xref: /openbmc/linux/arch/arm64/Kconfig (revision 2579af94)
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_IORT if ACPI
9	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
10	select ACPI_MCFG if (ACPI && PCI)
11	select ACPI_SPCR_TABLE if ACPI
12	select ACPI_PPTT if ACPI
13	select ARCH_HAS_DEBUG_WX
14	select ARCH_BINFMT_ELF_EXTRA_PHDRS
15	select ARCH_BINFMT_ELF_STATE
16	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
17	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
18	select ARCH_ENABLE_MEMORY_HOTPLUG
19	select ARCH_ENABLE_MEMORY_HOTREMOVE
20	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
21	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
22	select ARCH_HAS_CACHE_LINE_SIZE
23	select ARCH_HAS_CURRENT_STACK_POINTER
24	select ARCH_HAS_DEBUG_VIRTUAL
25	select ARCH_HAS_DEBUG_VM_PGTABLE
26	select ARCH_HAS_DMA_PREP_COHERENT
27	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
28	select ARCH_HAS_FAST_MULTIPLIER
29	select ARCH_HAS_FORTIFY_SOURCE
30	select ARCH_HAS_GCOV_PROFILE_ALL
31	select ARCH_HAS_GIGANTIC_PAGE
32	select ARCH_HAS_KCOV
33	select ARCH_HAS_KEEPINITRD
34	select ARCH_HAS_MEMBARRIER_SYNC_CORE
35	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
36	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
37	select ARCH_HAS_PTE_DEVMAP
38	select ARCH_HAS_PTE_SPECIAL
39	select ARCH_HAS_SETUP_DMA_OPS
40	select ARCH_HAS_SET_DIRECT_MAP
41	select ARCH_HAS_SET_MEMORY
42	select ARCH_STACKWALK
43	select ARCH_HAS_STRICT_KERNEL_RWX
44	select ARCH_HAS_STRICT_MODULE_RWX
45	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
46	select ARCH_HAS_SYNC_DMA_FOR_CPU
47	select ARCH_HAS_SYSCALL_WRAPPER
48	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
49	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
50	select ARCH_HAS_ZONE_DMA_SET if EXPERT
51	select ARCH_HAVE_ELF_PROT
52	select ARCH_HAVE_NMI_SAFE_CMPXCHG
53	select ARCH_HAVE_TRACE_MMIO_ACCESS
54	select ARCH_INLINE_READ_LOCK if !PREEMPTION
55	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
56	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
57	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
58	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
59	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
60	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
61	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
62	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
63	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
64	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
65	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
66	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
67	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
68	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
69	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
70	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
71	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
72	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
73	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
74	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
75	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
76	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
77	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
78	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
79	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
80	select ARCH_KEEP_MEMBLOCK
81	select ARCH_USE_CMPXCHG_LOCKREF
82	select ARCH_USE_GNU_PROPERTY
83	select ARCH_USE_MEMTEST
84	select ARCH_USE_QUEUED_RWLOCKS
85	select ARCH_USE_QUEUED_SPINLOCKS
86	select ARCH_USE_SYM_ANNOTATIONS
87	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
88	select ARCH_SUPPORTS_HUGETLBFS
89	select ARCH_SUPPORTS_MEMORY_FAILURE
90	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
91	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
92	select ARCH_SUPPORTS_LTO_CLANG_THIN
93	select ARCH_SUPPORTS_CFI_CLANG
94	select ARCH_SUPPORTS_ATOMIC_RMW
95	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
96	select ARCH_SUPPORTS_NUMA_BALANCING
97	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
98	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
99	select ARCH_WANT_DEFAULT_BPF_JIT
100	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
101	select ARCH_WANT_FRAME_POINTERS
102	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
103	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
104	select ARCH_WANT_LD_ORPHAN_WARN
105	select ARCH_WANTS_NO_INSTR
106	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
107	select ARCH_HAS_UBSAN_SANITIZE_ALL
108	select ARM_AMBA
109	select ARM_ARCH_TIMER
110	select ARM_GIC
111	select AUDIT_ARCH_COMPAT_GENERIC
112	select ARM_GIC_V2M if PCI
113	select ARM_GIC_V3
114	select ARM_GIC_V3_ITS if PCI
115	select ARM_PSCI_FW
116	select BUILDTIME_TABLE_SORT
117	select CLONE_BACKWARDS
118	select COMMON_CLK
119	select CPU_PM if (SUSPEND || CPU_IDLE)
120	select CRC32
121	select DCACHE_WORD_ACCESS
122	select DYNAMIC_FTRACE if FUNCTION_TRACER
123	select DMA_DIRECT_REMAP
124	select EDAC_SUPPORT
125	select FRAME_POINTER
126	select GENERIC_ALLOCATOR
127	select GENERIC_ARCH_TOPOLOGY
128	select GENERIC_CLOCKEVENTS_BROADCAST
129	select GENERIC_CPU_AUTOPROBE
130	select GENERIC_CPU_VULNERABILITIES
131	select GENERIC_EARLY_IOREMAP
132	select GENERIC_IDLE_POLL_SETUP
133	select GENERIC_IOREMAP
134	select GENERIC_IRQ_IPI
135	select GENERIC_IRQ_PROBE
136	select GENERIC_IRQ_SHOW
137	select GENERIC_IRQ_SHOW_LEVEL
138	select GENERIC_LIB_DEVMEM_IS_ALLOWED
139	select GENERIC_PCI_IOMAP
140	select GENERIC_PTDUMP
141	select GENERIC_SCHED_CLOCK
142	select GENERIC_SMP_IDLE_THREAD
143	select GENERIC_TIME_VSYSCALL
144	select GENERIC_GETTIMEOFDAY
145	select GENERIC_VDSO_TIME_NS
146	select HARDIRQS_SW_RESEND
147	select HAVE_MOVE_PMD
148	select HAVE_MOVE_PUD
149	select HAVE_PCI
150	select HAVE_ACPI_APEI if (ACPI && EFI)
151	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
152	select HAVE_ARCH_AUDITSYSCALL
153	select HAVE_ARCH_BITREVERSE
154	select HAVE_ARCH_COMPILER_H
155	select HAVE_ARCH_HUGE_VMALLOC
156	select HAVE_ARCH_HUGE_VMAP
157	select HAVE_ARCH_JUMP_LABEL
158	select HAVE_ARCH_JUMP_LABEL_RELATIVE
159	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
160	select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
161	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
162	select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
163	# Some instrumentation may be unsound, hence EXPERT
164	select HAVE_ARCH_KCSAN if EXPERT
165	select HAVE_ARCH_KFENCE
166	select HAVE_ARCH_KGDB
167	select HAVE_ARCH_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_STACKLEAK
173	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
174	select HAVE_ARCH_TRACEHOOK
175	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
176	select HAVE_ARCH_VMAP_STACK
177	select HAVE_ARM_SMCCC
178	select HAVE_ASM_MODVERSIONS
179	select HAVE_EBPF_JIT
180	select HAVE_C_RECORDMCOUNT
181	select HAVE_CMPXCHG_DOUBLE
182	select HAVE_CMPXCHG_LOCAL
183	select HAVE_CONTEXT_TRACKING_USER
184	select HAVE_DEBUG_KMEMLEAK
185	select HAVE_DMA_CONTIGUOUS
186	select HAVE_DYNAMIC_FTRACE
187	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
188		if $(cc-option,-fpatchable-function-entry=2)
189	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
190		if DYNAMIC_FTRACE_WITH_ARGS
191	select HAVE_EFFICIENT_UNALIGNED_ACCESS
192	select HAVE_FAST_GUP
193	select HAVE_FTRACE_MCOUNT_RECORD
194	select HAVE_FUNCTION_TRACER
195	select HAVE_FUNCTION_ERROR_INJECTION
196	select HAVE_FUNCTION_GRAPH_TRACER
197	select HAVE_GCC_PLUGINS
198	select HAVE_HW_BREAKPOINT if PERF_EVENTS
199	select HAVE_IOREMAP_PROT
200	select HAVE_IRQ_TIME_ACCOUNTING
201	select HAVE_KVM
202	select HAVE_NMI
203	select HAVE_PERF_EVENTS
204	select HAVE_PERF_REGS
205	select HAVE_PERF_USER_STACK_DUMP
206	select HAVE_PREEMPT_DYNAMIC_KEY
207	select HAVE_REGS_AND_STACK_ACCESS_API
208	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
209	select HAVE_FUNCTION_ARG_ACCESS_API
210	select MMU_GATHER_RCU_TABLE_FREE
211	select HAVE_RSEQ
212	select HAVE_STACKPROTECTOR
213	select HAVE_SYSCALL_TRACEPOINTS
214	select HAVE_KPROBES
215	select HAVE_KRETPROBES
216	select HAVE_GENERIC_VDSO
217	select IRQ_DOMAIN
218	select IRQ_FORCED_THREADING
219	select KASAN_VMALLOC if KASAN
220	select MODULES_USE_ELF_RELA
221	select NEED_DMA_MAP_STATE
222	select NEED_SG_DMA_LENGTH
223	select OF
224	select OF_EARLY_FLATTREE
225	select PCI_DOMAINS_GENERIC if PCI
226	select PCI_ECAM if (ACPI && PCI)
