xref: /openbmc/linux/arch/arm64/Kconfig (revision 2f4e3926)
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-A720 erratum 3456091
1083	  * ARM Cortex-A725 erratum 3456106
1084	  * ARM Cortex-X1 erratum 3324344
1085	  * ARM Cortex-X1C erratum 3324346
1086	  * ARM Cortex-X2 erratum 3324338
1087	  * ARM Cortex-X3 erratum 3324335
1088	  * ARM Cortex-X4 erratum 3194386
1089	  * ARM Cortex-X925 erratum 3324334
1090	  * ARM Neoverse-N1 erratum 3324349
1091	  * ARM Neoverse N2 erratum 3324339
1092	  * ARM Neoverse-V1 erratum 3324341
1093	  * ARM Neoverse V2 erratum 3324336
1094	  * ARM Neoverse-V3 erratum 3312417
1095
1096	  On affected cores "MSR SSBS, #0" instructions may not affect
1097	  subsequent speculative instructions, which may permit unexepected
1098	  speculative store bypassing.
1099
1100	  Work around this problem by placing a Speculation Barrier (SB) or
1101	  Instruction Synchronization Barrier (ISB) after kernel changes to
1102	  SSBS. The presence of the SSBS special-purpose register is hidden
1103	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1104	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1105
1106	  If unsure, say Y.
1107
1108config CAVIUM_ERRATUM_22375
1109	bool "Cavium erratum 22375, 24313"
1110	default y
1111	help
1112	  Enable workaround for errata 22375 and 24313.
1113
1114	  This implements two gicv3-its errata workarounds for ThunderX. Both
1115	  with a small impact affecting only ITS table allocation.
1116
1117	    erratum 22375: only alloc 8MB table size
1118	    erratum 24313: ignore memory access type
1119
1120	  The fixes are in ITS initialization and basically ignore memory access
1121	  type and table size provided by the TYPER and BASER registers.
1122
1123	  If unsure, say Y.
1124
1125config CAVIUM_ERRATUM_23144
1126	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1127	depends on NUMA
1128	default y
1129	help
1130	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1131
1132	  If unsure, say Y.
1133
1134config CAVIUM_ERRATUM_23154
1135	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1136	default y
1137	help
1138	  The ThunderX GICv3 implementation requires a modified version for
1139	  reading the IAR status to ensure data synchronization
1140	  (access to icc_iar1_el1 is not sync'ed before and after).
1141
1142	  It also suffers from erratum 38545 (also present on Marvell's
1143	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1144	  spuriously presented to the CPU interface.
1145
1146	  If unsure, say Y.
1147
1148config CAVIUM_ERRATUM_27456
1149	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1150	default y
1151	help
1152	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1153	  instructions may cause the icache to become corrupted if it
1154	  contains data for a non-current ASID.  The fix is to
1155	  invalidate the icache when changing the mm context.
1156
1157	  If unsure, say Y.
1158
1159config CAVIUM_ERRATUM_30115
1160	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1161	default y
1162	help
1163	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1164	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1165	  interrupts in host. Trapping both GICv3 group-0 and group-1
1166	  accesses sidesteps the issue.
1167
1168	  If unsure, say Y.
1169
1170config CAVIUM_TX2_ERRATUM_219
1171	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1172	default y
1173	help
1174	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1175	  TTBR update and the corresponding context synchronizing operation can
1176	  cause a spurious Data Abort to be delivered to any hardware thread in
1177	  the CPU core.
1178
1179	  Work around the issue by avoiding the problematic code sequence and
1180	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1181	  trap handler performs the corresponding register access, skips the
1182	  instruction and ensures context synchronization by virtue of the
1183	  exception return.
1184
1185	  If unsure, say Y.
1186
1187config FUJITSU_ERRATUM_010001
1188	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1189	default y
1190	help
1191	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1192	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1193	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1194	  This fault occurs under a specific hardware condition when a
1195	  load/store instruction performs an address translation using:
1196	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1197	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1198	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1199	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1200
1201	  The workaround is to ensure these bits are clear in TCR_ELx.
1202	  The workaround only affects the Fujitsu-A64FX.
1203
1204	  If unsure, say Y.
1205
1206config HISILICON_ERRATUM_161600802
1207	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1208	default y
1209	help
1210	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1211	  when issued ITS commands such as VMOVP and VMAPP, and requires
1212	  a 128kB offset to be applied to the target address in this commands.
1213
1214	  If unsure, say Y.
1215
1216config QCOM_FALKOR_ERRATUM_1003
1217	bool "Falkor E1003: Incorrect translation due to ASID change"
1218	default y
1219	help
1220	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1221	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1222	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1223	  then only for entries in the walk cache, since the leaf translation
1224	  is unchanged. Work around the erratum by invalidating the walk cache
1225	  entries for the trampoline before entering the kernel proper.
1226
1227config QCOM_FALKOR_ERRATUM_1009
1228	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1229	default y
1230	select ARM64_WORKAROUND_REPEAT_TLBI
1231	help
1232	  On Falkor v1, the CPU may prematurely complete a DSB following a
1233	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1234	  one more time to fix the issue.
1235
1236	  If unsure, say Y.
1237
1238config QCOM_QDF2400_ERRATUM_0065
1239	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1240	default y
1241	help
1242	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1243	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1244	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1245
1246	  If unsure, say Y.
1247
1248config QCOM_FALKOR_ERRATUM_E1041
1249	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1250	default y
1251	help
1252	  Falkor CPU may speculatively fetch instructions from an improper
1253	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1254	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1255
1256	  If unsure, say Y.
1257
1258config NVIDIA_CARMEL_CNP_ERRATUM
1259	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1260	default y
1261	help
1262	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1263	  invalidate shared TLB entries installed by a different core, as it would
1264	  on standard ARM cores.
