xref: /openbmc/linux/arch/arm64/Kconfig (revision 22aaaa7a)
1# SPDX-License-Identifier: GPL-2.0-only
2config ARM64
3	def_bool y
4	select ACPI_APMT if ACPI
5	select ACPI_CCA_REQUIRED if ACPI
6	select ACPI_GENERIC_GSI if ACPI
7	select ACPI_GTDT if ACPI
8	select ACPI_IORT if ACPI
9	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
10	select ACPI_MCFG if (ACPI && PCI)
11	select ACPI_SPCR_TABLE if ACPI
12	select ACPI_PPTT if ACPI
13	select ARCH_HAS_DEBUG_WX
14	select ARCH_BINFMT_ELF_EXTRA_PHDRS
15	select ARCH_BINFMT_ELF_STATE
16	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
17	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
18	select ARCH_ENABLE_MEMORY_HOTPLUG
19	select ARCH_ENABLE_MEMORY_HOTREMOVE
20	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
21	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
22	select ARCH_HAS_CACHE_LINE_SIZE
23	select ARCH_HAS_CURRENT_STACK_POINTER
24	select ARCH_HAS_DEBUG_VIRTUAL
25	select ARCH_HAS_DEBUG_VM_PGTABLE
26	select ARCH_HAS_DMA_PREP_COHERENT
27	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
28	select ARCH_HAS_FAST_MULTIPLIER
29	select ARCH_HAS_FORTIFY_SOURCE
30	select ARCH_HAS_GCOV_PROFILE_ALL
31	select ARCH_HAS_GIGANTIC_PAGE
32	select ARCH_HAS_KCOV
33	select ARCH_HAS_KEEPINITRD
34	select ARCH_HAS_MEMBARRIER_SYNC_CORE
35	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
36	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
37	select ARCH_HAS_PTE_DEVMAP
38	select ARCH_HAS_PTE_SPECIAL
39	select ARCH_HAS_SETUP_DMA_OPS
40	select ARCH_HAS_SET_DIRECT_MAP
41	select ARCH_HAS_SET_MEMORY
42	select ARCH_STACKWALK
43	select ARCH_HAS_STRICT_KERNEL_RWX
44	select ARCH_HAS_STRICT_MODULE_RWX
45	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
46	select ARCH_HAS_SYNC_DMA_FOR_CPU
47	select ARCH_HAS_SYSCALL_WRAPPER
48	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
49	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
50	select ARCH_HAS_ZONE_DMA_SET if EXPERT
51	select ARCH_HAVE_ELF_PROT
52	select ARCH_HAVE_NMI_SAFE_CMPXCHG
53	select ARCH_HAVE_TRACE_MMIO_ACCESS
54	select ARCH_INLINE_READ_LOCK if !PREEMPTION
55	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
56	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
57	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
58	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
59	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
60	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
61	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
62	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
63	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
64	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
65	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
66	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
67	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
68	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
69	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
70	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
71	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
72	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
73	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
74	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
75	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
76	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
77	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
78	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
79	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
80	select ARCH_KEEP_MEMBLOCK
81	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
82	select ARCH_USE_CMPXCHG_LOCKREF
83	select ARCH_USE_GNU_PROPERTY
84	select ARCH_USE_MEMTEST
85	select ARCH_USE_QUEUED_RWLOCKS
86	select ARCH_USE_QUEUED_SPINLOCKS
87	select ARCH_USE_SYM_ANNOTATIONS
88	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
89	select ARCH_SUPPORTS_HUGETLBFS
90	select ARCH_SUPPORTS_MEMORY_FAILURE
91	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
92	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
93	select ARCH_SUPPORTS_LTO_CLANG_THIN
94	select ARCH_SUPPORTS_CFI_CLANG
95	select ARCH_SUPPORTS_ATOMIC_RMW
96	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
97	select ARCH_SUPPORTS_NUMA_BALANCING
98	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
99	select ARCH_SUPPORTS_PER_VMA_LOCK
100	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
101	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
102	select ARCH_WANT_DEFAULT_BPF_JIT
103	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
104	select ARCH_WANT_FRAME_POINTERS
105	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
106	select ARCH_WANT_LD_ORPHAN_WARN
107	select ARCH_WANTS_NO_INSTR
108	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
109	select ARCH_HAS_UBSAN_SANITIZE_ALL
110	select ARM_AMBA
111	select ARM_ARCH_TIMER
112	select ARM_GIC
113	select AUDIT_ARCH_COMPAT_GENERIC
114	select ARM_GIC_V2M if PCI
115	select ARM_GIC_V3
116	select ARM_GIC_V3_ITS if PCI
117	select ARM_PSCI_FW
118	select BUILDTIME_TABLE_SORT
119	select CLONE_BACKWARDS
120	select COMMON_CLK
121	select CPU_PM if (SUSPEND || CPU_IDLE)
122	select CRC32
123	select DCACHE_WORD_ACCESS
124	select DYNAMIC_FTRACE if FUNCTION_TRACER
125	select DMA_BOUNCE_UNALIGNED_KMALLOC
126	select DMA_DIRECT_REMAP
127	select EDAC_SUPPORT
128	select FRAME_POINTER
129	select FUNCTION_ALIGNMENT_4B
130	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
131	select GENERIC_ALLOCATOR
132	select GENERIC_ARCH_TOPOLOGY
133	select GENERIC_CLOCKEVENTS_BROADCAST
134	select GENERIC_CPU_AUTOPROBE
135	select GENERIC_CPU_VULNERABILITIES
136	select GENERIC_EARLY_IOREMAP
137	select GENERIC_IDLE_POLL_SETUP
138	select GENERIC_IOREMAP
139	select GENERIC_IRQ_IPI
140	select GENERIC_IRQ_PROBE
141	select GENERIC_IRQ_SHOW
142	select GENERIC_IRQ_SHOW_LEVEL
143	select GENERIC_LIB_DEVMEM_IS_ALLOWED
144	select GENERIC_PCI_IOMAP
145	select GENERIC_PTDUMP
146	select GENERIC_SCHED_CLOCK
147	select GENERIC_SMP_IDLE_THREAD
148	select GENERIC_TIME_VSYSCALL
149	select GENERIC_GETTIMEOFDAY
150	select GENERIC_VDSO_TIME_NS
151	select HARDIRQS_SW_RESEND
152	select HAS_IOPORT
153	select HAVE_MOVE_PMD
154	select HAVE_MOVE_PUD
155	select HAVE_PCI
156	select HAVE_ACPI_APEI if (ACPI && EFI)
157	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
158	select HAVE_ARCH_AUDITSYSCALL
159	select HAVE_ARCH_BITREVERSE
160	select HAVE_ARCH_COMPILER_H
161	select HAVE_ARCH_HUGE_VMALLOC
162	select HAVE_ARCH_HUGE_VMAP
163	select HAVE_ARCH_JUMP_LABEL
164	select HAVE_ARCH_JUMP_LABEL_RELATIVE
165	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
166	select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
167	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
168	select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
169	# Some instrumentation may be unsound, hence EXPERT
170	select HAVE_ARCH_KCSAN if EXPERT
171	select HAVE_ARCH_KFENCE
172	select HAVE_ARCH_KGDB
173	select HAVE_ARCH_MMAP_RND_BITS
174	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
175	select HAVE_ARCH_PREL32_RELOCATIONS
176	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
177	select HAVE_ARCH_SECCOMP_FILTER
178	select HAVE_ARCH_STACKLEAK
179	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
180	select HAVE_ARCH_TRACEHOOK
181	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
182	select HAVE_ARCH_VMAP_STACK
183	select HAVE_ARM_SMCCC
184	select HAVE_ASM_MODVERSIONS
185	select HAVE_EBPF_JIT
186	select HAVE_C_RECORDMCOUNT
187	select HAVE_CMPXCHG_DOUBLE
188	select HAVE_CMPXCHG_LOCAL
189	select HAVE_CONTEXT_TRACKING_USER
190	select HAVE_DEBUG_KMEMLEAK
191	select HAVE_DMA_CONTIGUOUS
192	select HAVE_DYNAMIC_FTRACE
193	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
194		if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
195		    CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
196	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
197		if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
198	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
199		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
200		    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
201	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
202		if DYNAMIC_FTRACE_WITH_ARGS
203	select HAVE_SAMPLE_FTRACE_DIRECT
204	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
205	select HAVE_EFFICIENT_UNALIGNED_ACCESS
206	select HAVE_FAST_GUP
207	select HAVE_FTRACE_MCOUNT_RECORD
208	select HAVE_FUNCTION_TRACER
209	select HAVE_FUNCTION_ERROR_INJECTION
210	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
211	select HAVE_FUNCTION_GRAPH_TRACER
212	select HAVE_GCC_PLUGINS
213	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
214		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
215	select HAVE_HW_BREAKPOINT if PERF_EVENTS
216	select HAVE_IOREMAP_PROT
217	select HAVE_IRQ_TIME_ACCOUNTING
218	select HAVE_KVM
219	select HAVE_MOD_ARCH_SPECIFIC
220	select HAVE_NMI
221	select HAVE_PERF_EVENTS
222	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
223	select HAVE_PERF_REGS
224	select HAVE_PERF_USER_STACK_DUMP
225	select HAVE_PREEMPT_DYNAMIC_KEY
226	select HAVE_REGS_AND_STACK_ACCESS_API
227	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
228	select HAVE_FUNCTION_ARG_ACCESS_API
229	select MMU_GATHER_RCU_TABLE_FREE
230	select HAVE_RSEQ
231	select HAVE_STACKPROTECTOR
232	select HAVE_SYSCALL_TRACEPOINTS
233	select HAVE_KPROBES
234	select HAVE_KRETPROBES
235	select HAVE_GENERIC_VDSO
236	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
237	select IRQ_DOMAIN
238	select IRQ_FORCED_THREADING
239	select KASAN_VMALLOC if KASAN
240	select LOCK_MM_AND_FIND_VMA
241	select MODULES_USE_ELF_RELA
242	select NEED_DMA_MAP_STATE
243	select NEED_SG_DMA_LENGTH
244	select OF
245	select OF_EARLY_FLATTREE
246	select PCI_DOMAINS_GENERIC if PCI
247	select PCI_ECAM if (ACPI && PCI)
