xref: /linux/arch/arm64/Kconfig (revision 2a6b6c9a226279b4f6668450ddb21ae655558087)
1# SPDX-License-Identifier: GPL-2.0-only
2config ARM64
3	def_bool y
4	select ACPI_APMT if ACPI
5	select ACPI_CCA_REQUIRED if ACPI
6	select ACPI_GENERIC_GSI if ACPI
7	select ACPI_GTDT if ACPI
8	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
9	select ACPI_IORT if ACPI
10	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
11	select ACPI_MCFG if (ACPI && PCI)
12	select ACPI_SPCR_TABLE if ACPI
13	select ACPI_PPTT if ACPI
14	select ARCH_HAS_DEBUG_WX
15	select ARCH_BINFMT_ELF_EXTRA_PHDRS
16	select ARCH_BINFMT_ELF_STATE
17	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
18	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
19	select ARCH_ENABLE_MEMORY_HOTPLUG
20	select ARCH_ENABLE_MEMORY_HOTREMOVE
21	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
22	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
23	select ARCH_HAS_CACHE_LINE_SIZE
24	select ARCH_HAS_CURRENT_STACK_POINTER
25	select ARCH_HAS_DEBUG_VIRTUAL
26	select ARCH_HAS_DEBUG_VM_PGTABLE
27	select ARCH_HAS_DMA_PREP_COHERENT
28	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
29	select ARCH_HAS_FAST_MULTIPLIER
30	select ARCH_HAS_FORTIFY_SOURCE
31	select ARCH_HAS_GCOV_PROFILE_ALL
32	select ARCH_HAS_GIGANTIC_PAGE
33	select ARCH_HAS_KCOV
34	select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON
35	select ARCH_HAS_KEEPINITRD
36	select ARCH_HAS_MEMBARRIER_SYNC_CORE
37	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
38	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
39	select ARCH_HAS_PTE_DEVMAP
40	select ARCH_HAS_PTE_SPECIAL
41	select ARCH_HAS_HW_PTE_YOUNG
42	select ARCH_HAS_SETUP_DMA_OPS
43	select ARCH_HAS_SET_DIRECT_MAP
44	select ARCH_HAS_SET_MEMORY
45	select ARCH_STACKWALK
46	select ARCH_HAS_STRICT_KERNEL_RWX
47	select ARCH_HAS_STRICT_MODULE_RWX
48	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
49	select ARCH_HAS_SYNC_DMA_FOR_CPU
50	select ARCH_HAS_SYSCALL_WRAPPER
51	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
52	select ARCH_HAS_ZONE_DMA_SET if EXPERT
53	select ARCH_HAVE_ELF_PROT
54	select ARCH_HAVE_NMI_SAFE_CMPXCHG
55	select ARCH_HAVE_TRACE_MMIO_ACCESS
56	select ARCH_INLINE_READ_LOCK if !PREEMPTION
57	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
58	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
59	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
60	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
61	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
62	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
63	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
64	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
65	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
66	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
67	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
68	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
69	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
70	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
71	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
72	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
73	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
74	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
75	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
76	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
77	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
78	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
79	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
80	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
81	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
82	select ARCH_KEEP_MEMBLOCK
83	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
84	select ARCH_USE_CMPXCHG_LOCKREF
85	select ARCH_USE_GNU_PROPERTY
86	select ARCH_USE_MEMTEST
87	select ARCH_USE_QUEUED_RWLOCKS
88	select ARCH_USE_QUEUED_SPINLOCKS
89	select ARCH_USE_SYM_ANNOTATIONS
90	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
91	select ARCH_SUPPORTS_HUGETLBFS
92	select ARCH_SUPPORTS_MEMORY_FAILURE
93	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
94	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
95	select ARCH_SUPPORTS_LTO_CLANG_THIN
96	select ARCH_SUPPORTS_CFI_CLANG
97	select ARCH_SUPPORTS_ATOMIC_RMW
98	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
99	select ARCH_SUPPORTS_NUMA_BALANCING
100	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
101	select ARCH_SUPPORTS_PER_VMA_LOCK
102	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
103	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
104	select ARCH_WANT_DEFAULT_BPF_JIT
105	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
106	select ARCH_WANT_FRAME_POINTERS
107	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