227	select PCI_SYSCALL if PCI
228	select POWER_RESET
229	select POWER_SUPPLY
230	select SPARSE_IRQ
231	select SWIOTLB
232	select SYSCTL_EXCEPTION_TRACE
233	select THREAD_INFO_IN_TASK
234	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
235	select TRACE_IRQFLAGS_SUPPORT
236	select TRACE_IRQFLAGS_NMI_SUPPORT
237	select HAVE_SOFTIRQ_ON_OWN_STACK
238	help
239	  ARM 64-bit (AArch64) Linux support.
240
241config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
242	def_bool CC_IS_CLANG
243	# https://github.com/ClangBuiltLinux/linux/issues/1507
244	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
245	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
246
247config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
248	def_bool CC_IS_GCC
249	depends on $(cc-option,-fpatchable-function-entry=2)
250	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
251
252config 64BIT
253	def_bool y
254
255config MMU
256	def_bool y
257
258config ARM64_PAGE_SHIFT
259	int
260	default 16 if ARM64_64K_PAGES
261	default 14 if ARM64_16K_PAGES
262	default 12
263
264config ARM64_CONT_PTE_SHIFT
265	int
266	default 5 if ARM64_64K_PAGES
267	default 7 if ARM64_16K_PAGES
268	default 4
269
270config ARM64_CONT_PMD_SHIFT
271	int
272	default 5 if ARM64_64K_PAGES
273	default 5 if ARM64_16K_PAGES
274	default 4
275
276config ARCH_MMAP_RND_BITS_MIN
277	default 14 if ARM64_64K_PAGES
278	default 16 if ARM64_16K_PAGES
279	default 18
280
281# max bits determined by the following formula:
282#  VA_BITS - PAGE_SHIFT - 3
283config ARCH_MMAP_RND_BITS_MAX
284	default 19 if ARM64_VA_BITS=36
285	default 24 if ARM64_VA_BITS=39
286	default 27 if ARM64_VA_BITS=42
287	default 30 if ARM64_VA_BITS=47
288	default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
289	default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
290	default 33 if ARM64_VA_BITS=48
291	default 14 if ARM64_64K_PAGES
292	default 16 if ARM64_16K_PAGES
293	default 18
294
295config ARCH_MMAP_RND_COMPAT_BITS_MIN
296	default 7 if ARM64_64K_PAGES
297	default 9 if ARM64_16K_PAGES
298	default 11
299
300config ARCH_MMAP_RND_COMPAT_BITS_MAX
301	default 16
302
303config NO_IOPORT_MAP
304	def_bool y if !PCI
305
306config STACKTRACE_SUPPORT
307	def_bool y
308
309config ILLEGAL_POINTER_VALUE
310	hex
311	default 0xdead000000000000
312
313config LOCKDEP_SUPPORT
314	def_bool y
315
316config GENERIC_BUG
317	def_bool y
318	depends on BUG
319
320config GENERIC_BUG_RELATIVE_POINTERS
321	def_bool y
322	depends on GENERIC_BUG
323
324config GENERIC_HWEIGHT
325	def_bool y
326
327config GENERIC_CSUM
328	def_bool y
329
330config GENERIC_CALIBRATE_DELAY
331	def_bool y
332
333config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
334	def_bool y
335
336config SMP
337	def_bool y
338
339config KERNEL_MODE_NEON
340	def_bool y
341
342config FIX_EARLYCON_MEM
343	def_bool y
344
345config PGTABLE_LEVELS
346	int
347	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
348	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
349	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
350	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
351	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
352	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
353
354config ARCH_SUPPORTS_UPROBES
355	def_bool y
356
357config ARCH_PROC_KCORE_TEXT
358	def_bool y
359
360config BROKEN_GAS_INST
361	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
362
363config KASAN_SHADOW_OFFSET
364	hex
365	depends on KASAN_GENERIC || KASAN_SW_TAGS
366	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
367	default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
368	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
369	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
370	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
371	default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
372	default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
373	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
374	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
375	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
376	default 0xffffffffffffffff
377
378config UNWIND_TABLES
379	bool
380
381source "arch/arm64/Kconfig.platforms"
382
383menu "Kernel Features"
384
385menu "ARM errata workarounds via the alternatives framework"
386
387config ARM64_WORKAROUND_CLEAN_CACHE
388	bool
389
390config ARM64_ERRATUM_826319
391	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
392	default y
393	select ARM64_WORKAROUND_CLEAN_CACHE
394	help
395	  This option adds an alternative code sequence to work around ARM
396	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
397	  AXI master interface and an L2 cache.
398
399	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
400	  and is unable to accept a certain write via this interface, it will
401	  not progress on read data presented on the read data channel and the
402	  system can deadlock.
403
404	  The workaround promotes data cache clean instructions to
405	  data cache clean-and-invalidate.
406	  Please note that this does not necessarily enable the workaround,
407	  as it depends on the alternative framework, which will only patch
408	  the kernel if an affected CPU is detected.
409
410	  If unsure, say Y.
411
412config ARM64_ERRATUM_827319
413	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
414	default y
415	select ARM64_WORKAROUND_CLEAN_CACHE
416	help
417	  This option adds an alternative code sequence to work around ARM
418	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
419	  master interface and an L2 cache.
420
421	  Under certain conditions this erratum can cause a clean line eviction
422	  to occur at the same time as another transaction to the same address
423	  on the AMBA 5 CHI interface, which can cause data corruption if the
424	  interconnect reorders the two transactions.
425
426	  The workaround promotes data cache clean instructions to
427	  data cache clean-and-invalidate.
428	  Please note that this does not necessarily enable the workaround,
429	  as it depends on the alternative framework, which will only patch
430	  the kernel if an affected CPU is detected.
431
432	  If unsure, say Y.
433
434config ARM64_ERRATUM_824069
435	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
436	default y
437	select ARM64_WORKAROUND_CLEAN_CACHE
438	help
439	  This option adds an alternative code sequence to work around ARM
440	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
441	  to a coherent interconnect.
442
443	  If a Cortex-A53 processor is executing a store or prefetch for
444	  write instruction at the same time as a processor in another
445	  cluster is executing a cache maintenance operation to the same
446	  address, then this erratum might cause a clean cache line to be
447	  incorrectly marked as dirty.
448
449	  The workaround promotes data cache clean instructions to
450	  data cache clean-and-invalidate.
451	  Please note that this option does not necessarily enable the
452	  workaround, as it depends on the alternative framework, which will
453	  only patch the kernel if an affected CPU is detected.
454
455	  If unsure, say Y.
456
457config ARM64_ERRATUM_819472
458	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
459	default y
460	select ARM64_WORKAROUND_CLEAN_CACHE
461	help
462	  This option adds an alternative code sequence to work around ARM
463	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
464	  present when it is connected to a coherent interconnect.
465
466	  If the processor is executing a load and store exclusive sequence at
467	  the same time as a processor in another cluster is executing a cache
468	  maintenance operation to the same address, then this erratum might
469	  cause data corruption.
470
471	  The workaround promotes data cache clean instructions to
472	  data cache clean-and-invalidate.
473	  Please note that this does not necessarily enable the workaround,
474	  as it depends on the alternative framework, which will only patch
475	  the kernel if an affected CPU is detected.
476
477	  If unsure, say Y.
478
479config ARM64_ERRATUM_832075
480	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
481	default y
482	help
483	  This option adds an alternative code sequence to work around ARM
484	  erratum 832075 on Cortex-A57 parts up to r1p2.
485
486	  Affected Cortex-A57 parts might deadlock when exclusive load/store
487	  instructions to Write-Back memory are mixed with Device loads.
488
489	  The workaround is to promote device loads to use Load-Acquire
490	  semantics.
491	  Please note that this does not necessarily enable the workaround,
492	  as it depends on the alternative framework, which will only patch
493	  the kernel if an affected CPU is detected.
494
495	  If unsure, say Y.
496
497config ARM64_ERRATUM_834220
498	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
499	depends on KVM
500	default y
501	help
502	  This option adds an alternative code sequence to work around ARM
503	  erratum 834220 on Cortex-A57 parts up to r1p2.
504
505	  Affected Cortex-A57 parts might report a Stage 2 translation
506	  fault as the result of a Stage 1 fault for load crossing a
507	  page boundary when there is a permission or device memory
508	  alignment fault at Stage 1 and a translation fault at Stage 2.
509
510	  The workaround is to verify that the Stage 1 translation
511	  doesn't generate a fault before handling the Stage 2 fault.
512	  Please note that this does not necessarily enable the workaround,
513	  as it depends on the alternative framework, which will only patch
514	  the kernel if an affected CPU is detected.
515
516	  If unsure, say Y.
517
518config ARM64_ERRATUM_1742098
519	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
520	depends on COMPAT
521	default y
522	help
523	  This option removes the AES hwcap for aarch32 user-space to
524	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
525
526	  Affected parts may corrupt the AES state if an interrupt is
527	  taken between a pair of AES instructions. These instructions
528	  are only present if the cryptography extensions are present.
529	  All software should have a fallback implementation for CPUs
530	  that don't implement the cryptography extensions.
531
532	  If unsure, say Y.
533
534config ARM64_ERRATUM_845719
535	bool "Cortex-A53: 845719: a load might read incorrect data"
536	depends on COMPAT
537	default y
538	help
539	  This option adds an alternative code sequence to work around ARM
540	  erratum 845719 on Cortex-A53 parts up to r0p4.
541
542	  When running a compat (AArch32) userspace on an affected Cortex-A53
543	  part, a load at EL0 from a virtual address that matches the bottom 32
544	  bits of the virtual address used by a recent load at (AArch64) EL1
545	  might return incorrect data.
546
547	  The workaround is to write the contextidr_el1 register on exception
548	  return to a 32-bit task.
549	  Please note that this does not necessarily enable the workaround,
550	  as it depends on the alternative framework, which will only patch
551	  the kernel if an affected CPU is detected.