1265
1266	  If unsure, say Y.
1267
1268config ROCKCHIP_ERRATUM_3588001
1269	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1270	default y
1271	help
1272	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1273	  This means, that its sharability feature may not be used, even though it
1274	  is supported by the IP itself.
1275
1276	  If unsure, say Y.
1277
1278config SOCIONEXT_SYNQUACER_PREITS
1279	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1280	default y
1281	help
1282	  Socionext Synquacer SoCs implement a separate h/w block to generate
1283	  MSI doorbell writes with non-zero values for the device ID.
1284
1285	  If unsure, say Y.
1286
1287endmenu # "ARM errata workarounds via the alternatives framework"
1288
1289choice
1290	prompt "Page size"
1291	default ARM64_4K_PAGES
1292	help
1293	  Page size (translation granule) configuration.
1294
1295config ARM64_4K_PAGES
1296	bool "4KB"
1297	help
1298	  This feature enables 4KB pages support.
1299
1300config ARM64_16K_PAGES
1301	bool "16KB"
1302	help
1303	  The system will use 16KB pages support. AArch32 emulation
1304	  requires applications compiled with 16K (or a multiple of 16K)
1305	  aligned segments.
1306
1307config ARM64_64K_PAGES
1308	bool "64KB"
1309	help
1310	  This feature enables 64KB pages support (4KB by default)
1311	  allowing only two levels of page tables and faster TLB
1312	  look-up. AArch32 emulation requires applications compiled
1313	  with 64K aligned segments.
1314
1315endchoice
1316
1317choice
1318	prompt "Virtual address space size"
1319	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1320	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1321	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1322	help
1323	  Allows choosing one of multiple possible virtual address
1324	  space sizes. The level of translation table is determined by
1325	  a combination of page size and virtual address space size.
1326
1327config ARM64_VA_BITS_36
1328	bool "36-bit" if EXPERT
1329	depends on ARM64_16K_PAGES
1330
1331config ARM64_VA_BITS_39
1332	bool "39-bit"
1333	depends on ARM64_4K_PAGES
1334
1335config ARM64_VA_BITS_42
1336	bool "42-bit"
1337	depends on ARM64_64K_PAGES
1338
1339config ARM64_VA_BITS_47
1340	bool "47-bit"
1341	depends on ARM64_16K_PAGES
1342
1343config ARM64_VA_BITS_48
1344	bool "48-bit"
1345
1346config ARM64_VA_BITS_52
1347	bool "52-bit"
1348	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1349	help
1350	  Enable 52-bit virtual addressing for userspace when explicitly
1351	  requested via a hint to mmap(). The kernel will also use 52-bit
1352	  virtual addresses for its own mappings (provided HW support for
1353	  this feature is available, otherwise it reverts to 48-bit).
1354
1355	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1356	  ARMv8.3 Pointer Authentication will result in the PAC being
1357	  reduced from 7 bits to 3 bits, which may have a significant
1358	  impact on its susceptibility to brute-force attacks.
1359
1360	  If unsure, select 48-bit virtual addressing instead.
1361
1362endchoice
1363
1364config ARM64_FORCE_52BIT
1365	bool "Force 52-bit virtual addresses for userspace"
1366	depends on ARM64_VA_BITS_52 && EXPERT
1367	help
1368	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1369	  to maintain compatibility with older software by providing 48-bit VAs
1370	  unless a hint is supplied to mmap.
1371
1372	  This configuration option disables the 48-bit compatibility logic, and
1373	  forces all userspace addresses to be 52-bit on HW that supports it. One
1374	  should only enable this configuration option for stress testing userspace
1375	  memory management code. If unsure say N here.
1376
1377config ARM64_VA_BITS
1378	int
1379	default 36 if ARM64_VA_BITS_36
1380	default 39 if ARM64_VA_BITS_39
1381	default 42 if ARM64_VA_BITS_42
1382	default 47 if ARM64_VA_BITS_47
1383	default 48 if ARM64_VA_BITS_48
1384	default 52 if ARM64_VA_BITS_52
1385
1386choice
1387	prompt "Physical address space size"
1388	default ARM64_PA_BITS_48
1389	help
1390	  Choose the maximum physical address range that the kernel will
1391	  support.
1392
1393config ARM64_PA_BITS_48
1394	bool "48-bit"
1395
1396config ARM64_PA_BITS_52
1397	bool "52-bit (ARMv8.2)"
1398	depends on ARM64_64K_PAGES
1399	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1400	help
1401	  Enable support for a 52-bit physical address space, introduced as
1402	  part of the ARMv8.2-LPA extension.
1403
1404	  With this enabled, the kernel will also continue to work on CPUs that
1405	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1406	  minor performance overhead).
1407
1408endchoice
1409
1410config ARM64_PA_BITS
1411	int
1412	default 48 if ARM64_PA_BITS_48
1413	default 52 if ARM64_PA_BITS_52
1414
1415choice
1416	prompt "Endianness"
1417	default CPU_LITTLE_ENDIAN
1418	help
1419	  Select the endianness of data accesses performed by the CPU. Userspace
1420	  applications will need to be compiled and linked for the endianness
1421	  that is selected here.
1422
1423config CPU_BIG_ENDIAN
1424	bool "Build big-endian kernel"
1425	depends on !LD_IS_LLD || LLD_VERSION >= 130000
1426	# https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1427	depends on AS_IS_GNU || AS_VERSION >= 150000
1428	help
1429	  Say Y if you plan on running a kernel with a big-endian userspace.
1430
1431config CPU_LITTLE_ENDIAN
1432	bool "Build little-endian kernel"
1433	help
1434	  Say Y if you plan on running a kernel with a little-endian userspace.
1435	  This is usually the case for distributions targeting arm64.
1436
1437endchoice
1438
1439config SCHED_MC
1440	bool "Multi-core scheduler support"
1441	help
1442	  Multi-core scheduler support improves the CPU scheduler's decision
1443	  making when dealing with multi-core CPU chips at a cost of slightly
1444	  increased overhead in some places. If unsure say N here.