248	select PCI_SYSCALL if PCI
249	select POWER_RESET
250	select POWER_SUPPLY
251	select SPARSE_IRQ
252	select SWIOTLB
253	select SYSCTL_EXCEPTION_TRACE
254	select THREAD_INFO_IN_TASK
255	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
256	select TRACE_IRQFLAGS_SUPPORT
257	select TRACE_IRQFLAGS_NMI_SUPPORT
258	select HAVE_SOFTIRQ_ON_OWN_STACK
259	help
260	  ARM 64-bit (AArch64) Linux support.
261
262config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
263	def_bool CC_IS_CLANG
264	# https://github.com/ClangBuiltLinux/linux/issues/1507
265	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
266
267config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
268	def_bool CC_IS_GCC
269	depends on $(cc-option,-fpatchable-function-entry=2)
270
271config 64BIT
272	def_bool y
273
274config MMU
275	def_bool y
276
277config ARM64_PAGE_SHIFT
278	int
279	default 16 if ARM64_64K_PAGES
280	default 14 if ARM64_16K_PAGES
281	default 12
282
283config ARM64_CONT_PTE_SHIFT
284	int
285	default 5 if ARM64_64K_PAGES
286	default 7 if ARM64_16K_PAGES
287	default 4
288
289config ARM64_CONT_PMD_SHIFT
290	int
291	default 5 if ARM64_64K_PAGES
292	default 5 if ARM64_16K_PAGES
293	default 4
294
295config ARCH_MMAP_RND_BITS_MIN
296	default 14 if ARM64_64K_PAGES
297	default 16 if ARM64_16K_PAGES
298	default 18
299
300# max bits determined by the following formula:
301#  VA_BITS - PAGE_SHIFT - 3
302config ARCH_MMAP_RND_BITS_MAX
303	default 19 if ARM64_VA_BITS=36
304	default 24 if ARM64_VA_BITS=39
305	default 27 if ARM64_VA_BITS=42
306	default 30 if ARM64_VA_BITS=47
307	default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
308	default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
309	default 33 if ARM64_VA_BITS=48
310	default 14 if ARM64_64K_PAGES
311	default 16 if ARM64_16K_PAGES
312	default 18
313
314config ARCH_MMAP_RND_COMPAT_BITS_MIN
315	default 7 if ARM64_64K_PAGES
316	default 9 if ARM64_16K_PAGES
317	default 11
318
319config ARCH_MMAP_RND_COMPAT_BITS_MAX
320	default 16
321
322config NO_IOPORT_MAP
323	def_bool y if !PCI
324
325config STACKTRACE_SUPPORT
326	def_bool y
327
328config ILLEGAL_POINTER_VALUE
329	hex
330	default 0xdead000000000000
331
332config LOCKDEP_SUPPORT
333	def_bool y
334
335config GENERIC_BUG
336	def_bool y
337	depends on BUG
338
339config GENERIC_BUG_RELATIVE_POINTERS
340	def_bool y
341	depends on GENERIC_BUG
342
343config GENERIC_HWEIGHT
344	def_bool y
345
346config GENERIC_CSUM
347	def_bool y
348
349config GENERIC_CALIBRATE_DELAY
350	def_bool y
351
352config SMP
353	def_bool y
354
355config KERNEL_MODE_NEON
356	def_bool y
357
358config FIX_EARLYCON_MEM
359	def_bool y
360
361config PGTABLE_LEVELS
362	int
363	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
364	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
365	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
366	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
367	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
368	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
369
370config ARCH_SUPPORTS_UPROBES
371	def_bool y
372
373config ARCH_PROC_KCORE_TEXT
374	def_bool y
375
376config BROKEN_GAS_INST
377	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
378
379config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
380	bool
381	# Clang's __builtin_return_adddress() strips the PAC since 12.0.0
382	# https://reviews.llvm.org/D75044
383	default y if CC_IS_CLANG && (CLANG_VERSION >= 120000)
384	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
385	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
386	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
387	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
388	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
389	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
390	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
391	default n
392
393config KASAN_SHADOW_OFFSET
394	hex
395	depends on KASAN_GENERIC || KASAN_SW_TAGS
396	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
397	default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
398	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
399	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
400	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
401	default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
402	default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
403	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
404	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
405	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
406	default 0xffffffffffffffff
407
408config UNWIND_TABLES
409	bool
410
411source "arch/arm64/Kconfig.platforms"
412
413menu "Kernel Features"
414
415menu "ARM errata workarounds via the alternatives framework"
416
417config AMPERE_ERRATUM_AC03_CPU_38
418        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
419	default y
420	help
421	  This option adds an alternative code sequence to work around Ampere
422	  errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
423
424	  The affected design reports FEAT_HAFDBS as not implemented in
425	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
426	  as required by the architecture. The unadvertised HAFDBS
427	  implementation suffers from an additional erratum where hardware
428	  A/D updates can occur after a PTE has been marked invalid.
429
430	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
431	  which avoids enabling unadvertised hardware Access Flag management
432	  at stage-2.
433
434	  If unsure, say Y.
435
436config ARM64_WORKAROUND_CLEAN_CACHE
437	bool
438
439config ARM64_ERRATUM_826319
440	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
441	default y
442	select ARM64_WORKAROUND_CLEAN_CACHE
443	help
444	  This option adds an alternative code sequence to work around ARM
445	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
446	  AXI master interface and an L2 cache.
447
448	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
449	  and is unable to accept a certain write via this interface, it will
450	  not progress on read data presented on the read data channel and the
451	  system can deadlock.
452
453	  The workaround promotes data cache clean instructions to
454	  data cache clean-and-invalidate.
455	  Please note that this does not necessarily enable the workaround,
456	  as it depends on the alternative framework, which will only patch
457	  the kernel if an affected CPU is detected.
458
459	  If unsure, say Y.
460
461config ARM64_ERRATUM_827319
462	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
463	default y
464	select ARM64_WORKAROUND_CLEAN_CACHE
465	help
466	  This option adds an alternative code sequence to work around ARM
467	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
468	  master interface and an L2 cache.
469
470	  Under certain conditions this erratum can cause a clean line eviction
471	  to occur at the same time as another transaction to the same address
472	  on the AMBA 5 CHI interface, which can cause data corruption if the
473	  interconnect reorders the two transactions.
474
475	  The workaround promotes data cache clean instructions to
476	  data cache clean-and-invalidate.
477	  Please note that this does not necessarily enable the workaround,
478	  as it depends on the alternative framework, which will only patch
479	  the kernel if an affected CPU is detected.
480
481	  If unsure, say Y.
482
483config ARM64_ERRATUM_824069
484	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
485	default y
486	select ARM64_WORKAROUND_CLEAN_CACHE
487	help
488	  This option adds an alternative code sequence to work around ARM
489	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
490	  to a coherent interconnect.
491
492	  If a Cortex-A53 processor is executing a store or prefetch for
493	  write instruction at the same time as a processor in another
494	  cluster is executing a cache maintenance operation to the same
495	  address, then this erratum might cause a clean cache line to be
496	  incorrectly marked as dirty.
497
498	  The workaround promotes data cache clean instructions to
499	  data cache clean-and-invalidate.
500	  Please note that this option does not necessarily enable the
501	  workaround, as it depends on the alternative framework, which will
502	  only patch the kernel if an affected CPU is detected.
503
504	  If unsure, say Y.
505
506config ARM64_ERRATUM_819472
507	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
508	default y
509	select ARM64_WORKAROUND_CLEAN_CACHE
510	help
511	  This option adds an alternative code sequence to work around ARM
512	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
513	  present when it is connected to a coherent interconnect.
514
515	  If the processor is executing a load and store exclusive sequence at
516	  the same time as a processor in another cluster is executing a cache
517	  maintenance operation to the same address, then this erratum might
518	  cause data corruption.
519
520	  The workaround promotes data cache clean instructions to
521	  data cache clean-and-invalidate.
522	  Please note that this does not necessarily enable the workaround,
523	  as it depends on the alternative framework, which will only patch
524	  the kernel if an affected CPU is detected.
525
526	  If unsure, say Y.
527
528config ARM64_ERRATUM_832075
529	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
530	default y
531	help
532	  This option adds an alternative code sequence to work around ARM
533	  erratum 832075 on Cortex-A57 parts up to r1p2.
534
535	  Affected Cortex-A57 parts might deadlock when exclusive load/store
536	  instructions to Write-Back memory are mixed with Device loads.
537
538	  The workaround is to promote device loads to use Load-Acquire
539	  semantics.
540	  Please note that this does not necessarily enable the workaround,
541	  as it depends on the alternative framework, which will only patch
542	  the kernel if an affected CPU is detected.
543
544	  If unsure, say Y.
545
546config ARM64_ERRATUM_834220
547	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
548	depends on KVM
549	default y
550	help
551	  This option adds an alternative code sequence to work around ARM
552	  erratum 834220 on Cortex-A57 parts up to r1p2.
553
554	  Affected Cortex-A57 parts might report a Stage 2 translation
555	  fault as the result of a Stage 1 fault for load crossing a
556	  page boundary when there is a permission or device memory
557	  alignment fault at Stage 1 and a translation fault at Stage 2.
558
559	  The workaround is to verify that the Stage 1 translation
560	  doesn't generate a fault before handling the Stage 2 fault.
561	  Please note that this does not necessarily enable the workaround,
562	  as it depends on the alternative framework, which will only patch
563	  the kernel if an affected CPU is detected.
