_FW
109	select BUILDTIME_TABLE_SORT
110	select CLONE_BACKWARDS
111	select COMMON_CLK
112	select CPU_PM if (SUSPEND || CPU_IDLE)
113	select CPUMASK_OFFSTACK if NR_CPUS > 256
114	select DCACHE_WORD_ACCESS
115	select HAVE_EXTRA_IPI_TRACEPOINTS
116	select DYNAMIC_FTRACE if FUNCTION_TRACER
117	select DMA_BOUNCE_UNALIGNED_KMALLOC
118	select DMA_DIRECT_REMAP
119	select EDAC_SUPPORT
120	select FRAME_POINTER
121	select FUNCTION_ALIGNMENT_4B
122	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
123	select GENERIC_ALLOCATOR
124	select GENERIC_ARCH_TOPOLOGY
125	select GENERIC_CLOCKEVENTS_BROADCAST
126	select GENERIC_CPU_AUTOPROBE
127	select GENERIC_CPU_CACHE_MAINTENANCE
128	select GENERIC_CPU_DEVICES
129	select GENERIC_CPU_VULNERABILITIES
130	select GENERIC_EARLY_IOREMAP
131	select GENERIC_IDLE_POLL_SETUP
132	select GENERIC_IOREMAP
133	select GENERIC_IRQ_ENTRY
134	select GENERIC_IRQ_IPI
135	select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
136	select GENERIC_IRQ_PROBE
137	select GENERIC_IRQ_SHOW
138	select GENERIC_IRQ_SHOW_LEVEL
139	select GENERIC_LIB_DEVMEM_IS_ALLOWED
140	select GENERIC_PCI_IOMAP
141	select GENERIC_SCHED_CLOCK
142	select GENERIC_SMP_IDLE_THREAD
143	select GENERIC_GETTIMEOFDAY
144	select HARDIRQS_SW_RESEND
145	select HAS_IOPORT
146	select HAVE_MOVE_PMD
147	select HAVE_MOVE_PUD
148	select HAVE_PCI
149	select HAVE_ACPI_APEI if (ACPI && EFI)
150	select HAVE_ALIGNED_STRUCT_PAGE
151	select HAVE_ARCH_AUDITSYSCALL
152	select HAVE_ARCH_BITREVERSE if BITREVERSE
153	select HAVE_ARCH_COMPILER_H
154	select HAVE_ARCH_HUGE_VMALLOC
155	select HAVE_ARCH_HUGE_VMAP
156	select HAVE_ARCH_JUMP_LABEL
157	select HAVE_ARCH_JUMP_LABEL_RELATIVE
158	select HAVE_ARCH_KASAN
159	select HAVE_ARCH_KASAN_VMALLOC
160	select HAVE_ARCH_KASAN_SW_TAGS
161	select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
162	# Some instrumentation may be unsound, hence EXPERT
163	select HAVE_ARCH_KCSAN if EXPERT
164	select HAVE_ARCH_KFENCE
165	select HAVE_ARCH_KGDB
166	select HAVE_ARCH_KSTACK_ERASE
167	select HAVE_ARCH_MMAP_RND_BITS
168	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
169	select HAVE_ARCH_PREL32_RELOCATIONS
170	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
171	select HAVE_ARCH_SECCOMP_FILTER
172	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
173	select HAVE_ARCH_TRACEHOOK
174	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
175	select HAVE_ARCH_VMAP_STACK
176	select HAVE_ARM_SMCCC
177	select HAVE_ASM_MODVERSIONS
178	select HAVE_EBPF_JIT
179	select HAVE_C_RECORDMCOUNT
180	select HAVE_CMPXCHG_DOUBLE
181	select HAVE_CMPXCHG_LOCAL
182	select HAVE_CONTEXT_TRACKING_USER
183	select HAVE_DEBUG_KMEMLEAK
184	select HAVE_DMA_CONTIGUOUS
185	select HAVE_DYNAMIC_FTRACE
186	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
187		if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
188		    CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
189	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
190		if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
191	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
192		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \
193		    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
194	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
195		if DYNAMIC_FTRACE_WITH_ARGS
196	select HAVE_SAMPLE_FTRACE_DIRECT
197	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
198	select HAVE_BUILDTIME_MCOUNT_SORT
199	select HAVE_EFFICIENT_UNALIGNED_ACCESS
200	select HAVE_GUP_FAST
201	select HAVE_FTRACE_GRAPH_FUNC
202	select HAVE_FUNCTION_TRACER
203	select HAVE_FUNCTION_ERROR_INJECTION
204	select HAVE_FUNCTION_GRAPH_FREGS
205	select HAVE_FUNCTION_GRAPH_TRACER
206	select HAVE_GCC_PLUGINS
207	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
208		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
209	select HAVE_HW_BREAKPOINT if PERF_EVENTS
210	select HAVE_IOREMAP_PROT
211	select HAVE_IRQ_TIME_ACCOUNTING
212	select HAVE_LIVEPATCH
213	select HAVE_MOD_ARCH_SPECIFIC
214	select HAVE_NMI
215	select HAVE_PERF_EVENTS
216	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
217	select HAVE_PERF_REGS
218	select HAVE_PERF_USER_STACK_DUMP
219	select HAVE_PREEMPT_DYNAMIC_KEY
220	select HAVE_REGS_AND_STACK_ACCESS_API
221	select HAVE_RELIABLE_STACKTRACE
222	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
223	select HAVE_FUNCTION_ARG_ACCESS_API
224	select MMU_GATHER_RCU_TABLE_FREE
225	select HAVE_RSEQ
226	select HAVE_RUST if RUSTC_SUPPORTS_ARM64
227	select HAVE_STACKPROTECTOR
228	select HAVE_STATIC_CALL if CFI
229	select HAVE_SYSCALL_TRACEPOINTS
230	select HAVE_KPROBES
231	select HAVE_KRETPROBES
232	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
233	select HOTPLUG_SMT if HOTPLUG_CPU
234	select IRQ_DOMAIN
235	select IRQ_FORCED_THREADING
236	select JUMP_LABEL
237	select KASAN_VMALLOC if KASAN
238	select LOCK_MM_AND_FIND_VMA
239	select MODULES_USE_ELF_RELA
240	select NEED_DMA_MAP_STATE
241	select NEED_SG_DMA_LENGTH
242	select OF
243	select OF_EARLY_FLATTREE
244	select PCI_DOMAINS_GENERIC if PCI
245	select PCI_ECAM if (ACPI && PCI)
246	select PCI_SYSCALL if PCI
247	select POWER_RESET
248	select POWER_SUPPLY
249	select SPARSE_IRQ
250	select SWIOTLB
251	select SYSCTL_EXCEPTION_TRACE
252	select THREAD_INFO_IN_TASK
253	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
254	select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
255	select TRACE_IRQFLAGS_SUPPORT
256	select TRACE_IRQFLAGS_NMI_SUPPORT
257	select HAVE_SOFTIRQ_ON_OWN_STACK
258	select USER_STACKTRACE_SUPPORT
259	select VDSO_GETRANDOM
260	select VMAP_STACK
261	help
262	  ARM 64-bit (AArch64) Linux support.
263
264config RUSTC_SUPPORTS_ARM64
265	def_bool y
266	depends on CPU_LITTLE_ENDIAN
267
268config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
269	def_bool CC_IS_CLANG
270	# https://github.com/ClangBuiltLinux/linux/issues/1507
271	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
272
273config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
274	def_bool CC_IS_GCC
275	depends on $(cc-option,-fpatchable-function-entry=2)
276
277config 64BIT
278	def_bool y
279
280config MMU
281	def_bool y
282
283config ARM64_CONT_PTE_SHIFT
284	int
285	default 5 if PAGE_SIZE_64KB
286	default 7 if PAGE_SIZE_16KB
287	default 4
288
289config ARM64_CONT_PMD_SHIFT
290	int
291	default 5 if PAGE_SIZE_64KB
292	default 5 if PAGE_SIZE_16KB
293	default 4
294
295config ARCH_MMAP_RND_BITS_MIN
296	default 14 if PAGE_SIZE_64KB
297	default 16 if PAGE_SIZE_16KB
298	default 18
299
300# max bits determined by the following formula:
301#  VA_BITS - PTDESC_TABLE_SHIFT
302config ARCH_MMAP_RND_BITS_MAX
303	default 19 if ARM64_VA_BITS=36
304	default 24 if ARM64_VA_BITS=39
305	default 27 if ARM64_VA_BITS=42
306	default 30 if ARM64_VA_BITS=47
307	default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES
308	default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES
309	default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52)
310	default 14 if ARM64_64K_PAGES
311	default 16 if ARM64_16K_PAGES
312	default 18
313
314config ARCH_MMAP_RND_COMPAT_BITS_MIN
315	default 7 if ARM64_64K_PAGES
316	default 9 if ARM64_16K_PAGES
317	default 11
318
319config ARCH_MMAP_RND_COMPAT_BITS_MAX
320	default 16
321
322config NO_IOPORT_MAP
323	def_bool y if !PCI
324
325config STACKTRACE_SUPPORT
326	def_bool y
327
328config ILLEGAL_POINTER_VALUE
329	hex
330	default 0xdead000000000000
331
332config LOCKDEP_SUPPORT
333	def_bool y
334
335config GENERIC_BUG
336	def_bool y
337	depends on BUG
338
339config GENERIC_BUG_RELATIVE_POINTERS
340	def_bool y
341	depends on GENERIC_BUG
342
343config GENERIC_HWEIGHT
344	def_bool y
345
346config GENERIC_CSUM
347	def_bool y
348
349config GENERIC_CALIBRATE_DELAY
350	def_bool y
351
352config SMP
353	def_bool y
354
355config KERNEL_MODE_NEON
356	def_bool y
357
358config FIX_EARLYCON_MEM
359	def_bool y
360
361config PGTABLE_LEVELS
362	int
363	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
364	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
365	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
366	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
367	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
368	default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
369	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
370	default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
371
372config ARCH_SUPPORTS_UPROBES
373	def_bool y
374
375config ARCH_PROC_KCORE_TEXT
376	def_bool y
377
378config BROKEN_GAS_INST
379	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
380
381config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
382	bool
383	# Clang's __builtin_return_address() strips the PAC since 12.0.0
384	# https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
385	default y if CC_IS_CLANG
386	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
387	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
388	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
389	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
390	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
391	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
392	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
393	default n
394
395config KASAN_SHADOW_OFFSET
396	hex
397	depends on KASAN_GENERIC || KASAN_SW_TAGS
398	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
399	default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
400	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
401	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
402	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
403	default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
404	default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
405	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
406	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
407	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
408	default 0xffffffffffffffff
409
410config UNWIND_TABLES
411	bool
412
413source "arch/arm64/Kconfig.platforms"
414
415menu "Kernel Features"
416
417menu "ARM errata workarounds via the alternatives framework"
418
419config AMPERE_ERRATUM_AC03_CPU_38
420        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
421	default y
422	help
423	  This option adds an alternative code sequence to work around Ampere
424	  errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
425
426	  The affected design reports FEAT_HAFDBS as not implemented in
427	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
428	  as required by the architecture. The unadvertised HAFDBS
429	  implementation suffers from an additional erratum where hardware
430	  A/D updates can occur after a PTE has been marked invalid.
431
432	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
433	  which avoids enabling unadvertised hardware Access Flag management
434	  at stage-2.