1445
1446config SCHED_CLUSTER
1447	bool "Cluster scheduler support"
1448	help
1449	  Cluster scheduler support improves the CPU scheduler's decision
1450	  making when dealing with machines that have clusters of CPUs.
1451	  Cluster usually means a couple of CPUs which are placed closely
1452	  by sharing mid-level caches, last-level cache tags or internal
1453	  busses.
1454
1455config SCHED_SMT
1456	bool "SMT scheduler support"
1457	help
1458	  Improves the CPU scheduler's decision making when dealing with
1459	  MultiThreading at a cost of slightly increased overhead in some
1460	  places. If unsure say N here.
1461
1462config NR_CPUS
1463	int "Maximum number of CPUs (2-4096)"
1464	range 2 4096
1465	default "256"
1466
1467config HOTPLUG_CPU
1468	bool "Support for hot-pluggable CPUs"
1469	select GENERIC_IRQ_MIGRATION
1470	help
1471	  Say Y here to experiment with turning CPUs off and on.  CPUs
1472	  can be controlled through /sys/devices/system/cpu.
1473
1474# Common NUMA Features
1475config NUMA
1476	bool "NUMA Memory Allocation and Scheduler Support"
1477	select GENERIC_ARCH_NUMA
1478	select ACPI_NUMA if ACPI
1479	select OF_NUMA
1480	select HAVE_SETUP_PER_CPU_AREA
1481	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1482	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1483	select USE_PERCPU_NUMA_NODE_ID
1484	help
1485	  Enable NUMA (Non-Uniform Memory Access) support.
1486
1487	  The kernel will try to allocate memory used by a CPU on the
1488	  local memory of the CPU and add some more
1489	  NUMA awareness to the kernel.
1490
1491config NODES_SHIFT
1492	int "Maximum NUMA Nodes (as a power of 2)"
1493	range 1 10
1494	default "4"
1495	depends on NUMA
1496	help
1497	  Specify the maximum number of NUMA Nodes available on the target
1498	  system.  Increases memory reserved to accommodate various tables.
1499
1500source "kernel/Kconfig.hz"
1501
1502config ARCH_SPARSEMEM_ENABLE
1503	def_bool y
1504	select SPARSEMEM_VMEMMAP_ENABLE
1505	select SPARSEMEM_VMEMMAP
1506
1507config HW_PERF_EVENTS
1508	def_bool y
1509	depends on ARM_PMU
1510
1511# Supported by clang >= 7.0 or GCC >= 12.0.0
1512config CC_HAVE_SHADOW_CALL_STACK
1513	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1514
1515config PARAVIRT
1516	bool "Enable paravirtualization code"
1517	help
1518	  This changes the kernel so it can modify itself when it is run
1519	  under a hypervisor, potentially improving performance significantly
1520	  over full virtualization.
1521
1522config PARAVIRT_TIME_ACCOUNTING
1523	bool "Paravirtual steal time accounting"
1524	select PARAVIRT
1525	help
1526	  Select this option to enable fine granularity task steal time
1527	  accounting. Time spent executing other tasks in parallel with
1528	  the current vCPU is discounted from the vCPU power. To account for
1529	  that, there can be a small performance impact.
1530
1531	  If in doubt, say N here.
1532
1533config ARCH_SUPPORTS_KEXEC
1534	def_bool PM_SLEEP_SMP
1535
1536config ARCH_SUPPORTS_KEXEC_FILE
1537	def_bool y
1538
1539config ARCH_SELECTS_KEXEC_FILE
1540	def_bool y
1541	depends on KEXEC_FILE
1542	select HAVE_IMA_KEXEC if IMA
1543
1544config ARCH_SUPPORTS_KEXEC_SIG
1545	def_bool y
1546
1547config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1548	def_bool y
1549
1550config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1551	def_bool y
1552
1553config ARCH_SUPPORTS_CRASH_DUMP
1554	def_bool y
1555
1556config TRANS_TABLE
1557	def_bool y
1558	depends on HIBERNATION || KEXEC_CORE
1559
1560config XEN_DOM0
1561	def_bool y
1562	depends on XEN
1563
1564config XEN
1565	bool "Xen guest support on ARM64"
1566	depends on ARM64 && OF
1567	select SWIOTLB_XEN
1568	select PARAVIRT
1569	help
1570	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1571
1572# include/linux/mmzone.h requires the following to be true:
1573#
1574#   MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1575#
1576# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1577#
1578#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_ORDER  |  default MAX_ORDER |
1579# ----+-------------------+--------------+-----------------+--------------------+
1580# 4K  |       27          |      12      |       15        |         10         |
1581# 16K |       27          |      14      |       13        |         11         |
1582# 64K |       29          |      16      |       13        |         13         |
1583config ARCH_FORCE_MAX_ORDER
1584	int
1585	default "13" if ARM64_64K_PAGES
1586	default "11" if ARM64_16K_PAGES
1587	default "10"
1588	help
1589	  The kernel page allocator limits the size of maximal physically
1590	  contiguous allocations. The limit is called MAX_ORDER and it
1591	  defines the maximal power of two of number of pages that can be
1592	  allocated as a single contiguous block. This option allows
1593	  overriding the default setting when ability to allocate very
1594	  large blocks of physically contiguous memory is required.