108	select ARCH_WANT_LD_ORPHAN_WARN
109	select ARCH_WANTS_EXECMEM_LATE if EXECMEM
110	select ARCH_WANTS_NO_INSTR
111	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
112	select ARCH_HAS_UBSAN
113	select ARM_AMBA
114	select ARM_ARCH_TIMER
115	select ARM_GIC
116	select AUDIT_ARCH_COMPAT_GENERIC
117	select ARM_GIC_V2M if PCI
118	select ARM_GIC_V3
119	select ARM_GIC_V3_ITS if PCI
120	select ARM_PSCI_FW
121	select BUILDTIME_TABLE_SORT
122	select CLONE_BACKWARDS
123	select COMMON_CLK
124	select CPU_PM if (SUSPEND || CPU_IDLE)
125	select CPUMASK_OFFSTACK if NR_CPUS > 256
126	select CRC32
127	select DCACHE_WORD_ACCESS
128	select DYNAMIC_FTRACE if FUNCTION_TRACER
129	select DMA_BOUNCE_UNALIGNED_KMALLOC
130	select DMA_DIRECT_REMAP
131	select EDAC_SUPPORT
132	select FRAME_POINTER
133	select FUNCTION_ALIGNMENT_4B
134	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
135	select GENERIC_ALLOCATOR
136	select GENERIC_ARCH_TOPOLOGY
137	select GENERIC_CLOCKEVENTS_BROADCAST
138	select GENERIC_CPU_AUTOPROBE
139	select GENERIC_CPU_DEVICES
140	select GENERIC_CPU_VULNERABILITIES
141	select GENERIC_EARLY_IOREMAP
142	select GENERIC_IDLE_POLL_SETUP
143	select GENERIC_IOREMAP
144	select GENERIC_IRQ_IPI
145	select GENERIC_IRQ_PROBE
146	select GENERIC_IRQ_SHOW
147	select GENERIC_IRQ_SHOW_LEVEL
148	select GENERIC_LIB_DEVMEM_IS_ALLOWED
149	select GENERIC_PCI_IOMAP
150	select GENERIC_PTDUMP
151	select GENERIC_SCHED_CLOCK
152	select GENERIC_SMP_IDLE_THREAD
153	select GENERIC_TIME_VSYSCALL
154	select GENERIC_GETTIMEOFDAY
155	select GENERIC_VDSO_TIME_NS
156	select HARDIRQS_SW_RESEND
157	select HAS_IOPORT
158	select HAVE_MOVE_PMD
159	select HAVE_MOVE_PUD
160	select HAVE_PCI
161	select HAVE_ACPI_APEI if (ACPI && EFI)
162	select HAVE_ALIGNED_STRUCT_PAGE
163	select HAVE_ARCH_AUDITSYSCALL
164	select HAVE_ARCH_BITREVERSE
165	select HAVE_ARCH_COMPILER_H
166	select HAVE_ARCH_HUGE_VMALLOC
167	select HAVE_ARCH_HUGE_VMAP
168	select HAVE_ARCH_JUMP_LABEL
169	select HAVE_ARCH_JUMP_LABEL_RELATIVE
170	select HAVE_ARCH_KASAN
171	select HAVE_ARCH_KASAN_VMALLOC
172	select HAVE_ARCH_KASAN_SW_TAGS
173	select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
174	# Some instrumentation may be unsound, hence EXPERT
175	select HAVE_ARCH_KCSAN if EXPERT
176	select HAVE_ARCH_KFENCE
177	select HAVE_ARCH_KGDB
178	select HAVE_ARCH_MMAP_RND_BITS
179	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
180	select HAVE_ARCH_PREL32_RELOCATIONS
181	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
182	select HAVE_ARCH_SECCOMP_FILTER
183	select HAVE_ARCH_STACKLEAK
184	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
185	select HAVE_ARCH_TRACEHOOK
186	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
187	select HAVE_ARCH_VMAP_STACK
188	select HAVE_ARM_SMCCC
189	select HAVE_ASM_MODVERSIONS
190	select HAVE_EBPF_JIT
191	select HAVE_C_RECORDMCOUNT
192	select HAVE_CMPXCHG_DOUBLE
193	select HAVE_CMPXCHG_LOCAL
194	select HAVE_CONTEXT_TRACKING_USER
195	select HAVE_DEBUG_KMEMLEAK
196	select HAVE_DMA_CONTIGUOUS
197	select HAVE_DYNAMIC_FTRACE
198	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
199		if $(cc-option,-fpatchable-function-entry=2)
200	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
201		if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
202	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
203		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
204		    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
205	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
206		if DYNAMIC_FTRACE_WITH_ARGS
207	select HAVE_SAMPLE_FTRACE_DIRECT
208	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
209	select HAVE_EFFICIENT_UNALIGNED_ACCESS
210	select HAVE_GUP_FAST
211	select HAVE_FTRACE_MCOUNT_RECORD
212	select HAVE_FUNCTION_TRACER
213	select HAVE_FUNCTION_ERROR_INJECTION
214	select HAVE_FUNCTION_GRAPH_TRACER
215	select HAVE_FUNCTION_GRAPH_RETVAL
216	select HAVE_GCC_PLUGINS
217	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
218		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
219	select HAVE_HW_BREAKPOINT if PERF_EVENTS
220	select HAVE_IOREMAP_PROT
221	select HAVE_IRQ_TIME_ACCOUNTING
222	select HAVE_MOD_ARCH_SPECIFIC
223	select HAVE_NMI
224	select HAVE_PERF_EVENTS
225	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
226	select HAVE_PERF_REGS
227	select HAVE_PERF_USER_STACK_DUMP
228	select HAVE_PREEMPT_DYNAMIC_KEY
229	select HAVE_REGS_AND_STACK_ACCESS_API
230	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
231	select HAVE_FUNCTION_ARG_ACCESS_API
232	select MMU_GATHER_RCU_TABLE_FREE
233	select HAVE_RSEQ
234	select HAVE_RUST if CPU_LITTLE_ENDIAN
235	select HAVE_STACKPROTECTOR
236	select HAVE_SYSCALL_TRACEPOINTS
237	select HAVE_KPROBES
238	select HAVE_KRETPROBES
239	select HAVE_GENERIC_VDSO