435
436	  If unsure, say Y.
437
438config AMPERE_ERRATUM_AC04_CPU_23
439        bool "AmpereOne: AC04_CPU_23:  Failure to synchronize writes to HCR_EL2 may corrupt address translations."
440	default y
441	help
442	  This option adds an alternative code sequence to work around Ampere
443	  errata AC04_CPU_23 on AmpereOne.
444
445	  Updates to HCR_EL2 can rarely corrupt simultaneous translations for
446	  data addresses initiated by load/store instructions. Only
447	  instruction initiated translations are vulnerable, not translations
448	  from prefetches for example. A DSB before the store to HCR_EL2 is
449	  sufficient to prevent older instructions from hitting the window
450	  for corruption, and an ISB after is sufficient to prevent younger
451	  instructions from hitting the window for corruption.
452
453	  If unsure, say Y.
454
455config ARM64_WORKAROUND_CLEAN_CACHE
456	bool
457
458config ARM64_ERRATUM_826319
459	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
460	default y
461	select ARM64_WORKAROUND_CLEAN_CACHE
462	help
463	  This option adds an alternative code sequence to work around ARM
464	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
465	  AXI master interface and an L2 cache.
466
467	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
468	  and is unable to accept a certain write via this interface, it will
469	  not progress on read data presented on the read data channel and the
470	  system can deadlock.
471
472	  The workaround promotes data cache clean instructions to
473	  data cache clean-and-invalidate.
474	  Please note that this does not necessarily enable the workaround,
475	  as it depends on the alternative framework, which will only patch
476	  the kernel if an affected CPU is detected.
477
478	  If unsure, say Y.
479
480config ARM64_ERRATUM_827319
481	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
482	default y
483	select ARM64_WORKAROUND_CLEAN_CACHE
484	help
485	  This option adds an alternative code sequence to work around ARM
486	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
487	  master interface and an L2 cache.
488
489	  Under certain conditions this erratum can cause a clean line eviction
490	  to occur at the same time as another transaction to the same address
491	  on the AMBA 5 CHI interface, which can cause data corruption if the
492	  interconnect reorders the two transactions.
493
494	  The workaround promotes data cache clean instructions to
495	  data cache clean-and-invalidate.
496	  Please note that this does not necessarily enable the workaround,
497	  as it depends on the alternative framework, which will only patch
498	  the kernel if an affected CPU is detected.
499
500	  If unsure, say Y.
501
502config ARM64_ERRATUM_824069
503	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
504	default y
505	select ARM64_WORKAROUND_CLEAN_CACHE
506	help
507	  This option adds an alternative code sequence to work around ARM
508	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
509	  to a coherent interconnect.
510
511	  If a Cortex-A53 processor is executing a store or prefetch for
512	  write instruction at the same time as a processor in another
513	  cluster is executing a cache maintenance operation to the same
514	  address, then this erratum might cause a clean cache line to be
515	  incorrectly marked as dirty.
516
517	  The workaround promotes data cache clean instructions to
518	  data cache clean-and-invalidate.
519	  Please note that this option does not necessarily enable the
520	  workaround, as it depends on the alternative framework, which will
521	  only patch the kernel if an affected CPU is detected.
522
523	  If unsure, say Y.
524
525config ARM64_ERRATUM_819472
526	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
527	default y
528	select ARM64_WORKAROUND_CLEAN_CACHE
529	help
530	  This option adds an alternative code sequence to work around ARM
531	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
532	  present when it is connected to a coherent interconnect.
533
534	  If the processor is executing a load and store exclusive sequence at
535	  the same time as a processor in another cluster is executing a cache
536	  maintenance operation to the same address, then this erratum might
537	  cause data corruption.
538
539	  The workaround promotes data cache clean instructions to
540	  data cache clean-and-invalidate.
541	  Please note that this does not necessarily enable the workaround,
542	  as it depends on the alternative framework, which will only patch
543	  the kernel if an affected CPU is detected.
544
545	  If unsure, say Y.
546
547config ARM64_ERRATUM_832075
548	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
549	default y
550	help
551	  This option adds an alternative code sequence to work around ARM
552	  erratum 832075 on Cortex-A57 parts up to r1p2.
553
554	  Affected Cortex-A57 parts might deadlock when exclusive load/store
555	  instructions to Write-Back memory are mixed with Device loads.
556
557	  The workaround is to promote device loads to use Load-Acquire
558	  semantics.
559	  Please note that this does not necessarily enable the workaround,
560	  as it depends on the alternative framework, which will only patch
561	  the kernel if an affected CPU is detected.
562
563	  If unsure, say Y.
564
565config ARM64_ERRATUM_834220
566	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
567	depends on KVM
568	help
569	  This option adds an alternative code sequence to work around ARM
570	  erratum 834220 on Cortex-A57 parts up to r1p2.
571
572	  Affected Cortex-A57 parts might report a Stage 2 translation
573	  fault as the result of a Stage 1 fault for load crossing a
574	  page boundary when there is a permission or device memory
575	  alignment fault at Stage 1 and a translation fault at Stage 2.
576
577	  The workaround is to verify that the Stage 1 translation
578	  doesn't generate a fault before handling the Stage 2 fault.
579	  Please note that this does not necessarily enable the workaround,
580	  as it depends on the alternative framework, which will only patch
581	  the kernel if an affected CPU is detected.
582
583	  If unsure, say N.
584
585config ARM64_ERRATUM_1742098
586	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
587	depends on COMPAT
588	default y
589	help
590	  This option removes the AES hwcap for aarch32 user-space to
591	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
592
593	  Affected parts may corrupt the AES state if an interrupt is
594	  taken between a pair of AES instructions. These instructions
595	  are only present if the cryptography extensions are present.
596	  All software should have a fallback implementation for CPUs
597	  that don't implement the cryptography extensions.
598
599	  If unsure, say Y.
600
601config ARM64_ERRATUM_845719
602	bool "Cortex-A53: 845719: a load might read incorrect data"
603	depends on COMPAT
604	default y
605	help
606	  This option adds an alternative code sequence to work around ARM
607	  erratum 845719 on Cortex-A53 parts up to r0p4.
608
609	  When running a compat (AArch32) userspace on an affected Cortex-A53
610	  part, a load at EL0 from a virtual address that matches the bottom 32
611	  bits of the virtual address used by a recent load at (AArch64) EL1
612	  might return incorrect data.
613
614	  The workaround is to write the contextidr_el1 register on exception
615	  return to a 32-bit task.
616	  Please note that this does not necessarily enable the workaround,
617	  as it depends on the alternative framework, which will only patch
618	  the kernel if an affected CPU is detected.
619
620	  If unsure, say Y.
621
622config ARM64_ERRATUM_843419
623	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
624	default y
625	help
626	  This option links the kernel with '--fix-cortex-a53-843419' and
627	  enables PLT support to replace certain ADRP instructions, which can
628	  cause subsequent memory accesses to use an incorrect address on
629	  Cortex-A53 parts up to r0p4.
630
631	  If unsure, say Y.
632
633config ARM64_ERRATUM_1024718
634	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
635	default y
636	help
637	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
638
639	  Affected Cortex-A55 cores (all revisions) could cause incorrect
640	  update of the hardware dirty bit when the DBM/AP bits are updated
641	  without a break-before-make. The workaround is to disable the usage
642	  of hardware DBM locally on the affected cores. CPUs not affected by
643	  this erratum will continue to use the feature.
644
645	  If unsure, say Y.
646
647config ARM64_ERRATUM_1418040
648	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
649	default y
650	depends on COMPAT
651	help
652	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
653	  errata 1188873 and 1418040.
654
655	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
656	  cause register corruption when accessing the timer registers
657	  from AArch32 userspace.
658
659	  If unsure, say Y.
660
661config ARM64_WORKAROUND_SPECULATIVE_AT
662	bool
663
664config ARM64_ERRATUM_1165522
665	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
666	default y
667	select ARM64_WORKAROUND_SPECULATIVE_AT
668	help
669	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
670
671	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
672	  corrupted TLBs by speculating an AT instruction during a guest
673	  context switch.
674
675	  If unsure, say Y.
676
677config ARM64_ERRATUM_1319367
678	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
679	default y
680	select ARM64_WORKAROUND_SPECULATIVE_AT
681	help
682	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
683	  and A72 erratum 1319367
684
685	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
686	  speculating an AT instruction during a guest context switch.
687
688	  If unsure, say Y.
689
690config ARM64_ERRATUM_1530923
691	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
692	default y
693	select ARM64_WORKAROUND_SPECULATIVE_AT
694	help
695	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
696
697	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
698	  corrupted TLBs by speculating an AT instruction during a guest
699	  context switch.
700
701	  If unsure, say Y.
702
703config ARM64_WORKAROUND_REPEAT_TLBI
704	bool
705
706config ARM64_ERRATUM_2441007
707	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
708	select ARM64_WORKAROUND_REPEAT_TLBI
709	help
710	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
711
712	  Under very rare circumstances, affected Cortex-A55 CPUs
713	  may not handle a race between a break-before-make sequence on one
714	  CPU, and another CPU accessing the same page. This could allow a
715	  store to a page that has been unmapped.