564
565	  If unsure, say Y.
566
567config ARM64_ERRATUM_1742098
568	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
569	depends on COMPAT
570	default y
571	help
572	  This option removes the AES hwcap for aarch32 user-space to
573	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
574
575	  Affected parts may corrupt the AES state if an interrupt is
576	  taken between a pair of AES instructions. These instructions
577	  are only present if the cryptography extensions are present.
578	  All software should have a fallback implementation for CPUs
579	  that don't implement the cryptography extensions.
580
581	  If unsure, say Y.
582
583config ARM64_ERRATUM_845719
584	bool "Cortex-A53: 845719: a load might read incorrect data"
585	depends on COMPAT
586	default y
587	help
588	  This option adds an alternative code sequence to work around ARM
589	  erratum 845719 on Cortex-A53 parts up to r0p4.
590
591	  When running a compat (AArch32) userspace on an affected Cortex-A53
592	  part, a load at EL0 from a virtual address that matches the bottom 32
593	  bits of the virtual address used by a recent load at (AArch64) EL1
594	  might return incorrect data.
595
596	  The workaround is to write the contextidr_el1 register on exception
597	  return to a 32-bit task.
598	  Please note that this does not necessarily enable the workaround,
599	  as it depends on the alternative framework, which will only patch
600	  the kernel if an affected CPU is detected.
601
602	  If unsure, say Y.
603
604config ARM64_ERRATUM_843419
605	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
606	default y
607	help
608	  This option links the kernel with '--fix-cortex-a53-843419' and
609	  enables PLT support to replace certain ADRP instructions, which can
610	  cause subsequent memory accesses to use an incorrect address on
611	  Cortex-A53 parts up to r0p4.
612
613	  If unsure, say Y.
614
615config ARM64_LD_HAS_FIX_ERRATUM_843419
616	def_bool $(ld-option,--fix-cortex-a53-843419)
617
618config ARM64_ERRATUM_1024718
619	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
620	default y
621	help
622	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
623
624	  Affected Cortex-A55 cores (all revisions) could cause incorrect
625	  update of the hardware dirty bit when the DBM/AP bits are updated
626	  without a break-before-make. The workaround is to disable the usage
627	  of hardware DBM locally on the affected cores. CPUs not affected by
628	  this erratum will continue to use the feature.
629
630	  If unsure, say Y.
631
632config ARM64_ERRATUM_1418040
633	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
634	default y
635	depends on COMPAT
636	help
637	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
638	  errata 1188873 and 1418040.
639
640	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
641	  cause register corruption when accessing the timer registers
642	  from AArch32 userspace.
643
644	  If unsure, say Y.
645
646config ARM64_WORKAROUND_SPECULATIVE_AT
647	bool
648
649config ARM64_ERRATUM_1165522
650	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
651	default y
652	select ARM64_WORKAROUND_SPECULATIVE_AT
653	help
654	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
655
656	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
657	  corrupted TLBs by speculating an AT instruction during a guest
658	  context switch.
659
660	  If unsure, say Y.
661
662config ARM64_ERRATUM_1319367
663	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
664	default y
665	select ARM64_WORKAROUND_SPECULATIVE_AT
666	help
667	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
668	  and A72 erratum 1319367
669
670	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
671	  speculating an AT instruction during a guest context switch.
672
673	  If unsure, say Y.
674
675config ARM64_ERRATUM_1530923
676	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
677	default y
678	select ARM64_WORKAROUND_SPECULATIVE_AT
679	help
680	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
681
682	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
683	  corrupted TLBs by speculating an AT instruction during a guest
684	  context switch.
685
686	  If unsure, say Y.
687
688config ARM64_WORKAROUND_REPEAT_TLBI
689	bool
690
691config ARM64_ERRATUM_2441007
692	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
693	default y
694	select ARM64_WORKAROUND_REPEAT_TLBI
695	help
696	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
697
698	  Under very rare circumstances, affected Cortex-A55 CPUs
699	  may not handle a race between a break-before-make sequence on one
700	  CPU, and another CPU accessing the same page. This could allow a
701	  store to a page that has been unmapped.
702
703	  Work around this by adding the affected CPUs to the list that needs
704	  TLB sequences to be done twice.
705
706	  If unsure, say Y.
707
708config ARM64_ERRATUM_1286807
709	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
710	default y
711	select ARM64_WORKAROUND_REPEAT_TLBI
712	help
713	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
714
715	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
716	  address for a cacheable mapping of a location is being
717	  accessed by a core while another core is remapping the virtual
718	  address to a new physical page using the recommended
719	  break-before-make sequence, then under very rare circumstances
720	  TLBI+DSB completes before a read using the translation being
721	  invalidated has been observed by other observers. The
722	  workaround repeats the TLBI+DSB operation.
723
724config ARM64_ERRATUM_1463225
725	bool "Cortex-A76: Software Step might prevent interrupt recognition"
726	default y
727	help
728	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
729
730	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
731	  of a system call instruction (SVC) can prevent recognition of
732	  subsequent interrupts when software stepping is disabled in the
733	  exception handler of the system call and either kernel debugging
734	  is enabled or VHE is in use.
735
736	  Work around the erratum by triggering a dummy step exception
737	  when handling a system call from a task that is being stepped
738	  in a VHE configuration of the kernel.
739
740	  If unsure, say Y.
741
742config ARM64_ERRATUM_1542419
743	bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
744	default y
745	help
746	  This option adds a workaround for ARM Neoverse-N1 erratum
747	  1542419.
748
749	  Affected Neoverse-N1 cores could execute a stale instruction when
750	  modified by another CPU. The workaround depends on a firmware
751	  counterpart.
752
753	  Workaround the issue by hiding the DIC feature from EL0. This
754	  forces user-space to perform cache maintenance.
755
756	  If unsure, say Y.
757
758config ARM64_ERRATUM_1508412
759	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
760	default y
761	help
762	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
763
764	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
765	  of a store-exclusive or read of PAR_EL1 and a load with device or
766	  non-cacheable memory attributes. The workaround depends on a firmware
767	  counterpart.
768
769	  KVM guests must also have the workaround implemented or they can
770	  deadlock the system.
771
772	  Work around the issue by inserting DMB SY barriers around PAR_EL1
773	  register reads and warning KVM users. The DMB barrier is sufficient
774	  to prevent a speculative PAR_EL1 read.
775
776	  If unsure, say Y.
777
778config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
779	bool
780
781config ARM64_ERRATUM_2051678
782	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
783	default y
784	help
785	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
786	  Affected Cortex-A510 might not respect the ordering rules for
787	  hardware update of the page table's dirty bit. The workaround
788	  is to not enable the feature on affected CPUs.
789
790	  If unsure, say Y.
791
792config ARM64_ERRATUM_2077057
793	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
794	default y
795	help
796	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
797	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
798	  expected, but a Pointer Authentication trap is taken instead. The
799	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
800	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
801
802	  This can only happen when EL2 is stepping EL1.
803
804	  When these conditions occur, the SPSR_EL2 value is unchanged from the
805	  previous guest entry, and can be restored from the in-memory copy.
806
807	  If unsure, say Y.
808
809config ARM64_ERRATUM_2658417
810	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
811	default y
812	help
813	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
814	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
815	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
816	  A510 CPUs are using shared neon hardware. As the sharing is not
817	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
818	  user-space should not be using these instructions.
819
820	  If unsure, say Y.
821
822config ARM64_ERRATUM_2119858
823	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
824	default y
825	depends on CORESIGHT_TRBE
826	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
827	help
828	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
829
830	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
831	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
832	  the event of a WRAP event.
833
834	  Work around the issue by always making sure we move the TRBPTR_EL1 by
835	  256 bytes before enabling the buffer and filling the first 256 bytes of
836	  the buffer with ETM ignore packets upon disabling.
837
838	  If unsure, say Y.
839
840config ARM64_ERRATUM_2139208
841	bool "Neoverse-N2: 2139208: 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 Neoverse-N2 erratum 2139208.
847
848	  Affected Neoverse-N2 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_WORKAROUND_TSB_FLUSH_FAILURE
859	bool
860
861config ARM64_ERRATUM_2054223
862	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
863	default y
864	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
865	help
866	  Enable workaround for ARM Cortex-A710 erratum 2054223
867
868	  Affected cores may fail to flush the trace data on a TSB instruction, when
869	  the PE is in trace prohibited state. This will cause losing a few bytes
870	  of the trace cached.
871
872	  Workaround is to issue two TSB consecutively on affected cores.
873
874	  If unsure, say Y.
875
876config ARM64_ERRATUM_2067961
877	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
878	default y
879	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
880	help
881	  Enable workaround for ARM Neoverse-N2 erratum 2067961
882
883	  Affected cores may fail to flush the trace data on a TSB instruction, when
884	  the PE is in trace prohibited state. This will cause losing a few bytes
885	  of the trace cached.
886
887	  Workaround is to issue two TSB consecutively on affected cores.
888
889	  If unsure, say Y.
890
891config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
892	bool
893
894config ARM64_ERRATUM_2253138
895	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
896	depends on CORESIGHT_TRBE
897	default y
898	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
899	help
900	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
901
902	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
903	  for TRBE. Under some conditions, the TRBE might generate a write to the next
904	  virtually addressed page following the last page of the TRBE address space
905	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
906
907	  Work around this in the driver by always making sure that there is a
908	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
909
910	  If unsure, say Y.
911
912config ARM64_ERRATUM_2224489
913	bool "Cortex-A710/X2: 2224489: 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 Cortex-A710/X2 erratum 2224489.
919
920	  Affected Cortex-A710/X2 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_2441009
931	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
932	default y
933	select ARM64_WORKAROUND_REPEAT_TLBI
934	help
935	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
936
937	  Under very rare circumstances, affected Cortex-A510 CPUs
938	  may not handle a race between a break-before-make sequence on one
939	  CPU, and another CPU accessing the same page. This could allow a
940	  store to a page that has been unmapped.
