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_CORRECT_STACKTRACE_ON_KRETPROBE
18	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
19	select ARCH_ENABLE_MEMORY_HOTPLUG
20	select ARCH_ENABLE_MEMORY_HOTREMOVE
21	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
22	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
23	select ARCH_HAS_CACHE_LINE_SIZE
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_MEMBARRIER_SYNC_CORE
38	select ARCH_HAS_MEM_ENCRYPT
39	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
40	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
41	select ARCH_HAS_PTE_DEVMAP
42	select ARCH_HAS_PTE_SPECIAL
43	select ARCH_HAS_HW_PTE_YOUNG
44	select ARCH_HAS_SETUP_DMA_OPS
45	select ARCH_HAS_SET_DIRECT_MAP
46	select ARCH_HAS_SET_MEMORY
47	select ARCH_STACKWALK
48	select ARCH_HAS_STRICT_KERNEL_RWX
49	select ARCH_HAS_STRICT_MODULE_RWX
50	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
51	select ARCH_HAS_SYNC_DMA_FOR_CPU
52	select ARCH_HAS_SYSCALL_WRAPPER
53	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
54	select ARCH_HAS_ZONE_DMA_SET if EXPERT
55	select ARCH_HAVE_ELF_PROT
56	select ARCH_HAVE_NMI_SAFE_CMPXCHG
57	select ARCH_HAVE_TRACE_MMIO_ACCESS
58	select ARCH_INLINE_READ_LOCK if !PREEMPTION
59	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
60	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
61	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
62	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
63	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
64	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
65	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
66	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
67	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
68	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
69	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
70	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
71	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
72	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
73	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
74	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
75	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
76	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
77	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
78	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
79	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
80	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
81	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
82	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
83	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
84	select ARCH_KEEP_MEMBLOCK
85	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
86	select ARCH_USE_CMPXCHG_LOCKREF
87	select ARCH_USE_GNU_PROPERTY
88	select ARCH_USE_MEMTEST
89	select ARCH_USE_QUEUED_RWLOCKS
90	select ARCH_USE_QUEUED_SPINLOCKS
91	select ARCH_USE_SYM_ANNOTATIONS
92	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
93	select ARCH_SUPPORTS_HUGETLBFS
94	select ARCH_SUPPORTS_MEMORY_FAILURE
95	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
96	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
97	select ARCH_SUPPORTS_LTO_CLANG_THIN
98	select ARCH_SUPPORTS_CFI_CLANG
99	select ARCH_SUPPORTS_ATOMIC_RMW
100	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
101	select ARCH_SUPPORTS_NUMA_BALANCING
102	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
103	select ARCH_SUPPORTS_PER_VMA_LOCK
104	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
105	select ARCH_SUPPORTS_RT
106	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
107	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
108	select ARCH_WANT_DEFAULT_BPF_JIT
109	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
110	select ARCH_WANT_FRAME_POINTERS
111	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
112	select ARCH_WANT_LD_ORPHAN_WARN
113	select ARCH_WANTS_EXECMEM_LATE if EXECMEM
114	select ARCH_WANTS_NO_INSTR
115	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
116	select ARCH_HAS_UBSAN
117	select ARM_AMBA
118	select ARM_ARCH_TIMER
119	select ARM_GIC
120	select AUDIT_ARCH_COMPAT_GENERIC
121	select ARM_GIC_V2M if PCI
122	select ARM_GIC_V3
123	select ARM_GIC_V3_ITS if PCI
124	select ARM_PSCI_FW
125	select BUILDTIME_TABLE_SORT
126	select CLONE_BACKWARDS
127	select COMMON_CLK
128	select CPU_PM if (SUSPEND || CPU_IDLE)
129	select CPUMASK_OFFSTACK if NR_CPUS > 256
130	select CRC32
131	select DCACHE_WORD_ACCESS
132	select DYNAMIC_FTRACE if FUNCTION_TRACER
133	select DMA_BOUNCE_UNALIGNED_KMALLOC
134	select DMA_DIRECT_REMAP
135	select EDAC_SUPPORT
136	select FRAME_POINTER
137	select FUNCTION_ALIGNMENT_4B
138	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
139	select GENERIC_ALLOCATOR
140	select GENERIC_ARCH_TOPOLOGY
141	select GENERIC_CLOCKEVENTS_BROADCAST
142	select GENERIC_CPU_AUTOPROBE
143	select GENERIC_CPU_DEVICES
144	select GENERIC_CPU_VULNERABILITIES
145	select GENERIC_EARLY_IOREMAP
146	select GENERIC_IDLE_POLL_SETUP
147	select GENERIC_IOREMAP
148	select GENERIC_IRQ_IPI
149	select GENERIC_IRQ_PROBE
150	select GENERIC_IRQ_SHOW
151	select GENERIC_IRQ_SHOW_LEVEL
152	select GENERIC_LIB_DEVMEM_IS_ALLOWED
153	select GENERIC_PCI_IOMAP
154	select GENERIC_PTDUMP
155	select GENERIC_SCHED_CLOCK
156	select GENERIC_SMP_IDLE_THREAD
157	select GENERIC_TIME_VSYSCALL
158	select GENERIC_GETTIMEOFDAY
159	select GENERIC_VDSO_TIME_NS
160	select HARDIRQS_SW_RESEND
161	select HAS_IOPORT
162	select HAVE_MOVE_PMD
163	select HAVE_MOVE_PUD
164	select HAVE_PCI
165	select HAVE_ACPI_APEI if (ACPI && EFI)
166	select HAVE_ALIGNED_STRUCT_PAGE
167	select HAVE_ARCH_AUDITSYSCALL
168	select HAVE_ARCH_BITREVERSE
169	select HAVE_ARCH_COMPILER_H
170	select HAVE_ARCH_HUGE_VMALLOC
171	select HAVE_ARCH_HUGE_VMAP
172	select HAVE_ARCH_JUMP_LABEL
173	select HAVE_ARCH_JUMP_LABEL_RELATIVE
174	select HAVE_ARCH_KASAN
175	select HAVE_ARCH_KASAN_VMALLOC
176	select HAVE_ARCH_KASAN_SW_TAGS
177	select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
178	# Some instrumentation may be unsound, hence EXPERT
179	select HAVE_ARCH_KCSAN if EXPERT
180	select HAVE_ARCH_KFENCE
181	select HAVE_ARCH_KGDB
182	select HAVE_ARCH_MMAP_RND_BITS
183	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
184	select HAVE_ARCH_PREL32_RELOCATIONS
185	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
186	select HAVE_ARCH_SECCOMP_FILTER
187	select HAVE_ARCH_STACKLEAK
188	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
189	select HAVE_ARCH_TRACEHOOK
190	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
191	select HAVE_ARCH_VMAP_STACK
192	select HAVE_ARM_SMCCC
193	select HAVE_ASM_MODVERSIONS
194	select HAVE_EBPF_JIT
195	select HAVE_C_RECORDMCOUNT
196	select HAVE_CMPXCHG_DOUBLE
197	select HAVE_CMPXCHG_LOCAL
198	select HAVE_CONTEXT_TRACKING_USER
199	select HAVE_DEBUG_KMEMLEAK
200	select HAVE_DMA_CONTIGUOUS
201	select HAVE_DYNAMIC_FTRACE
202	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
203		if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
204		    CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
205	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
206		if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
207	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
208		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
209		    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
210	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
211		if DYNAMIC_FTRACE_WITH_ARGS
212	select HAVE_SAMPLE_FTRACE_DIRECT
213	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
214	select HAVE_EFFICIENT_UNALIGNED_ACCESS
215	select HAVE_GUP_FAST
216	select HAVE_FTRACE_MCOUNT_RECORD
217	select HAVE_FUNCTION_TRACER
218	select HAVE_FUNCTION_ERROR_INJECTION
219	select HAVE_FUNCTION_GRAPH_TRACER
220	select HAVE_FUNCTION_GRAPH_RETVAL
221	select HAVE_GCC_PLUGINS
222	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
223		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
224	select HAVE_HW_BREAKPOINT if PERF_EVENTS
225	select HAVE_IOREMAP_PROT
226	select HAVE_IRQ_TIME_ACCOUNTING
227	select HAVE_MOD_ARCH_SPECIFIC
228	select HAVE_NMI
229	select HAVE_PERF_EVENTS
230	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
231	select HAVE_PERF_REGS
232	select HAVE_PERF_USER_STACK_DUMP
233	select HAVE_PREEMPT_DYNAMIC_KEY
234	select HAVE_REGS_AND_STACK_ACCESS_API
235	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
236	select HAVE_FUNCTION_ARG_ACCESS_API
237	select MMU_GATHER_RCU_TABLE_FREE
238	select HAVE_RSEQ
239	select HAVE_RUST if RUSTC_SUPPORTS_ARM64
240	select HAVE_STACKPROTECTOR
241	select HAVE_SYSCALL_TRACEPOINTS
242	select HAVE_KPROBES
243	select HAVE_KRETPROBES
244	select HAVE_GENERIC_VDSO
245	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
246	select IRQ_DOMAIN
247	select IRQ_FORCED_THREADING
248	select KASAN_VMALLOC if KASAN
249	select LOCK_MM_AND_FIND_VMA
250	select MODULES_USE_ELF_RELA
251	select NEED_DMA_MAP_STATE
252	select NEED_SG_DMA_LENGTH
253	select OF
254	select OF_EARLY_FLATTREE
255	select PCI_DOMAINS_GENERIC if PCI
256	select PCI_ECAM if (ACPI && PCI)
257	select PCI_SYSCALL if PCI
258	select POWER_RESET
259	select POWER_SUPPLY
260	select SPARSE_IRQ
261	select SWIOTLB
262	select SYSCTL_EXCEPTION_TRACE
263	select THREAD_INFO_IN_TASK
264	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
265	select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
266	select TRACE_IRQFLAGS_SUPPORT
267	select TRACE_IRQFLAGS_NMI_SUPPORT
268	select HAVE_SOFTIRQ_ON_OWN_STACK
269	select USER_STACKTRACE_SUPPORT
270	select VDSO_GETRANDOM
271	help
272	  ARM 64-bit (AArch64) Linux support.
273
274config RUSTC_SUPPORTS_ARM64
275	def_bool y
276	depends on CPU_LITTLE_ENDIAN
277	# Shadow call stack is only supported on certain rustc versions.