716
717	  Work around this by adding the affected CPUs to the list that needs
718	  TLB sequences to be done twice.
719
720	  If unsure, say N.
721
722config ARM64_ERRATUM_1286807
723	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
724	select ARM64_WORKAROUND_REPEAT_TLBI
725	help
726	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
727
728	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
729	  address for a cacheable mapping of a location is being
730	  accessed by a core while another core is remapping the virtual
731	  address to a new physical page using the recommended
732	  break-before-make sequence, then under very rare circumstances
733	  TLBI+DSB completes before a read using the translation being
734	  invalidated has been observed by other observers. The
735	  workaround repeats the TLBI+DSB operation.
736
737	  If unsure, say N.
738
739config ARM64_ERRATUM_1463225
740	bool "Cortex-A76: Software Step might prevent interrupt recognition"
741	default y
742	help
743	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
744
745	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
746	  of a system call instruction (SVC) can prevent recognition of
747	  subsequent interrupts when software stepping is disabled in the
748	  exception handler of the system call and either kernel debugging
749	  is enabled or VHE is in use.
750
751	  Work around the erratum by triggering a dummy step exception
752	  when handling a system call from a task that is being stepped
753	  in a VHE configuration of the kernel.
754
755	  If unsure, say Y.
756
757config ARM64_ERRATUM_1542419
758	bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
759	help
760	  This option adds a workaround for ARM Neoverse-N1 erratum
761	  1542419.
762
763	  Affected Neoverse-N1 cores could execute a stale instruction when
764	  modified by another CPU. The workaround depends on a firmware
765	  counterpart.
766
767	  Workaround the issue by hiding the DIC feature from EL0. This
768	  forces user-space to perform cache maintenance.
769
770	  If unsure, say N.
771
772config ARM64_ERRATUM_1508412
773	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
774	default y
775	help
776	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
777
778	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
779	  of a store-exclusive or read of PAR_EL1 and a load with device or
780	  non-cacheable memory attributes. The workaround depends on a firmware
781	  counterpart.
782
783	  KVM guests must also have the workaround implemented or they can
784	  deadlock the system.
785
786	  Work around the issue by inserting DMB SY barriers around PAR_EL1
787	  register reads and warning KVM users. The DMB barrier is sufficient
788	  to prevent a speculative PAR_EL1 read.
789
790	  If unsure, say Y.
791
792config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
793	bool
794
795config ARM64_ERRATUM_2051678
796	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
797	default y
798	help
799	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
800	  Affected Cortex-A510 might not respect the ordering rules for
801	  hardware update of the page table's dirty bit. The workaround
802	  is to not enable the feature on affected CPUs.
803
804	  If unsure, say Y.
805
806config ARM64_ERRATUM_2077057
807	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
808	default y
809	help
810	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
811	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
812	  expected, but a Pointer Authentication trap is taken instead. The
813	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
814	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
815
816	  This can only happen when EL2 is stepping EL1.
817
818	  When these conditions occur, the SPSR_EL2 value is unchanged from the
819	  previous guest entry, and can be restored from the in-memory copy.
820
821	  If unsure, say Y.
822
823config ARM64_ERRATUM_2658417
824	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
825	default y
826	help
827	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
828	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
829	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
830	  A510 CPUs are using shared neon hardware. As the sharing is not
831	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
832	  user-space should not be using these instructions.
833
834	  If unsure, say Y.
835
836config ARM64_ERRATUM_2119858
837	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
838	default y
839	depends on CORESIGHT_TRBE
840	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
841	help
842	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
843
844	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
845	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
846	  the event of a WRAP event.
847
848	  Work around the issue by always making sure we move the TRBPTR_EL1 by
849	  256 bytes before enabling the buffer and filling the first 256 bytes of
850	  the buffer with ETM ignore packets upon disabling.
851
852	  If unsure, say Y.
853
854config ARM64_ERRATUM_2139208
855	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
856	default y
857	depends on CORESIGHT_TRBE
858	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
859	help
860	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
861
862	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
863	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
864	  the event of a WRAP event.
865
866	  Work around the issue by always making sure we move the TRBPTR_EL1 by
867	  256 bytes before enabling the buffer and filling the first 256 bytes of
868	  the buffer with ETM ignore packets upon disabling.
869
870	  If unsure, say Y.
871
872config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
873	bool
874
875config ARM64_ERRATUM_2054223
876	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
877	default y
878	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
879	help
880	  Enable workaround for ARM Cortex-A710 erratum 2054223
881
882	  Affected cores may fail to flush the trace data on a TSB instruction, when
883	  the PE is in trace prohibited state. This will cause losing a few bytes
884	  of the trace cached.
885
886	  Workaround is to issue two TSB consecutively on affected cores.
887
888	  If unsure, say Y.
889
890config ARM64_ERRATUM_2067961
891	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
892	default y
893	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
894	help
895	  Enable workaround for ARM Neoverse-N2 erratum 2067961
896
897	  Affected cores may fail to flush the trace data on a TSB instruction, when
898	  the PE is in trace prohibited state. This will cause losing a few bytes
899	  of the trace cached.
900
901	  Workaround is to issue two TSB consecutively on affected cores.
902
903	  If unsure, say Y.
904
905config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
906	bool
907
908config ARM64_ERRATUM_2253138
909	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
910	depends on CORESIGHT_TRBE
911	default y
912	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
913	help
914	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
915
916	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
917	  for TRBE. Under some conditions, the TRBE might generate a write to the next
918	  virtually addressed page following the last page of the TRBE address space
919	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
920
921	  Work around this in the driver by always making sure that there is a
922	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
923
924	  If unsure, say Y.
925
926config ARM64_ERRATUM_2224489
927	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
928	depends on CORESIGHT_TRBE
929	default y
930	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
931	help
932	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
933
934	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
935	  for TRBE. Under some conditions, the TRBE might generate a write to the next
936	  virtually addressed page following the last page of the TRBE address space
937	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
938
939	  Work around this in the driver by always making sure that there is a
940	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
941
942	  If unsure, say Y.
943
944config ARM64_ERRATUM_2441009
945	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
946	select ARM64_WORKAROUND_REPEAT_TLBI
947	help
948	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
949
950	  Under very rare circumstances, affected Cortex-A510 CPUs
951	  may not handle a race between a break-before-make sequence on one
952	  CPU, and another CPU accessing the same page. This could allow a
953	  store to a page that has been unmapped.
954
955	  Work around this by adding the affected CPUs to the list that needs
956	  TLB sequences to be done twice.
957
958	  If unsure, say N.
959
960config ARM64_ERRATUM_2064142
961	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
962	depends on CORESIGHT_TRBE
963	default y
964	help
965	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
966
967	  Affected Cortex-A510 core might fail to write into system registers after the
968	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
969	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
970	  and TRBTRG_EL1 will be ignored and will not be effected.
971
972	  Work around this in the driver by executing TSB CSYNC and DSB after collection
973	  is stopped and before performing a system register write to one of the affected
974	  registers.
975
976	  If unsure, say Y.
977
978config ARM64_ERRATUM_2038923
979	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
980	depends on CORESIGHT_TRBE
981	default y
982	help
983	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
984
985	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
986	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
987	  might be corrupted. This happens after TRBE buffer has been enabled by setting
988	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
989	  execution changes from a context, in which trace is prohibited to one where it
990	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
991	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
992	  the trace buffer state might be corrupted.
993
994	  Work around this in the driver by preventing an inconsistent view of whether the
995	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
996	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
997	  two ISB instructions if no ERET is to take place.
998
999	  If unsure, say Y.
1000
1001config ARM64_ERRATUM_1902691
1002	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1003	depends on CORESIGHT_TRBE
1004	default y
1005	help
1006	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1007
1008	  Affected Cortex-A510 core might cause trace data corruption, when being written
1009	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
1010	  trace data.
1011
1012	  Work around this problem in the driver by just preventing TRBE initialization on
1013	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1014	  on such implementations. This will cover the kernel for any firmware that doesn't
1015	  do this already.
1016
1017	  If unsure, say Y.
1018
1019config ARM64_ERRATUM_2457168
1020	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1021	depends on ARM64_AMU_EXTN
1022	default y
1023	help
1024	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1025
1026	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1027	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1028	  incorrectly giving a significantly higher output value.
1029
1030	  Work around this problem by returning 0 when reading the affected counter in
1031	  key locations that results in disabling all users of this counter. This effect
1032	  is the same to firmware disabling affected counters.
1033
1034	  If unsure, say Y.
1035
1036config ARM64_ERRATUM_2645198
1037	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1038	default y
1039	help
1040	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1041
1042	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1043	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1044	  next instruction abort caused by permission fault.
1045
1046	  Only user-space does executable to non-executable permission transition via
1047	  mprotect() system call. Workaround the problem by doing a break-before-make
1048	  TLB invalidation, for all changes to executable user space mappings.
1049
1050	  If unsure, say Y.
1051
1052config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1053	bool
1054
1055config ARM64_ERRATUM_2966298
1056	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1057	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1058	default y
1059	help
1060	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1061
1062	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1063	  load might leak data from a privileged level via a cache side channel.
1064
1065	  Work around this problem by executing a TLBI before returning to EL0.
1066
1067	  If unsure, say Y.
1068
1069config ARM64_ERRATUM_3117295
1070	bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1071	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1072	default y
1073	help
1074	  This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1075
1076	  On an affected Cortex-A510 core, a speculatively executed unprivileged
1077	  load might leak data from a privileged level via a cache side channel.