941
942	  Work around this by adding the affected CPUs to the list that needs
943	  TLB sequences to be done twice.
944
945	  If unsure, say Y.
946
947config ARM64_ERRATUM_2064142
948	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
949	depends on CORESIGHT_TRBE
950	default y
951	help
952	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
953
954	  Affected Cortex-A510 core might fail to write into system registers after the
955	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
956	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
957	  and TRBTRG_EL1 will be ignored and will not be effected.
958
959	  Work around this in the driver by executing TSB CSYNC and DSB after collection
960	  is stopped and before performing a system register write to one of the affected
961	  registers.
962
963	  If unsure, say Y.
964
965config ARM64_ERRATUM_2038923
966	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
967	depends on CORESIGHT_TRBE
968	default y
969	help
970	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
971
972	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
973	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
974	  might be corrupted. This happens after TRBE buffer has been enabled by setting
975	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
976	  execution changes from a context, in which trace is prohibited to one where it
977	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
978	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
979	  the trace buffer state might be corrupted.
980
981	  Work around this in the driver by preventing an inconsistent view of whether the
982	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
983	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
984	  two ISB instructions if no ERET is to take place.
985
986	  If unsure, say Y.
987
988config ARM64_ERRATUM_1902691
989	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
990	depends on CORESIGHT_TRBE
991	default y
992	help
993	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
994
995	  Affected Cortex-A510 core might cause trace data corruption, when being written
996	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
997	  trace data.
998
999	  Work around this problem in the driver by just preventing TRBE initialization on
1000	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1001	  on such implementations. This will cover the kernel for any firmware that doesn't
1002	  do this already.
1003
1004	  If unsure, say Y.
1005
1006config ARM64_ERRATUM_2457168
1007	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1008	depends on ARM64_AMU_EXTN
1009	default y
1010	help
1011	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1012
1013	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1014	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1015	  incorrectly giving a significantly higher output value.
1016
1017	  Work around this problem by returning 0 when reading the affected counter in
1018	  key locations that results in disabling all users of this counter. This effect
1019	  is the same to firmware disabling affected counters.
1020
1021	  If unsure, say Y.
1022
1023config ARM64_ERRATUM_2645198
1024	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1025	default y
1026	help
1027	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1028
1029	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1030	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1031	  next instruction abort caused by permission fault.
1032
1033	  Only user-space does executable to non-executable permission transition via
1034	  mprotect() system call. Workaround the problem by doing a break-before-make
1035	  TLB invalidation, for all changes to executable user space mappings.
1036
1037	  If unsure, say Y.
1038
1039config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1040	bool
1041
1042config ARM64_ERRATUM_2966298
1043	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1044	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1045	default y
1046	help
1047	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1048
1049	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1050	  load might leak data from a privileged level via a cache side channel.
1051
1052	  Work around this problem by executing a TLBI before returning to EL0.
1053
1054	  If unsure, say Y.
1055
1056config ARM64_ERRATUM_3117295
1057	bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1058	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1059	default y
1060	help
1061	  This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1062
1063	  On an affected Cortex-A510 core, a speculatively executed unprivileged
1064	  load might leak data from a privileged level via a cache side channel.
1065
1066	  Work around this problem by executing a TLBI before returning to EL0.
1067
1068	  If unsure, say Y.
1069
1070config ARM64_ERRATUM_3194386
1071	bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1072	default y
1073	help
1074	  This option adds the workaround for the following errata:
1075
1076	  * ARM Cortex-A76 erratum 3324349
1077	  * ARM Cortex-A77 erratum 3324348
1078	  * ARM Cortex-A78 erratum 3324344
1079	  * ARM Cortex-A78C erratum 3324346
1080	  * ARM Cortex-A78C erratum 3324347
1081	  * ARM Cortex-A710 erratam 3324338
1082	  * ARM Cortex-A715 errartum 3456084
1083	  * ARM Cortex-A720 erratum 3456091
1084	  * ARM Cortex-A725 erratum 3456106
1085	  * ARM Cortex-X1 erratum 3324344
1086	  * ARM Cortex-X1C erratum 3324346
1087	  * ARM Cortex-X2 erratum 3324338
1088	  * ARM Cortex-X3 erratum 3324335
1089	  * ARM Cortex-X4 erratum 3194386
1090	  * ARM Cortex-X925 erratum 3324334
1091	  * ARM Neoverse-N1 erratum 3324349
1092	  * ARM Neoverse N2 erratum 3324339
1093	  * ARM Neoverse-N3 erratum 3456111
1094	  * ARM Neoverse-V1 erratum 3324341
1095	  * ARM Neoverse V2 erratum 3324336
1096	  * ARM Neoverse-V3 erratum 3312417
1097
1098	  On affected cores "MSR SSBS, #0" instructions may not affect
1099	  subsequent speculative instructions, which may permit unexepected
1100	  speculative store bypassing.
1101
1102	  Work around this problem by placing a Speculation Barrier (SB) or
1103	  Instruction Synchronization Barrier (ISB) after kernel changes to
1104	  SSBS. The presence of the SSBS special-purpose register is hidden
1105	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1106	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1107
1108	  If unsure, say Y.
1109
1110config CAVIUM_ERRATUM_22375
1111	bool "Cavium erratum 22375, 24313"
1112	default y
1113	help
1114	  Enable workaround for errata 22375 and 24313.
1115
1116	  This implements two gicv3-its errata workarounds for ThunderX. Both
1117	  with a small impact affecting only ITS table allocation.
1118
1119	    erratum 22375: only alloc 8MB table size
1120	    erratum 24313: ignore memory access type
1121
1122	  The fixes are in ITS initialization and basically ignore memory access
1123	  type and table size provided by the TYPER and BASER registers.
1124
1125	  If unsure, say Y.
1126
1127config CAVIUM_ERRATUM_23144
1128	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1129	depends on NUMA
1130	default y
1131	help
1132	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1133
1134	  If unsure, say Y.
1135
1136config CAVIUM_ERRATUM_23154
1137	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1138	default y
1139	help
1140	  The ThunderX GICv3 implementation requires a modified version for
1141	  reading the IAR status to ensure data synchronization
1142	  (access to icc_iar1_el1 is not sync'ed before and after).
1143
1144	  It also suffers from erratum 38545 (also present on Marvell's
1145	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1146	  spuriously presented to the CPU interface.
1147
1148	  If unsure, say Y.
1149
1150config CAVIUM_ERRATUM_27456
1151	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1152	default y
1153	help
1154	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1155	  instructions may cause the icache to become corrupted if it
1156	  contains data for a non-current ASID.  The fix is to
1157	  invalidate the icache when changing the mm context.
1158
1159	  If unsure, say Y.
1160
1161config CAVIUM_ERRATUM_30115
1162	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1163	default y
1164	help
1165	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1166	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1167	  interrupts in host. Trapping both GICv3 group-0 and group-1
1168	  accesses sidesteps the issue.
1169
1170	  If unsure, say Y.
1171
1172config CAVIUM_TX2_ERRATUM_219
1173	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1174	default y
1175	help
1176	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1177	  TTBR update and the corresponding context synchronizing operation can
1178	  cause a spurious Data Abort to be delivered to any hardware thread in
1179	  the CPU core.
1180
1181	  Work around the issue by avoiding the problematic code sequence and
1182	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1183	  trap handler performs the corresponding register access, skips the
1184	  instruction and ensures context synchronization by virtue of the
1185	  exception return.
1186
1187	  If unsure, say Y.
1188
1189config FUJITSU_ERRATUM_010001
1190	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1191	default y
1192	help
1193	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1194	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1195	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1196	  This fault occurs under a specific hardware condition when a
1197	  load/store instruction performs an address translation using:
1198	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1199	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1200	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1201	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1202
1203	  The workaround is to ensure these bits are clear in TCR_ELx.
1204	  The workaround only affects the Fujitsu-A64FX.
1205
1206	  If unsure, say Y.
1207
1208config HISILICON_ERRATUM_161600802
1209	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1210	default y
1211	help
1212	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1213	  when issued ITS commands such as VMOVP and VMAPP, and requires
1214	  a 128kB offset to be applied to the target address in this commands.
1215
1216	  If unsure, say Y.
1217
1218config QCOM_FALKOR_ERRATUM_1003
1219	bool "Falkor E1003: Incorrect translation due to ASID change"
1220	default y
1221	help
1222	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1223	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1224	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1225	  then only for entries in the walk cache, since the leaf translation
1226	  is unchanged. Work around the erratum by invalidating the walk cache
1227	  entries for the trampoline before entering the kernel proper.
1228
1229config QCOM_FALKOR_ERRATUM_1009
1230	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1231	default y
1232	select ARM64_WORKAROUND_REPEAT_TLBI
1233	help
1234	  On Falkor v1, the CPU may prematurely complete a DSB following a
1235	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1236	  one more time to fix the issue.
1237
1238	  If unsure, say Y.
1239
1240config QCOM_QDF2400_ERRATUM_0065
1241	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1242	default y
1243	help
1244	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1245	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1246	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1247
1248	  If unsure, say Y.
1249
1250config QCOM_FALKOR_ERRATUM_E1041
1251	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1252	default y
1253	help
1254	  Falkor CPU may speculatively fetch instructions from an improper
1255	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1256	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1257
1258	  If unsure, say Y.
1259
1260config NVIDIA_CARMEL_CNP_ERRATUM
1261	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1262	default y
1263	help
1264	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1265	  invalidate shared TLB entries installed by a different core, as it would
1266	  on standard ARM cores.
1267
1268	  If unsure, say Y.
1269
1270config ROCKCHIP_ERRATUM_3588001
1271	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1272	default y
1273	help
1274	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1275	  This means, that its sharability feature may not be used, even though it
1276	  is supported by the IP itself.