240	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
241	select IRQ_DOMAIN
242	select IRQ_FORCED_THREADING
243	select KASAN_VMALLOC if KASAN
244	select LOCK_MM_AND_FIND_VMA
245	select MODULES_USE_ELF_RELA
246	select NEED_DMA_MAP_STATE
247	select NEED_SG_DMA_LENGTH
248	select OF
249	select OF_EARLY_FLATTREE
250	select PCI_DOMAINS_GENERIC if PCI
251	select PCI_ECAM if (ACPI && PCI)
252	select PCI_SYSCALL if PCI
253	select POWER_RESET
254	select POWER_SUPPLY
255	select SPARSE_IRQ
256	select SWIOTLB
257	select SYSCTL_EXCEPTION_TRACE
258	select THREAD_INFO_IN_TASK
259	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
260	select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
261	select TRACE_IRQFLAGS_SUPPORT
262	select TRACE_IRQFLAGS_NMI_SUPPORT
263	select HAVE_SOFTIRQ_ON_OWN_STACK
264	select USER_STACKTRACE_SUPPORT
265	help
266	  ARM 64-bit (AArch64) Linux support.
267
268config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
269	def_bool CC_IS_CLANG
270	# https://github.com/ClangBuiltLinux/linux/issues/1507
271	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
272	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
273
274config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
275	def_bool CC_IS_GCC
276	depends on $(cc-option,-fpatchable-function-entry=2)
277	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
278
279config 64BIT
280	def_bool y
281
282config MMU
283	def_bool y
284
285config ARM64_CONT_PTE_SHIFT
286	int
287	default 5 if PAGE_SIZE_64KB
288	default 7 if PAGE_SIZE_16KB
289	default 4
290
291config ARM64_CONT_PMD_SHIFT
292	int
293	default 5 if PAGE_SIZE_64KB
294	default 5 if PAGE_SIZE_16KB
295	default 4
296
297config ARCH_MMAP_RND_BITS_MIN
298	default 14 if PAGE_SIZE_64KB
299	default 16 if PAGE_SIZE_16KB
300	default 18
301
302# max bits determined by the following formula:
303#  VA_BITS - PAGE_SHIFT - 3
304config ARCH_MMAP_RND_BITS_MAX
305	default 19 if ARM64_VA_BITS=36
306	default 24 if ARM64_VA_BITS=39
307	default 27 if ARM64_VA_BITS=42
308	default 30 if ARM64_VA_BITS=47
309	default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
310	default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
311	default 33 if ARM64_VA_BITS=48
312	default 14 if ARM64_64K_PAGES
313	default 16 if ARM64_16K_PAGES
314	default 18
315
316config ARCH_MMAP_RND_COMPAT_BITS_MIN
317	default 7 if ARM64_64K_PAGES
318	default 9 if ARM64_16K_PAGES
319	default 11
320
321config ARCH_MMAP_RND_COMPAT_BITS_MAX
322	default 16
323
324config NO_IOPORT_MAP
325	def_bool y if !PCI
326
327config STACKTRACE_SUPPORT
328	def_bool y
329
330config ILLEGAL_POINTER_VALUE
331	hex
332	default 0xdead000000000000
333
334config LOCKDEP_SUPPORT
335	def_bool y
336
337config GENERIC_BUG
338	def_bool y
339	depends on BUG
340
341config GENERIC_BUG_RELATIVE_POINTERS
342	def_bool y
343	depends on GENERIC_BUG
344
345config GENERIC_HWEIGHT
346	def_bool y
347
348config GENERIC_CSUM
349	def_bool y
350
351config GENERIC_CALIBRATE_DELAY
352	def_bool y
353
354config SMP
355	def_bool y
356
357config KERNEL_MODE_NEON
358	def_bool y
359
360config FIX_EARLYCON_MEM
361	def_bool y
362
363config PGTABLE_LEVELS
364	int
365	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
366	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
367	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
368	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
369	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
370	default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
371	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
372	default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
373
374config ARCH_SUPPORTS_UPROBES
375	def_bool y
376
377config ARCH_PROC_KCORE_TEXT
378	def_bool y
379
380config BROKEN_GAS_INST
381	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
382
383config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
384	bool
385	# Clang's __builtin_return_address() strips the PAC since 12.0.0
386	# https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
387	default y if CC_IS_CLANG
388	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
389	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
390	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
391	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
392	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
393	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
394	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
395	default n
396
397config KASAN_SHADOW_OFFSET
398	hex
399	depends on KASAN_GENERIC || KASAN_SW_TAGS
400	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
401	default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
402	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
403	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