552
553	  If unsure, say Y.
554
555config ARM64_ERRATUM_843419
556	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
557	default y
558	select ARM64_MODULE_PLTS if MODULES
559	help
560	  This option links the kernel with '--fix-cortex-a53-843419' and
561	  enables PLT support to replace certain ADRP instructions, which can
562	  cause subsequent memory accesses to use an incorrect address on
563	  Cortex-A53 parts up to r0p4.
564
565	  If unsure, say Y.
566
567config ARM64_LD_HAS_FIX_ERRATUM_843419
568	def_bool $(ld-option,--fix-cortex-a53-843419)
569
570config ARM64_ERRATUM_1024718
571	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
572	default y
573	help
574	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
575
576	  Affected Cortex-A55 cores (all revisions) could cause incorrect
577	  update of the hardware dirty bit when the DBM/AP bits are updated
578	  without a break-before-make. The workaround is to disable the usage
579	  of hardware DBM locally on the affected cores. CPUs not affected by
580	  this erratum will continue to use the feature.
581
582	  If unsure, say Y.
583
584config ARM64_ERRATUM_1418040
585	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
586	default y
587	depends on COMPAT
588	help
589	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
590	  errata 1188873 and 1418040.
591
592	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
593	  cause register corruption when accessing the timer registers
594	  from AArch32 userspace.
595
596	  If unsure, say Y.
597
598config ARM64_WORKAROUND_SPECULATIVE_AT
599	bool
600
601config ARM64_ERRATUM_1165522
602	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
603	default y
604	select ARM64_WORKAROUND_SPECULATIVE_AT
605	help
606	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
607
608	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
609	  corrupted TLBs by speculating an AT instruction during a guest
610	  context switch.
611
612	  If unsure, say Y.
613
614config ARM64_ERRATUM_1319367
615	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
616	default y
617	select ARM64_WORKAROUND_SPECULATIVE_AT
618	help
619	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
620	  and A72 erratum 1319367
621
622	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
623	  speculating an AT instruction during a guest context switch.
624
625	  If unsure, say Y.
626
627config ARM64_ERRATUM_1530923
628	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
629	default y
630	select ARM64_WORKAROUND_SPECULATIVE_AT
631	help
632	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
633
634	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
635	  corrupted TLBs by speculating an AT instruction during a guest
636	  context switch.
637
638	  If unsure, say Y.
639
640config ARM64_WORKAROUND_REPEAT_TLBI
641	bool
642
643config ARM64_ERRATUM_2441007
644	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
645	default y
646	select ARM64_WORKAROUND_REPEAT_TLBI
647	help
648	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
649
650	  Under very rare circumstances, affected Cortex-A55 CPUs
651	  may not handle a race between a break-before-make sequence on one
652	  CPU, and another CPU accessing the same page. This could allow a
653	  store to a page that has been unmapped.
654
655	  Work around this by adding the affected CPUs to the list that needs
656	  TLB sequences to be done twice.
657
658	  If unsure, say Y.
659
660config ARM64_ERRATUM_1286807
661	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
662	default y
663	select ARM64_WORKAROUND_REPEAT_TLBI
664	help
665	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
666
667	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
668	  address for a cacheable mapping of a location is being
669	  accessed by a core while another core is remapping the virtual
670	  address to a new physical page using the recommended
671	  break-before-make sequence, then under very rare circumstances
672	  TLBI+DSB completes before a read using the translation being
673	  invalidated has been observed by other observers. The
674	  workaround repeats the TLBI+DSB operation.
675
676config ARM64_ERRATUM_1463225
677	bool "Cortex-A76: Software Step might prevent interrupt recognition"
678	default y
679	help
680	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
681
682	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
683	  of a system call instruction (SVC) can prevent recognition of
684	  subsequent interrupts when software stepping is disabled in the
685	  exception handler of the system call and either kernel debugging
686	  is enabled or VHE is in use.
687
688	  Work around the erratum by triggering a dummy step exception
689	  when handling a system call from a task that is being stepped
690	  in a VHE configuration of the kernel.
691
692	  If unsure, say Y.
693
694config ARM64_ERRATUM_1542419
695	bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
696	default y
697	help
698	  This option adds a workaround for ARM Neoverse-N1 erratum
699	  1542419.
700
701	  Affected Neoverse-N1 cores could execute a stale instruction when
702	  modified by another CPU. The workaround depends on a firmware
703	  counterpart.
704
705	  Workaround the issue by hiding the DIC feature from EL0. This
706	  forces user-space to perform cache maintenance.
707
708	  If unsure, say Y.
709
710config ARM64_ERRATUM_1508412
711	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
712	default y
713	help
714	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
715
716	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
717	  of a store-exclusive or read of PAR_EL1 and a load with device or
718	  non-cacheable memory attributes. The workaround depends on a firmware
719	  counterpart.
720
721	  KVM guests must also have the workaround implemented or they can
722	  deadlock the system.
723
724	  Work around the issue by inserting DMB SY barriers around PAR_EL1
725	  register reads and warning KVM users. The DMB barrier is sufficient
726	  to prevent a speculative PAR_EL1 read.
727
728	  If unsure, say Y.
729
730config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
731	bool
732
733config ARM64_ERRATUM_2051678
734	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
735	default y
736	help
737	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
738	  Affected Cortex-A510 might not respect the ordering rules for
739	  hardware update of the page table's dirty bit. The workaround
740	  is to not enable the feature on affected CPUs.
741
742	  If unsure, say Y.
743
744config ARM64_ERRATUM_2077057
745	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
746	default y
747	help
748	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
749	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
750	  expected, but a Pointer Authentication trap is taken instead. The
751	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
752	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
753
754	  This can only happen when EL2 is stepping EL1.
755
756	  When these conditions occur, the SPSR_EL2 value is unchanged from the
757	  previous guest entry, and can be restored from the in-memory copy.
758
759	  If unsure, say Y.
760
761config ARM64_ERRATUM_2658417
762	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
763	default y
764	help
765	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
766	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
767	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
768	  A510 CPUs are using shared neon hardware. As the sharing is not
769	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
770	  user-space should not be using these instructions.
771
772	  If unsure, say Y.
773
774config ARM64_ERRATUM_2119858
775	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
776	default y
777	depends on CORESIGHT_TRBE
778	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
779	help
780	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
781
782	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
783	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
784	  the event of a WRAP event.
785
786	  Work around the issue by always making sure we move the TRBPTR_EL1 by
787	  256 bytes before enabling the buffer and filling the first 256 bytes of
788	  the buffer with ETM ignore packets upon disabling.
789
790	  If unsure, say Y.
791
792config ARM64_ERRATUM_2139208
793	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
794	default y
795	depends on CORESIGHT_TRBE
796	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
797	help
798	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
799
800	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
801	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
802	  the event of a WRAP event.
803
804	  Work around the issue by always making sure we move the TRBPTR_EL1 by
805	  256 bytes before enabling the buffer and filling the first 256 bytes of
806	  the buffer with ETM ignore packets upon disabling.
807
808	  If unsure, say Y.
809
810config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
811	bool
812
813config ARM64_ERRATUM_2054223
814	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
815	default y
816	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
817	help
818	  Enable workaround for ARM Cortex-A710 erratum 2054223
819
820	  Affected cores may fail to flush the trace data on a TSB instruction, when
821	  the PE is in trace prohibited state. This will cause losing a few bytes
822	  of the trace cached.
823
824	  Workaround is to issue two TSB consecutively on affected cores.
825
826	  If unsure, say Y.
827
828config ARM64_ERRATUM_2067961
829	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
830	default y
831	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
832	help
833	  Enable workaround for ARM Neoverse-N2 erratum 2067961
834
835	  Affected cores may fail to flush the trace data on a TSB instruction, when
836	  the PE is in trace prohibited state. This will cause losing a few bytes
837	  of the trace cached.
838
839	  Workaround is to issue two TSB consecutively on affected cores.
840
841	  If unsure, say Y.
842
843config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
844	bool
845
846config ARM64_ERRATUM_2253138
847	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
848	depends on CORESIGHT_TRBE
849	default y
850	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
851	help
852	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
853
854	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
855	  for TRBE. Under some conditions, the TRBE might generate a write to the next
856	  virtually addressed page following the last page of the TRBE address space
857	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
858
859	  Work around this in the driver by always making sure that there is a
860	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
861
862	  If unsure, say Y.
863
864config ARM64_ERRATUM_2224489
865	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
866	depends on CORESIGHT_TRBE
867	default y
868	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
869	help
870	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
871
872	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
873	  for TRBE. Under some conditions, the TRBE might generate a write to the next
874	  virtually addressed page following the last page of the TRBE address space
875	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
876
877	  Work around this in the driver by always making sure that there is a
878	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
879
880	  If unsure, say Y.
881
882config ARM64_ERRATUM_2441009
883	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
884	default y
885	select ARM64_WORKAROUND_REPEAT_TLBI
886	help
887	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
888
889	  Under very rare circumstances, affected Cortex-A510 CPUs
890	  may not handle a race between a break-before-make sequence on one
891	  CPU, and another CPU accessing the same page. This could allow a
892	  store to a page that has been unmapped.
893
894	  Work around this by adding the affected CPUs to the list that needs
895	  TLB sequences to be done twice.
896
897	  If unsure, say Y.
898
899config ARM64_ERRATUM_2064142
900	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
901	depends on CORESIGHT_TRBE
902	default y
903	help
904	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
905
906	  Affected Cortex-A510 core might fail to write into system registers after the
907	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
908	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
909	  and TRBTRG_EL1 will be ignored and will not be effected.