278	#
279	# When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is
280	# required due to use of the -Zfixed-x18 flag.
281	#
282	# Otherwise, rustc version 1.82+ is required due to use of the
283	# -Zsanitizer=shadow-call-stack flag.
284	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS
285
286config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
287	def_bool CC_IS_CLANG
288	# https://github.com/ClangBuiltLinux/linux/issues/1507
289	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
290
291config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
292	def_bool CC_IS_GCC
293	depends on $(cc-option,-fpatchable-function-entry=2)
294
295config 64BIT
296	def_bool y
297
298config MMU
299	def_bool y
300
301config ARM64_CONT_PTE_SHIFT
302	int
303	default 5 if PAGE_SIZE_64KB
304	default 7 if PAGE_SIZE_16KB
305	default 4
306
307config ARM64_CONT_PMD_SHIFT
308	int
309	default 5 if PAGE_SIZE_64KB
310	default 5 if PAGE_SIZE_16KB
311	default 4
312
313config ARCH_MMAP_RND_BITS_MIN
314	default 14 if PAGE_SIZE_64KB
315	default 16 if PAGE_SIZE_16KB
316	default 18
317
318# max bits determined by the following formula:
319#  VA_BITS - PAGE_SHIFT - 3
320config ARCH_MMAP_RND_BITS_MAX
321	default 19 if ARM64_VA_BITS=36
322	default 24 if ARM64_VA_BITS=39
323	default 27 if ARM64_VA_BITS=42
324	default 30 if ARM64_VA_BITS=47
325	default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
326	default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
327	default 33 if ARM64_VA_BITS=48
328	default 14 if ARM64_64K_PAGES
329	default 16 if ARM64_16K_PAGES
330	default 18
331
332config ARCH_MMAP_RND_COMPAT_BITS_MIN
333	default 7 if ARM64_64K_PAGES
334	default 9 if ARM64_16K_PAGES
335	default 11
336
337config ARCH_MMAP_RND_COMPAT_BITS_MAX
338	default 16
339
340config NO_IOPORT_MAP
341	def_bool y if !PCI
342
343config STACKTRACE_SUPPORT
344	def_bool y
345
346config ILLEGAL_POINTER_VALUE
347	hex
348	default 0xdead000000000000
349
350config LOCKDEP_SUPPORT
351	def_bool y
352
353config GENERIC_BUG
354	def_bool y
355	depends on BUG
356
357config GENERIC_BUG_RELATIVE_POINTERS
358	def_bool y
359	depends on GENERIC_BUG
360
361config GENERIC_HWEIGHT
362	def_bool y
363
364config GENERIC_CSUM
365	def_bool y
366
367config GENERIC_CALIBRATE_DELAY
368	def_bool y
369
370config SMP
371	def_bool y
372
373config KERNEL_MODE_NEON
374	def_bool y
375
376config FIX_EARLYCON_MEM
377	def_bool y
378
379config PGTABLE_LEVELS
380	int
381	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
382	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
383	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
384	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
385	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
386	default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
387	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
388	default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
389
390config ARCH_SUPPORTS_UPROBES
391	def_bool y
392
393config ARCH_PROC_KCORE_TEXT
394	def_bool y
395
396config BROKEN_GAS_INST
397	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
398
399config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
400	bool
401	# Clang's __builtin_return_address() strips the PAC since 12.0.0
402	# https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
403	default y if CC_IS_CLANG
404	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
405	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
406	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
407	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
408	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
409	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
410	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
411	default n
412
413config KASAN_SHADOW_OFFSET
414	hex
415	depends on KASAN_GENERIC || KASAN_SW_TAGS
416	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
417	default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
418	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
419	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
420	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
421	default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
422	default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
423	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
424	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
425	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
426	default 0xffffffffffffffff
427
428config UNWIND_TABLES
429	bool
430
431source "arch/arm64/Kconfig.platforms"
432
433menu "Kernel Features"
434
435menu "ARM errata workarounds via the alternatives framework"
436
437config AMPERE_ERRATUM_AC03_CPU_38
438        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
439	default y
440	help
441	  This option adds an alternative code sequence to work around Ampere
442	  errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
443
444	  The affected design reports FEAT_HAFDBS as not implemented in
445	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
446	  as required by the architecture. The unadvertised HAFDBS
447	  implementation suffers from an additional erratum where hardware
448	  A/D updates can occur after a PTE has been marked invalid.
449
450	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
451	  which avoids enabling unadvertised hardware Access Flag management
452	  at stage-2.
453
454	  If unsure, say Y.
455
456config ARM64_WORKAROUND_CLEAN_CACHE
457	bool
458
459config ARM64_ERRATUM_826319
460	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
461	default y
462	select ARM64_WORKAROUND_CLEAN_CACHE
463	help
464	  This option adds an alternative code sequence to work around ARM
465	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
466	  AXI master interface and an L2 cache.
467
468	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
469	  and is unable to accept a certain write via this interface, it will
470	  not progress on read data presented on the read data channel and the
471	  system can deadlock.
472
473	  The workaround promotes data cache clean instructions to
474	  data cache clean-and-invalidate.
475	  Please note that this does not necessarily enable the workaround,
476	  as it depends on the alternative framework, which will only patch
477	  the kernel if an affected CPU is detected.
478
479	  If unsure, say Y.
480
481config ARM64_ERRATUM_827319
482	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
483	default y
484	select ARM64_WORKAROUND_CLEAN_CACHE
485	help
486	  This option adds an alternative code sequence to work around ARM
487	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
488	  master interface and an L2 cache.
489
490	  Under certain conditions this erratum can cause a clean line eviction
491	  to occur at the same time as another transaction to the same address
492	  on the AMBA 5 CHI interface, which can cause data corruption if the
493	  interconnect reorders the two transactions.
494
495	  The workaround promotes data cache clean instructions to
496	  data cache clean-and-invalidate.
497	  Please note that this does not necessarily enable the workaround,
498	  as it depends on the alternative framework, which will only patch
499	  the kernel if an affected CPU is detected.
500
501	  If unsure, say Y.
502
503config ARM64_ERRATUM_824069
504	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
505	default y
506	select ARM64_WORKAROUND_CLEAN_CACHE
507	help
508	  This option adds an alternative code sequence to work around ARM
509	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
510	  to a coherent interconnect.
511
512	  If a Cortex-A53 processor is executing a store or prefetch for
513	  write instruction at the same time as a processor in another
514	  cluster is executing a cache maintenance operation to the same
515	  address, then this erratum might cause a clean cache line to be
516	  incorrectly marked as dirty.
517
518	  The workaround promotes data cache clean instructions to
519	  data cache clean-and-invalidate.
520	  Please note that this option does not necessarily enable the
521	  workaround, as it depends on the alternative framework, which will
522	  only patch the kernel if an affected CPU is detected.
523
524	  If unsure, say Y.
525
526config ARM64_ERRATUM_819472
527	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
528	default y
529	select ARM64_WORKAROUND_CLEAN_CACHE
530	help
531	  This option adds an alternative code sequence to work around ARM
532	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
533	  present when it is connected to a coherent interconnect.
534
535	  If the processor is executing a load and store exclusive sequence at
536	  the same time as a processor in another cluster is executing a cache
537	  maintenance operation to the same address, then this erratum might
538	  cause data corruption.
539
540	  The workaround promotes data cache clean instructions to
541	  data cache clean-and-invalidate.
542	  Please note that this does not necessarily enable the workaround,
543	  as it depends on the alternative framework, which will only patch
544	  the kernel if an affected CPU is detected.
545
546	  If unsure, say Y.
547
548config ARM64_ERRATUM_832075
549	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
550	default y
551	help
552	  This option adds an alternative code sequence to work around ARM
553	  erratum 832075 on Cortex-A57 parts up to r1p2.
554
555	  Affected Cortex-A57 parts might deadlock when exclusive load/store
556	  instructions to Write-Back memory are mixed with Device loads.
557
558	  The workaround is to promote device loads to use Load-Acquire
559	  semantics.
560	  Please note that this does not necessarily enable the workaround,
561	  as it depends on the alternative framework, which will only patch
562	  the kernel if an affected CPU is detected.
563
564	  If unsure, say Y.
565
566config ARM64_ERRATUM_834220
567	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
568	depends on KVM
569	help
570	  This option adds an alternative code sequence to work around ARM
571	  erratum 834220 on Cortex-A57 parts up to r1p2.
572
573	  Affected Cortex-A57 parts might report a Stage 2 translation
574	  fault as the result of a Stage 1 fault for load crossing a
575	  page boundary when there is a permission or device memory
576	  alignment fault at Stage 1 and a translation fault at Stage 2.
577
578	  The workaround is to verify that the Stage 1 translation
579	  doesn't generate a fault before handling the Stage 2 fault.
580	  Please note that this does not necessarily enable the workaround,
581	  as it depends on the alternative framework, which will only patch
582	  the kernel if an affected CPU is detected.
583
584	  If unsure, say N.
585
586config ARM64_ERRATUM_1742098
587	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
588	depends on COMPAT
589	default y
590	help
591	  This option removes the AES hwcap for aarch32 user-space to
592	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
593
594	  Affected parts may corrupt the AES state if an interrupt is
595	  taken between a pair of AES instructions. These instructions
596	  are only present if the cryptography extensions are present.
597	  All software should have a fallback implementation for CPUs
598	  that don't implement the cryptography extensions.
599
600	  If unsure, say Y.
601
602config ARM64_ERRATUM_845719
603	bool "Cortex-A53: 845719: a load might read incorrect data"
604	depends on COMPAT
605	default y
606	help
607	  This option adds an alternative code sequence to work around ARM
608	  erratum 845719 on Cortex-A53 parts up to r0p4.