1595
1596	  The maximal size of allocation cannot exceed the size of the
1597	  section, so the value of MAX_ORDER should satisfy
1598
1599	    MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1600
1601	  Don't change if unsure.
1602
1603config UNMAP_KERNEL_AT_EL0
1604	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1605	default y
1606	help
1607	  Speculation attacks against some high-performance processors can
1608	  be used to bypass MMU permission checks and leak kernel data to
1609	  userspace. This can be defended against by unmapping the kernel
1610	  when running in userspace, mapping it back in on exception entry
1611	  via a trampoline page in the vector table.
1612
1613	  If unsure, say Y.
1614
1615config MITIGATE_SPECTRE_BRANCH_HISTORY
1616	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1617	default y
1618	help
1619	  Speculation attacks against some high-performance processors can
1620	  make use of branch history to influence future speculation.
1621	  When taking an exception from user-space, a sequence of branches
1622	  or a firmware call overwrites the branch history.
1623
1624config RODATA_FULL_DEFAULT_ENABLED
1625	bool "Apply r/o permissions of VM areas also to their linear aliases"
1626	default y
1627	help
1628	  Apply read-only attributes of VM areas to the linear alias of
1629	  the backing pages as well. This prevents code or read-only data
1630	  from being modified (inadvertently or intentionally) via another
1631	  mapping of the same memory page. This additional enhancement can
1632	  be turned off at runtime by passing rodata=[off|on] (and turned on
1633	  with rodata=full if this option is set to 'n')
1634
1635	  This requires the linear region to be mapped down to pages,
1636	  which may adversely affect performance in some cases.
1637
1638config ARM64_SW_TTBR0_PAN
1639	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1640	help
1641	  Enabling this option prevents the kernel from accessing
1642	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1643	  zeroed area and reserved ASID. The user access routines
1644	  restore the valid TTBR0_EL1 temporarily.
1645
1646config ARM64_TAGGED_ADDR_ABI
1647	bool "Enable the tagged user addresses syscall ABI"
1648	default y
1649	help
1650	  When this option is enabled, user applications can opt in to a
1651	  relaxed ABI via prctl() allowing tagged addresses to be passed
1652	  to system calls as pointer arguments. For details, see
1653	  Documentation/arch/arm64/tagged-address-abi.rst.
1654
1655menuconfig COMPAT
1656	bool "Kernel support for 32-bit EL0"
1657	depends on ARM64_4K_PAGES || EXPERT
1658	select HAVE_UID16
1659	select OLD_SIGSUSPEND3
1660	select COMPAT_OLD_SIGACTION
1661	help
1662	  This option enables support for a 32-bit EL0 running under a 64-bit
1663	  kernel at EL1. AArch32-specific components such as system calls,
1664	  the user helper functions, VFP support and the ptrace interface are
1665	  handled appropriately by the kernel.
1666
1667	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1668	  that you will only be able to execute AArch32 binaries that were compiled
1669	  with page size aligned segments.
1670
1671	  If you want to execute 32-bit userspace applications, say Y.
1672
1673if COMPAT
1674
1675config KUSER_HELPERS
1676	bool "Enable kuser helpers page for 32-bit applications"
1677	default y
1678	help
1679	  Warning: disabling this option may break 32-bit user programs.
1680
1681	  Provide kuser helpers to compat tasks. The kernel provides
1682	  helper code to userspace in read only form at a fixed location
1683	  to allow userspace to be independent of the CPU type fitted to
1684	  the system. This permits binaries to be run on ARMv4 through
1685	  to ARMv8 without modification.
1686
1687	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1688
1689	  However, the fixed address nature of these helpers can be used
1690	  by ROP (return orientated programming) authors when creating
1691	  exploits.
1692
1693	  If all of the binaries and libraries which run on your platform
1694	  are built specifically for your platform, and make no use of
1695	  these helpers, then you can turn this option off to hinder
1696	  such exploits. However, in that case, if a binary or library
1697	  relying on those helpers is run, it will not function correctly.
1698
1699	  Say N here only if you are absolutely certain that you do not
1700	  need these helpers; otherwise, the safe option is to say Y.
1701
1702config COMPAT_VDSO
1703	bool "Enable vDSO for 32-bit applications"
1704	depends on !CPU_BIG_ENDIAN
1705	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1706	select GENERIC_COMPAT_VDSO
1707	default y
1708	help
1709	  Place in the process address space of 32-bit applications an
1710	  ELF shared object providing fast implementations of gettimeofday
1711	  and clock_gettime.
1712
1713	  You must have a 32-bit build of glibc 2.22 or later for programs
1714	  to seamlessly take advantage of this.
1715
1716config THUMB2_COMPAT_VDSO
1717	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1718	depends on COMPAT_VDSO
1719	default y
1720	help
1721	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1722	  otherwise with '-marm'.
1723
1724config COMPAT_ALIGNMENT_FIXUPS
1725	bool "Fix up misaligned multi-word loads and stores in user space"
1726
1727menuconfig ARMV8_DEPRECATED
1728	bool "Emulate deprecated/obsolete ARMv8 instructions"
1729	depends on SYSCTL
1730	help
1731	  Legacy software support may require certain instructions
1732	  that have been deprecated or obsoleted in the architecture.
1733
1734	  Enable this config to enable selective emulation of these
1735	  features.
1736
1737	  If unsure, say Y
1738
1739if ARMV8_DEPRECATED
1740
1741config SWP_EMULATION
1742	bool "Emulate SWP/SWPB instructions"
1743	help
1744	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1745	  they are always undefined. Say Y here to enable software
1746	  emulation of these instructions for userspace using LDXR/STXR.
1747	  This feature can be controlled at runtime with the abi.swp
1748	  sysctl which is disabled by default.