910
911	  Work around this in the driver by executing TSB CSYNC and DSB after collection
912	  is stopped and before performing a system register write to one of the affected
913	  registers.
914
915	  If unsure, say Y.
916
917config ARM64_ERRATUM_2038923
918	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
919	depends on CORESIGHT_TRBE
920	default y
921	help
922	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
923
924	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
925	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
926	  might be corrupted. This happens after TRBE buffer has been enabled by setting
927	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
928	  execution changes from a context, in which trace is prohibited to one where it
929	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
930	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
931	  the trace buffer state might be corrupted.
932
933	  Work around this in the driver by preventing an inconsistent view of whether the
934	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
935	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
936	  two ISB instructions if no ERET is to take place.
937
938	  If unsure, say Y.
939
940config ARM64_ERRATUM_1902691
941	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
942	depends on CORESIGHT_TRBE
943	default y
944	help
945	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
946
947	  Affected Cortex-A510 core might cause trace data corruption, when being written
948	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
949	  trace data.
950
951	  Work around this problem in the driver by just preventing TRBE initialization on
952	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
953	  on such implementations. This will cover the kernel for any firmware that doesn't
954	  do this already.
955
956	  If unsure, say Y.
957
958config ARM64_ERRATUM_2457168
959	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
960	depends on ARM64_AMU_EXTN
961	default y
962	help
963	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
964
965	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
966	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
967	  incorrectly giving a significantly higher output value.
968
969	  Work around this problem by returning 0 when reading the affected counter in
970	  key locations that results in disabling all users of this counter. This effect
971	  is the same to firmware disabling affected counters.
972
973	  If unsure, say Y.
974
975config CAVIUM_ERRATUM_22375
976	bool "Cavium erratum 22375, 24313"
977	default y
978	help
979	  Enable workaround for errata 22375 and 24313.
980
981	  This implements two gicv3-its errata workarounds for ThunderX. Both
982	  with a small impact affecting only ITS table allocation.
983
984	    erratum 22375: only alloc 8MB table size
985	    erratum 24313: ignore memory access type
986
987	  The fixes are in ITS initialization and basically ignore memory access
988	  type and table size provided by the TYPER and BASER registers.
989
990	  If unsure, say Y.
991
992config CAVIUM_ERRATUM_23144
993	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
994	depends on NUMA
995	default y
996	help
997	  ITS SYNC command hang for cross node io and collections/cpu mapping.
998
999	  If unsure, say Y.
1000
1001config CAVIUM_ERRATUM_23154
1002	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1003	default y
1004	help
1005	  The ThunderX GICv3 implementation requires a modified version for
1006	  reading the IAR status to ensure data synchronization
1007	  (access to icc_iar1_el1 is not sync'ed before and after).
1008
1009	  It also suffers from erratum 38545 (also present on Marvell's
1010	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1011	  spuriously presented to the CPU interface.
1012
1013	  If unsure, say Y.
1014
1015config CAVIUM_ERRATUM_27456
1016	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1017	default y
1018	help
1019	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1020	  instructions may cause the icache to become corrupted if it
1021	  contains data for a non-current ASID.  The fix is to
1022	  invalidate the icache when changing the mm context.
1023
1024	  If unsure, say Y.
1025
1026config CAVIUM_ERRATUM_30115
1027	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1028	default y
1029	help
1030	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1031	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1032	  interrupts in host. Trapping both GICv3 group-0 and group-1
1033	  accesses sidesteps the issue.
1034
1035	  If unsure, say Y.
1036
1037config CAVIUM_TX2_ERRATUM_219
1038	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1039	default y
1040	help
1041	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1042	  TTBR update and the corresponding context synchronizing operation can
1043	  cause a spurious Data Abort to be delivered to any hardware thread in
1044	  the CPU core.
1045
1046	  Work around the issue by avoiding the problematic code sequence and
1047	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1048	  trap handler performs the corresponding register access, skips the
1049	  instruction and ensures context synchronization by virtue of the
1050	  exception return.
1051
1052	  If unsure, say Y.
1053
1054config FUJITSU_ERRATUM_010001
1055	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1056	default y
1057	help
1058	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1059	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1060	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1061	  This fault occurs under a specific hardware condition when a
1062	  load/store instruction performs an address translation using:
1063	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1064	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1065	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1066	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1067
1068	  The workaround is to ensure these bits are clear in TCR_ELx.
1069	  The workaround only affects the Fujitsu-A64FX.
1070
1071	  If unsure, say Y.
1072
1073config HISILICON_ERRATUM_161600802
1074	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1075	default y
1076	help
1077	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1078	  when issued ITS commands such as VMOVP and VMAPP, and requires
1079	  a 128kB offset to be applied to the target address in this commands.
1080
1081	  If unsure, say Y.
1082
1083config QCOM_FALKOR_ERRATUM_1003
1084	bool "Falkor E1003: Incorrect translation due to ASID change"
1085	default y
1086	help
1087	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1088	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1089	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1090	  then only for entries in the walk cache, since the leaf translation
1091	  is unchanged. Work around the erratum by invalidating the walk cache
1092	  entries for the trampoline before entering the kernel proper.
1093
1094config QCOM_FALKOR_ERRATUM_1009
1095	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1096	default y
1097	select ARM64_WORKAROUND_REPEAT_TLBI
1098	help
1099	  On Falkor v1, the CPU may prematurely complete a DSB following a
1100	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1101	  one more time to fix the issue.
1102
1103	  If unsure, say Y.
1104
1105config QCOM_QDF2400_ERRATUM_0065
1106	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1107	default y
1108	help
1109	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1110	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1111	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1112
1113	  If unsure, say Y.
1114
1115config QCOM_FALKOR_ERRATUM_E1041
1116	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1117	default y
1118	help
1119	  Falkor CPU may speculatively fetch instructions from an improper
1120	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1121	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1122
1123	  If unsure, say Y.
1124
1125config NVIDIA_CARMEL_CNP_ERRATUM
1126	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1127	default y
1128	help
1129	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1130	  invalidate shared TLB entries installed by a different core, as it would
1131	  on standard ARM cores.
1132
1133	  If unsure, say Y.
1134
1135config SOCIONEXT_SYNQUACER_PREITS
1136	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1137	default y
1138	help
1139	  Socionext Synquacer SoCs implement a separate h/w block to generate
1140	  MSI doorbell writes with non-zero values for the device ID.
1141
1142	  If unsure, say Y.
1143
1144endmenu # "ARM errata workarounds via the alternatives framework"
1145
1146choice
1147	prompt "Page size"
1148	default ARM64_4K_PAGES
1149	help
1150	  Page size (translation granule) configuration.
1151
1152config ARM64_4K_PAGES
1153	bool "4KB"
1154	help
1155	  This feature enables 4KB pages support.
1156
1157config ARM64_16K_PAGES
1158	bool "16KB"
1159	help
1160	  The system will use 16KB pages support. AArch32 emulation
1161	  requires applications compiled with 16K (or a multiple of 16K)
1162	  aligned segments.
1163
1164config ARM64_64K_PAGES
1165	bool "64KB"
1166	help
1167	  This feature enables 64KB pages support (4KB by default)
1168	  allowing only two levels of page tables and faster TLB
1169	  look-up. AArch32 emulation requires applications compiled
1170	  with 64K aligned segments.
1171
1172endchoice
1173
1174choice
1175	prompt "Virtual address space size"
1176	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1177	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1178	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1179	help
1180	  Allows choosing one of multiple possible virtual address
1181	  space sizes. The level of translation table is determined by
1182	  a combination of page size and virtual address space size.
1183
1184config ARM64_VA_BITS_36
1185	bool "36-bit" if EXPERT
1186	depends on ARM64_16K_PAGES
1187
1188config ARM64_VA_BITS_39
1189	bool "39-bit"
1190	depends on ARM64_4K_PAGES
1191
1192config ARM64_VA_BITS_42
1193	bool "42-bit"
1194	depends on ARM64_64K_PAGES
1195
1196config ARM64_VA_BITS_47
1197	bool "47-bit"
1198	depends on ARM64_16K_PAGES
1199
1200config ARM64_VA_BITS_48
1201	bool "48-bit"
1202
1203config ARM64_VA_BITS_52
1204	bool "52-bit"
1205	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1206	help
1207	  Enable 52-bit virtual addressing for userspace when explicitly
1208	  requested via a hint to mmap(). The kernel will also use 52-bit
1209	  virtual addresses for its own mappings (provided HW support for
1210	  this feature is available, otherwise it reverts to 48-bit).
1211
1212	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1213	  ARMv8.3 Pointer Authentication will result in the PAC being
1214	  reduced from 7 bits to 3 bits, which may have a significant
1215	  impact on its susceptibility to brute-force attacks.
1216
1217	  If unsure, select 48-bit virtual addressing instead.
1218
1219endchoice
1220
1221config ARM64_FORCE_52BIT
1222	bool "Force 52-bit virtual addresses for userspace"
1223	depends on ARM64_VA_BITS_52 && EXPERT
1224	help
1225	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1226	  to maintain compatibility with older software by providing 48-bit VAs
1227	  unless a hint is supplied to mmap.
1228
1229	  This configuration option disables the 48-bit compatibility logic, and
1230	  forces all userspace addresses to be 52-bit on HW that supports it. One
1231	  should only enable this configuration option for stress testing userspace
1232	  memory management code. If unsure say N here.