609
610	  When running a compat (AArch32) userspace on an affected Cortex-A53
611	  part, a load at EL0 from a virtual address that matches the bottom 32
612	  bits of the virtual address used by a recent load at (AArch64) EL1
613	  might return incorrect data.
614
615	  The workaround is to write the contextidr_el1 register on exception
616	  return to a 32-bit task.
617	  Please note that this does not necessarily enable the workaround,
618	  as it depends on the alternative framework, which will only patch
619	  the kernel if an affected CPU is detected.
620
621	  If unsure, say Y.
622
623config ARM64_ERRATUM_843419
624	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
625	default y
626	help
627	  This option links the kernel with '--fix-cortex-a53-843419' and
628	  enables PLT support to replace certain ADRP instructions, which can
629	  cause subsequent memory accesses to use an incorrect address on
630	  Cortex-A53 parts up to r0p4.
631
632	  If unsure, say Y.
633
634config ARM64_LD_HAS_FIX_ERRATUM_843419
635	def_bool $(ld-option,--fix-cortex-a53-843419)
636
637config ARM64_ERRATUM_1024718
638	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
639	default y
640	help
641	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
642
643	  Affected Cortex-A55 cores (all revisions) could cause incorrect
644	  update of the hardware dirty bit when the DBM/AP bits are updated
645	  without a break-before-make. The workaround is to disable the usage
646	  of hardware DBM locally on the affected cores. CPUs not affected by
647	  this erratum will continue to use the feature.
648
649	  If unsure, say Y.
650
651config ARM64_ERRATUM_1418040
652	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
653	default y
654	depends on COMPAT
655	help
656	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
657	  errata 1188873 and 1418040.
658
659	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
660	  cause register corruption when accessing the timer registers
661	  from AArch32 userspace.
662
663	  If unsure, say Y.
664
665config ARM64_WORKAROUND_SPECULATIVE_AT
666	bool
667
668config ARM64_ERRATUM_1165522
669	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
670	default y
671	select ARM64_WORKAROUND_SPECULATIVE_AT
672	help
673	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
674
675	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
676	  corrupted TLBs by speculating an AT instruction during a guest
677	  context switch.
678
679	  If unsure, say Y.
680
681config ARM64_ERRATUM_1319367
682	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
683	default y
684	select ARM64_WORKAROUND_SPECULATIVE_AT
685	help
686	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
687	  and A72 erratum 1319367
688
689	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
690	  speculating an AT instruction during a guest context switch.
691
692	  If unsure, say Y.
693
694config ARM64_ERRATUM_1530923
695	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
696	default y
697	select ARM64_WORKAROUND_SPECULATIVE_AT
698	help
699	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
700
701	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
702	  corrupted TLBs by speculating an AT instruction during a guest
703	  context switch.
704
705	  If unsure, say Y.
706
707config ARM64_WORKAROUND_REPEAT_TLBI
708	bool
709
710config ARM64_ERRATUM_2441007
711	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
712	select ARM64_WORKAROUND_REPEAT_TLBI
713	help
714	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
715
716	  Under very rare circumstances, affected Cortex-A55 CPUs
717	  may not handle a race between a break-before-make sequence on one
718	  CPU, and another CPU accessing the same page. This could allow a
719	  store to a page that has been unmapped.
720
721	  Work around this by adding the affected CPUs to the list that needs
722	  TLB sequences to be done twice.
723
724	  If unsure, say N.
725
726config ARM64_ERRATUM_1286807
727	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
728	select ARM64_WORKAROUND_REPEAT_TLBI
729	help
730	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
731
732	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
733	  address for a cacheable mapping of a location is being
734	  accessed by a core while another core is remapping the virtual
735	  address to a new physical page using the recommended
736	  break-before-make sequence, then under very rare circumstances
737	  TLBI+DSB completes before a read using the translation being
738	  invalidated has been observed by other observers. The
739	  workaround repeats the TLBI+DSB operation.
740
741	  If unsure, say N.
742
743config ARM64_ERRATUM_1463225
744	bool "Cortex-A76: Software Step might prevent interrupt recognition"
745	default y
746	help
747	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
748
749	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
750	  of a system call instruction (SVC) can prevent recognition of
751	  subsequent interrupts when software stepping is disabled in the
752	  exception handler of the system call and either kernel debugging
753	  is enabled or VHE is in use.
754
755	  Work around the erratum by triggering a dummy step exception
756	  when handling a system call from a task that is being stepped
757	  in a VHE configuration of the kernel.
758
759	  If unsure, say Y.
760
761config ARM64_ERRATUM_1542419
762	bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
763	help
764	  This option adds a workaround for ARM Neoverse-N1 erratum
765	  1542419.
766
767	  Affected Neoverse-N1 cores could execute a stale instruction when
768	  modified by another CPU. The workaround depends on a firmware
769	  counterpart.
770
771	  Workaround the issue by hiding the DIC feature from EL0. This
772	  forces user-space to perform cache maintenance.
773
774	  If unsure, say N.
775
776config ARM64_ERRATUM_1508412
777	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
778	default y
779	help
780	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
781
782	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
783	  of a store-exclusive or read of PAR_EL1 and a load with device or
784	  non-cacheable memory attributes. The workaround depends on a firmware
785	  counterpart.
786
787	  KVM guests must also have the workaround implemented or they can
788	  deadlock the system.
789
790	  Work around the issue by inserting DMB SY barriers around PAR_EL1
791	  register reads and warning KVM users. The DMB barrier is sufficient
792	  to prevent a speculative PAR_EL1 read.
793
794	  If unsure, say Y.
795
796config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
797	bool
798
799config ARM64_ERRATUM_2051678
800	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
801	default y
802	help
803	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
804	  Affected Cortex-A510 might not respect the ordering rules for
805	  hardware update of the page table's dirty bit. The workaround
806	  is to not enable the feature on affected CPUs.
807
808	  If unsure, say Y.
809
810config ARM64_ERRATUM_2077057
811	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
812	default y
813	help
814	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
815	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
816	  expected, but a Pointer Authentication trap is taken instead. The
817	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
818	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
819
820	  This can only happen when EL2 is stepping EL1.
821
822	  When these conditions occur, the SPSR_EL2 value is unchanged from the
823	  previous guest entry, and can be restored from the in-memory copy.
824
825	  If unsure, say Y.
826
827config ARM64_ERRATUM_2658417
828	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
829	default y
830	help
831	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
832	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
833	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
834	  A510 CPUs are using shared neon hardware. As the sharing is not
835	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
836	  user-space should not be using these instructions.
837
838	  If unsure, say Y.
839
840config ARM64_ERRATUM_2119858
841	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
842	default y
843	depends on CORESIGHT_TRBE
844	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
845	help
846	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
847
848	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
849	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
850	  the event of a WRAP event.
851
852	  Work around the issue by always making sure we move the TRBPTR_EL1 by
853	  256 bytes before enabling the buffer and filling the first 256 bytes of
854	  the buffer with ETM ignore packets upon disabling.
855
856	  If unsure, say Y.
857
858config ARM64_ERRATUM_2139208
859	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
860	default y
861	depends on CORESIGHT_TRBE
862	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
863	help
864	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
865
866	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
867	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
868	  the event of a WRAP event.
869
870	  Work around the issue by always making sure we move the TRBPTR_EL1 by
871	  256 bytes before enabling the buffer and filling the first 256 bytes of
872	  the buffer with ETM ignore packets upon disabling.
873
874	  If unsure, say Y.
875
876config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
877	bool
878
879config ARM64_ERRATUM_2054223
880	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
881	default y
882	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
883	help
884	  Enable workaround for ARM Cortex-A710 erratum 2054223
885
886	  Affected cores may fail to flush the trace data on a TSB instruction, when
887	  the PE is in trace prohibited state. This will cause losing a few bytes
888	  of the trace cached.
889
890	  Workaround is to issue two TSB consecutively on affected cores.
891
892	  If unsure, say Y.
893
894config ARM64_ERRATUM_2067961
895	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
896	default y
897	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
898	help
899	  Enable workaround for ARM Neoverse-N2 erratum 2067961
900
901	  Affected cores may fail to flush the trace data on a TSB instruction, when
902	  the PE is in trace prohibited state. This will cause losing a few bytes
903	  of the trace cached.
904
905	  Workaround is to issue two TSB consecutively on affected cores.
906
907	  If unsure, say Y.
908
909config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
910	bool
911
912config ARM64_ERRATUM_2253138
913	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
914	depends on CORESIGHT_TRBE
915	default y
916	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
917	help
918	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
919
920	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
921	  for TRBE. Under some conditions, the TRBE might generate a write to the next
922	  virtually addressed page following the last page of the TRBE address space
923	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
924
925	  Work around this in the driver by always making sure that there is a
926	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
927
928	  If unsure, say Y.
929
930config ARM64_ERRATUM_2224489
931	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
932	depends on CORESIGHT_TRBE
933	default y
934	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
935	help
936	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
937
938	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
939	  for TRBE. Under some conditions, the TRBE might generate a write to the next
940	  virtually addressed page following the last page of the TRBE address space
941	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
942
943	  Work around this in the driver by always making sure that there is a
944	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
945
946	  If unsure, say Y.
947
948config ARM64_ERRATUM_2441009
949	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
950	select ARM64_WORKAROUND_REPEAT_TLBI
951	help
952	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
953
954	  Under very rare circumstances, affected Cortex-A510 CPUs
955	  may not handle a race between a break-before-make sequence on one
956	  CPU, and another CPU accessing the same page. This could allow a
957	  store to a page that has been unmapped.
958
959	  Work around this by adding the affected CPUs to the list that needs
960	  TLB sequences to be done twice.
961
962	  If unsure, say N.
963
964config ARM64_ERRATUM_2064142
965	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
966	depends on CORESIGHT_TRBE
967	default y
968	help
969	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
970
971	  Affected Cortex-A510 core might fail to write into system registers after the
972	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
973	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
974	  and TRBTRG_EL1 will be ignored and will not be effected.