1078
1079	  Work around this problem by executing a TLBI before returning to EL0.
1080
1081	  If unsure, say Y.
1082
1083config ARM64_ERRATUM_3194386
1084	bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1085	default y
1086	help
1087	  This option adds the workaround for the following errata:
1088
1089	  * ARM Cortex-A76 erratum 3324349
1090	  * ARM Cortex-A77 erratum 3324348
1091	  * ARM Cortex-A78 erratum 3324344
1092	  * ARM Cortex-A78C erratum 3324346
1093	  * ARM Cortex-A78C erratum 3324347
1094	  * ARM Cortex-A710 erratam 3324338
1095	  * ARM Cortex-A715 errartum 3456084
1096	  * ARM Cortex-A720 erratum 3456091
1097	  * ARM Cortex-A725 erratum 3456106
1098	  * ARM Cortex-X1 erratum 3324344
1099	  * ARM Cortex-X1C erratum 3324346
1100	  * ARM Cortex-X2 erratum 3324338
1101	  * ARM Cortex-X3 erratum 3324335
1102	  * ARM Cortex-X4 erratum 3194386
1103	  * ARM Cortex-X925 erratum 3324334
1104	  * ARM Neoverse-N1 erratum 3324349
1105	  * ARM Neoverse N2 erratum 3324339
1106	  * ARM Neoverse-N3 erratum 3456111
1107	  * ARM Neoverse-V1 erratum 3324341
1108	  * ARM Neoverse V2 erratum 3324336
1109	  * ARM Neoverse-V3 erratum 3312417
1110	  * ARM Neoverse-V3AE erratum 3312417
1111
1112	  On affected cores "MSR SSBS, #0" instructions may not affect
1113	  subsequent speculative instructions, which may permit unexepected
1114	  speculative store bypassing.
1115
1116	  Work around this problem by placing a Speculation Barrier (SB) or
1117	  Instruction Synchronization Barrier (ISB) after kernel changes to
1118	  SSBS. The presence of the SSBS special-purpose register is hidden
1119	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1120	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1121
1122	  If unsure, say Y.
1123
1124config ARM64_ERRATUM_4311569
1125	bool "SI L1: 4311569: workaround for premature CMO completion erratum"
1126	default y
1127	help
1128	  This option adds the workaround for ARM SI L1 erratum 4311569.
1129
1130	  The erratum of SI L1 can cause an early response to a combined write
1131	  and cache maintenance operation (WR+CMO) before the operation is fully
1132	  completed to the Point of Serialization (POS).
1133	  This can result in a non-I/O coherent agent observing stale data,
1134	  potentially leading to system instability or incorrect behavior.
1135
1136	  Enabling this option implements a software workaround by inserting a
1137	  second loop of Cache Maintenance Operation (CMO) immediately following the
1138	  end of function to do CMOs. This ensures that the data is correctly serialized
1139	  before the buffer is handed off to a non-coherent agent.
1140
1141	  If unsure, say Y.
1142
1143config ARM64_ERRATUM_4193714
1144	bool "C1-Pro: 4193714: SME DVMSync early acknowledgement"
1145	depends on ARM64_SME
1146	default y
1147	help
1148	  Enable workaround for C1-Pro acknowledging the DVMSync before
1149	  the SME memory accesses are complete. This will cause TLB
1150	  maintenance for processes using SME to also issue an IPI to
1151	  the affected CPUs.
1152
1153	  If unsure, say Y.
1154
1155config ARM64_ERRATUM_4118414
1156	bool "Various: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
1157	default y
1158	select ARM64_WORKAROUND_REPEAT_TLBI
1159	help
1160	  This option adds a workaround for the following errata:
1161
1162	  * ARM C1-Premium erratum 4193780
1163	  * ARM C1-Ultra erratum 4193780
1164	  * ARM Cortex-A76 erratum 4193800
1165	  * ARM Cortex-A76AE erratum 4193801
1166	  * ARM Cortex-A77 erratum 4193798
1167	  * ARM Cortex-A78 erratum 4193791
1168	  * ARM Cortex-A78AE erratum 4193793
1169	  * ARM Cortex-A78C erratum 4193794
1170	  * ARM Cortex-A710 erratum 4193788
1171	  * ARM Cortex-X1 erratum 4193791
1172	  * ARM Cortex-X1C erratum 4193792
1173	  * ARM Cortex-X2 erratum 4193788
1174	  * ARM Cortex-X3 erratum 4193786
1175	  * ARM Cortex-X4 erratum 4118414
1176	  * ARM Cortex-X925 erratum 4193781
1177	  * ARM Neoverse-N1 erratum 4193800
1178	  * ARM Neoverse-N2 erratum 4193789
1179	  * ARM Neoverse-V1 erratum 4193790
1180	  * ARM Neoverse-V2 erratum 4193787
1181	  * ARM Neoverse-V3 erratum 4193784
1182	  * ARM Neoverse-V3AE erratum 4193784
1183	  * Microsoft Azure Cobalt 100 4193789
1184	  * NVIDIA Olympus erratum T410-OLY-1029
1185
1186	  On affected cores, some memory accesses might not be completed by
1187	  broadcast TLB invalidation.
1188
1189	  This issue is also known as CVE-2025-10263.
1190
1191	  If unsure, say Y.
1192
1193config CAVIUM_ERRATUM_22375
1194	bool "Cavium erratum 22375, 24313"
1195	default y
1196	help
1197	  Enable workaround for errata 22375 and 24313.
1198
1199	  This implements two gicv3-its errata workarounds for ThunderX. Both
1200	  with a small impact affecting only ITS table allocation.
1201
1202	    erratum 22375: only alloc 8MB table size
1203	    erratum 24313: ignore memory access type
1204
1205	  The fixes are in ITS initialization and basically ignore memory access
1206	  type and table size provided by the TYPER and BASER registers.
1207
1208	  If unsure, say Y.
1209
1210config CAVIUM_ERRATUM_23144
1211	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1212	depends on NUMA
1213	default y
1214	help
1215	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1216
1217	  If unsure, say Y.
1218
1219config CAVIUM_ERRATUM_23154
1220	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1221	default y
1222	help
1223	  The ThunderX GICv3 implementation requires a modified version for
1224	  reading the IAR status to ensure data synchronization
1225	  (access to icc_iar1_el1 is not sync'ed before and after).
1226
1227	  It also suffers from erratum 38545 (also present on Marvell's
1228	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1229	  spuriously presented to the CPU interface.
1230
1231	  If unsure, say Y.
1232
1233config CAVIUM_ERRATUM_27456
1234	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1235	default y
1236	help
1237	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1238	  instructions may cause the icache to become corrupted if it
1239	  contains data for a non-current ASID.  The fix is to
1240	  invalidate the icache when changing the mm context.
1241
1242	  If unsure, say Y.
1243
1244config CAVIUM_ERRATUM_30115
1245	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1246	default y
1247	help
1248	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1249	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1250	  interrupts in host. Trapping both GICv3 group-0 and group-1
1251	  accesses sidesteps the issue.
1252
1253	  If unsure, say Y.
1254
1255config CAVIUM_TX2_ERRATUM_219
1256	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1257	default y
1258	help
1259	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1260	  TTBR update and the corresponding context synchronizing operation can
1261	  cause a spurious Data Abort to be delivered to any hardware thread in
1262	  the CPU core.
1263
1264	  Work around the issue by avoiding the problematic code sequence and
1265	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1266	  trap handler performs the corresponding register access, skips the
1267	  instruction and ensures context synchronization by virtue of the
1268	  exception return.
1269
1270	  If unsure, say Y.
1271
1272config FUJITSU_ERRATUM_010001
1273	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1274	default y
1275	help
1276	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1277	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1278	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1279	  This fault occurs under a specific hardware condition when a
1280	  load/store instruction performs an address translation using:
1281	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1282	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1283	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1284	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1285
1286	  The workaround is to ensure these bits are clear in TCR_ELx.
1287	  The workaround only affects the Fujitsu-A64FX.
1288
1289	  If unsure, say Y.
1290
1291config HISILICON_ERRATUM_161600802
1292	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1293	default y
1294	help
1295	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1296	  when issued ITS commands such as VMOVP and VMAPP, and requires
1297	  a 128kB offset to be applied to the target address in this commands.
1298
1299	  If unsure, say Y.
1300
1301config HISILICON_ERRATUM_162100801
1302	bool "Hip09 162100801 erratum support"
1303	default y
1304	help
1305	  When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches
1306	  during unmapping operation, which will cause some vSGIs lost.
1307	  To fix the issue, invalidate related vPE cache through GICR_INVALLR
1308	  after VMOVP.
1309
1310	  If unsure, say Y.
1311
1312config HISILICON_ERRATUM_162100125
1313	bool "Hisilicon erratum 162100125"
1314	default y
1315	select ARM64_WORKAROUND_DISABLE_CNP
1316	help
1317	  On HiSilicon HIP09, TLB entry matching behavior when CNP
1318	  (TTBRx.CNP=1) is enabled differs from the ARM architecture
1319	  specification.
1320
1321	  TLB entries may be incorrectly shared between CPUs, potentially
1322	  causing TLB conflicts and stale mappings.
1323
1324	  Disable CNP support for affected HiSilicon HIP09 cores.
1325
1326	  If unsure, say Y.
1327
1328config QCOM_FALKOR_ERRATUM_1003
1329	bool "Falkor E1003: Incorrect translation due to ASID change"
1330	default y
1331	help
1332	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1333	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1334	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1335	  then only for entries in the walk cache, since the leaf translation
1336	  is unchanged. Work around the erratum by invalidating the walk cache
1337	  entries for the trampoline before entering the kernel proper.
1338
1339config QCOM_FALKOR_ERRATUM_1009
1340	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1341	default y
1342	select ARM64_WORKAROUND_REPEAT_TLBI
1343	help
1344	  On Falkor v1, the CPU may prematurely complete a DSB following a
1345	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1346	  one more time to fix the issue.
1347
1348	  If unsure, say Y.
1349
1350config QCOM_QDF2400_ERRATUM_0065
1351	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1352	default y
1353	help
1354	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1355	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1356	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1357
1358	  If unsure, say Y.
1359
1360config QCOM_FALKOR_ERRATUM_E1041
1361	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1362	default y
1363	help
1364	  Falkor CPU may speculatively fetch instructions from an improper
1365	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1366	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1367
1368	  If unsure, say Y.
1369
1370config ARM64_WORKAROUND_DISABLE_CNP
1371	bool
1372
1373config NVIDIA_CARMEL_CNP_ERRATUM
1374	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1375	default y
1376	select ARM64_WORKAROUND_DISABLE_CNP
1377	help
1378	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1379	  invalidate shared TLB entries installed by a different core, as it would
1380	  on standard ARM cores.
1381
1382	  If unsure, say Y.
1383
1384config ROCKCHIP_ERRATUM_3568002
1385	bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB"
1386	default y
1387	help
1388	  The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI
1389	  addressing limited to the first 32bit of physical address space.