1233
1234config ARM64_VA_BITS
1235	int
1236	default 36 if ARM64_VA_BITS_36
1237	default 39 if ARM64_VA_BITS_39
1238	default 42 if ARM64_VA_BITS_42
1239	default 47 if ARM64_VA_BITS_47
1240	default 48 if ARM64_VA_BITS_48
1241	default 52 if ARM64_VA_BITS_52
1242
1243choice
1244	prompt "Physical address space size"
1245	default ARM64_PA_BITS_48
1246	help
1247	  Choose the maximum physical address range that the kernel will
1248	  support.
1249
1250config ARM64_PA_BITS_48
1251	bool "48-bit"
1252
1253config ARM64_PA_BITS_52
1254	bool "52-bit (ARMv8.2)"
1255	depends on ARM64_64K_PAGES
1256	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1257	help
1258	  Enable support for a 52-bit physical address space, introduced as
1259	  part of the ARMv8.2-LPA extension.
1260
1261	  With this enabled, the kernel will also continue to work on CPUs that
1262	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1263	  minor performance overhead).
1264
1265endchoice
1266
1267config ARM64_PA_BITS
1268	int
1269	default 48 if ARM64_PA_BITS_48
1270	default 52 if ARM64_PA_BITS_52
1271
1272choice
1273	prompt "Endianness"
1274	default CPU_LITTLE_ENDIAN
1275	help
1276	  Select the endianness of data accesses performed by the CPU. Userspace
1277	  applications will need to be compiled and linked for the endianness
1278	  that is selected here.
1279
1280config CPU_BIG_ENDIAN
1281	bool "Build big-endian kernel"
1282	depends on !LD_IS_LLD || LLD_VERSION >= 130000
1283	help
1284	  Say Y if you plan on running a kernel with a big-endian userspace.
1285
1286config CPU_LITTLE_ENDIAN
1287	bool "Build little-endian kernel"
1288	help
1289	  Say Y if you plan on running a kernel with a little-endian userspace.
1290	  This is usually the case for distributions targeting arm64.
1291
1292endchoice
1293
1294config SCHED_MC
1295	bool "Multi-core scheduler support"
1296	help
1297	  Multi-core scheduler support improves the CPU scheduler's decision
1298	  making when dealing with multi-core CPU chips at a cost of slightly
1299	  increased overhead in some places. If unsure say N here.
1300
1301config SCHED_CLUSTER
1302	bool "Cluster scheduler support"
1303	help
1304	  Cluster scheduler support improves the CPU scheduler's decision
1305	  making when dealing with machines that have clusters of CPUs.
1306	  Cluster usually means a couple of CPUs which are placed closely
1307	  by sharing mid-level caches, last-level cache tags or internal
1308	  busses.
1309
1310config SCHED_SMT
1311	bool "SMT scheduler support"
1312	help
1313	  Improves the CPU scheduler's decision making when dealing with
1314	  MultiThreading at a cost of slightly increased overhead in some
1315	  places. If unsure say N here.
1316
1317config NR_CPUS
1318	int "Maximum number of CPUs (2-4096)"
1319	range 2 4096
1320	default "256"
1321
1322config HOTPLUG_CPU
1323	bool "Support for hot-pluggable CPUs"
1324	select GENERIC_IRQ_MIGRATION
1325	help
1326	  Say Y here to experiment with turning CPUs off and on.  CPUs
1327	  can be controlled through /sys/devices/system/cpu.
1328
1329# Common NUMA Features
1330config NUMA
1331	bool "NUMA Memory Allocation and Scheduler Support"
1332	select GENERIC_ARCH_NUMA
1333	select ACPI_NUMA if ACPI
1334	select OF_NUMA
1335	select HAVE_SETUP_PER_CPU_AREA
1336	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1337	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1338	select USE_PERCPU_NUMA_NODE_ID
1339	help
1340	  Enable NUMA (Non-Uniform Memory Access) support.
1341
1342	  The kernel will try to allocate memory used by a CPU on the
1343	  local memory of the CPU and add some more
1344	  NUMA awareness to the kernel.
1345
1346config NODES_SHIFT
1347	int "Maximum NUMA Nodes (as a power of 2)"
1348	range 1 10
1349	default "4"
1350	depends on NUMA
1351	help
1352	  Specify the maximum number of NUMA Nodes available on the target
1353	  system.  Increases memory reserved to accommodate various tables.
1354
1355source "kernel/Kconfig.hz"
1356
1357config ARCH_SPARSEMEM_ENABLE
1358	def_bool y
1359	select SPARSEMEM_VMEMMAP_ENABLE
1360	select SPARSEMEM_VMEMMAP
1361
1362config HW_PERF_EVENTS
1363	def_bool y
1364	depends on ARM_PMU
1365
1366# Supported by clang >= 7.0 or GCC >= 12.0.0
1367config CC_HAVE_SHADOW_CALL_STACK
1368	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1369
1370config PARAVIRT
1371	bool "Enable paravirtualization code"
1372	help
1373	  This changes the kernel so it can modify itself when it is run
1374	  under a hypervisor, potentially improving performance significantly
1375	  over full virtualization.
1376
1377config PARAVIRT_TIME_ACCOUNTING
1378	bool "Paravirtual steal time accounting"
1379	select PARAVIRT
1380	help
1381	  Select this option to enable fine granularity task steal time
1382	  accounting. Time spent executing other tasks in parallel with
1383	  the current vCPU is discounted from the vCPU power. To account for
1384	  that, there can be a small performance impact.
1385
1386	  If in doubt, say N here.
1387
1388config KEXEC
1389	depends on PM_SLEEP_SMP
1390	select KEXEC_CORE
1391	bool "kexec system call"
1392	help
1393	  kexec is a system call that implements the ability to shutdown your
1394	  current kernel, and to start another kernel.  It is like a reboot
1395	  but it is independent of the system firmware.   And like a reboot
1396	  you can start any kernel with it, not just Linux.
1397
1398config KEXEC_FILE
1399	bool "kexec file based system call"
1400	select KEXEC_CORE
1401	select HAVE_IMA_KEXEC if IMA
1402	help
1403	  This is new version of kexec system call. This system call is
1404	  file based and takes file descriptors as system call argument
1405	  for kernel and initramfs as opposed to list of segments as
1406	  accepted by previous system call.
1407
1408config KEXEC_SIG
1409	bool "Verify kernel signature during kexec_file_load() syscall"
1410	depends on KEXEC_FILE
1411	help
1412	  Select this option to verify a signature with loaded kernel
1413	  image. If configured, any attempt of loading a image without
1414	  valid signature will fail.
1415
1416	  In addition to that option, you need to enable signature
1417	  verification for the corresponding kernel image type being
1418	  loaded in order for this to work.
1419
1420config KEXEC_IMAGE_VERIFY_SIG
1421	bool "Enable Image signature verification support"
1422	default y
1423	depends on KEXEC_SIG
1424	depends on EFI && SIGNED_PE_FILE_VERIFICATION
1425	help
1426	  Enable Image signature verification support.
1427
1428comment "Support for PE file signature verification disabled"
1429	depends on KEXEC_SIG
1430	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
1431
1432config CRASH_DUMP
1433	bool "Build kdump crash kernel"
1434	help
1435	  Generate crash dump after being started by kexec. This should
1436	  be normally only set in special crash dump kernels which are
1437	  loaded in the main kernel with kexec-tools into a specially
1438	  reserved region and then later executed after a crash by
1439	  kdump/kexec.
1440
1441	  For more details see Documentation/admin-guide/kdump/kdump.rst
1442
1443config TRANS_TABLE
1444	def_bool y
1445	depends on HIBERNATION || KEXEC_CORE
1446
1447config XEN_DOM0
1448	def_bool y
1449	depends on XEN
1450
1451config XEN
1452	bool "Xen guest support on ARM64"
1453	depends on ARM64 && OF
1454	select SWIOTLB_XEN
1455	select PARAVIRT
1456	help
1457	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1458
1459config ARCH_FORCE_MAX_ORDER
1460	int
1461	default "14" if ARM64_64K_PAGES
1462	default "12" if ARM64_16K_PAGES
1463	default "11"
1464	help
1465	  The kernel memory allocator divides physically contiguous memory
1466	  blocks into "zones", where each zone is a power of two number of
1467	  pages.  This option selects the largest power of two that the kernel
1468	  keeps in the memory allocator.  If you need to allocate very large
1469	  blocks of physically contiguous memory, then you may need to
1470	  increase this value.
1471
1472	  This config option is actually maximum order plus one. For example,
1473	  a value of 11 means that the largest free memory block is 2^10 pages.
1474
1475	  We make sure that we can allocate upto a HugePage size for each configuration.
1476	  Hence we have :
1477		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1478
1479	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1480	  4M allocations matching the default size used by generic code.
1481
1482config UNMAP_KERNEL_AT_EL0
1483	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1484	default y
1485	help
1486	  Speculation attacks against some high-performance processors can
1487	  be used to bypass MMU permission checks and leak kernel data to
1488	  userspace. This can be defended against by unmapping the kernel
1489	  when running in userspace, mapping it back in on exception entry
1490	  via a trampoline page in the vector table.
1491
1492	  If unsure, say Y.
1493
1494config MITIGATE_SPECTRE_BRANCH_HISTORY
1495	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1496	default y
1497	help
1498	  Speculation attacks against some high-performance processors can
1499	  make use of branch history to influence future speculation.
1500	  When taking an exception from user-space, a sequence of branches
1501	  or a firmware call overwrites the branch history.