975
976	  Work around this in the driver by executing TSB CSYNC and DSB after collection
977	  is stopped and before performing a system register write to one of the affected
978	  registers.
979
980	  If unsure, say Y.
981
982config ARM64_ERRATUM_2038923
983	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
984	depends on CORESIGHT_TRBE
985	default y
986	help
987	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
988
989	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
990	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
991	  might be corrupted. This happens after TRBE buffer has been enabled by setting
992	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
993	  execution changes from a context, in which trace is prohibited to one where it
994	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
995	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
996	  the trace buffer state might be corrupted.
997
998	  Work around this in the driver by preventing an inconsistent view of whether the
999	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
1000	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
1001	  two ISB instructions if no ERET is to take place.
1002
1003	  If unsure, say Y.
1004
1005config ARM64_ERRATUM_1902691
1006	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1007	depends on CORESIGHT_TRBE
1008	default y
1009	help
1010	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1011
1012	  Affected Cortex-A510 core might cause trace data corruption, when being written
1013	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
1014	  trace data.
1015
1016	  Work around this problem in the driver by just preventing TRBE initialization on
1017	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1018	  on such implementations. This will cover the kernel for any firmware that doesn't
1019	  do this already.
1020
1021	  If unsure, say Y.
1022
1023config ARM64_ERRATUM_2457168
1024	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1025	depends on ARM64_AMU_EXTN
1026	default y
1027	help
1028	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1029
1030	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1031	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1032	  incorrectly giving a significantly higher output value.
1033
1034	  Work around this problem by returning 0 when reading the affected counter in
1035	  key locations that results in disabling all users of this counter. This effect
1036	  is the same to firmware disabling affected counters.
1037
1038	  If unsure, say Y.
1039
1040config ARM64_ERRATUM_2645198
1041	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1042	default y
1043	help
1044	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1045
1046	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1047	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1048	  next instruction abort caused by permission fault.
1049
1050	  Only user-space does executable to non-executable permission transition via
1051	  mprotect() system call. Workaround the problem by doing a break-before-make
1052	  TLB invalidation, for all changes to executable user space mappings.
1053
1054	  If unsure, say Y.
1055
1056config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1057	bool
1058
1059config ARM64_ERRATUM_2966298
1060	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1061	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1062	default y
1063	help
1064	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1065
1066	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1067	  load might leak data from a privileged level via a cache side channel.
1068
1069	  Work around this problem by executing a TLBI before returning to EL0.
1070
1071	  If unsure, say Y.
1072
1073config ARM64_ERRATUM_3117295
1074	bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1075	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1076	default y
1077	help
1078	  This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1079
1080	  On an affected Cortex-A510 core, a speculatively executed unprivileged
1081	  load might leak data from a privileged level via a cache side channel.
1082
1083	  Work around this problem by executing a TLBI before returning to EL0.
1084
1085	  If unsure, say Y.
1086
1087config ARM64_ERRATUM_3194386
1088	bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1089	default y
1090	help
1091	  This option adds the workaround for the following errata:
1092
1093	  * ARM Cortex-A76 erratum 3324349
1094	  * ARM Cortex-A77 erratum 3324348
1095	  * ARM Cortex-A78 erratum 3324344
1096	  * ARM Cortex-A78C erratum 3324346
1097	  * ARM Cortex-A78C erratum 3324347
1098	  * ARM Cortex-A710 erratam 3324338
1099	  * ARM Cortex-A715 errartum 3456084
1100	  * ARM Cortex-A720 erratum 3456091
1101	  * ARM Cortex-A725 erratum 3456106
1102	  * ARM Cortex-X1 erratum 3324344
1103	  * ARM Cortex-X1C erratum 3324346
1104	  * ARM Cortex-X2 erratum 3324338
1105	  * ARM Cortex-X3 erratum 3324335
1106	  * ARM Cortex-X4 erratum 3194386
1107	  * ARM Cortex-X925 erratum 3324334
1108	  * ARM Neoverse-N1 erratum 3324349
1109	  * ARM Neoverse N2 erratum 3324339
1110	  * ARM Neoverse-N3 erratum 3456111
1111	  * ARM Neoverse-V1 erratum 3324341
1112	  * ARM Neoverse V2 erratum 3324336
1113	  * ARM Neoverse-V3 erratum 3312417
1114
1115	  On affected cores "MSR SSBS, #0" instructions may not affect
1116	  subsequent speculative instructions, which may permit unexepected
1117	  speculative store bypassing.
1118
1119	  Work around this problem by placing a Speculation Barrier (SB) or
1120	  Instruction Synchronization Barrier (ISB) after kernel changes to
1121	  SSBS. The presence of the SSBS special-purpose register is hidden
1122	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1123	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1124
1125	  If unsure, say Y.
1126
1127config CAVIUM_ERRATUM_22375
1128	bool "Cavium erratum 22375, 24313"
1129	default y
1130	help
1131	  Enable workaround for errata 22375 and 24313.
1132
1133	  This implements two gicv3-its errata workarounds for ThunderX. Both
1134	  with a small impact affecting only ITS table allocation.
1135
1136	    erratum 22375: only alloc 8MB table size
1137	    erratum 24313: ignore memory access type
1138
1139	  The fixes are in ITS initialization and basically ignore memory access
1140	  type and table size provided by the TYPER and BASER registers.
1141
1142	  If unsure, say Y.
1143
1144config CAVIUM_ERRATUM_23144
1145	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1146	depends on NUMA
1147	default y
1148	help
1149	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1150
1151	  If unsure, say Y.
1152
1153config CAVIUM_ERRATUM_23154
1154	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1155	default y
1156	help
1157	  The ThunderX GICv3 implementation requires a modified version for
1158	  reading the IAR status to ensure data synchronization
1159	  (access to icc_iar1_el1 is not sync'ed before and after).
1160
1161	  It also suffers from erratum 38545 (also present on Marvell's
1162	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1163	  spuriously presented to the CPU interface.
1164
1165	  If unsure, say Y.
1166
1167config CAVIUM_ERRATUM_27456
1168	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1169	default y
1170	help
1171	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1172	  instructions may cause the icache to become corrupted if it
1173	  contains data for a non-current ASID.  The fix is to
1174	  invalidate the icache when changing the mm context.
1175
1176	  If unsure, say Y.
1177
1178config CAVIUM_ERRATUM_30115
1179	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1180	default y
1181	help
1182	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1183	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1184	  interrupts in host. Trapping both GICv3 group-0 and group-1
1185	  accesses sidesteps the issue.
1186
1187	  If unsure, say Y.
1188
1189config CAVIUM_TX2_ERRATUM_219
1190	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1191	default y
1192	help
1193	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1194	  TTBR update and the corresponding context synchronizing operation can
1195	  cause a spurious Data Abort to be delivered to any hardware thread in
1196	  the CPU core.
1197
1198	  Work around the issue by avoiding the problematic code sequence and
1199	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1200	  trap handler performs the corresponding register access, skips the
1201	  instruction and ensures context synchronization by virtue of the
1202	  exception return.
1203
1204	  If unsure, say Y.
1205
1206config FUJITSU_ERRATUM_010001
1207	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1208	default y
1209	help
1210	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1211	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1212	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1213	  This fault occurs under a specific hardware condition when a
1214	  load/store instruction performs an address translation using:
1215	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1216	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1217	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1218	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1219
1220	  The workaround is to ensure these bits are clear in TCR_ELx.
1221	  The workaround only affects the Fujitsu-A64FX.
1222
1223	  If unsure, say Y.
1224
1225config HISILICON_ERRATUM_161600802
1226	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1227	default y
1228	help
1229	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1230	  when issued ITS commands such as VMOVP and VMAPP, and requires
1231	  a 128kB offset to be applied to the target address in this commands.
1232
1233	  If unsure, say Y.
1234
1235config QCOM_FALKOR_ERRATUM_1003
1236	bool "Falkor E1003: Incorrect translation due to ASID change"
1237	default y
1238	help
1239	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1240	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1241	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1242	  then only for entries in the walk cache, since the leaf translation
1243	  is unchanged. Work around the erratum by invalidating the walk cache
1244	  entries for the trampoline before entering the kernel proper.
1245
1246config QCOM_FALKOR_ERRATUM_1009
1247	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1248	default y
1249	select ARM64_WORKAROUND_REPEAT_TLBI
1250	help
1251	  On Falkor v1, the CPU may prematurely complete a DSB following a
1252	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1253	  one more time to fix the issue.
1254
1255	  If unsure, say Y.
1256
1257config QCOM_QDF2400_ERRATUM_0065
1258	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1259	default y
1260	help
1261	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1262	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1263	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1264
1265	  If unsure, say Y.
1266
1267config QCOM_FALKOR_ERRATUM_E1041
1268	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1269	default y
1270	help
1271	  Falkor CPU may speculatively fetch instructions from an improper
1272	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1273	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1274
1275	  If unsure, say Y.
1276
1277config NVIDIA_CARMEL_CNP_ERRATUM
1278	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1279	default y
1280	help
1281	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1282	  invalidate shared TLB entries installed by a different core, as it would
1283	  on standard ARM cores.
1284
1285	  If unsure, say Y.
1286
1287config ROCKCHIP_ERRATUM_3588001
1288	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1289	default y
1290	help
1291	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1292	  This means, that its sharability feature may not be used, even though it
1293	  is supported by the IP itself.
1294
1295	  If unsure, say Y.
1296
1297config SOCIONEXT_SYNQUACER_PREITS
1298	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1299	default y
1300	help
1301	  Socionext Synquacer SoCs implement a separate h/w block to generate
1302	  MSI doorbell writes with non-zero values for the device ID.
1303
1304	  If unsure, say Y.
1305
1306endmenu # "ARM errata workarounds via the alternatives framework"
1307
1308choice
1309	prompt "Page size"
1310	default ARM64_4K_PAGES
1311	help
1312	  Page size (translation granule) configuration.
1313
1314config ARM64_4K_PAGES
1315	bool "4KB"
1316	select HAVE_PAGE_SIZE_4KB
1317	help
1318	  This feature enables 4KB pages support.
1319
1320config ARM64_16K_PAGES
1321	bool "16KB"
1322	select HAVE_PAGE_SIZE_16KB
1323	help
1324	  The system will use 16KB pages support. AArch32 emulation
1325	  requires applications compiled with 16K (or a multiple of 16K)
1326	  aligned segments.