1390
1391	  If unsure, say Y.
1392
1393config ROCKCHIP_ERRATUM_3588001
1394	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1395	default y
1396	help
1397	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1398	  This means, that its sharability feature may not be used, even though it
1399	  is supported by the IP itself.
1400
1401	  If unsure, say Y.
1402
1403config SOCIONEXT_SYNQUACER_PREITS
1404	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1405	default y
1406	help
1407	  Socionext Synquacer SoCs implement a separate h/w block to generate
1408	  MSI doorbell writes with non-zero values for the device ID.
1409
1410	  If unsure, say Y.
1411
1412endmenu # "ARM errata workarounds via the alternatives framework"
1413
1414choice
1415	prompt "Page size"
1416	default ARM64_4K_PAGES
1417	help
1418	  Page size (translation granule) configuration.
1419
1420config ARM64_4K_PAGES
1421	bool "4KB"
1422	select HAVE_PAGE_SIZE_4KB
1423	help
1424	  This feature enables 4KB pages support.
1425
1426config ARM64_16K_PAGES
1427	bool "16KB"
1428	select HAVE_PAGE_SIZE_16KB
1429	help
1430	  The system will use 16KB pages support. AArch32 emulation
1431	  requires applications compiled with 16K (or a multiple of 16K)
1432	  aligned segments.
1433
1434config ARM64_64K_PAGES
1435	bool "64KB"
1436	select HAVE_PAGE_SIZE_64KB
1437	help
1438	  This feature enables 64KB pages support (4KB by default)
1439	  allowing only two levels of page tables and faster TLB
1440	  look-up. AArch32 emulation requires applications compiled
1441	  with 64K aligned segments.
1442
1443endchoice
1444
1445choice
1446	prompt "Virtual address space size"
1447	default ARM64_VA_BITS_52
1448	help
1449	  Allows choosing one of multiple possible virtual address
1450	  space sizes. The level of translation table is determined by
1451	  a combination of page size and virtual address space size.
1452
1453config ARM64_VA_BITS_36
1454	bool "36-bit" if EXPERT
1455	depends on PAGE_SIZE_16KB
1456
1457config ARM64_VA_BITS_39
1458	bool "39-bit"
1459	depends on PAGE_SIZE_4KB
1460
1461config ARM64_VA_BITS_42
1462	bool "42-bit"
1463	depends on PAGE_SIZE_64KB
1464
1465config ARM64_VA_BITS_47
1466	bool "47-bit"
1467	depends on PAGE_SIZE_16KB
1468
1469config ARM64_VA_BITS_48
1470	bool "48-bit"
1471
1472config ARM64_VA_BITS_52
1473	bool "52-bit"
1474	help
1475	  Enable 52-bit virtual addressing for userspace when explicitly
1476	  requested via a hint to mmap(). The kernel will also use 52-bit
1477	  virtual addresses for its own mappings (provided HW support for
1478	  this feature is available, otherwise it reverts to 48-bit).
1479
1480	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1481	  ARMv8.3 Pointer Authentication will result in the PAC being
1482	  reduced from 7 bits to 3 bits, which may have a significant
1483	  impact on its susceptibility to brute-force attacks.
1484
1485	  If unsure, select 48-bit virtual addressing instead.
1486
1487endchoice
1488
1489config ARM64_FORCE_52BIT
1490	bool "Force 52-bit virtual addresses for userspace"
1491	depends on ARM64_VA_BITS_52 && EXPERT
1492	help
1493	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1494	  to maintain compatibility with older software by providing 48-bit VAs
1495	  unless a hint is supplied to mmap.
1496
1497	  This configuration option disables the 48-bit compatibility logic, and
1498	  forces all userspace addresses to be 52-bit on HW that supports it. One
1499	  should only enable this configuration option for stress testing userspace
1500	  memory management code. If unsure say N here.
1501
1502config ARM64_VA_BITS
1503	int
1504	default 36 if ARM64_VA_BITS_36
1505	default 39 if ARM64_VA_BITS_39
1506	default 42 if ARM64_VA_BITS_42
1507	default 47 if ARM64_VA_BITS_47
1508	default 48 if ARM64_VA_BITS_48
1509	default 52 if ARM64_VA_BITS_52
1510
1511choice
1512	prompt "Physical address space size"
1513	default ARM64_PA_BITS_48
1514	help
1515	  Choose the maximum physical address range that the kernel will
1516	  support.
1517
1518config ARM64_PA_BITS_48
1519	bool "48-bit"
1520	depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1521
1522config ARM64_PA_BITS_52
1523	bool "52-bit"
1524	depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1525	help
1526	  Enable support for a 52-bit physical address space, introduced as
1527	  part of the ARMv8.2-LPA extension.
1528
1529	  With this enabled, the kernel will also continue to work on CPUs that
1530	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1531	  minor performance overhead).
1532
1533endchoice
1534
1535config ARM64_PA_BITS
1536	int
1537	default 48 if ARM64_PA_BITS_48
1538	default 52 if ARM64_PA_BITS_52
1539
1540config ARM64_LPA2
1541	def_bool y
1542	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1543
1544choice
1545	prompt "Endianness"
1546	default CPU_LITTLE_ENDIAN
1547	help
1548	  Select the endianness of data accesses performed by the CPU. Userspace
1549	  applications will need to be compiled and linked for the endianness
1550	  that is selected here.
1551
1552config CPU_BIG_ENDIAN
1553	bool "Build big-endian kernel"
1554	depends on BROKEN
1555	help
1556	  Say Y if you plan on running a kernel with a big-endian userspace.
1557
1558config CPU_LITTLE_ENDIAN
1559	bool "Build little-endian kernel"
1560	help
1561	  Say Y if you plan on running a kernel with a little-endian userspace.
1562	  This is usually the case for distributions targeting arm64.
1563
1564endchoice
1565
1566config NR_CPUS
1567	int "Maximum number of CPUs (2-4096)"
1568	range 2 4096
1569	default "512"
1570
1571config HOTPLUG_CPU
1572	bool "Support for hot-pluggable CPUs"
1573	select GENERIC_IRQ_MIGRATION
1574	help
1575	  Say Y here to experiment with turning CPUs off and on.  CPUs
1576	  can be controlled through /sys/devices/system/cpu.
1577
1578# Common NUMA Features
1579config NUMA
1580	bool "NUMA Memory Allocation and Scheduler Support"
1581	select GENERIC_ARCH_NUMA
1582	select OF_NUMA
1583	select HAVE_SETUP_PER_CPU_AREA
1584	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1585	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1586	select USE_PERCPU_NUMA_NODE_ID
1587	help
1588	  Enable NUMA (Non-Uniform Memory Access) support.
1589
1590	  The kernel will try to allocate memory used by a CPU on the
1591	  local memory of the CPU and add some more
1592	  NUMA awareness to the kernel.
1593
1594config NODES_SHIFT
1595	int "Maximum NUMA Nodes (as a power of 2)"
1596	range 1 10
1597	default "4"
1598	depends on NUMA
1599	help
1600	  Specify the maximum number of NUMA Nodes available on the target
1601	  system.  Increases memory reserved to accommodate various tables.
1602
1603source "kernel/Kconfig.hz"
1604
1605config ARCH_SPARSEMEM_ENABLE
1606	def_bool y
1607	select SPARSEMEM_VMEMMAP_ENABLE
1608
1609config HW_PERF_EVENTS
1610	def_bool y
1611	depends on ARM_PMU
1612
1613# Supported by clang >= 7.0 or GCC >= 12.0.0
1614config CC_HAVE_SHADOW_CALL_STACK
1615	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1616
1617config PARAVIRT
1618	bool "Enable paravirtualization code"
1619	select HAVE_PV_STEAL_CLOCK_GEN
1620	help
1621	  This changes the kernel so it can modify itself when it is run
1622	  under a hypervisor, potentially improving performance significantly
1623	  over full virtualization.
1624
1625config PARAVIRT_TIME_ACCOUNTING
1626	bool "Paravirtual steal time accounting"
1627	select PARAVIRT
1628	help
1629	  Select this option to enable fine granularity task steal time
1630	  accounting. Time spent executing other tasks in parallel with
1631	  the current vCPU is discounted from the vCPU power. To account for
1632	  that, there can be a small performance impact.
1633
1634	  If in doubt, say N here.
1635
1636config ARCH_SUPPORTS_KEXEC
1637	def_bool PM_SLEEP_SMP
1638
1639config ARCH_SUPPORTS_KEXEC_FILE
1640	def_bool y
1641
1642config ARCH_SELECTS_KEXEC_FILE
1643	def_bool y
1644	depends on KEXEC_FILE
1645	select HAVE_IMA_KEXEC if IMA
1646
1647config ARCH_SUPPORTS_KEXEC_SIG
1648	def_bool y
1649
1650config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1651	def_bool y
1652
1653config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1654	def_bool y
1655
1656config ARCH_SUPPORTS_KEXEC_HANDOVER
1657	def_bool y
1658
1659config ARCH_SUPPORTS_CRASH_DUMP
1660	def_bool y
1661
1662config ARCH_DEFAULT_CRASH_DUMP
1663	def_bool y
1664
1665config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1666	def_bool CRASH_RESERVE
1667
1668config TRANS_TABLE
1669	def_bool y
1670	depends on HIBERNATION || KEXEC_CORE
1671
1672config XEN_DOM0
1673	def_bool y
1674	depends on XEN
1675
1676config XEN
1677	bool "Xen guest support on ARM64"
1678	depends on ARM64 && OF
1679	select SWIOTLB_XEN
1680	select PARAVIRT
1681	help
1682	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1683
1684# include/linux/mmzone.h requires the following to be true:
1685#
1686#   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1687#
1688# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1689#
1690#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1691# ----+-------------------+--------------+----------------------+-------------------------+
1692# 4K  |       27          |      12      |       15             |         10              |
1693# 16K |       27          |      14      |       13             |         11              |
1694# 64K |       29          |      16      |       13             |         13              |
1695config ARCH_FORCE_MAX_ORDER
1696	int
1697	default "13" if ARM64_64K_PAGES
1698	default "11" if ARM64_16K_PAGES
1699	default "10"
1700	help
1701	  The kernel page allocator limits the size of maximal physically
1702	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1703	  defines the maximal power of two of number of pages that can be
1704	  allocated as a single contiguous block. This option allows
1705	  overriding the default setting when ability to allocate very
1706	  large blocks of physically contiguous memory is required.