1502
1503config RODATA_FULL_DEFAULT_ENABLED
1504	bool "Apply r/o permissions of VM areas also to their linear aliases"
1505	default y
1506	help
1507	  Apply read-only attributes of VM areas to the linear alias of
1508	  the backing pages as well. This prevents code or read-only data
1509	  from being modified (inadvertently or intentionally) via another
1510	  mapping of the same memory page. This additional enhancement can
1511	  be turned off at runtime by passing rodata=[off|on] (and turned on
1512	  with rodata=full if this option is set to 'n')
1513
1514	  This requires the linear region to be mapped down to pages,
1515	  which may adversely affect performance in some cases.
1516
1517config ARM64_SW_TTBR0_PAN
1518	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1519	help
1520	  Enabling this option prevents the kernel from accessing
1521	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1522	  zeroed area and reserved ASID. The user access routines
1523	  restore the valid TTBR0_EL1 temporarily.
1524
1525config ARM64_TAGGED_ADDR_ABI
1526	bool "Enable the tagged user addresses syscall ABI"
1527	default y
1528	help
1529	  When this option is enabled, user applications can opt in to a
1530	  relaxed ABI via prctl() allowing tagged addresses to be passed
1531	  to system calls as pointer arguments. For details, see
1532	  Documentation/arm64/tagged-address-abi.rst.
1533
1534menuconfig COMPAT
1535	bool "Kernel support for 32-bit EL0"
1536	depends on ARM64_4K_PAGES || EXPERT
1537	select HAVE_UID16
1538	select OLD_SIGSUSPEND3
1539	select COMPAT_OLD_SIGACTION
1540	help
1541	  This option enables support for a 32-bit EL0 running under a 64-bit
1542	  kernel at EL1. AArch32-specific components such as system calls,
1543	  the user helper functions, VFP support and the ptrace interface are
1544	  handled appropriately by the kernel.
1545
1546	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1547	  that you will only be able to execute AArch32 binaries that were compiled
1548	  with page size aligned segments.
1549
1550	  If you want to execute 32-bit userspace applications, say Y.
1551
1552if COMPAT
1553
1554config KUSER_HELPERS
1555	bool "Enable kuser helpers page for 32-bit applications"
1556	default y
1557	help
1558	  Warning: disabling this option may break 32-bit user programs.
1559
1560	  Provide kuser helpers to compat tasks. The kernel provides
1561	  helper code to userspace in read only form at a fixed location
1562	  to allow userspace to be independent of the CPU type fitted to
1563	  the system. This permits binaries to be run on ARMv4 through
1564	  to ARMv8 without modification.
1565
1566	  See Documentation/arm/kernel_user_helpers.rst for details.
1567
1568	  However, the fixed address nature of these helpers can be used
1569	  by ROP (return orientated programming) authors when creating
1570	  exploits.
1571
1572	  If all of the binaries and libraries which run on your platform
1573	  are built specifically for your platform, and make no use of
1574	  these helpers, then you can turn this option off to hinder
1575	  such exploits. However, in that case, if a binary or library
1576	  relying on those helpers is run, it will not function correctly.
1577
1578	  Say N here only if you are absolutely certain that you do not
1579	  need these helpers; otherwise, the safe option is to say Y.
1580
1581config COMPAT_VDSO
1582	bool "Enable vDSO for 32-bit applications"
1583	depends on !CPU_BIG_ENDIAN
1584	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1585	select GENERIC_COMPAT_VDSO
1586	default y
1587	help
1588	  Place in the process address space of 32-bit applications an
1589	  ELF shared object providing fast implementations of gettimeofday
1590	  and clock_gettime.
1591
1592	  You must have a 32-bit build of glibc 2.22 or later for programs
1593	  to seamlessly take advantage of this.
1594
1595config THUMB2_COMPAT_VDSO
1596	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1597	depends on COMPAT_VDSO
1598	default y
1599	help
1600	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1601	  otherwise with '-marm'.
1602
1603config COMPAT_ALIGNMENT_FIXUPS
1604	bool "Fix up misaligned multi-word loads and stores in user space"
1605
1606menuconfig ARMV8_DEPRECATED
1607	bool "Emulate deprecated/obsolete ARMv8 instructions"
1608	depends on SYSCTL
1609	help
1610	  Legacy software support may require certain instructions
1611	  that have been deprecated or obsoleted in the architecture.
1612
1613	  Enable this config to enable selective emulation of these
1614	  features.
1615
1616	  If unsure, say Y
1617
1618if ARMV8_DEPRECATED
1619
1620config SWP_EMULATION
1621	bool "Emulate SWP/SWPB instructions"
1622	help
1623	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1624	  they are always undefined. Say Y here to enable software
1625	  emulation of these instructions for userspace using LDXR/STXR.
1626	  This feature can be controlled at runtime with the abi.swp
1627	  sysctl which is disabled by default.
1628
1629	  In some older versions of glibc [<=2.8] SWP is used during futex
1630	  trylock() operations with the assumption that the code will not
1631	  be preempted. This invalid assumption may be more likely to fail
1632	  with SWP emulation enabled, leading to deadlock of the user
1633	  application.
1634
1635	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1636	  on an external transaction monitoring block called a global
1637	  monitor to maintain update atomicity. If your system does not
1638	  implement a global monitor, this option can cause programs that
1639	  perform SWP operations to uncached memory to deadlock.
1640
1641	  If unsure, say Y
1642
1643config CP15_BARRIER_EMULATION
1644	bool "Emulate CP15 Barrier instructions"
1645	help
1646	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1647	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1648	  strongly recommended to use the ISB, DSB, and DMB
1649	  instructions instead.
1650
1651	  Say Y here to enable software emulation of these
1652	  instructions for AArch32 userspace code. When this option is
1653	  enabled, CP15 barrier usage is traced which can help
1654	  identify software that needs updating. This feature can be
1655	  controlled at runtime with the abi.cp15_barrier sysctl.
1656
1657	  If unsure, say Y
1658
1659config SETEND_EMULATION
1660	bool "Emulate SETEND instruction"
1661	help
1662	  The SETEND instruction alters the data-endianness of the
1663	  AArch32 EL0, and is deprecated in ARMv8.
1664
1665	  Say Y here to enable software emulation of the instruction
1666	  for AArch32 userspace code. This feature can be controlled
1667	  at runtime with the abi.setend sysctl.
1668
1669	  Note: All the cpus on the system must have mixed endian support at EL0
1670	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1671	  endian - is hotplugged in after this feature has been enabled, there could
1672	  be unexpected results in the applications.
1673
1674	  If unsure, say Y
1675endif # ARMV8_DEPRECATED
1676
1677endif # COMPAT
1678
1679menu "ARMv8.1 architectural features"
1680
1681config ARM64_HW_AFDBM
1682	bool "Support for hardware updates of the Access and Dirty page flags"
1683	default y
1684	help
1685	  The ARMv8.1 architecture extensions introduce support for
1686	  hardware updates of the access and dirty information in page
1687	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1688	  capable processors, accesses to pages with PTE_AF cleared will
1689	  set this bit instead of raising an access flag fault.
1690	  Similarly, writes to read-only pages with the DBM bit set will
1691	  clear the read-only bit (AP[2]) instead of raising a
1692	  permission fault.
1693
1694	  Kernels built with this configuration option enabled continue
1695	  to work on pre-ARMv8.1 hardware and the performance impact is
1696	  minimal. If unsure, say Y.
1697
1698config ARM64_PAN
1699	bool "Enable support for Privileged Access Never (PAN)"
1700	default y
1701	help
1702	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1703	  prevents the kernel or hypervisor from accessing user-space (EL0)
1704	  memory directly.
1705
1706	  Choosing this option will cause any unprotected (not using
1707	  copy_to_user et al) memory access to fail with a permission fault.
1708
1709	  The feature is detected at runtime, and will remain as a 'nop'
1710	  instruction if the cpu does not implement the feature.
1711
1712config AS_HAS_LDAPR
1713	def_bool $(as-instr,.arch_extension rcpc)
1714
1715config AS_HAS_LSE_ATOMICS
1716	def_bool $(as-instr,.arch_extension lse)
1717
1718config ARM64_LSE_ATOMICS
1719	bool
1720	default ARM64_USE_LSE_ATOMICS
1721	depends on AS_HAS_LSE_ATOMICS
1722
1723config ARM64_USE_LSE_ATOMICS
1724	bool "Atomic instructions"
1725	default y
1726	help
1727	  As part of the Large System Extensions, ARMv8.1 introduces new
1728	  atomic instructions that are designed specifically to scale in
1729	  very large systems.
1730
1731	  Say Y here to make use of these instructions for the in-kernel
1732	  atomic routines. This incurs a small overhead on CPUs that do
1733	  not support these instructions and requires the kernel to be
1734	  built with binutils >= 2.25 in order for the new instructions
1735	  to be used.
1736
1737endmenu # "ARMv8.1 architectural features"
1738
1739menu "ARMv8.2 architectural features"
1740
1741config AS_HAS_ARMV8_2
1742	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1743
1744config AS_HAS_SHA3
1745	def_bool $(as-instr,.arch armv8.2-a+sha3)
1746
1747config ARM64_PMEM
1748	bool "Enable support for persistent memory"
1749	select ARCH_HAS_PMEM_API
1750	select ARCH_HAS_UACCESS_FLUSHCACHE
1751	help
1752	  Say Y to enable support for the persistent memory API based on the
1753	  ARMv8.2 DCPoP feature.
1754
1755	  The feature is detected at runtime, and the kernel will use DC CVAC
1756	  operations if DC CVAP is not supported (following the behaviour of
1757	  DC CVAP itself if the system does not define a point of persistence).
1758
1759config ARM64_RAS_EXTN
1760	bool "Enable support for RAS CPU Extensions"
1761	default y
1762	help
1763	  CPUs that support the Reliability, Availability and Serviceability
1764	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1765	  errors, classify them and report them to software.