1277
1278	  If unsure, say Y.
1279
1280config SOCIONEXT_SYNQUACER_PREITS
1281	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1282	default y
1283	help
1284	  Socionext Synquacer SoCs implement a separate h/w block to generate
1285	  MSI doorbell writes with non-zero values for the device ID.
1286
1287	  If unsure, say Y.
1288
1289endmenu # "ARM errata workarounds via the alternatives framework"
1290
1291choice
1292	prompt "Page size"
1293	default ARM64_4K_PAGES
1294	help
1295	  Page size (translation granule) configuration.
1296
1297config ARM64_4K_PAGES
1298	bool "4KB"
1299	help
1300	  This feature enables 4KB pages support.
1301
1302config ARM64_16K_PAGES
1303	bool "16KB"
1304	help
1305	  The system will use 16KB pages support. AArch32 emulation
1306	  requires applications compiled with 16K (or a multiple of 16K)
1307	  aligned segments.
1308
1309config ARM64_64K_PAGES
1310	bool "64KB"
1311	help
1312	  This feature enables 64KB pages support (4KB by default)
1313	  allowing only two levels of page tables and faster TLB
1314	  look-up. AArch32 emulation requires applications compiled
1315	  with 64K aligned segments.
1316
1317endchoice
1318
1319choice
1320	prompt "Virtual address space size"
1321	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1322	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1323	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1324	help
1325	  Allows choosing one of multiple possible virtual address
1326	  space sizes. The level of translation table is determined by
1327	  a combination of page size and virtual address space size.
1328
1329config ARM64_VA_BITS_36
1330	bool "36-bit" if EXPERT
1331	depends on ARM64_16K_PAGES
1332
1333config ARM64_VA_BITS_39
1334	bool "39-bit"
1335	depends on ARM64_4K_PAGES
1336
1337config ARM64_VA_BITS_42
1338	bool "42-bit"
1339	depends on ARM64_64K_PAGES
1340
1341config ARM64_VA_BITS_47
1342	bool "47-bit"
1343	depends on ARM64_16K_PAGES
1344
1345config ARM64_VA_BITS_48
1346	bool "48-bit"
1347
1348config ARM64_VA_BITS_52
1349	bool "52-bit"
1350	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1351	help
1352	  Enable 52-bit virtual addressing for userspace when explicitly
1353	  requested via a hint to mmap(). The kernel will also use 52-bit
1354	  virtual addresses for its own mappings (provided HW support for
1355	  this feature is available, otherwise it reverts to 48-bit).
1356
1357	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1358	  ARMv8.3 Pointer Authentication will result in the PAC being
1359	  reduced from 7 bits to 3 bits, which may have a significant
1360	  impact on its susceptibility to brute-force attacks.
1361
1362	  If unsure, select 48-bit virtual addressing instead.
1363
1364endchoice
1365
1366config ARM64_FORCE_52BIT
1367	bool "Force 52-bit virtual addresses for userspace"
1368	depends on ARM64_VA_BITS_52 && EXPERT
1369	help
1370	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1371	  to maintain compatibility with older software by providing 48-bit VAs
1372	  unless a hint is supplied to mmap.
1373
1374	  This configuration option disables the 48-bit compatibility logic, and
1375	  forces all userspace addresses to be 52-bit on HW that supports it. One
1376	  should only enable this configuration option for stress testing userspace
1377	  memory management code. If unsure say N here.
1378
1379config ARM64_VA_BITS
1380	int
1381	default 36 if ARM64_VA_BITS_36
1382	default 39 if ARM64_VA_BITS_39
1383	default 42 if ARM64_VA_BITS_42
1384	default 47 if ARM64_VA_BITS_47
1385	default 48 if ARM64_VA_BITS_48
1386	default 52 if ARM64_VA_BITS_52
1387
1388choice
1389	prompt "Physical address space size"
1390	default ARM64_PA_BITS_48
1391	help
1392	  Choose the maximum physical address range that the kernel will
1393	  support.
1394
1395config ARM64_PA_BITS_48
1396	bool "48-bit"
1397
1398config ARM64_PA_BITS_52
1399	bool "52-bit (ARMv8.2)"
1400	depends on ARM64_64K_PAGES
1401	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1402	help
1403	  Enable support for a 52-bit physical address space, introduced as
1404	  part of the ARMv8.2-LPA extension.
1405
1406	  With this enabled, the kernel will also continue to work on CPUs that
1407	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1408	  minor performance overhead).
1409
1410endchoice
1411
1412config ARM64_PA_BITS
1413	int
1414	default 48 if ARM64_PA_BITS_48
1415	default 52 if ARM64_PA_BITS_52
1416
1417choice
1418	prompt "Endianness"
1419	default CPU_LITTLE_ENDIAN
1420	help
1421	  Select the endianness of data accesses performed by the CPU. Userspace
1422	  applications will need to be compiled and linked for the endianness
1423	  that is selected here.
1424
1425config CPU_BIG_ENDIAN
1426	bool "Build big-endian kernel"
1427	depends on !LD_IS_LLD || LLD_VERSION >= 130000
1428	# https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1429	depends on AS_IS_GNU || AS_VERSION >= 150000
1430	help
1431	  Say Y if you plan on running a kernel with a big-endian userspace.
1432
1433config CPU_LITTLE_ENDIAN
1434	bool "Build little-endian kernel"
1435	help
1436	  Say Y if you plan on running a kernel with a little-endian userspace.
1437	  This is usually the case for distributions targeting arm64.
1438
1439endchoice
1440
1441config SCHED_MC
1442	bool "Multi-core scheduler support"
1443	help
1444	  Multi-core scheduler support improves the CPU scheduler's decision
1445	  making when dealing with multi-core CPU chips at a cost of slightly
1446	  increased overhead in some places. If unsure say N here.
1447
1448config SCHED_CLUSTER
1449	bool "Cluster scheduler support"
1450	help
1451	  Cluster scheduler support improves the CPU scheduler's decision
1452	  making when dealing with machines that have clusters of CPUs.
1453	  Cluster usually means a couple of CPUs which are placed closely
1454	  by sharing mid-level caches, last-level cache tags or internal
1455	  busses.
1456
1457config SCHED_SMT
1458	bool "SMT scheduler support"
1459	help
1460	  Improves the CPU scheduler's decision making when dealing with
1461	  MultiThreading at a cost of slightly increased overhead in some
1462	  places. If unsure say N here.
1463
1464config NR_CPUS
1465	int "Maximum number of CPUs (2-4096)"
1466	range 2 4096
1467	default "256"
1468
1469config HOTPLUG_CPU
1470	bool "Support for hot-pluggable CPUs"
1471	select GENERIC_IRQ_MIGRATION
1472	help
1473	  Say Y here to experiment with turning CPUs off and on.  CPUs
1474	  can be controlled through /sys/devices/system/cpu.
1475
1476# Common NUMA Features
1477config NUMA
1478	bool "NUMA Memory Allocation and Scheduler Support"
1479	select GENERIC_ARCH_NUMA
1480	select ACPI_NUMA if ACPI
1481	select OF_NUMA
1482	select HAVE_SETUP_PER_CPU_AREA
1483	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1484	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1485	select USE_PERCPU_NUMA_NODE_ID
1486	help
1487	  Enable NUMA (Non-Uniform Memory Access) support.
1488
1489	  The kernel will try to allocate memory used by a CPU on the
1490	  local memory of the CPU and add some more
1491	  NUMA awareness to the kernel.
1492
1493config NODES_SHIFT
1494	int "Maximum NUMA Nodes (as a power of 2)"
1495	range 1 10
1496	default "4"
1497	depends on NUMA
1498	help
1499	  Specify the maximum number of NUMA Nodes available on the target
1500	  system.  Increases memory reserved to accommodate various tables.
1501
1502source "kernel/Kconfig.hz"
1503
1504config ARCH_SPARSEMEM_ENABLE
1505	def_bool y
1506	select SPARSEMEM_VMEMMAP_ENABLE
1507	select SPARSEMEM_VMEMMAP
1508
1509config HW_PERF_EVENTS
1510	def_bool y
1511	depends on ARM_PMU
1512
1513# Supported by clang >= 7.0 or GCC >= 12.0.0
1514config CC_HAVE_SHADOW_CALL_STACK
1515	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1516
1517config PARAVIRT
1518	bool "Enable paravirtualization code"
1519	help
1520	  This changes the kernel so it can modify itself when it is run
1521	  under a hypervisor, potentially improving performance significantly
1522	  over full virtualization.
1523
1524config PARAVIRT_TIME_ACCOUNTING
1525	bool "Paravirtual steal time accounting"
1526	select PARAVIRT
1527	help
1528	  Select this option to enable fine granularity task steal time
1529	  accounting. Time spent executing other tasks in parallel with
1530	  the current vCPU is discounted from the vCPU power. To account for
1531	  that, there can be a small performance impact.