1707
1708	  The maximal size of allocation cannot exceed the size of the
1709	  section, so the value of MAX_PAGE_ORDER should satisfy
1710
1711	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1712
1713	  Don't change if unsure.
1714
1715config UNMAP_KERNEL_AT_EL0
1716	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1717	default y
1718	help
1719	  Speculation attacks against some high-performance processors can
1720	  be used to bypass MMU permission checks and leak kernel data to
1721	  userspace. This can be defended against by unmapping the kernel
1722	  when running in userspace, mapping it back in on exception entry
1723	  via a trampoline page in the vector table.
1724
1725	  If unsure, say Y.
1726
1727config MITIGATE_SPECTRE_BRANCH_HISTORY
1728	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1729	default y
1730	help
1731	  Speculation attacks against some high-performance processors can
1732	  make use of branch history to influence future speculation.
1733	  When taking an exception from user-space, a sequence of branches
1734	  or a firmware call overwrites the branch history.
1735
1736config ARM64_SW_TTBR0_PAN
1737	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1738	depends on !KCSAN
1739	help
1740	  Enabling this option prevents the kernel from accessing
1741	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1742	  zeroed area and reserved ASID. The user access routines
1743	  restore the valid TTBR0_EL1 temporarily.
1744
1745config ARM64_TAGGED_ADDR_ABI
1746	bool "Enable the tagged user addresses syscall ABI"
1747	default y
1748	help
1749	  When this option is enabled, user applications can opt in to a
1750	  relaxed ABI via prctl() allowing tagged addresses to be passed
1751	  to system calls as pointer arguments. For details, see
1752	  Documentation/arch/arm64/tagged-address-abi.rst.
1753
1754menuconfig COMPAT
1755	bool "Kernel support for 32-bit EL0"
1756	depends on ARM64_4K_PAGES || EXPERT
1757	select HAVE_UID16
1758	select OLD_SIGSUSPEND3
1759	select COMPAT_OLD_SIGACTION
1760	help
1761	  This option enables support for a 32-bit EL0 running under a 64-bit
1762	  kernel at EL1. AArch32-specific components such as system calls,
1763	  the user helper functions, VFP support and the ptrace interface are
1764	  handled appropriately by the kernel.
1765
1766	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1767	  that you will only be able to execute AArch32 binaries that were compiled
1768	  with page size aligned segments.
1769
1770	  If you want to execute 32-bit userspace applications, say Y.
1771
1772if COMPAT
1773
1774config KUSER_HELPERS
1775	bool "Enable kuser helpers page for 32-bit applications"
1776	default y
1777	help
1778	  Warning: disabling this option may break 32-bit user programs.
1779
1780	  Provide kuser helpers to compat tasks. The kernel provides
1781	  helper code to userspace in read only form at a fixed location
1782	  to allow userspace to be independent of the CPU type fitted to
1783	  the system. This permits binaries to be run on ARMv4 through
1784	  to ARMv8 without modification.
1785
1786	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1787
1788	  However, the fixed address nature of these helpers can be used
1789	  by ROP (return orientated programming) authors when creating
1790	  exploits.
1791
1792	  If all of the binaries and libraries which run on your platform
1793	  are built specifically for your platform, and make no use of
1794	  these helpers, then you can turn this option off to hinder
1795	  such exploits. However, in that case, if a binary or library
1796	  relying on those helpers is run, it will not function correctly.
1797
1798	  Say N here only if you are absolutely certain that you do not
1799	  need these helpers; otherwise, the safe option is to say Y.
1800
1801config COMPAT_VDSO
1802	bool "Enable vDSO for 32-bit applications"
1803	depends on !CPU_BIG_ENDIAN
1804	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1805	default y
1806	help
1807	  Place in the process address space of 32-bit applications an
1808	  ELF shared object providing fast implementations of gettimeofday
1809	  and clock_gettime.
1810
1811	  You must have a 32-bit build of glibc 2.22 or later for programs
1812	  to seamlessly take advantage of this.
1813
1814config THUMB2_COMPAT_VDSO
1815	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1816	depends on COMPAT_VDSO
1817	default y
1818	help
1819	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1820	  otherwise with '-marm'.
1821
1822config COMPAT_ALIGNMENT_FIXUPS
1823	bool "Fix up misaligned multi-word loads and stores in user space"
1824
1825menuconfig ARMV8_DEPRECATED
1826	bool "Emulate deprecated/obsolete ARMv8 instructions"
1827	depends on SYSCTL
1828	help
1829	  Legacy software support may require certain instructions
1830	  that have been deprecated or obsoleted in the architecture.
1831
1832	  Enable this config to enable selective emulation of these
1833	  features.
1834
1835	  If unsure, say Y
1836
1837if ARMV8_DEPRECATED
1838
1839config SWP_EMULATION
1840	bool "Emulate SWP/SWPB instructions"
1841	help
1842	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1843	  they are always undefined. Say Y here to enable software
1844	  emulation of these instructions for userspace using LDXR/STXR.
1845	  This feature can be controlled at runtime with the abi.swp
1846	  sysctl which is disabled by default.
1847
1848	  In some older versions of glibc [<=2.8] SWP is used during futex
1849	  trylock() operations with the assumption that the code will not
1850	  be preempted. This invalid assumption may be more likely to fail
1851	  with SWP emulation enabled, leading to deadlock of the user
1852	  application.
1853
1854	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1855	  on an external transaction monitoring block called a global
1856	  monitor to maintain update atomicity. If your system does not
1857	  implement a global monitor, this option can cause programs that
1858	  perform SWP operations to uncached memory to deadlock.
1859
1860	  If unsure, say Y
1861
1862config CP15_BARRIER_EMULATION
1863	bool "Emulate CP15 Barrier instructions"
1864	help
1865	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1866	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1867	  strongly recommended to use the ISB, DSB, and DMB
1868	  instructions instead.
1869
1870	  Say Y here to enable software emulation of these
1871	  instructions for AArch32 userspace code. When this option is
1872	  enabled, CP15 barrier usage is traced which can help
1873	  identify software that needs updating. This feature can be
1874	  controlled at runtime with the abi.cp15_barrier sysctl.
1875
1876	  If unsure, say Y
1877
1878config SETEND_EMULATION
1879	bool "Emulate SETEND instruction"
1880	help
1881	  The SETEND instruction alters the data-endianness of the
1882	  AArch32 EL0, and is deprecated in ARMv8.
1883
1884	  Say Y here to enable software emulation of the instruction
1885	  for AArch32 userspace code. This feature can be controlled
1886	  at runtime with the abi.setend sysctl.
1887
1888	  Note: All the cpus on the system must have mixed endian support at EL0
1889	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1890	  endian - is hotplugged in after this feature has been enabled, there could
1891	  be unexpected results in the applications.
1892
1893	  If unsure, say Y
1894endif # ARMV8_DEPRECATED
1895
1896endif # COMPAT
1897
1898menu "ARMv8.1 architectural features"
1899
1900config ARM64_HW_AFDBM
1901	bool "Support for hardware updates of the Access and Dirty page flags"
1902	default y
1903	help
1904	  The ARMv8.1 architecture extensions introduce support for
1905	  hardware updates of the access and dirty information in page
1906	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1907	  capable processors, accesses to pages with PTE_AF cleared will
1908	  set this bit instead of raising an access flag fault.
1909	  Similarly, writes to read-only pages with the DBM bit set will
1910	  clear the read-only bit (AP[2]) instead of raising a
1911	  permission fault.
1912
1913	  Kernels built with this configuration option enabled continue
1914	  to work on pre-ARMv8.1 hardware and the performance impact is
1915	  minimal. If unsure, say Y.
1916
1917endmenu # "ARMv8.1 architectural features"
1918
1919menu "ARMv8.2 architectural features"
1920
1921config ARM64_PMEM
1922	bool "Enable support for persistent memory"
1923	select ARCH_HAS_PMEM_API
1924	select ARCH_HAS_UACCESS_FLUSHCACHE
1925	help
1926	  Say Y to enable support for the persistent memory API based on the
1927	  ARMv8.2 DCPoP feature.
1928
1929	  The feature is detected at runtime, and the kernel will use DC CVAC
1930	  operations if DC CVAP is not supported (following the behaviour of
1931	  DC CVAP itself if the system does not define a point of persistence).
1932
1933config ARM64_RAS_EXTN
1934	bool "Enable support for RAS CPU Extensions"
1935	default y
1936	help
1937	  CPUs that support the Reliability, Availability and Serviceability
1938	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1939	  errors, classify them and report them to software.
1940
1941	  On CPUs with these extensions system software can use additional
1942	  barriers to determine if faults are pending and read the
1943	  classification from a new set of registers.
1944
1945	  Selecting this feature will allow the kernel to use these barriers
1946	  and access the new registers if the system supports the extension.
1947	  Platform RAS features may additionally depend on firmware support.
1948
1949config ARM64_CNP
1950	bool "Enable support for Common Not Private (CNP) translations"
1951	default y
1952	help
1953	  Common Not Private (CNP) allows translation table entries to
1954	  be shared between different PEs in the same inner shareable
1955	  domain, so the hardware can use this fact to optimise the
1956	  caching of such entries in the TLB.
1957
1958	  Selecting this option allows the CNP feature to be detected
1959	  at runtime, and does not affect PEs that do not implement
1960	  this feature.
1961
1962endmenu # "ARMv8.2 architectural features"
1963
1964menu "ARMv8.3 architectural features"
1965
1966config ARM64_PTR_AUTH
1967	bool "Enable support for pointer authentication"
1968	default y
1969	help
1970	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1971	  instructions for signing and authenticating pointers against secret
1972	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1973	  and other attacks.
1974
1975	  This option enables these instructions at EL0 (i.e. for userspace).
1976	  Choosing this option will cause the kernel to initialise secret keys
1977	  for each process at exec() time, with these keys being
1978	  context-switched along with the process.
1979
1980	  The feature is detected at runtime. If the feature is not present in
1981	  hardware it will not be advertised to userspace/KVM guest nor will it
1982	  be enabled.