1327
1328config ARM64_64K_PAGES
1329	bool "64KB"
1330	select HAVE_PAGE_SIZE_64KB
1331	help
1332	  This feature enables 64KB pages support (4KB by default)
1333	  allowing only two levels of page tables and faster TLB
1334	  look-up. AArch32 emulation requires applications compiled
1335	  with 64K aligned segments.
1336
1337endchoice
1338
1339choice
1340	prompt "Virtual address space size"
1341	default ARM64_VA_BITS_52
1342	help
1343	  Allows choosing one of multiple possible virtual address
1344	  space sizes. The level of translation table is determined by
1345	  a combination of page size and virtual address space size.
1346
1347config ARM64_VA_BITS_36
1348	bool "36-bit" if EXPERT
1349	depends on PAGE_SIZE_16KB
1350
1351config ARM64_VA_BITS_39
1352	bool "39-bit"
1353	depends on PAGE_SIZE_4KB
1354
1355config ARM64_VA_BITS_42
1356	bool "42-bit"
1357	depends on PAGE_SIZE_64KB
1358
1359config ARM64_VA_BITS_47
1360	bool "47-bit"
1361	depends on PAGE_SIZE_16KB
1362
1363config ARM64_VA_BITS_48
1364	bool "48-bit"
1365
1366config ARM64_VA_BITS_52
1367	bool "52-bit"
1368	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1369	help
1370	  Enable 52-bit virtual addressing for userspace when explicitly
1371	  requested via a hint to mmap(). The kernel will also use 52-bit
1372	  virtual addresses for its own mappings (provided HW support for
1373	  this feature is available, otherwise it reverts to 48-bit).
1374
1375	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1376	  ARMv8.3 Pointer Authentication will result in the PAC being
1377	  reduced from 7 bits to 3 bits, which may have a significant
1378	  impact on its susceptibility to brute-force attacks.
1379
1380	  If unsure, select 48-bit virtual addressing instead.
1381
1382endchoice
1383
1384config ARM64_FORCE_52BIT
1385	bool "Force 52-bit virtual addresses for userspace"
1386	depends on ARM64_VA_BITS_52 && EXPERT
1387	help
1388	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1389	  to maintain compatibility with older software by providing 48-bit VAs
1390	  unless a hint is supplied to mmap.
1391
1392	  This configuration option disables the 48-bit compatibility logic, and
1393	  forces all userspace addresses to be 52-bit on HW that supports it. One
1394	  should only enable this configuration option for stress testing userspace
1395	  memory management code. If unsure say N here.
1396
1397config ARM64_VA_BITS
1398	int
1399	default 36 if ARM64_VA_BITS_36
1400	default 39 if ARM64_VA_BITS_39
1401	default 42 if ARM64_VA_BITS_42
1402	default 47 if ARM64_VA_BITS_47
1403	default 48 if ARM64_VA_BITS_48
1404	default 52 if ARM64_VA_BITS_52
1405
1406choice
1407	prompt "Physical address space size"
1408	default ARM64_PA_BITS_48
1409	help
1410	  Choose the maximum physical address range that the kernel will
1411	  support.
1412
1413config ARM64_PA_BITS_48
1414	bool "48-bit"
1415	depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1416
1417config ARM64_PA_BITS_52
1418	bool "52-bit"
1419	depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1420	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1421	help
1422	  Enable support for a 52-bit physical address space, introduced as
1423	  part of the ARMv8.2-LPA extension.
1424
1425	  With this enabled, the kernel will also continue to work on CPUs that
1426	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1427	  minor performance overhead).
1428
1429endchoice
1430
1431config ARM64_PA_BITS
1432	int
1433	default 48 if ARM64_PA_BITS_48
1434	default 52 if ARM64_PA_BITS_52
1435
1436config ARM64_LPA2
1437	def_bool y
1438	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1439
1440choice
1441	prompt "Endianness"
1442	default CPU_LITTLE_ENDIAN
1443	help
1444	  Select the endianness of data accesses performed by the CPU. Userspace
1445	  applications will need to be compiled and linked for the endianness
1446	  that is selected here.
1447
1448config CPU_BIG_ENDIAN
1449	bool "Build big-endian kernel"
1450	# https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1451	depends on AS_IS_GNU || AS_VERSION >= 150000
1452	help
1453	  Say Y if you plan on running a kernel with a big-endian userspace.
1454
1455config CPU_LITTLE_ENDIAN
1456	bool "Build little-endian kernel"
1457	help
1458	  Say Y if you plan on running a kernel with a little-endian userspace.
1459	  This is usually the case for distributions targeting arm64.
1460
1461endchoice
1462
1463config SCHED_MC
1464	bool "Multi-core scheduler support"
1465	help
1466	  Multi-core scheduler support improves the CPU scheduler's decision
1467	  making when dealing with multi-core CPU chips at a cost of slightly
1468	  increased overhead in some places. If unsure say N here.
1469
1470config SCHED_CLUSTER
1471	bool "Cluster scheduler support"
1472	help
1473	  Cluster scheduler support improves the CPU scheduler's decision
1474	  making when dealing with machines that have clusters of CPUs.
1475	  Cluster usually means a couple of CPUs which are placed closely
1476	  by sharing mid-level caches, last-level cache tags or internal
1477	  busses.
1478
1479config SCHED_SMT
1480	bool "SMT scheduler support"
1481	help
1482	  Improves the CPU scheduler's decision making when dealing with
1483	  MultiThreading at a cost of slightly increased overhead in some
1484	  places. If unsure say N here.
1485
1486config NR_CPUS
1487	int "Maximum number of CPUs (2-4096)"
1488	range 2 4096
1489	default "512"
1490
1491config HOTPLUG_CPU
1492	bool "Support for hot-pluggable CPUs"
1493	select GENERIC_IRQ_MIGRATION
1494	help
1495	  Say Y here to experiment with turning CPUs off and on.  CPUs
1496	  can be controlled through /sys/devices/system/cpu.
1497
1498# Common NUMA Features
1499config NUMA
1500	bool "NUMA Memory Allocation and Scheduler Support"
1501	select GENERIC_ARCH_NUMA
1502	select OF_NUMA
1503	select HAVE_SETUP_PER_CPU_AREA
1504	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1505	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1506	select USE_PERCPU_NUMA_NODE_ID
1507	help
1508	  Enable NUMA (Non-Uniform Memory Access) support.
1509
1510	  The kernel will try to allocate memory used by a CPU on the
1511	  local memory of the CPU and add some more
1512	  NUMA awareness to the kernel.
1513
1514config NODES_SHIFT
1515	int "Maximum NUMA Nodes (as a power of 2)"
1516	range 1 10
1517	default "4"
1518	depends on NUMA
1519	help
1520	  Specify the maximum number of NUMA Nodes available on the target
1521	  system.  Increases memory reserved to accommodate various tables.
1522
1523source "kernel/Kconfig.hz"
1524
1525config ARCH_SPARSEMEM_ENABLE
1526	def_bool y
1527	select SPARSEMEM_VMEMMAP_ENABLE
1528	select SPARSEMEM_VMEMMAP
1529
1530config HW_PERF_EVENTS
1531	def_bool y
1532	depends on ARM_PMU
1533
1534# Supported by clang >= 7.0 or GCC >= 12.0.0
1535config CC_HAVE_SHADOW_CALL_STACK
1536	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1537
1538config PARAVIRT
1539	bool "Enable paravirtualization code"
1540	help
1541	  This changes the kernel so it can modify itself when it is run
1542	  under a hypervisor, potentially improving performance significantly
1543	  over full virtualization.
1544
1545config PARAVIRT_TIME_ACCOUNTING
1546	bool "Paravirtual steal time accounting"
1547	select PARAVIRT
1548	help
1549	  Select this option to enable fine granularity task steal time
1550	  accounting. Time spent executing other tasks in parallel with
1551	  the current vCPU is discounted from the vCPU power. To account for
1552	  that, there can be a small performance impact.
1553
1554	  If in doubt, say N here.
1555
1556config ARCH_SUPPORTS_KEXEC
1557	def_bool PM_SLEEP_SMP
1558
1559config ARCH_SUPPORTS_KEXEC_FILE
1560	def_bool y
1561
1562config ARCH_SELECTS_KEXEC_FILE
1563	def_bool y
1564	depends on KEXEC_FILE
1565	select HAVE_IMA_KEXEC if IMA
1566
1567config ARCH_SUPPORTS_KEXEC_SIG
1568	def_bool y
1569
1570config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1571	def_bool y
1572
1573config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1574	def_bool y
1575
1576config ARCH_SUPPORTS_CRASH_DUMP
1577	def_bool y
1578
1579config ARCH_DEFAULT_CRASH_DUMP
1580	def_bool y
1581
1582config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1583	def_bool CRASH_RESERVE
1584
1585config TRANS_TABLE
1586	def_bool y
1587	depends on HIBERNATION || KEXEC_CORE
1588
1589config XEN_DOM0
1590	def_bool y
1591	depends on XEN
1592
1593config XEN
1594	bool "Xen guest support on ARM64"
1595	depends on ARM64 && OF
1596	select SWIOTLB_XEN
1597	select PARAVIRT
1598	help
1599	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1600
1601# include/linux/mmzone.h requires the following to be true:
1602#
1603#   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1604#
1605# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1606#
1607#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1608# ----+-------------------+--------------+----------------------+-------------------------+
1609# 4K  |       27          |      12      |       15             |         10              |
1610# 16K |       27          |      14      |       13             |         11              |
1611# 64K |       29          |      16      |       13             |         13              |
1612config ARCH_FORCE_MAX_ORDER
1613	int
1614	default "13" if ARM64_64K_PAGES
1615	default "11" if ARM64_16K_PAGES
1616	default "10"
1617	help
1618	  The kernel page allocator limits the size of maximal physically
1619	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1620	  defines the maximal power of two of number of pages that can be
1621	  allocated as a single contiguous block. This option allows
1622	  overriding the default setting when ability to allocate very
1623	  large blocks of physically contiguous memory is required.