1532
1533	  If in doubt, say N here.
1534
1535config ARCH_SUPPORTS_KEXEC
1536	def_bool PM_SLEEP_SMP
1537
1538config ARCH_SUPPORTS_KEXEC_FILE
1539	def_bool y
1540
1541config ARCH_SELECTS_KEXEC_FILE
1542	def_bool y
1543	depends on KEXEC_FILE
1544	select HAVE_IMA_KEXEC if IMA
1545
1546config ARCH_SUPPORTS_KEXEC_SIG
1547	def_bool y
1548
1549config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1550	def_bool y
1551
1552config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1553	def_bool y
1554
1555config ARCH_SUPPORTS_CRASH_DUMP
1556	def_bool y
1557
1558config TRANS_TABLE
1559	def_bool y
1560	depends on HIBERNATION || KEXEC_CORE
1561
1562config XEN_DOM0
1563	def_bool y
1564	depends on XEN
1565
1566config XEN
1567	bool "Xen guest support on ARM64"
1568	depends on ARM64 && OF
1569	select SWIOTLB_XEN
1570	select PARAVIRT
1571	help
1572	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1573
1574# include/linux/mmzone.h requires the following to be true:
1575#
1576#   MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1577#
1578# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1579#
1580#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_ORDER  |  default MAX_ORDER |
1581# ----+-------------------+--------------+-----------------+--------------------+
1582# 4K  |       27          |      12      |       15        |         10         |
1583# 16K |       27          |      14      |       13        |         11         |
1584# 64K |       29          |      16      |       13        |         13         |
1585config ARCH_FORCE_MAX_ORDER
1586	int
1587	default "13" if ARM64_64K_PAGES
1588	default "11" if ARM64_16K_PAGES
1589	default "10"
1590	help
1591	  The kernel page allocator limits the size of maximal physically
1592	  contiguous allocations. The limit is called MAX_ORDER and it
1593	  defines the maximal power of two of number of pages that can be
1594	  allocated as a single contiguous block. This option allows
1595	  overriding the default setting when ability to allocate very
1596	  large blocks of physically contiguous memory is required.
1597
1598	  The maximal size of allocation cannot exceed the size of the
1599	  section, so the value of MAX_ORDER should satisfy
1600
1601	    MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1602
1603	  Don't change if unsure.
1604
1605config UNMAP_KERNEL_AT_EL0
1606	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1607	default y
1608	help
1609	  Speculation attacks against some high-performance processors can
1610	  be used to bypass MMU permission checks and leak kernel data to
1611	  userspace. This can be defended against by unmapping the kernel
1612	  when running in userspace, mapping it back in on exception entry
1613	  via a trampoline page in the vector table.
1614
1615	  If unsure, say Y.
1616
1617config MITIGATE_SPECTRE_BRANCH_HISTORY
1618	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1619	default y
1620	help
1621	  Speculation attacks against some high-performance processors can
1622	  make use of branch history to influence future speculation.
1623	  When taking an exception from user-space, a sequence of branches
1624	  or a firmware call overwrites the branch history.
1625
1626config RODATA_FULL_DEFAULT_ENABLED
1627	bool "Apply r/o permissions of VM areas also to their linear aliases"
1628	default y
1629	help
1630	  Apply read-only attributes of VM areas to the linear alias of
1631	  the backing pages as well. This prevents code or read-only data
1632	  from being modified (inadvertently or intentionally) via another
1633	  mapping of the same memory page. This additional enhancement can
1634	  be turned off at runtime by passing rodata=[off|on] (and turned on
1635	  with rodata=full if this option is set to 'n')
1636
1637	  This requires the linear region to be mapped down to pages,
1638	  which may adversely affect performance in some cases.
1639
1640config ARM64_SW_TTBR0_PAN
1641	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1642	help
1643	  Enabling this option prevents the kernel from accessing
1644	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1645	  zeroed area and reserved ASID. The user access routines
1646	  restore the valid TTBR0_EL1 temporarily.
1647
1648config ARM64_TAGGED_ADDR_ABI
1649	bool "Enable the tagged user addresses syscall ABI"
1650	default y
1651	help
1652	  When this option is enabled, user applications can opt in to a
1653	  relaxed ABI via prctl() allowing tagged addresses to be passed
1654	  to system calls as pointer arguments. For details, see
1655	  Documentation/arch/arm64/tagged-address-abi.rst.
1656
1657menuconfig COMPAT
1658	bool "Kernel support for 32-bit EL0"
1659	depends on ARM64_4K_PAGES || EXPERT
1660	select HAVE_UID16
1661	select OLD_SIGSUSPEND3
1662	select COMPAT_OLD_SIGACTION
1663	help
1664	  This option enables support for a 32-bit EL0 running under a 64-bit
1665	  kernel at EL1. AArch32-specific components such as system calls,
1666	  the user helper functions, VFP support and the ptrace interface are
1667	  handled appropriately by the kernel.
1668
1669	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1670	  that you will only be able to execute AArch32 binaries that were compiled
1671	  with page size aligned segments.
1672
1673	  If you want to execute 32-bit userspace applications, say Y.
1674
1675if COMPAT
1676
1677config KUSER_HELPERS
1678	bool "Enable kuser helpers page for 32-bit applications"
1679	default y
1680	help
1681	  Warning: disabling this option may break 32-bit user programs.
1682
1683	  Provide kuser helpers to compat tasks. The kernel provides
1684	  helper code to userspace in read only form at a fixed location
1685	  to allow userspace to be independent of the CPU type fitted to
1686	  the system. This permits binaries to be run on ARMv4 through
1687	  to ARMv8 without modification.
1688
1689	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1690
1691	  However, the fixed address nature of these helpers can be used
1692	  by ROP (return orientated programming) authors when creating
1693	  exploits.
1694
1695	  If all of the binaries and libraries which run on your platform
1696	  are built specifically for your platform, and make no use of
1697	  these helpers, then you can turn this option off to hinder
1698	  such exploits. However, in that case, if a binary or library
1699	  relying on those helpers is run, it will not function correctly.
1700
1701	  Say N here only if you are absolutely certain that you do not
1702	  need these helpers; otherwise, the safe option is to say Y.
1703
1704config COMPAT_VDSO
1705	bool "Enable vDSO for 32-bit applications"
1706	depends on !CPU_BIG_ENDIAN
1707	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1708	select GENERIC_COMPAT_VDSO
1709	default y
1710	help
1711	  Place in the process address space of 32-bit applications an
1712	  ELF shared object providing fast implementations of gettimeofday
1713	  and clock_gettime.
1714
1715	  You must have a 32-bit build of glibc 2.22 or later for programs
1716	  to seamlessly take advantage of this.
1717
1718config THUMB2_COMPAT_VDSO
1719	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1720	depends on COMPAT_VDSO
1721	default y
1722	help
1723	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1724	  otherwise with '-marm'.
1725
1726config COMPAT_ALIGNMENT_FIXUPS
1727	bool "Fix up misaligned multi-word loads and stores in user space"
1728
1729menuconfig ARMV8_DEPRECATED
1730	bool "Emulate deprecated/obsolete ARMv8 instructions"
1731	depends on SYSCTL
1732	help
1733	  Legacy software support may require certain instructions
1734	  that have been deprecated or obsoleted in the architecture.
1735
1736	  Enable this config to enable selective emulation of these
1737	  features.
1738
1739	  If unsure, say Y
1740
1741if ARMV8_DEPRECATED
1742
1743config SWP_EMULATION
1744	bool "Emulate SWP/SWPB instructions"
1745	help
1746	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1747	  they are always undefined. Say Y here to enable software
1748	  emulation of these instructions for userspace using LDXR/STXR.
1749	  This feature can be controlled at runtime with the abi.swp
1750	  sysctl which is disabled by default.
1751
1752	  In some older versions of glibc [<=2.8] SWP is used during futex
1753	  trylock() operations with the assumption that the code will not
1754	  be preempted. This invalid assumption may be more likely to fail
1755	  with SWP emulation enabled, leading to deadlock of the user
1756	  application.
1757
1758	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1759	  on an external transaction monitoring block called a global
1760	  monitor to maintain update atomicity. If your system does not
1761	  implement a global monitor, this option can cause programs that
1762	  perform SWP operations to uncached memory to deadlock.
1763
1764	  If unsure, say Y
1765
1766config CP15_BARRIER_EMULATION
1767	bool "Emulate CP15 Barrier instructions"
1768	help
1769	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1770	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1771	  strongly recommended to use the ISB, DSB, and DMB
1772	  instructions instead.
1773
1774	  Say Y here to enable software emulation of these
1775	  instructions for AArch32 userspace code. When this option is
1776	  enabled, CP15 barrier usage is traced which can help
1777	  identify software that needs updating. This feature can be
1778	  controlled at runtime with the abi.cp15_barrier sysctl.
1779
1780	  If unsure, say Y
1781
1782config SETEND_EMULATION
1783	bool "Emulate SETEND instruction"
1784	help
1785	  The SETEND instruction alters the data-endianness of the
1786	  AArch32 EL0, and is deprecated in ARMv8.
1787
1788	  Say Y here to enable software emulation of the instruction
1789	  for AArch32 userspace code. This feature can be controlled
1790	  at runtime with the abi.setend sysctl.
1791
1792	  Note: All the cpus on the system must have mixed endian support at EL0
1793	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1794	  endian - is hotplugged in after this feature has been enabled, there could
1795	  be unexpected results in the applications.
1796
1797	  If unsure, say Y
1798endif # ARMV8_DEPRECATED
1799
1800endif # COMPAT
1801
1802menu "ARMv8.1 architectural features"
1803
1804config ARM64_HW_AFDBM
1805	bool "Support for hardware updates of the Access and Dirty page flags"
1806	default y
1807	help
1808	  The ARMv8.1 architecture extensions introduce support for
1809	  hardware updates of the access and dirty information in page
1810	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1811	  capable processors, accesses to pages with PTE_AF cleared will
1812	  set this bit instead of raising an access flag fault.
1813	  Similarly, writes to read-only pages with the DBM bit set will
1814	  clear the read-only bit (AP[2]) instead of raising a
1815	  permission fault.
1816
1817	  Kernels built with this configuration option enabled continue
1818	  to work on pre-ARMv8.1 hardware and the performance impact is
1819	  minimal. If unsure, say Y.
1820
1821config ARM64_PAN
1822	bool "Enable support for Privileged Access Never (PAN)"
1823	default y
1824	help
1825	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1826	  prevents the kernel or hypervisor from accessing user-space (EL0)
1827	  memory directly.
1828
1829	  Choosing this option will cause any unprotected (not using
1830	  copy_to_user et al) memory access to fail with a permission fault.