1983
1984	  If the feature is present on the boot CPU but not on a late CPU, then
1985	  the late CPU will be parked. Also, if the boot CPU does not have
1986	  address auth and the late CPU has then the late CPU will still boot
1987	  but with the feature disabled. On such a system, this option should
1988	  not be selected.
1989
1990config ARM64_PTR_AUTH_KERNEL
1991	bool "Use pointer authentication for kernel"
1992	default y
1993	depends on ARM64_PTR_AUTH
1994	# Modern compilers insert a .note.gnu.property section note for PAC
1995	# which is only understood by binutils starting with version 2.33.1.
1996	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1997	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1998	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1999	help
2000	  If the compiler supports the -mbranch-protection or
2001	  -msign-return-address flag (e.g. GCC 7 or later), then this option
2002	  will cause the kernel itself to be compiled with return address
2003	  protection. In this case, and if the target hardware is known to
2004	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
2005	  disabled with minimal loss of protection.
2006
2007	  This feature works with FUNCTION_GRAPH_TRACER option only if
2008	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
2009
2010config CC_HAS_BRANCH_PROT_PAC_RET
2011	# GCC 9 or later, clang 8 or later
2012	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
2013
2014config AS_HAS_CFI_NEGATE_RA_STATE
2015	# binutils 2.34+
2016	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
2017
2018endmenu # "ARMv8.3 architectural features"
2019
2020menu "ARMv8.4 architectural features"
2021
2022config ARM64_AMU_EXTN
2023	bool "Enable support for the Activity Monitors Unit CPU extension"
2024	default y
2025	help
2026	  The activity monitors extension is an optional extension introduced
2027	  by the ARMv8.4 CPU architecture. This enables support for version 1
2028	  of the activity monitors architecture, AMUv1.
2029
2030	  To enable the use of this extension on CPUs that implement it, say Y.
2031
2032	  Note that for architectural reasons, firmware _must_ implement AMU
2033	  support when running on CPUs that present the activity monitors
2034	  extension. The required support is present in:
2035	    * Version 1.5 and later of the ARM Trusted Firmware
2036
2037	  For kernels that have this configuration enabled but boot with broken
2038	  firmware, you may need to say N here until the firmware is fixed.
2039	  Otherwise you may experience firmware panics or lockups when
2040	  accessing the counter registers. Even if you are not observing these
2041	  symptoms, the values returned by the register reads might not
2042	  correctly reflect reality. Most commonly, the value read will be 0,
2043	  indicating that the counter is not enabled.
2044
2045config ARM64_TLB_RANGE
2046	bool "Enable support for tlbi range feature"
2047	default y
2048	help
2049	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2050	  range of input addresses.
2051
2052config ARM64_MPAM
2053	bool "Enable support for MPAM"
2054	select ARM64_MPAM_DRIVER
2055	select ARCH_HAS_CPU_RESCTRL
2056	help
2057	  Memory System Resource Partitioning and Monitoring (MPAM) is an
2058	  optional extension to the Arm architecture that allows each
2059	  transaction issued to the memory system to be labelled with a
2060	  Partition identifier (PARTID) and Performance Monitoring Group
2061	  identifier (PMG).
2062
2063	  Memory system components, such as the caches, can be configured with
2064	  policies to control how much of various physical resources (such as
2065	  memory bandwidth or cache memory) the transactions labelled with each
2066	  PARTID can consume.  Depending on the capabilities of the hardware,
2067	  the PARTID and PMG can also be used as filtering criteria to measure
2068	  the memory system resource consumption of different parts of a
2069	  workload.
2070
2071	  Use of this extension requires CPU support, support in the
2072	  Memory System Components (MSC), and a description from firmware
2073	  of where the MSCs are in the address space.
2074
2075	  MPAM is exposed to user-space via the resctrl pseudo filesystem.
2076
2077	  This option enables the extra context switch code.
2078
2079endmenu # "ARMv8.4 architectural features"
2080
2081menu "ARMv8.5 architectural features"
2082
2083config AS_HAS_ARMV8_5
2084	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2085
2086config ARM64_BTI
2087	bool "Branch Target Identification support"
2088	default y
2089	help
2090	  Branch Target Identification (part of the ARMv8.5 Extensions)
2091	  provides a mechanism to limit the set of locations to which computed
2092	  branch instructions such as BR or BLR can jump.
2093
2094	  To make use of BTI on CPUs that support it, say Y.
2095
2096	  BTI is intended to provide complementary protection to other control
2097	  flow integrity protection mechanisms, such as the Pointer
2098	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2099	  For this reason, it does not make sense to enable this option without
2100	  also enabling support for pointer authentication.  Thus, when
2101	  enabling this option you should also select ARM64_PTR_AUTH=y.
2102
2103	  Userspace binaries must also be specifically compiled to make use of
2104	  this mechanism.  If you say N here or the hardware does not support
2105	  BTI, such binaries can still run, but you get no additional
2106	  enforcement of branch destinations.
2107
2108config ARM64_BTI_KERNEL
2109	bool "Use Branch Target Identification for kernel"
2110	default y
2111	depends on ARM64_BTI
2112	depends on ARM64_PTR_AUTH_KERNEL
2113	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2114	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2115	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2116	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2117	depends on !CC_IS_GCC
2118	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2119	help
2120	  Build the kernel with Branch Target Identification annotations
2121	  and enable enforcement of this for kernel code. When this option
2122	  is enabled and the system supports BTI all kernel code including
2123	  modular code must have BTI enabled.
2124
2125config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2126	# GCC 9 or later, clang 8 or later
2127	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2128
2129config ARM64_E0PD
2130	bool "Enable support for E0PD"
2131	default y
2132	help
2133	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2134	  that EL0 accesses made via TTBR1 always fault in constant time,
2135	  providing similar benefits to KASLR as those provided by KPTI, but
2136	  with lower overhead and without disrupting legitimate access to
2137	  kernel memory such as SPE.
2138
2139	  This option enables E0PD for TTBR1 where available.
2140
2141config ARM64_AS_HAS_MTE
2142	# Initial support for MTE went in binutils 2.32.0, checked with
2143	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2144	# as a late addition to the final architecture spec (LDGM/STGM)
2145	# is only supported in the newer 2.32.x and 2.33 binutils
2146	# versions, hence the extra "stgm" instruction check below.
2147	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2148
2149config ARM64_MTE
2150	bool "Memory Tagging Extension support"
2151	default y
2152	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2153	depends on AS_HAS_ARMV8_5
2154	# Required for tag checking in the uaccess routines
2155	select ARCH_HAS_SUBPAGE_FAULTS
2156	select ARCH_USES_HIGH_VMA_FLAGS
2157	select ARCH_USES_PG_ARCH_2
2158	select ARCH_USES_PG_ARCH_3
2159	help
2160	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2161	  architectural support for run-time, always-on detection of
2162	  various classes of memory error to aid with software debugging
2163	  to eliminate vulnerabilities arising from memory-unsafe
2164	  languages.
2165
2166	  This option enables the support for the Memory Tagging
2167	  Extension at EL0 (i.e. for userspace).
2168
2169	  Selecting this option allows the feature to be detected at
2170	  runtime. Any secondary CPU not implementing this feature will
2171	  not be allowed a late bring-up.
2172
2173	  Userspace binaries that want to use this feature must
2174	  explicitly opt in. The mechanism for the userspace is
2175	  described in:
2176
2177	  Documentation/arch/arm64/memory-tagging-extension.rst.
2178
2179endmenu # "ARMv8.5 architectural features"
2180
2181menu "ARMv8.7 architectural features"
2182
2183config ARM64_EPAN
2184	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2185	default y
2186	help
2187	  Enhanced Privileged Access Never (EPAN) allows Privileged
2188	  Access Never to be used with Execute-only mappings.
2189
2190	  The feature is detected at runtime, and will remain disabled
2191	  if the cpu does not implement the feature.
2192endmenu # "ARMv8.7 architectural features"
2193
2194config AS_HAS_MOPS
2195	def_bool $(as-instr,.arch_extension mops)
2196
2197menu "ARMv8.9 architectural features"
2198
2199config ARM64_POE
2200	prompt "Permission Overlay Extension"
2201	def_bool y
2202	select ARCH_USES_HIGH_VMA_FLAGS
2203	select ARCH_HAS_PKEYS
2204	help
2205	  The Permission Overlay Extension is used to implement Memory
2206	  Protection Keys. Memory Protection Keys provides a mechanism for
2207	  enforcing page-based protections, but without requiring modification
2208	  of the page tables when an application changes protection domains.
2209
2210	  For details, see Documentation/core-api/protection-keys.rst
2211
2212	  If unsure, say y.
2213
2214config ARCH_PKEY_BITS
2215	int
2216	default 3
2217
2218config ARM64_HAFT
2219	bool "Support for Hardware managed Access Flag for Table Descriptors"
2220	depends on ARM64_HW_AFDBM
2221	default y
2222	help
2223	  The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access
2224	  Flag for Table descriptors. When enabled an architectural executed
2225	  memory access will update the Access Flag in each Table descriptor
2226	  which is accessed during the translation table walk and for which
2227	  the Access Flag is 0. The Access Flag of the Table descriptor use
2228	  the same bit of PTE_AF.
2229
2230	  The feature will only be enabled if all the CPUs in the system
2231	  support this feature. If unsure, say Y.
2232
2233endmenu # "ARMv8.9 architectural features"
2234
2235menu "ARMv9.4 architectural features"
2236
2237config ARM64_GCS
2238	bool "Enable support for Guarded Control Stack (GCS)"
2239	default y
2240	select ARCH_HAS_USER_SHADOW_STACK
2241	select ARCH_USES_HIGH_VMA_FLAGS
2242	help
2243	  Guarded Control Stack (GCS) provides support for a separate
2244	  stack with restricted access which contains only return
2245	  addresses.  This can be used to harden against some attacks
2246	  by comparing return address used by the program with what is
2247	  stored in the GCS, and may also be used to efficiently obtain
2248	  the call stack for applications such as profiling.
2249
2250	  The feature is detected at runtime, and will remain disabled
2251	  if the system does not implement the feature.