1624
1625	  The maximal size of allocation cannot exceed the size of the
1626	  section, so the value of MAX_PAGE_ORDER should satisfy
1627
1628	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1629
1630	  Don't change if unsure.
1631
1632config UNMAP_KERNEL_AT_EL0
1633	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1634	default y
1635	help
1636	  Speculation attacks against some high-performance processors can
1637	  be used to bypass MMU permission checks and leak kernel data to
1638	  userspace. This can be defended against by unmapping the kernel
1639	  when running in userspace, mapping it back in on exception entry
1640	  via a trampoline page in the vector table.
1641
1642	  If unsure, say Y.
1643
1644config MITIGATE_SPECTRE_BRANCH_HISTORY
1645	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1646	default y
1647	help
1648	  Speculation attacks against some high-performance processors can
1649	  make use of branch history to influence future speculation.
1650	  When taking an exception from user-space, a sequence of branches
1651	  or a firmware call overwrites the branch history.
1652
1653config RODATA_FULL_DEFAULT_ENABLED
1654	bool "Apply r/o permissions of VM areas also to their linear aliases"
1655	default y
1656	help
1657	  Apply read-only attributes of VM areas to the linear alias of
1658	  the backing pages as well. This prevents code or read-only data
1659	  from being modified (inadvertently or intentionally) via another
1660	  mapping of the same memory page. This additional enhancement can
1661	  be turned off at runtime by passing rodata=[off|on] (and turned on
1662	  with rodata=full if this option is set to 'n')
1663
1664	  This requires the linear region to be mapped down to pages,
1665	  which may adversely affect performance in some cases.
1666
1667config ARM64_SW_TTBR0_PAN
1668	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1669	depends on !KCSAN
1670	help
1671	  Enabling this option prevents the kernel from accessing
1672	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1673	  zeroed area and reserved ASID. The user access routines
1674	  restore the valid TTBR0_EL1 temporarily.
1675
1676config ARM64_TAGGED_ADDR_ABI
1677	bool "Enable the tagged user addresses syscall ABI"
1678	default y
1679	help
1680	  When this option is enabled, user applications can opt in to a
1681	  relaxed ABI via prctl() allowing tagged addresses to be passed
1682	  to system calls as pointer arguments. For details, see
1683	  Documentation/arch/arm64/tagged-address-abi.rst.
1684
1685menuconfig COMPAT
1686	bool "Kernel support for 32-bit EL0"
1687	depends on ARM64_4K_PAGES || EXPERT
1688	select HAVE_UID16
1689	select OLD_SIGSUSPEND3
1690	select COMPAT_OLD_SIGACTION
1691	help
1692	  This option enables support for a 32-bit EL0 running under a 64-bit
1693	  kernel at EL1. AArch32-specific components such as system calls,
1694	  the user helper functions, VFP support and the ptrace interface are
1695	  handled appropriately by the kernel.
1696
1697	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1698	  that you will only be able to execute AArch32 binaries that were compiled
1699	  with page size aligned segments.
1700
1701	  If you want to execute 32-bit userspace applications, say Y.
1702
1703if COMPAT
1704
1705config KUSER_HELPERS
1706	bool "Enable kuser helpers page for 32-bit applications"
1707	default y
1708	help
1709	  Warning: disabling this option may break 32-bit user programs.
1710
1711	  Provide kuser helpers to compat tasks. The kernel provides
1712	  helper code to userspace in read only form at a fixed location
1713	  to allow userspace to be independent of the CPU type fitted to
1714	  the system. This permits binaries to be run on ARMv4 through
1715	  to ARMv8 without modification.
1716
1717	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1718
1719	  However, the fixed address nature of these helpers can be used
1720	  by ROP (return orientated programming) authors when creating
1721	  exploits.
1722
1723	  If all of the binaries and libraries which run on your platform
1724	  are built specifically for your platform, and make no use of
1725	  these helpers, then you can turn this option off to hinder
1726	  such exploits. However, in that case, if a binary or library
1727	  relying on those helpers is run, it will not function correctly.
1728
1729	  Say N here only if you are absolutely certain that you do not
1730	  need these helpers; otherwise, the safe option is to say Y.
1731
1732config COMPAT_VDSO
1733	bool "Enable vDSO for 32-bit applications"
1734	depends on !CPU_BIG_ENDIAN
1735	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1736	select GENERIC_COMPAT_VDSO
1737	default y
1738	help
1739	  Place in the process address space of 32-bit applications an
1740	  ELF shared object providing fast implementations of gettimeofday
1741	  and clock_gettime.
1742
1743	  You must have a 32-bit build of glibc 2.22 or later for programs
1744	  to seamlessly take advantage of this.
1745
1746config THUMB2_COMPAT_VDSO
1747	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1748	depends on COMPAT_VDSO
1749	default y
1750	help
1751	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1752	  otherwise with '-marm'.
1753
1754config COMPAT_ALIGNMENT_FIXUPS
1755	bool "Fix up misaligned multi-word loads and stores in user space"
1756
1757menuconfig ARMV8_DEPRECATED
1758	bool "Emulate deprecated/obsolete ARMv8 instructions"
1759	depends on SYSCTL
1760	help
1761	  Legacy software support may require certain instructions
1762	  that have been deprecated or obsoleted in the architecture.
1763
1764	  Enable this config to enable selective emulation of these
1765	  features.
1766
1767	  If unsure, say Y
1768
1769if ARMV8_DEPRECATED
1770
1771config SWP_EMULATION
1772	bool "Emulate SWP/SWPB instructions"
1773	help
1774	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1775	  they are always undefined. Say Y here to enable software
1776	  emulation of these instructions for userspace using LDXR/STXR.
1777	  This feature can be controlled at runtime with the abi.swp
1778	  sysctl which is disabled by default.
1779
1780	  In some older versions of glibc [<=2.8] SWP is used during futex
1781	  trylock() operations with the assumption that the code will not
1782	  be preempted. This invalid assumption may be more likely to fail
1783	  with SWP emulation enabled, leading to deadlock of the user
1784	  application.
1785
1786	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1787	  on an external transaction monitoring block called a global
1788	  monitor to maintain update atomicity. If your system does not
1789	  implement a global monitor, this option can cause programs that
1790	  perform SWP operations to uncached memory to deadlock.
1791
1792	  If unsure, say Y
1793
1794config CP15_BARRIER_EMULATION
1795	bool "Emulate CP15 Barrier instructions"
1796	help
1797	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1798	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1799	  strongly recommended to use the ISB, DSB, and DMB
1800	  instructions instead.
1801
1802	  Say Y here to enable software emulation of these
1803	  instructions for AArch32 userspace code. When this option is
1804	  enabled, CP15 barrier usage is traced which can help
1805	  identify software that needs updating. This feature can be
1806	  controlled at runtime with the abi.cp15_barrier sysctl.
1807
1808	  If unsure, say Y
1809
1810config SETEND_EMULATION
1811	bool "Emulate SETEND instruction"
1812	help
1813	  The SETEND instruction alters the data-endianness of the
1814	  AArch32 EL0, and is deprecated in ARMv8.
1815
1816	  Say Y here to enable software emulation of the instruction
1817	  for AArch32 userspace code. This feature can be controlled
1818	  at runtime with the abi.setend sysctl.
1819
1820	  Note: All the cpus on the system must have mixed endian support at EL0
1821	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1822	  endian - is hotplugged in after this feature has been enabled, there could
1823	  be unexpected results in the applications.
1824
1825	  If unsure, say Y
1826endif # ARMV8_DEPRECATED
1827
1828endif # COMPAT
1829
1830menu "ARMv8.1 architectural features"
1831
1832config ARM64_HW_AFDBM
1833	bool "Support for hardware updates of the Access and Dirty page flags"
1834	default y
1835	help
1836	  The ARMv8.1 architecture extensions introduce support for
1837	  hardware updates of the access and dirty information in page
1838	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1839	  capable processors, accesses to pages with PTE_AF cleared will
1840	  set this bit instead of raising an access flag fault.
1841	  Similarly, writes to read-only pages with the DBM bit set will
1842	  clear the read-only bit (AP[2]) instead of raising a
1843	  permission fault.
1844
1845	  Kernels built with this configuration option enabled continue
1846	  to work on pre-ARMv8.1 hardware and the performance impact is
1847	  minimal. If unsure, say Y.
1848
1849config ARM64_PAN
1850	bool "Enable support for Privileged Access Never (PAN)"
1851	default y
1852	help
1853	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1854	  prevents the kernel or hypervisor from accessing user-space (EL0)
1855	  memory directly.
1856
1857	  Choosing this option will cause any unprotected (not using
1858	  copy_to_user et al) memory access to fail with a permission fault.
1859
1860	  The feature is detected at runtime, and will remain as a 'nop'
1861	  instruction if the cpu does not implement the feature.
1862
1863config AS_HAS_LSE_ATOMICS
1864	def_bool $(as-instr,.arch_extension lse)
1865
1866config ARM64_LSE_ATOMICS
1867	bool
1868	default ARM64_USE_LSE_ATOMICS
1869	depends on AS_HAS_LSE_ATOMICS
1870
1871config ARM64_USE_LSE_ATOMICS
1872	bool "Atomic instructions"
1873	default y
1874	help
1875	  As part of the Large System Extensions, ARMv8.1 introduces new
1876	  atomic instructions that are designed specifically to scale in
1877	  very large systems.
1878
1879	  Say Y here to make use of these instructions for the in-kernel
1880	  atomic routines. This incurs a small overhead on CPUs that do
1881	  not support these instructions and requires the kernel to be
1882	  built with binutils >= 2.25 in order for the new instructions
1883	  to be used.