1749
1750	  In some older versions of glibc [<=2.8] SWP is used during futex
1751	  trylock() operations with the assumption that the code will not
1752	  be preempted. This invalid assumption may be more likely to fail
1753	  with SWP emulation enabled, leading to deadlock of the user
1754	  application.
1755
1756	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1757	  on an external transaction monitoring block called a global
1758	  monitor to maintain update atomicity. If your system does not
1759	  implement a global monitor, this option can cause programs that
1760	  perform SWP operations to uncached memory to deadlock.
1761
1762	  If unsure, say Y
1763
1764config CP15_BARRIER_EMULATION
1765	bool "Emulate CP15 Barrier instructions"
1766	help
1767	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1768	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1769	  strongly recommended to use the ISB, DSB, and DMB
1770	  instructions instead.
1771
1772	  Say Y here to enable software emulation of these
1773	  instructions for AArch32 userspace code. When this option is
1774	  enabled, CP15 barrier usage is traced which can help
1775	  identify software that needs updating. This feature can be
1776	  controlled at runtime with the abi.cp15_barrier sysctl.
1777
1778	  If unsure, say Y
1779
1780config SETEND_EMULATION
1781	bool "Emulate SETEND instruction"
1782	help
1783	  The SETEND instruction alters the data-endianness of the
1784	  AArch32 EL0, and is deprecated in ARMv8.
1785
1786	  Say Y here to enable software emulation of the instruction
1787	  for AArch32 userspace code. This feature can be controlled
1788	  at runtime with the abi.setend sysctl.
1789
1790	  Note: All the cpus on the system must have mixed endian support at EL0
1791	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1792	  endian - is hotplugged in after this feature has been enabled, there could
1793	  be unexpected results in the applications.
1794
1795	  If unsure, say Y
1796endif # ARMV8_DEPRECATED
1797
1798endif # COMPAT
1799
1800menu "ARMv8.1 architectural features"
1801
1802config ARM64_HW_AFDBM
1803	bool "Support for hardware updates of the Access and Dirty page flags"
1804	default y
1805	help
1806	  The ARMv8.1 architecture extensions introduce support for
1807	  hardware updates of the access and dirty information in page
1808	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1809	  capable processors, accesses to pages with PTE_AF cleared will
1810	  set this bit instead of raising an access flag fault.
1811	  Similarly, writes to read-only pages with the DBM bit set will
1812	  clear the read-only bit (AP[2]) instead of raising a
1813	  permission fault.
1814
1815	  Kernels built with this configuration option enabled continue
1816	  to work on pre-ARMv8.1 hardware and the performance impact is
1817	  minimal. If unsure, say Y.
1818
1819config ARM64_PAN
1820	bool "Enable support for Privileged Access Never (PAN)"
1821	default y
1822	help
1823	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1824	  prevents the kernel or hypervisor from accessing user-space (EL0)
1825	  memory directly.
1826
1827	  Choosing this option will cause any unprotected (not using
1828	  copy_to_user et al) memory access to fail with a permission fault.
1829
1830	  The feature is detected at runtime, and will remain as a 'nop'
1831	  instruction if the cpu does not implement the feature.
1832
1833config AS_HAS_LSE_ATOMICS
1834	def_bool $(as-instr,.arch_extension lse)
1835
1836config ARM64_LSE_ATOMICS
1837	bool
1838	default ARM64_USE_LSE_ATOMICS
1839	depends on AS_HAS_LSE_ATOMICS
1840
1841config ARM64_USE_LSE_ATOMICS
1842	bool "Atomic instructions"
1843	default y
1844	help
1845	  As part of the Large System Extensions, ARMv8.1 introduces new
1846	  atomic instructions that are designed specifically to scale in
1847	  very large systems.
1848
1849	  Say Y here to make use of these instructions for the in-kernel
1850	  atomic routines. This incurs a small overhead on CPUs that do
1851	  not support these instructions and requires the kernel to be
1852	  built with binutils >= 2.25 in order for the new instructions
1853	  to be used.
1854
1855endmenu # "ARMv8.1 architectural features"
1856
1857menu "ARMv8.2 architectural features"
1858
1859config AS_HAS_ARMV8_2
1860	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1861
1862config AS_HAS_SHA3
1863	def_bool $(as-instr,.arch armv8.2-a+sha3)
1864
1865config ARM64_PMEM
1866	bool "Enable support for persistent memory"
1867	select ARCH_HAS_PMEM_API
1868	select ARCH_HAS_UACCESS_FLUSHCACHE
1869	help
1870	  Say Y to enable support for the persistent memory API based on the
1871	  ARMv8.2 DCPoP feature.
1872
1873	  The feature is detected at runtime, and the kernel will use DC CVAC
1874	  operations if DC CVAP is not supported (following the behaviour of
1875	  DC CVAP itself if the system does not define a point of persistence).
1876
1877config ARM64_RAS_EXTN
1878	bool "Enable support for RAS CPU Extensions"
1879	default y
1880	help
1881	  CPUs that support the Reliability, Availability and Serviceability
1882	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1883	  errors, classify them and report them to software.
1884
1885	  On CPUs with these extensions system software can use additional
1886	  barriers to determine if faults are pending and read the
1887	  classification from a new set of registers.
1888
1889	  Selecting this feature will allow the kernel to use these barriers
1890	  and access the new registers if the system supports the extension.
1891	  Platform RAS features may additionally depend on firmware support.
1892
1893config ARM64_CNP
1894	bool "Enable support for Common Not Private (CNP) translations"
1895	default y
1896	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1897	help
1898	  Common Not Private (CNP) allows translation table entries to
1899	  be shared between different PEs in the same inner shareable
1900	  domain, so the hardware can use this fact to optimise the
1901	  caching of such entries in the TLB.