1766
1767	  On CPUs with these extensions system software can use additional
1768	  barriers to determine if faults are pending and read the
1769	  classification from a new set of registers.
1770
1771	  Selecting this feature will allow the kernel to use these barriers
1772	  and access the new registers if the system supports the extension.
1773	  Platform RAS features may additionally depend on firmware support.
1774
1775config ARM64_CNP
1776	bool "Enable support for Common Not Private (CNP) translations"
1777	default y
1778	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1779	help
1780	  Common Not Private (CNP) allows translation table entries to
1781	  be shared between different PEs in the same inner shareable
1782	  domain, so the hardware can use this fact to optimise the
1783	  caching of such entries in the TLB.
1784
1785	  Selecting this option allows the CNP feature to be detected
1786	  at runtime, and does not affect PEs that do not implement
1787	  this feature.
1788
1789endmenu # "ARMv8.2 architectural features"
1790
1791menu "ARMv8.3 architectural features"
1792
1793config ARM64_PTR_AUTH
1794	bool "Enable support for pointer authentication"
1795	default y
1796	help
1797	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1798	  instructions for signing and authenticating pointers against secret
1799	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1800	  and other attacks.
1801
1802	  This option enables these instructions at EL0 (i.e. for userspace).
1803	  Choosing this option will cause the kernel to initialise secret keys
1804	  for each process at exec() time, with these keys being
1805	  context-switched along with the process.
1806
1807	  The feature is detected at runtime. If the feature is not present in
1808	  hardware it will not be advertised to userspace/KVM guest nor will it
1809	  be enabled.
1810
1811	  If the feature is present on the boot CPU but not on a late CPU, then
1812	  the late CPU will be parked. Also, if the boot CPU does not have
1813	  address auth and the late CPU has then the late CPU will still boot
1814	  but with the feature disabled. On such a system, this option should
1815	  not be selected.
1816
1817config ARM64_PTR_AUTH_KERNEL
1818	bool "Use pointer authentication for kernel"
1819	default y
1820	depends on ARM64_PTR_AUTH
1821	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC
1822	# Modern compilers insert a .note.gnu.property section note for PAC
1823	# which is only understood by binutils starting with version 2.33.1.
1824	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1825	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1826	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1827	help
1828	  If the compiler supports the -mbranch-protection or
1829	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1830	  will cause the kernel itself to be compiled with return address
1831	  protection. In this case, and if the target hardware is known to
1832	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1833	  disabled with minimal loss of protection.
1834
1835	  This feature works with FUNCTION_GRAPH_TRACER option only if
1836	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
1837
1838config CC_HAS_BRANCH_PROT_PAC_RET
1839	# GCC 9 or later, clang 8 or later
1840	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1841
1842config CC_HAS_SIGN_RETURN_ADDRESS
1843	# GCC 7, 8
1844	def_bool $(cc-option,-msign-return-address=all)
1845
1846config AS_HAS_PAC
1847	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1848
1849config AS_HAS_CFI_NEGATE_RA_STATE
1850	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1851
1852endmenu # "ARMv8.3 architectural features"
1853
1854menu "ARMv8.4 architectural features"
1855
1856config ARM64_AMU_EXTN
1857	bool "Enable support for the Activity Monitors Unit CPU extension"
1858	default y
1859	help
1860	  The activity monitors extension is an optional extension introduced
1861	  by the ARMv8.4 CPU architecture. This enables support for version 1
1862	  of the activity monitors architecture, AMUv1.
1863
1864	  To enable the use of this extension on CPUs that implement it, say Y.
1865
1866	  Note that for architectural reasons, firmware _must_ implement AMU
1867	  support when running on CPUs that present the activity monitors
1868	  extension. The required support is present in:
1869	    * Version 1.5 and later of the ARM Trusted Firmware
1870
1871	  For kernels that have this configuration enabled but boot with broken
1872	  firmware, you may need to say N here until the firmware is fixed.
1873	  Otherwise you may experience firmware panics or lockups when
1874	  accessing the counter registers. Even if you are not observing these
1875	  symptoms, the values returned by the register reads might not
1876	  correctly reflect reality. Most commonly, the value read will be 0,
1877	  indicating that the counter is not enabled.
1878
1879config AS_HAS_ARMV8_4
1880	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1881
1882config ARM64_TLB_RANGE
1883	bool "Enable support for tlbi range feature"
1884	default y
1885	depends on AS_HAS_ARMV8_4
1886	help
1887	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1888	  range of input addresses.
1889
1890	  The feature introduces new assembly instructions, and they were
1891	  support when binutils >= 2.30.
1892
1893endmenu # "ARMv8.4 architectural features"
1894
1895menu "ARMv8.5 architectural features"
1896
1897config AS_HAS_ARMV8_5
1898	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1899
1900config ARM64_BTI
1901	bool "Branch Target Identification support"
1902	default y
1903	help
1904	  Branch Target Identification (part of the ARMv8.5 Extensions)
1905	  provides a mechanism to limit the set of locations to which computed
1906	  branch instructions such as BR or BLR can jump.
1907
1908	  To make use of BTI on CPUs that support it, say Y.
1909
1910	  BTI is intended to provide complementary protection to other control
1911	  flow integrity protection mechanisms, such as the Pointer
1912	  authentication mechanism provided as part of the ARMv8.3 Extensions.
1913	  For this reason, it does not make sense to enable this option without
1914	  also enabling support for pointer authentication.  Thus, when
1915	  enabling this option you should also select ARM64_PTR_AUTH=y.
1916
1917	  Userspace binaries must also be specifically compiled to make use of
1918	  this mechanism.  If you say N here or the hardware does not support
1919	  BTI, such binaries can still run, but you get no additional
1920	  enforcement of branch destinations.
1921
1922config ARM64_BTI_KERNEL
1923	bool "Use Branch Target Identification for kernel"
1924	default y
1925	depends on ARM64_BTI
1926	depends on ARM64_PTR_AUTH_KERNEL
1927	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1928	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1929	depends on !CC_IS_GCC || GCC_VERSION >= 100100
1930	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
1931	depends on !CC_IS_GCC
1932	# https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
1933	depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
1934	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1935	help
1936	  Build the kernel with Branch Target Identification annotations
1937	  and enable enforcement of this for kernel code. When this option
1938	  is enabled and the system supports BTI all kernel code including
1939	  modular code must have BTI enabled.
1940
1941config CC_HAS_BRANCH_PROT_PAC_RET_BTI
1942	# GCC 9 or later, clang 8 or later
1943	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
1944
1945config ARM64_E0PD
1946	bool "Enable support for E0PD"
1947	default y
1948	help
1949	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
1950	  that EL0 accesses made via TTBR1 always fault in constant time,
1951	  providing similar benefits to KASLR as those provided by KPTI, but
1952	  with lower overhead and without disrupting legitimate access to
1953	  kernel memory such as SPE.
1954
1955	  This option enables E0PD for TTBR1 where available.
1956
1957config ARM64_AS_HAS_MTE
1958	# Initial support for MTE went in binutils 2.32.0, checked with
1959	# ".arch armv8.5-a+memtag" below. However, this was incomplete
1960	# as a late addition to the final architecture spec (LDGM/STGM)
1961	# is only supported in the newer 2.32.x and 2.33 binutils
1962	# versions, hence the extra "stgm" instruction check below.
1963	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
1964
1965config ARM64_MTE
1966	bool "Memory Tagging Extension support"
1967	default y
1968	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
1969	depends on AS_HAS_ARMV8_5
1970	depends on AS_HAS_LSE_ATOMICS
1971	# Required for tag checking in the uaccess routines
1972	depends on ARM64_PAN
1973	select ARCH_HAS_SUBPAGE_FAULTS
1974	select ARCH_USES_HIGH_VMA_FLAGS
1975	select ARCH_USES_PG_ARCH_X
1976	help
1977	  Memory Tagging (part of the ARMv8.5 Extensions) provides
1978	  architectural support for run-time, always-on detection of
1979	  various classes of memory error to aid with software debugging
1980	  to eliminate vulnerabilities arising from memory-unsafe
1981	  languages.
1982
1983	  This option enables the support for the Memory Tagging
1984	  Extension at EL0 (i.e. for userspace).
1985
1986	  Selecting this option allows the feature to be detected at
1987	  runtime. Any secondary CPU not implementing this feature will
1988	  not be allowed a late bring-up.
1989
1990	  Userspace binaries that want to use this feature must
1991	  explicitly opt in. The mechanism for the userspace is
1992	  described in:
1993
1994	  Documentation/arm64/memory-tagging-extension.rst.
1995
1996endmenu # "ARMv8.5 architectural features"
1997
1998menu "ARMv8.7 architectural features"
1999
2000config ARM64_EPAN
2001	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2002	default y
2003	depends on ARM64_PAN
2004	help
2005	  Enhanced Privileged Access Never (EPAN) allows Privileged
2006	  Access Never to be used with Execute-only mappings.
2007
2008	  The feature is detected at runtime, and will remain disabled
2009	  if the cpu does not implement the feature.
2010endmenu # "ARMv8.7 architectural features"
2011
2012config ARM64_SVE
2013	bool "ARM Scalable Vector Extension support"
2014	default y
2015	help
2016	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2017	  execution state which complements and extends the SIMD functionality
2018	  of the base architecture to support much larger vectors and to enable
2019	  additional vectorisation opportunities.