1884
1885endmenu # "ARMv8.1 architectural features"
1886
1887menu "ARMv8.2 architectural features"
1888
1889config AS_HAS_ARMV8_2
1890	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1891
1892config AS_HAS_SHA3
1893	def_bool $(as-instr,.arch armv8.2-a+sha3)
1894
1895config ARM64_PMEM
1896	bool "Enable support for persistent memory"
1897	select ARCH_HAS_PMEM_API
1898	select ARCH_HAS_UACCESS_FLUSHCACHE
1899	help
1900	  Say Y to enable support for the persistent memory API based on the
1901	  ARMv8.2 DCPoP feature.
1902
1903	  The feature is detected at runtime, and the kernel will use DC CVAC
1904	  operations if DC CVAP is not supported (following the behaviour of
1905	  DC CVAP itself if the system does not define a point of persistence).
1906
1907config ARM64_RAS_EXTN
1908	bool "Enable support for RAS CPU Extensions"
1909	default y
1910	help
1911	  CPUs that support the Reliability, Availability and Serviceability
1912	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1913	  errors, classify them and report them to software.
1914
1915	  On CPUs with these extensions system software can use additional
1916	  barriers to determine if faults are pending and read the
1917	  classification from a new set of registers.
1918
1919	  Selecting this feature will allow the kernel to use these barriers
1920	  and access the new registers if the system supports the extension.
1921	  Platform RAS features may additionally depend on firmware support.
1922
1923config ARM64_CNP
1924	bool "Enable support for Common Not Private (CNP) translations"
1925	default y
1926	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1927	help
1928	  Common Not Private (CNP) allows translation table entries to
1929	  be shared between different PEs in the same inner shareable
1930	  domain, so the hardware can use this fact to optimise the
1931	  caching of such entries in the TLB.
1932
1933	  Selecting this option allows the CNP feature to be detected
1934	  at runtime, and does not affect PEs that do not implement
1935	  this feature.
1936
1937endmenu # "ARMv8.2 architectural features"
1938
1939menu "ARMv8.3 architectural features"
1940
1941config ARM64_PTR_AUTH
1942	bool "Enable support for pointer authentication"
1943	default y
1944	help
1945	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1946	  instructions for signing and authenticating pointers against secret
1947	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1948	  and other attacks.
1949
1950	  This option enables these instructions at EL0 (i.e. for userspace).
1951	  Choosing this option will cause the kernel to initialise secret keys
1952	  for each process at exec() time, with these keys being
1953	  context-switched along with the process.
1954
1955	  The feature is detected at runtime. If the feature is not present in
1956	  hardware it will not be advertised to userspace/KVM guest nor will it
1957	  be enabled.
1958
1959	  If the feature is present on the boot CPU but not on a late CPU, then
1960	  the late CPU will be parked. Also, if the boot CPU does not have
1961	  address auth and the late CPU has then the late CPU will still boot
1962	  but with the feature disabled. On such a system, this option should
1963	  not be selected.
1964
1965config ARM64_PTR_AUTH_KERNEL
1966	bool "Use pointer authentication for kernel"
1967	default y
1968	depends on ARM64_PTR_AUTH
1969	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1970	# Modern compilers insert a .note.gnu.property section note for PAC
1971	# which is only understood by binutils starting with version 2.33.1.
1972	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1973	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1974	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1975	help
1976	  If the compiler supports the -mbranch-protection or
1977	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1978	  will cause the kernel itself to be compiled with return address
1979	  protection. In this case, and if the target hardware is known to
1980	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1981	  disabled with minimal loss of protection.
1982
1983	  This feature works with FUNCTION_GRAPH_TRACER option only if
1984	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
1985
1986config CC_HAS_BRANCH_PROT_PAC_RET
1987	# GCC 9 or later, clang 8 or later
1988	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1989
1990config CC_HAS_SIGN_RETURN_ADDRESS
1991	# GCC 7, 8
1992	def_bool $(cc-option,-msign-return-address=all)
1993
1994config AS_HAS_ARMV8_3
1995	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1996
1997config AS_HAS_CFI_NEGATE_RA_STATE
1998	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1999
2000config AS_HAS_LDAPR
2001	def_bool $(as-instr,.arch_extension rcpc)
2002
2003endmenu # "ARMv8.3 architectural features"
2004
2005menu "ARMv8.4 architectural features"
2006
2007config ARM64_AMU_EXTN
2008	bool "Enable support for the Activity Monitors Unit CPU extension"
2009	default y
2010	help
2011	  The activity monitors extension is an optional extension introduced
2012	  by the ARMv8.4 CPU architecture. This enables support for version 1
2013	  of the activity monitors architecture, AMUv1.
2014
2015	  To enable the use of this extension on CPUs that implement it, say Y.
2016
2017	  Note that for architectural reasons, firmware _must_ implement AMU
2018	  support when running on CPUs that present the activity monitors
2019	  extension. The required support is present in:
2020	    * Version 1.5 and later of the ARM Trusted Firmware
2021
2022	  For kernels that have this configuration enabled but boot with broken
2023	  firmware, you may need to say N here until the firmware is fixed.
2024	  Otherwise you may experience firmware panics or lockups when
2025	  accessing the counter registers. Even if you are not observing these
2026	  symptoms, the values returned by the register reads might not
2027	  correctly reflect reality. Most commonly, the value read will be 0,
2028	  indicating that the counter is not enabled.
2029
2030config AS_HAS_ARMV8_4
2031	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
2032
2033config ARM64_TLB_RANGE
2034	bool "Enable support for tlbi range feature"
2035	default y
2036	depends on AS_HAS_ARMV8_4
2037	help
2038	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2039	  range of input addresses.
2040
2041	  The feature introduces new assembly instructions, and they were
2042	  support when binutils >= 2.30.
2043
2044endmenu # "ARMv8.4 architectural features"
2045
2046menu "ARMv8.5 architectural features"
2047
2048config AS_HAS_ARMV8_5
2049	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2050
2051config ARM64_BTI
2052	bool "Branch Target Identification support"
2053	default y
2054	help
2055	  Branch Target Identification (part of the ARMv8.5 Extensions)
2056	  provides a mechanism to limit the set of locations to which computed
2057	  branch instructions such as BR or BLR can jump.
2058
2059	  To make use of BTI on CPUs that support it, say Y.
2060
2061	  BTI is intended to provide complementary protection to other control
2062	  flow integrity protection mechanisms, such as the Pointer
2063	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2064	  For this reason, it does not make sense to enable this option without
2065	  also enabling support for pointer authentication.  Thus, when
2066	  enabling this option you should also select ARM64_PTR_AUTH=y.
2067
2068	  Userspace binaries must also be specifically compiled to make use of
2069	  this mechanism.  If you say N here or the hardware does not support
2070	  BTI, such binaries can still run, but you get no additional
2071	  enforcement of branch destinations.
2072
2073config ARM64_BTI_KERNEL
2074	bool "Use Branch Target Identification for kernel"
2075	default y
2076	depends on ARM64_BTI
2077	depends on ARM64_PTR_AUTH_KERNEL
2078	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2079	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2080	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2081	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2082	depends on !CC_IS_GCC
2083	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2084	help
2085	  Build the kernel with Branch Target Identification annotations
2086	  and enable enforcement of this for kernel code. When this option
2087	  is enabled and the system supports BTI all kernel code including
2088	  modular code must have BTI enabled.
2089
2090config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2091	# GCC 9 or later, clang 8 or later
2092	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2093
2094config ARM64_E0PD
2095	bool "Enable support for E0PD"
2096	default y
2097	help
2098	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2099	  that EL0 accesses made via TTBR1 always fault in constant time,
2100	  providing similar benefits to KASLR as those provided by KPTI, but
2101	  with lower overhead and without disrupting legitimate access to
2102	  kernel memory such as SPE.
2103
2104	  This option enables E0PD for TTBR1 where available.
2105
2106config ARM64_AS_HAS_MTE
2107	# Initial support for MTE went in binutils 2.32.0, checked with
2108	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2109	# as a late addition to the final architecture spec (LDGM/STGM)
2110	# is only supported in the newer 2.32.x and 2.33 binutils
2111	# versions, hence the extra "stgm" instruction check below.
2112	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2113
2114config ARM64_MTE
2115	bool "Memory Tagging Extension support"
2116	default y
2117	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2118	depends on AS_HAS_ARMV8_5
2119	depends on AS_HAS_LSE_ATOMICS
2120	# Required for tag checking in the uaccess routines
2121	depends on ARM64_PAN
2122	select ARCH_HAS_SUBPAGE_FAULTS
2123	select ARCH_USES_HIGH_VMA_FLAGS
2124	select ARCH_USES_PG_ARCH_2
2125	select ARCH_USES_PG_ARCH_3
2126	help
2127	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2128	  architectural support for run-time, always-on detection of
2129	  various classes of memory error to aid with software debugging
2130	  to eliminate vulnerabilities arising from memory-unsafe
2131	  languages.
2132
2133	  This option enables the support for the Memory Tagging
2134	  Extension at EL0 (i.e. for userspace).
2135
2136	  Selecting this option allows the feature to be detected at
2137	  runtime. Any secondary CPU not implementing this feature will
2138	  not be allowed a late bring-up.
2139
2140	  Userspace binaries that want to use this feature must
2141	  explicitly opt in. The mechanism for the userspace is
2142	  described in:
2143
2144	  Documentation/arch/arm64/memory-tagging-extension.rst.
2145
2146endmenu # "ARMv8.5 architectural features"
2147
2148menu "ARMv8.7 architectural features"
2149
2150config ARM64_EPAN
2151	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2152	default y
2153	depends on ARM64_PAN
2154	help
2155	  Enhanced Privileged Access Never (EPAN) allows Privileged
2156	  Access Never to be used with Execute-only mappings.
2157
2158	  The feature is detected at runtime, and will remain disabled
2159	  if the cpu does not implement the feature.