1902
1903	  Selecting this option allows the CNP feature to be detected
1904	  at runtime, and does not affect PEs that do not implement
1905	  this feature.
1906
1907endmenu # "ARMv8.2 architectural features"
1908
1909menu "ARMv8.3 architectural features"
1910
1911config ARM64_PTR_AUTH
1912	bool "Enable support for pointer authentication"
1913	default y
1914	help
1915	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1916	  instructions for signing and authenticating pointers against secret
1917	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1918	  and other attacks.
1919
1920	  This option enables these instructions at EL0 (i.e. for userspace).
1921	  Choosing this option will cause the kernel to initialise secret keys
1922	  for each process at exec() time, with these keys being
1923	  context-switched along with the process.
1924
1925	  The feature is detected at runtime. If the feature is not present in
1926	  hardware it will not be advertised to userspace/KVM guest nor will it
1927	  be enabled.
1928
1929	  If the feature is present on the boot CPU but not on a late CPU, then
1930	  the late CPU will be parked. Also, if the boot CPU does not have
1931	  address auth and the late CPU has then the late CPU will still boot
1932	  but with the feature disabled. On such a system, this option should
1933	  not be selected.
1934
1935config ARM64_PTR_AUTH_KERNEL
1936	bool "Use pointer authentication for kernel"
1937	default y
1938	depends on ARM64_PTR_AUTH
1939	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1940	# Modern compilers insert a .note.gnu.property section note for PAC
1941	# which is only understood by binutils starting with version 2.33.1.
1942	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1943	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1944	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1945	help
1946	  If the compiler supports the -mbranch-protection or
1947	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1948	  will cause the kernel itself to be compiled with return address
1949	  protection. In this case, and if the target hardware is known to
1950	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1951	  disabled with minimal loss of protection.
1952
1953	  This feature works with FUNCTION_GRAPH_TRACER option only if
1954	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
1955
1956config CC_HAS_BRANCH_PROT_PAC_RET
1957	# GCC 9 or later, clang 8 or later
1958	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1959
1960config CC_HAS_SIGN_RETURN_ADDRESS
1961	# GCC 7, 8
1962	def_bool $(cc-option,-msign-return-address=all)
1963
1964config AS_HAS_ARMV8_3
1965	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1966
1967config AS_HAS_CFI_NEGATE_RA_STATE
1968	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1969
1970config AS_HAS_LDAPR
1971	def_bool $(as-instr,.arch_extension rcpc)
1972
1973endmenu # "ARMv8.3 architectural features"
1974
1975menu "ARMv8.4 architectural features"
1976
1977config ARM64_AMU_EXTN
1978	bool "Enable support for the Activity Monitors Unit CPU extension"
1979	default y
1980	help
1981	  The activity monitors extension is an optional extension introduced
1982	  by the ARMv8.4 CPU architecture. This enables support for version 1
1983	  of the activity monitors architecture, AMUv1.
1984
1985	  To enable the use of this extension on CPUs that implement it, say Y.
1986
1987	  Note that for architectural reasons, firmware _must_ implement AMU
1988	  support when running on CPUs that present the activity monitors
1989	  extension. The required support is present in:
1990	    * Version 1.5 and later of the ARM Trusted Firmware
1991
1992	  For kernels that have this configuration enabled but boot with broken
1993	  firmware, you may need to say N here until the firmware is fixed.
1994	  Otherwise you may experience firmware panics or lockups when
1995	  accessing the counter registers. Even if you are not observing these
1996	  symptoms, the values returned by the register reads might not
1997	  correctly reflect reality. Most commonly, the value read will be 0,
1998	  indicating that the counter is not enabled.
1999
2000config AS_HAS_ARMV8_4
2001	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
2002
2003config ARM64_TLB_RANGE
2004	bool "Enable support for tlbi range feature"
2005	default y
2006	depends on AS_HAS_ARMV8_4
2007	help
2008	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2009	  range of input addresses.
2010
2011	  The feature introduces new assembly instructions, and they were
2012	  support when binutils >= 2.30.
2013
2014endmenu # "ARMv8.4 architectural features"
2015
2016menu "ARMv8.5 architectural features"
2017
2018config AS_HAS_ARMV8_5
2019	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2020
2021config ARM64_BTI
2022	bool "Branch Target Identification support"
2023	default y
2024	help
2025	  Branch Target Identification (part of the ARMv8.5 Extensions)
2026	  provides a mechanism to limit the set of locations to which computed
2027	  branch instructions such as BR or BLR can jump.
2028
2029	  To make use of BTI on CPUs that support it, say Y.
2030
2031	  BTI is intended to provide complementary protection to other control
2032	  flow integrity protection mechanisms, such as the Pointer
2033	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2034	  For this reason, it does not make sense to enable this option without
2035	  also enabling support for pointer authentication.  Thus, when
2036	  enabling this option you should also select ARM64_PTR_AUTH=y.
2037
2038	  Userspace binaries must also be specifically compiled to make use of
2039	  this mechanism.  If you say N here or the hardware does not support
2040	  BTI, such binaries can still run, but you get no additional
2041	  enforcement of branch destinations.
2042
2043config ARM64_BTI_KERNEL
2044	bool "Use Branch Target Identification for kernel"
2045	default y
2046	depends on ARM64_BTI
2047	depends on ARM64_PTR_AUTH_KERNEL
2048	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2049	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2050	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2051	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2052	depends on !CC_IS_GCC
2053	# https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
2054	depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
2055	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2056	help
2057	  Build the kernel with Branch Target Identification annotations
2058	  and enable enforcement of this for kernel code. When this option
2059	  is enabled and the system supports BTI all kernel code including
2060	  modular code must have BTI enabled.