1831
1832	  The feature is detected at runtime, and will remain as a 'nop'
1833	  instruction if the cpu does not implement the feature.
1834
1835config AS_HAS_LSE_ATOMICS
1836	def_bool $(as-instr,.arch_extension lse)
1837
1838config ARM64_LSE_ATOMICS
1839	bool
1840	default ARM64_USE_LSE_ATOMICS
1841	depends on AS_HAS_LSE_ATOMICS
1842
1843config ARM64_USE_LSE_ATOMICS
1844	bool "Atomic instructions"
1845	default y
1846	help
1847	  As part of the Large System Extensions, ARMv8.1 introduces new
1848	  atomic instructions that are designed specifically to scale in
1849	  very large systems.
1850
1851	  Say Y here to make use of these instructions for the in-kernel
1852	  atomic routines. This incurs a small overhead on CPUs that do
1853	  not support these instructions and requires the kernel to be
1854	  built with binutils >= 2.25 in order for the new instructions
1855	  to be used.
1856
1857endmenu # "ARMv8.1 architectural features"
1858
1859menu "ARMv8.2 architectural features"
1860
1861config AS_HAS_ARMV8_2
1862	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1863
1864config AS_HAS_SHA3
1865	def_bool $(as-instr,.arch armv8.2-a+sha3)
1866
1867config ARM64_PMEM
1868	bool "Enable support for persistent memory"
1869	select ARCH_HAS_PMEM_API
1870	select ARCH_HAS_UACCESS_FLUSHCACHE
1871	help
1872	  Say Y to enable support for the persistent memory API based on the
1873	  ARMv8.2 DCPoP feature.
1874
1875	  The feature is detected at runtime, and the kernel will use DC CVAC
1876	  operations if DC CVAP is not supported (following the behaviour of
1877	  DC CVAP itself if the system does not define a point of persistence).
1878
1879config ARM64_RAS_EXTN
1880	bool "Enable support for RAS CPU Extensions"
1881	default y
1882	help
1883	  CPUs that support the Reliability, Availability and Serviceability
1884	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1885	  errors, classify them and report them to software.
1886
1887	  On CPUs with these extensions system software can use additional
1888	  barriers to determine if faults are pending and read the
1889	  classification from a new set of registers.
1890
1891	  Selecting this feature will allow the kernel to use these barriers
1892	  and access the new registers if the system supports the extension.
1893	  Platform RAS features may additionally depend on firmware support.
1894
1895config ARM64_CNP
1896	bool "Enable support for Common Not Private (CNP) translations"
1897	default y
1898	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1899	help
1900	  Common Not Private (CNP) allows translation table entries to
1901	  be shared between different PEs in the same inner shareable
1902	  domain, so the hardware can use this fact to optimise the
1903	  caching of such entries in the TLB.
1904
1905	  Selecting this option allows the CNP feature to be detected
1906	  at runtime, and does not affect PEs that do not implement
1907	  this feature.
1908
1909endmenu # "ARMv8.2 architectural features"
1910
1911menu "ARMv8.3 architectural features"
1912
1913config ARM64_PTR_AUTH
1914	bool "Enable support for pointer authentication"
1915	default y
1916	help
1917	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1918	  instructions for signing and authenticating pointers against secret
1919	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1920	  and other attacks.
1921
1922	  This option enables these instructions at EL0 (i.e. for userspace).
1923	  Choosing this option will cause the kernel to initialise secret keys
1924	  for each process at exec() time, with these keys being
1925	  context-switched along with the process.
1926
1927	  The feature is detected at runtime. If the feature is not present in
1928	  hardware it will not be advertised to userspace/KVM guest nor will it
1929	  be enabled.
1930
1931	  If the feature is present on the boot CPU but not on a late CPU, then
1932	  the late CPU will be parked. Also, if the boot CPU does not have
1933	  address auth and the late CPU has then the late CPU will still boot
1934	  but with the feature disabled. On such a system, this option should
1935	  not be selected.
1936
1937config ARM64_PTR_AUTH_KERNEL
1938	bool "Use pointer authentication for kernel"
1939	default y
1940	depends on ARM64_PTR_AUTH
1941	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1942	# Modern compilers insert a .note.gnu.property section note for PAC
1943	# which is only understood by binutils starting with version 2.33.1.
1944	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1945	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1946	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1947	help
1948	  If the compiler supports the -mbranch-protection or
1949	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1950	  will cause the kernel itself to be compiled with return address
1951	  protection. In this case, and if the target hardware is known to
1952	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1953	  disabled with minimal loss of protection.
1954
1955	  This feature works with FUNCTION_GRAPH_TRACER option only if
1956	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
1957
1958config CC_HAS_BRANCH_PROT_PAC_RET
1959	# GCC 9 or later, clang 8 or later
1960	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1961
1962config CC_HAS_SIGN_RETURN_ADDRESS
1963	# GCC 7, 8
1964	def_bool $(cc-option,-msign-return-address=all)
1965
1966config AS_HAS_ARMV8_3
1967	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1968
1969config AS_HAS_CFI_NEGATE_RA_STATE
1970	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1971
1972config AS_HAS_LDAPR
1973	def_bool $(as-instr,.arch_extension rcpc)
1974
1975endmenu # "ARMv8.3 architectural features"
1976
1977menu "ARMv8.4 architectural features"
1978
1979config ARM64_AMU_EXTN
1980	bool "Enable support for the Activity Monitors Unit CPU extension"
1981	default y
1982	help
1983	  The activity monitors extension is an optional extension introduced
1984	  by the ARMv8.4 CPU architecture. This enables support for version 1
1985	  of the activity monitors architecture, AMUv1.
1986
1987	  To enable the use of this extension on CPUs that implement it, say Y.
1988
1989	  Note that for architectural reasons, firmware _must_ implement AMU
1990	  support when running on CPUs that present the activity monitors
1991	  extension. The required support is present in:
1992	    * Version 1.5 and later of the ARM Trusted Firmware
1993
1994	  For kernels that have this configuration enabled but boot with broken
1995	  firmware, you may need to say N here until the firmware is fixed.
1996	  Otherwise you may experience firmware panics or lockups when
1997	  accessing the counter registers. Even if you are not observing these
1998	  symptoms, the values returned by the register reads might not
1999	  correctly reflect reality. Most commonly, the value read will be 0,
2000	  indicating that the counter is not enabled.
2001
2002config AS_HAS_ARMV8_4
2003	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
2004
2005config ARM64_TLB_RANGE
2006	bool "Enable support for tlbi range feature"
2007	default y
2008	depends on AS_HAS_ARMV8_4
2009	help
2010	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2011	  range of input addresses.
2012
2013	  The feature introduces new assembly instructions, and they were
2014	  support when binutils >= 2.30.
2015
2016endmenu # "ARMv8.4 architectural features"
2017
2018menu "ARMv8.5 architectural features"
2019
2020config AS_HAS_ARMV8_5
2021	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2022
2023config ARM64_BTI
2024	bool "Branch Target Identification support"
2025	default y
2026	help
2027	  Branch Target Identification (part of the ARMv8.5 Extensions)
2028	  provides a mechanism to limit the set of locations to which computed
2029	  branch instructions such as BR or BLR can jump.
2030
2031	  To make use of BTI on CPUs that support it, say Y.
2032
2033	  BTI is intended to provide complementary protection to other control
2034	  flow integrity protection mechanisms, such as the Pointer
2035	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2036	  For this reason, it does not make sense to enable this option without
2037	  also enabling support for pointer authentication.  Thus, when
2038	  enabling this option you should also select ARM64_PTR_AUTH=y.
2039
2040	  Userspace binaries must also be specifically compiled to make use of
2041	  this mechanism.  If you say N here or the hardware does not support
2042	  BTI, such binaries can still run, but you get no additional
2043	  enforcement of branch destinations.
2044
2045config ARM64_BTI_KERNEL
2046	bool "Use Branch Target Identification for kernel"
2047	default y
2048	depends on ARM64_BTI
2049	depends on ARM64_PTR_AUTH_KERNEL
2050	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2051	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2052	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2053	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2054	depends on !CC_IS_GCC
2055	# https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
2056	depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
2057	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2058	help
2059	  Build the kernel with Branch Target Identification annotations
2060	  and enable enforcement of this for kernel code. When this option
2061	  is enabled and the system supports BTI all kernel code including
2062	  modular code must have BTI enabled.
2063
2064config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2065	# GCC 9 or later, clang 8 or later
2066	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2067
2068config ARM64_E0PD
2069	bool "Enable support for E0PD"
2070	default y
2071	help
2072	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2073	  that EL0 accesses made via TTBR1 always fault in constant time,
2074	  providing similar benefits to KASLR as those provided by KPTI, but
2075	  with lower overhead and without disrupting legitimate access to
2076	  kernel memory such as SPE.
2077
2078	  This option enables E0PD for TTBR1 where available.
2079
2080config ARM64_AS_HAS_MTE
2081	# Initial support for MTE went in binutils 2.32.0, checked with
2082	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2083	# as a late addition to the final architecture spec (LDGM/STGM)
2084	# is only supported in the newer 2.32.x and 2.33 binutils
2085	# versions, hence the extra "stgm" instruction check below.
2086	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2087
2088config ARM64_MTE
2089	bool "Memory Tagging Extension support"
2090	default y
2091	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2092	depends on AS_HAS_ARMV8_5
2093	depends on AS_HAS_LSE_ATOMICS
2094	# Required for tag checking in the uaccess routines
2095	depends on ARM64_PAN
2096	select ARCH_HAS_SUBPAGE_FAULTS
2097	select ARCH_USES_HIGH_VMA_FLAGS
2098	select ARCH_USES_PG_ARCH_X
2099	help
2100	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2101	  architectural support for run-time, always-on detection of
2102	  various classes of memory error to aid with software debugging
2103	  to eliminate vulnerabilities arising from memory-unsafe
2104	  languages.