2020
2021	  To enable use of this extension on CPUs that implement it, say Y.
2022
2023	  On CPUs that support the SVE2 extensions, this option will enable
2024	  those too.
2025
2026	  Note that for architectural reasons, firmware _must_ implement SVE
2027	  support when running on SVE capable hardware.  The required support
2028	  is present in:
2029
2030	    * version 1.5 and later of the ARM Trusted Firmware
2031	    * the AArch64 boot wrapper since commit 5e1261e08abf
2032	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2033
2034	  For other firmware implementations, consult the firmware documentation
2035	  or vendor.
2036
2037	  If you need the kernel to boot on SVE-capable hardware with broken
2038	  firmware, you may need to say N here until you get your firmware
2039	  fixed.  Otherwise, you may experience firmware panics or lockups when
2040	  booting the kernel.  If unsure and you are not observing these
2041	  symptoms, you should assume that it is safe to say Y.
2042
2043config ARM64_SME
2044	bool "ARM Scalable Matrix Extension support"
2045	default y
2046	depends on ARM64_SVE
2047	help
2048	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2049	  execution state which utilises a substantial subset of the SVE
2050	  instruction set, together with the addition of new architectural
2051	  register state capable of holding two dimensional matrix tiles to
2052	  enable various matrix operations.
2053
2054config ARM64_MODULE_PLTS
2055	bool "Use PLTs to allow module memory to spill over into vmalloc area"
2056	depends on MODULES
2057	select HAVE_MOD_ARCH_SPECIFIC
2058	help
2059	  Allocate PLTs when loading modules so that jumps and calls whose
2060	  targets are too far away for their relative offsets to be encoded
2061	  in the instructions themselves can be bounced via veneers in the
2062	  module's PLT. This allows modules to be allocated in the generic
2063	  vmalloc area after the dedicated module memory area has been
2064	  exhausted.
2065
2066	  When running with address space randomization (KASLR), the module
2067	  region itself may be too far away for ordinary relative jumps and
2068	  calls, and so in that case, module PLTs are required and cannot be
2069	  disabled.
2070
2071	  Specific errata workaround(s) might also force module PLTs to be
2072	  enabled (ARM64_ERRATUM_843419).
2073
2074config ARM64_PSEUDO_NMI
2075	bool "Support for NMI-like interrupts"
2076	select ARM_GIC_V3
2077	help
2078	  Adds support for mimicking Non-Maskable Interrupts through the use of
2079	  GIC interrupt priority. This support requires version 3 or later of
2080	  ARM GIC.
2081
2082	  This high priority configuration for interrupts needs to be
2083	  explicitly enabled by setting the kernel parameter
2084	  "irqchip.gicv3_pseudo_nmi" to 1.
2085
2086	  If unsure, say N
2087
2088if ARM64_PSEUDO_NMI
2089config ARM64_DEBUG_PRIORITY_MASKING
2090	bool "Debug interrupt priority masking"
2091	help
2092	  This adds runtime checks to functions enabling/disabling
2093	  interrupts when using priority masking. The additional checks verify
2094	  the validity of ICC_PMR_EL1 when calling concerned functions.
2095
2096	  If unsure, say N
2097endif # ARM64_PSEUDO_NMI
2098
2099config RELOCATABLE
2100	bool "Build a relocatable kernel image" if EXPERT
2101	select ARCH_HAS_RELR
2102	default y
2103	help
2104	  This builds the kernel as a Position Independent Executable (PIE),
2105	  which retains all relocation metadata required to relocate the
2106	  kernel binary at runtime to a different virtual address than the
2107	  address it was linked at.
2108	  Since AArch64 uses the RELA relocation format, this requires a
2109	  relocation pass at runtime even if the kernel is loaded at the
2110	  same address it was linked at.
2111
2112config RANDOMIZE_BASE
2113	bool "Randomize the address of the kernel image"
2114	select ARM64_MODULE_PLTS if MODULES
2115	select RELOCATABLE
2116	help
2117	  Randomizes the virtual address at which the kernel image is
2118	  loaded, as a security feature that deters exploit attempts
2119	  relying on knowledge of the location of kernel internals.
2120
2121	  It is the bootloader's job to provide entropy, by passing a
2122	  random u64 value in /chosen/kaslr-seed at kernel entry.
2123
2124	  When booting via the UEFI stub, it will invoke the firmware's
2125	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2126	  to the kernel proper. In addition, it will randomise the physical
2127	  location of the kernel Image as well.
2128
2129	  If unsure, say N.
2130
2131config RANDOMIZE_MODULE_REGION_FULL
2132	bool "Randomize the module region over a 2 GB range"
2133	depends on RANDOMIZE_BASE
2134	default y
2135	help
2136	  Randomizes the location of the module region inside a 2 GB window
2137	  covering the core kernel. This way, it is less likely for modules
2138	  to leak information about the location of core kernel data structures
2139	  but it does imply that function calls between modules and the core
2140	  kernel will need to be resolved via veneers in the module PLT.
2141
2142	  When this option is not set, the module region will be randomized over
2143	  a limited range that contains the [_stext, _etext] interval of the
2144	  core kernel, so branch relocations are almost always in range unless
2145	  ARM64_MODULE_PLTS is enabled and the region is exhausted. In this
2146	  particular case of region exhaustion, modules might be able to fall
2147	  back to a larger 2GB area.
2148
2149config CC_HAVE_STACKPROTECTOR_SYSREG
2150	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2151
2152config STACKPROTECTOR_PER_TASK
2153	def_bool y
2154	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2155
2156config UNWIND_PATCH_PAC_INTO_SCS
2157	bool "Enable shadow call stack dynamically using code patching"
2158	# needs Clang with https://reviews.llvm.org/D111780 incorporated
2159	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2160	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2161	depends on SHADOW_CALL_STACK
2162	select UNWIND_TABLES
2163	select DYNAMIC_SCS
2164
2165endmenu # "Kernel Features"
2166
2167menu "Boot options"
2168
2169config ARM64_ACPI_PARKING_PROTOCOL
2170	bool "Enable support for the ARM64 ACPI parking protocol"
2171	depends on ACPI
2172	help
2173	  Enable support for the ARM64 ACPI parking protocol. If disabled
2174	  the kernel will not allow booting through the ARM64 ACPI parking
2175	  protocol even if the corresponding data is present in the ACPI
2176	  MADT table.
2177
2178config CMDLINE
2179	string "Default kernel command string"
2180	default ""
2181	help
2182	  Provide a set of default command-line options at build time by
2183	  entering them here. As a minimum, you should specify the the
2184	  root device (e.g. root=/dev/nfs).
2185
2186choice
2187	prompt "Kernel command line type" if CMDLINE != ""
2188	default CMDLINE_FROM_BOOTLOADER
2189	help
2190	  Choose how the kernel will handle the provided default kernel
2191	  command line string.
2192
2193config CMDLINE_FROM_BOOTLOADER
2194	bool "Use bootloader kernel arguments if available"
2195	help
2196	  Uses the command-line options passed by the boot loader. If
2197	  the boot loader doesn't provide any, the default kernel command
2198	  string provided in CMDLINE will be used.
2199
2200config CMDLINE_FORCE
2201	bool "Always use the default kernel command string"
2202	help
2203	  Always use the default kernel command string, even if the boot
2204	  loader passes other arguments to the kernel.
2205	  This is useful if you cannot or don't want to change the
2206	  command-line options your boot loader passes to the kernel.
2207
2208endchoice
2209
2210config EFI_STUB
2211	bool
2212
2213config EFI
2214	bool "UEFI runtime support"
2215	depends on OF && !CPU_BIG_ENDIAN
2216	depends on KERNEL_MODE_NEON
2217	select ARCH_SUPPORTS_ACPI
2218	select LIBFDT
2219	select UCS2_STRING
2220	select EFI_PARAMS_FROM_FDT
2221	select EFI_RUNTIME_WRAPPERS
2222	select EFI_STUB
2223	select EFI_GENERIC_STUB
2224	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2225	default y
2226	help
2227	  This option provides support for runtime services provided
2228	  by UEFI firmware (such as non-volatile variables, realtime
2229	  clock, and platform reset). A UEFI stub is also provided to
2230	  allow the kernel to be booted as an EFI application. This
2231	  is only useful on systems that have UEFI firmware.
2232
2233config DMI
2234	bool "Enable support for SMBIOS (DMI) tables"
2235	depends on EFI
2236	default y
2237	help
2238	  This enables SMBIOS/DMI feature for systems.
2239
2240	  This option is only useful on systems that have UEFI firmware.
2241	  However, even with this option, the resultant kernel should
2242	  continue to boot on existing non-UEFI platforms.
2243
2244endmenu # "Boot options"
2245
2246menu "Power management options"
2247
2248source "kernel/power/Kconfig"
2249
2250config ARCH_HIBERNATION_POSSIBLE
2251	def_bool y
2252	depends on CPU_PM
2253
2254config ARCH_HIBERNATION_HEADER
2255	def_bool y
2256	depends on HIBERNATION
2257
2258config ARCH_SUSPEND_POSSIBLE
2259	def_bool y
2260
2261endmenu # "Power management options"
2262
2263menu "CPU Power Management"
2264
2265source "drivers/cpuidle/Kconfig"
2266
2267source "drivers/cpufreq/Kconfig"
2268
2269endmenu # "CPU Power Management"
2270
2271source "drivers/acpi/Kconfig"
2272
2273source "arch/arm64/kvm/Kconfig"
2274
2275