2061
2062config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2063	# GCC 9 or later, clang 8 or later
2064	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2065
2066config ARM64_E0PD
2067	bool "Enable support for E0PD"
2068	default y
2069	help
2070	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2071	  that EL0 accesses made via TTBR1 always fault in constant time,
2072	  providing similar benefits to KASLR as those provided by KPTI, but
2073	  with lower overhead and without disrupting legitimate access to
2074	  kernel memory such as SPE.
2075
2076	  This option enables E0PD for TTBR1 where available.
2077
2078config ARM64_AS_HAS_MTE
2079	# Initial support for MTE went in binutils 2.32.0, checked with
2080	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2081	# as a late addition to the final architecture spec (LDGM/STGM)
2082	# is only supported in the newer 2.32.x and 2.33 binutils
2083	# versions, hence the extra "stgm" instruction check below.
2084	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2085
2086config ARM64_MTE
2087	bool "Memory Tagging Extension support"
2088	default y
2089	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2090	depends on AS_HAS_ARMV8_5
2091	depends on AS_HAS_LSE_ATOMICS
2092	# Required for tag checking in the uaccess routines
2093	depends on ARM64_PAN
2094	select ARCH_HAS_SUBPAGE_FAULTS
2095	select ARCH_USES_HIGH_VMA_FLAGS
2096	select ARCH_USES_PG_ARCH_X
2097	help
2098	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2099	  architectural support for run-time, always-on detection of
2100	  various classes of memory error to aid with software debugging
2101	  to eliminate vulnerabilities arising from memory-unsafe
2102	  languages.
2103
2104	  This option enables the support for the Memory Tagging
2105	  Extension at EL0 (i.e. for userspace).
2106
2107	  Selecting this option allows the feature to be detected at
2108	  runtime. Any secondary CPU not implementing this feature will
2109	  not be allowed a late bring-up.
2110
2111	  Userspace binaries that want to use this feature must
2112	  explicitly opt in. The mechanism for the userspace is
2113	  described in:
2114
2115	  Documentation/arch/arm64/memory-tagging-extension.rst.
2116
2117endmenu # "ARMv8.5 architectural features"
2118
2119menu "ARMv8.7 architectural features"
2120
2121config ARM64_EPAN
2122	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2123	default y
2124	depends on ARM64_PAN
2125	help
2126	  Enhanced Privileged Access Never (EPAN) allows Privileged
2127	  Access Never to be used with Execute-only mappings.
2128
2129	  The feature is detected at runtime, and will remain disabled
2130	  if the cpu does not implement the feature.
2131endmenu # "ARMv8.7 architectural features"
2132
2133config ARM64_SVE
2134	bool "ARM Scalable Vector Extension support"
2135	default y
2136	help
2137	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2138	  execution state which complements and extends the SIMD functionality
2139	  of the base architecture to support much larger vectors and to enable
2140	  additional vectorisation opportunities.
2141
2142	  To enable use of this extension on CPUs that implement it, say Y.
2143
2144	  On CPUs that support the SVE2 extensions, this option will enable
2145	  those too.
2146
2147	  Note that for architectural reasons, firmware _must_ implement SVE
2148	  support when running on SVE capable hardware.  The required support
2149	  is present in:
2150
2151	    * version 1.5 and later of the ARM Trusted Firmware
2152	    * the AArch64 boot wrapper since commit 5e1261e08abf
2153	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2154
2155	  For other firmware implementations, consult the firmware documentation
2156	  or vendor.
2157
2158	  If you need the kernel to boot on SVE-capable hardware with broken
2159	  firmware, you may need to say N here until you get your firmware
2160	  fixed.  Otherwise, you may experience firmware panics or lockups when
2161	  booting the kernel.  If unsure and you are not observing these
2162	  symptoms, you should assume that it is safe to say Y.
2163
2164config ARM64_SME
2165	bool "ARM Scalable Matrix Extension support"
2166	default y
2167	depends on ARM64_SVE
2168	help
2169	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2170	  execution state which utilises a substantial subset of the SVE
2171	  instruction set, together with the addition of new architectural
2172	  register state capable of holding two dimensional matrix tiles to
2173	  enable various matrix operations.
2174
2175config ARM64_PSEUDO_NMI
2176	bool "Support for NMI-like interrupts"
2177	select ARM_GIC_V3
2178	help
2179	  Adds support for mimicking Non-Maskable Interrupts through the use of
2180	  GIC interrupt priority. This support requires version 3 or later of
2181	  ARM GIC.
2182
2183	  This high priority configuration for interrupts needs to be
2184	  explicitly enabled by setting the kernel parameter
2185	  "irqchip.gicv3_pseudo_nmi" to 1.
2186
2187	  If unsure, say N
2188
2189if ARM64_PSEUDO_NMI
2190config ARM64_DEBUG_PRIORITY_MASKING
2191	bool "Debug interrupt priority masking"
2192	help
2193	  This adds runtime checks to functions enabling/disabling
2194	  interrupts when using priority masking. The additional checks verify
2195	  the validity of ICC_PMR_EL1 when calling concerned functions.
2196
2197	  If unsure, say N
2198endif # ARM64_PSEUDO_NMI
2199
2200config RELOCATABLE
2201	bool "Build a relocatable kernel image" if EXPERT
2202	select ARCH_HAS_RELR
2203	default y
2204	help
2205	  This builds the kernel as a Position Independent Executable (PIE),
2206	  which retains all relocation metadata required to relocate the
2207	  kernel binary at runtime to a different virtual address than the
2208	  address it was linked at.
2209	  Since AArch64 uses the RELA relocation format, this requires a
2210	  relocation pass at runtime even if the kernel is loaded at the
2211	  same address it was linked at.