2105
2106	  This option enables the support for the Memory Tagging
2107	  Extension at EL0 (i.e. for userspace).
2108
2109	  Selecting this option allows the feature to be detected at
2110	  runtime. Any secondary CPU not implementing this feature will
2111	  not be allowed a late bring-up.
2112
2113	  Userspace binaries that want to use this feature must
2114	  explicitly opt in. The mechanism for the userspace is
2115	  described in:
2116
2117	  Documentation/arch/arm64/memory-tagging-extension.rst.
2118
2119endmenu # "ARMv8.5 architectural features"
2120
2121menu "ARMv8.7 architectural features"
2122
2123config ARM64_EPAN
2124	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2125	default y
2126	depends on ARM64_PAN
2127	help
2128	  Enhanced Privileged Access Never (EPAN) allows Privileged
2129	  Access Never to be used with Execute-only mappings.
2130
2131	  The feature is detected at runtime, and will remain disabled
2132	  if the cpu does not implement the feature.
2133endmenu # "ARMv8.7 architectural features"
2134
2135config ARM64_SVE
2136	bool "ARM Scalable Vector Extension support"
2137	default y
2138	help
2139	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2140	  execution state which complements and extends the SIMD functionality
2141	  of the base architecture to support much larger vectors and to enable
2142	  additional vectorisation opportunities.
2143
2144	  To enable use of this extension on CPUs that implement it, say Y.
2145
2146	  On CPUs that support the SVE2 extensions, this option will enable
2147	  those too.
2148
2149	  Note that for architectural reasons, firmware _must_ implement SVE
2150	  support when running on SVE capable hardware.  The required support
2151	  is present in:
2152
2153	    * version 1.5 and later of the ARM Trusted Firmware
2154	    * the AArch64 boot wrapper since commit 5e1261e08abf
2155	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2156
2157	  For other firmware implementations, consult the firmware documentation
2158	  or vendor.
2159
2160	  If you need the kernel to boot on SVE-capable hardware with broken
2161	  firmware, you may need to say N here until you get your firmware
2162	  fixed.  Otherwise, you may experience firmware panics or lockups when
2163	  booting the kernel.  If unsure and you are not observing these
2164	  symptoms, you should assume that it is safe to say Y.
2165
2166config ARM64_SME
2167	bool "ARM Scalable Matrix Extension support"
2168	default y
2169	depends on ARM64_SVE
2170	depends on BROKEN
2171	help
2172	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2173	  execution state which utilises a substantial subset of the SVE
2174	  instruction set, together with the addition of new architectural
2175	  register state capable of holding two dimensional matrix tiles to
2176	  enable various matrix operations.
2177
2178config ARM64_PSEUDO_NMI
2179	bool "Support for NMI-like interrupts"
2180	select ARM_GIC_V3
2181	help
2182	  Adds support for mimicking Non-Maskable Interrupts through the use of
2183	  GIC interrupt priority. This support requires version 3 or later of
2184	  ARM GIC.
2185
2186	  This high priority configuration for interrupts needs to be
2187	  explicitly enabled by setting the kernel parameter
2188	  "irqchip.gicv3_pseudo_nmi" to 1.
2189
2190	  If unsure, say N
2191
2192if ARM64_PSEUDO_NMI
2193config ARM64_DEBUG_PRIORITY_MASKING
2194	bool "Debug interrupt priority masking"
2195	help
2196	  This adds runtime checks to functions enabling/disabling
2197	  interrupts when using priority masking. The additional checks verify
2198	  the validity of ICC_PMR_EL1 when calling concerned functions.
2199
2200	  If unsure, say N
2201endif # ARM64_PSEUDO_NMI
2202
2203config RELOCATABLE
2204	bool "Build a relocatable kernel image" if EXPERT
2205	select ARCH_HAS_RELR
2206	default y
2207	help
2208	  This builds the kernel as a Position Independent Executable (PIE),
2209	  which retains all relocation metadata required to relocate the
2210	  kernel binary at runtime to a different virtual address than the
2211	  address it was linked at.
2212	  Since AArch64 uses the RELA relocation format, this requires a
2213	  relocation pass at runtime even if the kernel is loaded at the
2214	  same address it was linked at.
2215
2216config RANDOMIZE_BASE
2217	bool "Randomize the address of the kernel image"
2218	select RELOCATABLE
2219	help
2220	  Randomizes the virtual address at which the kernel image is
2221	  loaded, as a security feature that deters exploit attempts
2222	  relying on knowledge of the location of kernel internals.
2223
2224	  It is the bootloader's job to provide entropy, by passing a
2225	  random u64 value in /chosen/kaslr-seed at kernel entry.
2226
2227	  When booting via the UEFI stub, it will invoke the firmware's
2228	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2229	  to the kernel proper. In addition, it will randomise the physical
2230	  location of the kernel Image as well.
2231
2232	  If unsure, say N.
2233
2234config RANDOMIZE_MODULE_REGION_FULL
2235	bool "Randomize the module region over a 2 GB range"
2236	depends on RANDOMIZE_BASE
2237	default y
2238	help
2239	  Randomizes the location of the module region inside a 2 GB window
2240	  covering the core kernel. This way, it is less likely for modules
2241	  to leak information about the location of core kernel data structures
2242	  but it does imply that function calls between modules and the core
2243	  kernel will need to be resolved via veneers in the module PLT.
2244
2245	  When this option is not set, the module region will be randomized over
2246	  a limited range that contains the [_stext, _etext] interval of the
2247	  core kernel, so branch relocations are almost always in range unless
2248	  the region is exhausted. In this particular case of region
2249	  exhaustion, modules might be able to fall back to a larger 2GB area.
2250
2251config CC_HAVE_STACKPROTECTOR_SYSREG
2252	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2253
2254config STACKPROTECTOR_PER_TASK
2255	def_bool y
2256	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2257
2258config UNWIND_PATCH_PAC_INTO_SCS
2259	bool "Enable shadow call stack dynamically using code patching"
2260	# needs Clang with https://reviews.llvm.org/D111780 incorporated
2261	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2262	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2263	depends on SHADOW_CALL_STACK
2264	select UNWIND_TABLES
2265	select DYNAMIC_SCS
2266
2267endmenu # "Kernel Features"
2268
2269menu "Boot options"
2270
2271config ARM64_ACPI_PARKING_PROTOCOL
2272	bool "Enable support for the ARM64 ACPI parking protocol"
2273	depends on ACPI
2274	help
2275	  Enable support for the ARM64 ACPI parking protocol. If disabled
2276	  the kernel will not allow booting through the ARM64 ACPI parking
2277	  protocol even if the corresponding data is present in the ACPI
2278	  MADT table.
2279
2280config CMDLINE
2281	string "Default kernel command string"
2282	default ""
2283	help
2284	  Provide a set of default command-line options at build time by
2285	  entering them here. As a minimum, you should specify the the
2286	  root device (e.g. root=/dev/nfs).
2287
2288choice
2289	prompt "Kernel command line type" if CMDLINE != ""
2290	default CMDLINE_FROM_BOOTLOADER
2291	help
2292	  Choose how the kernel will handle the provided default kernel
2293	  command line string.
2294
2295config CMDLINE_FROM_BOOTLOADER
2296	bool "Use bootloader kernel arguments if available"
2297	help
2298	  Uses the command-line options passed by the boot loader. If
2299	  the boot loader doesn't provide any, the default kernel command
2300	  string provided in CMDLINE will be used.
2301
2302config CMDLINE_FORCE
2303	bool "Always use the default kernel command string"
2304	help
2305	  Always use the default kernel command string, even if the boot
2306	  loader passes other arguments to the kernel.
2307	  This is useful if you cannot or don't want to change the
2308	  command-line options your boot loader passes to the kernel.
2309
2310endchoice
2311
2312config EFI_STUB
2313	bool
2314
2315config EFI
2316	bool "UEFI runtime support"
2317	depends on OF && !CPU_BIG_ENDIAN
2318	depends on KERNEL_MODE_NEON
2319	select ARCH_SUPPORTS_ACPI
2320	select LIBFDT
2321	select UCS2_STRING
2322	select EFI_PARAMS_FROM_FDT
2323	select EFI_RUNTIME_WRAPPERS
2324	select EFI_STUB
2325	select EFI_GENERIC_STUB
2326	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2327	default y
2328	help
2329	  This option provides support for runtime services provided
2330	  by UEFI firmware (such as non-volatile variables, realtime
2331	  clock, and platform reset). A UEFI stub is also provided to
2332	  allow the kernel to be booted as an EFI application. This
2333	  is only useful on systems that have UEFI firmware.
2334
2335config DMI
2336	bool "Enable support for SMBIOS (DMI) tables"
2337	depends on EFI
2338	default y
2339	help
2340	  This enables SMBIOS/DMI feature for systems.
2341
2342	  This option is only useful on systems that have UEFI firmware.
2343	  However, even with this option, the resultant kernel should
2344	  continue to boot on existing non-UEFI platforms.
2345
2346endmenu # "Boot options"
2347
2348menu "Power management options"
2349
2350source "kernel/power/Kconfig"
2351
2352config ARCH_HIBERNATION_POSSIBLE
2353	def_bool y
2354	depends on CPU_PM
2355
2356config ARCH_HIBERNATION_HEADER
2357	def_bool y
2358	depends on HIBERNATION
2359
2360config ARCH_SUSPEND_POSSIBLE
2361	def_bool y
2362
2363endmenu # "Power management options"
2364
2365menu "CPU Power Management"
2366
2367source "drivers/cpuidle/Kconfig"
2368
2369source "drivers/cpufreq/Kconfig"
2370
2371endmenu # "CPU Power Management"
2372
2373source "drivers/acpi/Kconfig"
2374
2375source "arch/arm64/kvm/Kconfig"
2376
2377