2160endmenu # "ARMv8.7 architectural features"
2161
2162menu "ARMv8.9 architectural features"
2163
2164config ARM64_POE
2165	prompt "Permission Overlay Extension"
2166	def_bool y
2167	select ARCH_USES_HIGH_VMA_FLAGS
2168	select ARCH_HAS_PKEYS
2169	help
2170	  The Permission Overlay Extension is used to implement Memory
2171	  Protection Keys. Memory Protection Keys provides a mechanism for
2172	  enforcing page-based protections, but without requiring modification
2173	  of the page tables when an application changes protection domains.
2174
2175	  For details, see Documentation/core-api/protection-keys.rst
2176
2177	  If unsure, say y.
2178
2179config ARCH_PKEY_BITS
2180	int
2181	default 3
2182
2183endmenu # "ARMv8.9 architectural features"
2184
2185config ARM64_SVE
2186	bool "ARM Scalable Vector Extension support"
2187	default y
2188	help
2189	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2190	  execution state which complements and extends the SIMD functionality
2191	  of the base architecture to support much larger vectors and to enable
2192	  additional vectorisation opportunities.
2193
2194	  To enable use of this extension on CPUs that implement it, say Y.
2195
2196	  On CPUs that support the SVE2 extensions, this option will enable
2197	  those too.
2198
2199	  Note that for architectural reasons, firmware _must_ implement SVE
2200	  support when running on SVE capable hardware.  The required support
2201	  is present in:
2202
2203	    * version 1.5 and later of the ARM Trusted Firmware
2204	    * the AArch64 boot wrapper since commit 5e1261e08abf
2205	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2206
2207	  For other firmware implementations, consult the firmware documentation
2208	  or vendor.
2209
2210	  If you need the kernel to boot on SVE-capable hardware with broken
2211	  firmware, you may need to say N here until you get your firmware
2212	  fixed.  Otherwise, you may experience firmware panics or lockups when
2213	  booting the kernel.  If unsure and you are not observing these
2214	  symptoms, you should assume that it is safe to say Y.
2215
2216config ARM64_SME
2217	bool "ARM Scalable Matrix Extension support"
2218	default y
2219	depends on ARM64_SVE
2220	depends on BROKEN
2221	help
2222	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2223	  execution state which utilises a substantial subset of the SVE
2224	  instruction set, together with the addition of new architectural
2225	  register state capable of holding two dimensional matrix tiles to
2226	  enable various matrix operations.
2227
2228config ARM64_PSEUDO_NMI
2229	bool "Support for NMI-like interrupts"
2230	select ARM_GIC_V3
2231	help
2232	  Adds support for mimicking Non-Maskable Interrupts through the use of
2233	  GIC interrupt priority. This support requires version 3 or later of
2234	  ARM GIC.
2235
2236	  This high priority configuration for interrupts needs to be
2237	  explicitly enabled by setting the kernel parameter
2238	  "irqchip.gicv3_pseudo_nmi" to 1.
2239
2240	  If unsure, say N
2241
2242if ARM64_PSEUDO_NMI
2243config ARM64_DEBUG_PRIORITY_MASKING
2244	bool "Debug interrupt priority masking"
2245	help
2246	  This adds runtime checks to functions enabling/disabling
2247	  interrupts when using priority masking. The additional checks verify
2248	  the validity of ICC_PMR_EL1 when calling concerned functions.
2249
2250	  If unsure, say N
2251endif # ARM64_PSEUDO_NMI
2252
2253config RELOCATABLE
2254	bool "Build a relocatable kernel image" if EXPERT
2255	select ARCH_HAS_RELR
2256	default y
2257	help
2258	  This builds the kernel as a Position Independent Executable (PIE),
2259	  which retains all relocation metadata required to relocate the
2260	  kernel binary at runtime to a different virtual address than the
2261	  address it was linked at.
2262	  Since AArch64 uses the RELA relocation format, this requires a
2263	  relocation pass at runtime even if the kernel is loaded at the
2264	  same address it was linked at.
2265
2266config RANDOMIZE_BASE
2267	bool "Randomize the address of the kernel image"
2268	select RELOCATABLE
2269	help
2270	  Randomizes the virtual address at which the kernel image is
2271	  loaded, as a security feature that deters exploit attempts
2272	  relying on knowledge of the location of kernel internals.
2273
2274	  It is the bootloader's job to provide entropy, by passing a
2275	  random u64 value in /chosen/kaslr-seed at kernel entry.
2276
2277	  When booting via the UEFI stub, it will invoke the firmware's
2278	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2279	  to the kernel proper. In addition, it will randomise the physical
2280	  location of the kernel Image as well.
2281
2282	  If unsure, say N.
2283
2284config RANDOMIZE_MODULE_REGION_FULL
2285	bool "Randomize the module region over a 2 GB range"
2286	depends on RANDOMIZE_BASE
2287	default y
2288	help
2289	  Randomizes the location of the module region inside a 2 GB window
2290	  covering the core kernel. This way, it is less likely for modules
2291	  to leak information about the location of core kernel data structures
2292	  but it does imply that function calls between modules and the core
2293	  kernel will need to be resolved via veneers in the module PLT.
2294
2295	  When this option is not set, the module region will be randomized over
2296	  a limited range that contains the [_stext, _etext] interval of the
2297	  core kernel, so branch relocations are almost always in range unless
2298	  the region is exhausted. In this particular case of region
2299	  exhaustion, modules might be able to fall back to a larger 2GB area.
2300
2301config CC_HAVE_STACKPROTECTOR_SYSREG
2302	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2303
2304config STACKPROTECTOR_PER_TASK
2305	def_bool y
2306	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2307
2308config UNWIND_PATCH_PAC_INTO_SCS
2309	bool "Enable shadow call stack dynamically using code patching"
2310	# needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated
2311	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2312	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2313	depends on SHADOW_CALL_STACK
2314	select UNWIND_TABLES
2315	select DYNAMIC_SCS
2316
2317config ARM64_CONTPTE
2318	bool "Contiguous PTE mappings for user memory" if EXPERT
2319	depends on TRANSPARENT_HUGEPAGE
2320	default y
2321	help
2322	  When enabled, user mappings are configured using the PTE contiguous
2323	  bit, for any mappings that meet the size and alignment requirements.
2324	  This reduces TLB pressure and improves performance.
2325
2326endmenu # "Kernel Features"
2327
2328menu "Boot options"
2329
2330config ARM64_ACPI_PARKING_PROTOCOL
2331	bool "Enable support for the ARM64 ACPI parking protocol"
2332	depends on ACPI
2333	help
2334	  Enable support for the ARM64 ACPI parking protocol. If disabled
2335	  the kernel will not allow booting through the ARM64 ACPI parking
2336	  protocol even if the corresponding data is present in the ACPI
2337	  MADT table.
2338
2339config CMDLINE
2340	string "Default kernel command string"
2341	default ""
2342	help
2343	  Provide a set of default command-line options at build time by
2344	  entering them here. As a minimum, you should specify the the
2345	  root device (e.g. root=/dev/nfs).
2346
2347choice
2348	prompt "Kernel command line type"
2349	depends on CMDLINE != ""
2350	default CMDLINE_FROM_BOOTLOADER
2351	help
2352	  Choose how the kernel will handle the provided default kernel
2353	  command line string.
2354
2355config CMDLINE_FROM_BOOTLOADER
2356	bool "Use bootloader kernel arguments if available"
2357	help
2358	  Uses the command-line options passed by the boot loader. If
2359	  the boot loader doesn't provide any, the default kernel command
2360	  string provided in CMDLINE will be used.
2361
2362config CMDLINE_FORCE
2363	bool "Always use the default kernel command string"
2364	help
2365	  Always use the default kernel command string, even if the boot
2366	  loader passes other arguments to the kernel.
2367	  This is useful if you cannot or don't want to change the
2368	  command-line options your boot loader passes to the kernel.
2369
2370endchoice
2371
2372config EFI_STUB
2373	bool
2374
2375config EFI
2376	bool "UEFI runtime support"
2377	depends on OF && !CPU_BIG_ENDIAN
2378	depends on KERNEL_MODE_NEON
2379	select ARCH_SUPPORTS_ACPI
2380	select LIBFDT
2381	select UCS2_STRING
2382	select EFI_PARAMS_FROM_FDT
2383	select EFI_RUNTIME_WRAPPERS
2384	select EFI_STUB
2385	select EFI_GENERIC_STUB
2386	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2387	default y
2388	help
2389	  This option provides support for runtime services provided
2390	  by UEFI firmware (such as non-volatile variables, realtime
2391	  clock, and platform reset). A UEFI stub is also provided to
2392	  allow the kernel to be booted as an EFI application. This
2393	  is only useful on systems that have UEFI firmware.
2394
2395config COMPRESSED_INSTALL
2396	bool "Install compressed image by default"
2397	help
2398	  This makes the regular "make install" install the compressed
2399	  image we built, not the legacy uncompressed one.
2400
2401	  You can check that a compressed image works for you by doing
2402	  "make zinstall" first, and verifying that everything is fine
2403	  in your environment before making "make install" do this for
2404	  you.
2405
2406config DMI
2407	bool "Enable support for SMBIOS (DMI) tables"
2408	depends on EFI
2409	default y
2410	help
2411	  This enables SMBIOS/DMI feature for systems.
2412
2413	  This option is only useful on systems that have UEFI firmware.
2414	  However, even with this option, the resultant kernel should
2415	  continue to boot on existing non-UEFI platforms.
2416
2417endmenu # "Boot options"
2418
2419menu "Power management options"
2420
2421source "kernel/power/Kconfig"
2422
2423config ARCH_HIBERNATION_POSSIBLE
2424	def_bool y
2425	depends on CPU_PM
2426
2427config ARCH_HIBERNATION_HEADER
2428	def_bool y
2429	depends on HIBERNATION
2430
2431config ARCH_SUSPEND_POSSIBLE
2432	def_bool y
2433
2434endmenu # "Power management options"
2435
2436menu "CPU Power Management"
2437
2438source "drivers/cpuidle/Kconfig"
2439
2440source "drivers/cpufreq/Kconfig"
2441
2442endmenu # "CPU Power Management"
2443
2444source "drivers/acpi/Kconfig"
2445
2446source "arch/arm64/kvm/Kconfig"
2447
2448