2212
2213config RANDOMIZE_BASE
2214	bool "Randomize the address of the kernel image"
2215	select RELOCATABLE
2216	help
2217	  Randomizes the virtual address at which the kernel image is
2218	  loaded, as a security feature that deters exploit attempts
2219	  relying on knowledge of the location of kernel internals.
2220
2221	  It is the bootloader's job to provide entropy, by passing a
2222	  random u64 value in /chosen/kaslr-seed at kernel entry.
2223
2224	  When booting via the UEFI stub, it will invoke the firmware's
2225	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2226	  to the kernel proper. In addition, it will randomise the physical
2227	  location of the kernel Image as well.
2228
2229	  If unsure, say N.
2230
2231config RANDOMIZE_MODULE_REGION_FULL
2232	bool "Randomize the module region over a 2 GB range"
2233	depends on RANDOMIZE_BASE
2234	default y
2235	help
2236	  Randomizes the location of the module region inside a 2 GB window
2237	  covering the core kernel. This way, it is less likely for modules
2238	  to leak information about the location of core kernel data structures
2239	  but it does imply that function calls between modules and the core
2240	  kernel will need to be resolved via veneers in the module PLT.
2241
2242	  When this option is not set, the module region will be randomized over
2243	  a limited range that contains the [_stext, _etext] interval of the
2244	  core kernel, so branch relocations are almost always in range unless
2245	  the region is exhausted. In this particular case of region
2246	  exhaustion, modules might be able to fall back to a larger 2GB area.
2247
2248config CC_HAVE_STACKPROTECTOR_SYSREG
2249	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2250
2251config STACKPROTECTOR_PER_TASK
2252	def_bool y
2253	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2254
2255config UNWIND_PATCH_PAC_INTO_SCS
2256	bool "Enable shadow call stack dynamically using code patching"
2257	# needs Clang with https://reviews.llvm.org/D111780 incorporated
2258	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2259	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2260	depends on SHADOW_CALL_STACK
2261	select UNWIND_TABLES
2262	select DYNAMIC_SCS
2263
2264endmenu # "Kernel Features"
2265
2266menu "Boot options"
2267
2268config ARM64_ACPI_PARKING_PROTOCOL
2269	bool "Enable support for the ARM64 ACPI parking protocol"
2270	depends on ACPI
2271	help
2272	  Enable support for the ARM64 ACPI parking protocol. If disabled
2273	  the kernel will not allow booting through the ARM64 ACPI parking
2274	  protocol even if the corresponding data is present in the ACPI
2275	  MADT table.
2276
2277config CMDLINE
2278	string "Default kernel command string"
2279	default ""
2280	help
2281	  Provide a set of default command-line options at build time by
2282	  entering them here. As a minimum, you should specify the the
2283	  root device (e.g. root=/dev/nfs).
2284
2285choice
2286	prompt "Kernel command line type" if CMDLINE != ""
2287	default CMDLINE_FROM_BOOTLOADER
2288	help
2289	  Choose how the kernel will handle the provided default kernel
2290	  command line string.
2291
2292config CMDLINE_FROM_BOOTLOADER
2293	bool "Use bootloader kernel arguments if available"
2294	help
2295	  Uses the command-line options passed by the boot loader. If
2296	  the boot loader doesn't provide any, the default kernel command
2297	  string provided in CMDLINE will be used.
2298
2299config CMDLINE_FORCE
2300	bool "Always use the default kernel command string"
2301	help
2302	  Always use the default kernel command string, even if the boot
2303	  loader passes other arguments to the kernel.
2304	  This is useful if you cannot or don't want to change the
2305	  command-line options your boot loader passes to the kernel.
2306
2307endchoice
2308
2309config EFI_STUB
2310	bool
2311
2312config EFI
2313	bool "UEFI runtime support"
2314	depends on OF && !CPU_BIG_ENDIAN
2315	depends on KERNEL_MODE_NEON
2316	select ARCH_SUPPORTS_ACPI
2317	select LIBFDT
2318	select UCS2_STRING
2319	select EFI_PARAMS_FROM_FDT
2320	select EFI_RUNTIME_WRAPPERS
2321	select EFI_STUB
2322	select EFI_GENERIC_STUB
2323	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2324	default y
2325	help
2326	  This option provides support for runtime services provided
2327	  by UEFI firmware (such as non-volatile variables, realtime
2328	  clock, and platform reset). A UEFI stub is also provided to
2329	  allow the kernel to be booted as an EFI application. This
2330	  is only useful on systems that have UEFI firmware.
2331
2332config DMI
2333	bool "Enable support for SMBIOS (DMI) tables"
2334	depends on EFI
2335	default y
2336	help
2337	  This enables SMBIOS/DMI feature for systems.
2338
2339	  This option is only useful on systems that have UEFI firmware.
2340	  However, even with this option, the resultant kernel should
2341	  continue to boot on existing non-UEFI platforms.
2342
2343endmenu # "Boot options"
2344
2345menu "Power management options"
2346
2347source "kernel/power/Kconfig"
2348
2349config ARCH_HIBERNATION_POSSIBLE
2350	def_bool y
2351	depends on CPU_PM
2352
2353config ARCH_HIBERNATION_HEADER
2354	def_bool y
2355	depends on HIBERNATION
2356
2357config ARCH_SUSPEND_POSSIBLE
2358	def_bool y
2359
2360endmenu # "Power management options"
2361
2362menu "CPU Power Management"
2363
2364source "drivers/cpuidle/Kconfig"
2365
2366source "drivers/cpufreq/Kconfig"
2367
2368endmenu # "CPU Power Management"
2369
2370source "drivers/acpi/Kconfig"
2371
2372source "arch/arm64/kvm/Kconfig"
2373
2374