2252
2253endmenu # "ARMv9.4 architectural features"
2254
2255config AS_HAS_LSUI
2256	def_bool $(as-instr,.arch_extension lsui)
2257	help
2258	  Supported by LLVM 20+ and binutils 2.45+.
2259
2260menu "ARMv9.6 architectural features"
2261
2262config ARM64_LSUI
2263	bool "Support Unprivileged Load Store Instructions (LSUI)"
2264	default y
2265	depends on AS_HAS_LSUI && !CPU_BIG_ENDIAN
2266	help
2267	  The Unprivileged Load Store Instructions (LSUI) provides
2268	  variants load/store instructions that access user-space memory
2269	  from the kernel without clearing PSTATE.PAN bit.
2270
2271	  This feature is supported by LLVM 20+ and binutils 2.45+.
2272
2273endmenu # "ARMv9.6 architectural feature"
2274
2275config ARM64_SVE
2276	bool "ARM Scalable Vector Extension support"
2277	default y
2278	help
2279	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2280	  execution state which complements and extends the SIMD functionality
2281	  of the base architecture to support much larger vectors and to enable
2282	  additional vectorisation opportunities.
2283
2284	  To enable use of this extension on CPUs that implement it, say Y.
2285
2286	  On CPUs that support the SVE2 extensions, this option will enable
2287	  those too.
2288
2289	  Note that for architectural reasons, firmware _must_ implement SVE
2290	  support when running on SVE capable hardware.  The required support
2291	  is present in:
2292
2293	    * version 1.5 and later of the ARM Trusted Firmware
2294	    * the AArch64 boot wrapper since commit 5e1261e08abf
2295	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2296
2297	  For other firmware implementations, consult the firmware documentation
2298	  or vendor.
2299
2300	  If you need the kernel to boot on SVE-capable hardware with broken
2301	  firmware, you may need to say N here until you get your firmware
2302	  fixed.  Otherwise, you may experience firmware panics or lockups when
2303	  booting the kernel.  If unsure and you are not observing these
2304	  symptoms, you should assume that it is safe to say Y.
2305
2306config AS_HAS_SME
2307	# Supported by LLVM 13+ and binutils 2.38+
2308	def_bool $(as-instr,.arch_extension sme)
2309
2310config ARM64_SME
2311	bool "ARM Scalable Matrix Extension support"
2312	default y
2313	depends on ARM64_SVE
2314	depends on AS_HAS_SME
2315	help
2316	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2317	  execution state which utilises a substantial subset of the SVE
2318	  instruction set, together with the addition of new architectural
2319	  register state capable of holding two dimensional matrix tiles to
2320	  enable various matrix operations.
2321
2322config ARM64_PSEUDO_NMI
2323	bool "Support for NMI-like interrupts"
2324	select ARM_GIC_V3
2325	help
2326	  Adds support for mimicking Non-Maskable Interrupts through the use of
2327	  GIC interrupt priority. This support requires version 3 or later of
2328	  ARM GIC.
2329
2330	  This high priority configuration for interrupts needs to be
2331	  explicitly enabled by setting the kernel parameter
2332	  "irqchip.gicv3_pseudo_nmi" to 1.
2333
2334	  If unsure, say N
2335
2336if ARM64_PSEUDO_NMI
2337config ARM64_DEBUG_PRIORITY_MASKING
2338	bool "Debug interrupt priority masking"
2339	help
2340	  This adds runtime checks to functions enabling/disabling
2341	  interrupts when using priority masking. The additional checks verify
2342	  the validity of ICC_PMR_EL1 when calling concerned functions.
2343
2344	  If unsure, say N
2345endif # ARM64_PSEUDO_NMI
2346
2347config RELOCATABLE
2348	bool "Build a relocatable kernel image" if EXPERT
2349	select ARCH_HAS_RELR
2350	default y
2351	help
2352	  This builds the kernel as a Position Independent Executable (PIE),
2353	  which retains all relocation metadata required to relocate the
2354	  kernel binary at runtime to a different virtual address than the
2355	  address it was linked at.
2356	  Since AArch64 uses the RELA relocation format, this requires a
2357	  relocation pass at runtime even if the kernel is loaded at the
2358	  same address it was linked at.
2359
2360config RANDOMIZE_BASE
2361	bool "Randomize the address of the kernel image"
2362	select RELOCATABLE
2363	help
2364	  Randomizes the virtual address at which the kernel image is
2365	  loaded, as a security feature that deters exploit attempts
2366	  relying on knowledge of the location of kernel internals.
2367
2368	  It is the bootloader's job to provide entropy, by passing a
2369	  random u64 value in /chosen/kaslr-seed at kernel entry.
2370
2371	  When booting via the UEFI stub, it will invoke the firmware's
2372	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2373	  to the kernel proper. In addition, it will randomise the physical
2374	  location of the kernel Image as well.
2375
2376	  If unsure, say N.
2377
2378config RANDOMIZE_MODULE_REGION_FULL
2379	bool "Randomize the module region over a 2 GB range"
2380	depends on RANDOMIZE_BASE
2381	default y
2382	help
2383	  Randomizes the location of the module region inside a 2 GB window
2384	  covering the core kernel. This way, it is less likely for modules
2385	  to leak information about the location of core kernel data structures
2386	  but it does imply that function calls between modules and the core
2387	  kernel will need to be resolved via veneers in the module PLT.
2388
2389	  When this option is not set, the module region will be randomized over
2390	  a limited range that contains the [_stext, _etext] interval of the
2391	  core kernel, so branch relocations are almost always in range unless
2392	  the region is exhausted. In this particular case of region
2393	  exhaustion, modules might be able to fall back to a larger 2GB area.
2394
2395config CC_HAVE_STACKPROTECTOR_SYSREG
2396	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2397
2398config STACKPROTECTOR_PER_TASK
2399	def_bool y
2400	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2401
2402config UNWIND_PATCH_PAC_INTO_SCS
2403	bool "Enable shadow call stack dynamically using code patching"
2404	depends on CC_IS_CLANG
2405	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2406	depends on SHADOW_CALL_STACK
2407	select UNWIND_TABLES
2408	select DYNAMIC_SCS
2409
2410config ARM64_CONTPTE
2411	bool "Contiguous PTE mappings for user memory" if EXPERT
2412	depends on TRANSPARENT_HUGEPAGE
2413	default y
2414	help
2415	  When enabled, user mappings are configured using the PTE contiguous
2416	  bit, for any mappings that meet the size and alignment requirements.
2417	  This reduces TLB pressure and improves performance.
2418
2419endmenu # "Kernel Features"
2420
2421menu "Boot options"
2422
2423config ARM64_ACPI_PARKING_PROTOCOL
2424	bool "Enable support for the ARM64 ACPI parking protocol"
2425	depends on ACPI
2426	help
2427	  Enable support for the ARM64 ACPI parking protocol. If disabled
2428	  the kernel will not allow booting through the ARM64 ACPI parking
2429	  protocol even if the corresponding data is present in the ACPI
2430	  MADT table.
2431
2432config CMDLINE
2433	string "Default kernel command string"
2434	default ""
2435	help
2436	  Provide a set of default command-line options at build time by
2437	  entering them here. As a minimum, you should specify the
2438	  root device (e.g. root=/dev/nfs).
2439
2440choice
2441	prompt "Kernel command line type"
2442	depends on CMDLINE != ""
2443	default CMDLINE_FROM_BOOTLOADER
2444	help
2445	  Choose how the kernel will handle the provided default kernel
2446	  command line string.
2447
2448config CMDLINE_FROM_BOOTLOADER
2449	bool "Use bootloader kernel arguments if available"
2450	help
2451	  Uses the command-line options passed by the boot loader. If
2452	  the boot loader doesn't provide any, the default kernel command
2453	  string provided in CMDLINE will be used.
2454
2455config CMDLINE_FORCE
2456	bool "Always use the default kernel command string"
2457	help
2458	  Always use the default kernel command string, even if the boot
2459	  loader passes other arguments to the kernel.
2460	  This is useful if you cannot or don't want to change the
2461	  command-line options your boot loader passes to the kernel.
2462
2463endchoice
2464
2465config EFI_STUB
2466	bool
2467
2468config EFI
2469	bool "UEFI runtime support"
2470	depends on OF && !CPU_BIG_ENDIAN
2471	depends on KERNEL_MODE_NEON
2472	select ARCH_SUPPORTS_ACPI
2473	select LIBFDT
2474	select UCS2_STRING
2475	select EFI_PARAMS_FROM_FDT
2476	select EFI_RUNTIME_WRAPPERS
2477	select EFI_STUB
2478	select EFI_GENERIC_STUB
2479	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2480	default y
2481	help
2482	  This option provides support for runtime services provided
2483	  by UEFI firmware (such as non-volatile variables, realtime
2484	  clock, and platform reset). A UEFI stub is also provided to
2485	  allow the kernel to be booted as an EFI application. This
2486	  is only useful on systems that have UEFI firmware.
2487
2488config COMPRESSED_INSTALL
2489	bool "Install compressed image by default"
2490	help
2491	  This makes the regular "make install" install the compressed
2492	  image we built, not the legacy uncompressed one.
2493
2494	  You can check that a compressed image works for you by doing
2495	  "make zinstall" first, and verifying that everything is fine
2496	  in your environment before making "make install" do this for
2497	  you.
2498
2499config DMI
2500	bool "Enable support for SMBIOS (DMI) tables"
2501	depends on EFI
2502	default y
2503	help
2504	  This enables SMBIOS/DMI feature for systems.
2505
2506	  This option is only useful on systems that have UEFI firmware.
2507	  However, even with this option, the resultant kernel should
2508	  continue to boot on existing non-UEFI platforms.
2509
2510endmenu # "Boot options"
2511
2512menu "Power management options"
2513
2514source "kernel/power/Kconfig"
2515
2516config ARCH_HIBERNATION_POSSIBLE
2517	def_bool y
2518	depends on CPU_PM
2519
2520config ARCH_HIBERNATION_HEADER
2521	def_bool y
2522	depends on HIBERNATION
2523
2524config ARCH_SUSPEND_POSSIBLE
2525	def_bool y
2526
2527endmenu # "Power management options"
2528
2529menu "CPU Power Management"
2530
2531source "drivers/cpuidle/Kconfig"
2532
2533source "drivers/cpufreq/Kconfig"
2534
2535endmenu # "CPU Power Management"
2536
2537source "drivers/acpi/Kconfig"
2538
2539source "arch/arm64/kvm/Kconfig"
2540
2541source "kernel/livepatch/Kconfig"
2542