404	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
405	default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
406	default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
407	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
408	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
409	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
410	default 0xffffffffffffffff
411
412config UNWIND_TABLES
413	bool
414
415source "arch/arm64/Kconfig.platforms"
416
417menu "Kernel Features"
418
419menu "ARM errata workarounds via the alternatives framework"
420
421config AMPERE_ERRATUM_AC03_CPU_38
422        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
423	default y
424	help
425	  This option adds an alternative code sequence to work around Ampere
426	  erratum AC03_CPU_38 on AmpereOne.
427
428	  The affected design reports FEAT_HAFDBS as not implemented in
429	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
430	  as required by the architecture. The unadvertised HAFDBS
431	  implementation suffers from an additional erratum where hardware
432	  A/D updates can occur after a PTE has been marked invalid.
433
434	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
435	  which avoids enabling unadvertised hardware Access Flag management
436	  at stage-2.
437
438	  If unsure, say Y.
439
440config ARM64_WORKAROUND_CLEAN_CACHE
441	bool
442
443config ARM64_ERRATUM_826319
444	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
445	default y
446	select ARM64_WORKAROUND_CLEAN_CACHE
447	help
448	  This option adds an alternative code sequence to work around ARM
449	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
450	  AXI master interface and an L2 cache.
451
452	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
453	  and is unable to accept a certain write via this interface, it will
454	  not progress on read data presented on the read data channel and the
455	  system can deadlock.
456
457	  The workaround promotes data cache clean instructions to
458	  data cache clean-and-invalidate.
459	  Please note that this does not necessarily enable the workaround,
460	  as it depends on the alternative framework, which will only patch
461	  the kernel if an affected CPU is detected.
462
463	  If unsure, say Y.
464
465config ARM64_ERRATUM_827319
466	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
467	default y
468	select ARM64_WORKAROUND_CLEAN_CACHE
469	help
470	  This option adds an alternative code sequence to work around ARM
471	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
472	  master interface and an L2 cache.
473
474	  Under certain conditions this erratum can cause a clean line eviction
475	  to occur at the same time as another transaction to the same address
476	  on the AMBA 5 CHI interface, which can cause data corruption if the
477	  interconnect reorders the two transactions.
478
479	  The workaround promotes data cache clean instructions to
480	  data cache clean-and-invalidate.
481	  Please note that this does not necessarily enable the workaround,
482	  as it depends on the alternative framework, which will only patch
483	  the kernel if an affected CPU is detected.
484
485	  If unsure, say Y.
486
487config ARM64_ERRATUM_824069
488	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
489	default y
490	select ARM64_WORKAROUND_CLEAN_CACHE
491	help
492	  This option adds an alternative code sequence to work around ARM
493	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
494	  to a coherent interconnect.
495
496	  If a Cortex-A53 processor is executing a store or prefetch for
497	  write instruction at the same time as a processor in another
498	  cluster is executing a cache maintenance operation to the same
499	  address, then this erratum might cause a clean cache line to be
500	  incorrectly marked as dirty.
501
502	  The workaround promotes data cache clean instructions to
503	  data cache clean-and-invalidate.
504	  Please note that this option does not necessarily enable the
505	  workaround, as it depends on the alternative framework, which will
506	  only patch the kernel if an affected CPU is detected.
507
508	  If unsure, say Y.
509
510config ARM64_ERRATUM_819472
511	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
512	default y
513	select ARM64_WORKAROUND_CLEAN_CACHE
514	help
515	  This option adds an alternative code sequence to work around ARM
516	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
517	  present when it is connected to a coherent interconnect.
518
519	  If the processor is executing a load and store exclusive sequence at
520	  the same time as a processor in another cluster is executing a cache
521	  maintenance operation to the same address, then this erratum might
522	  cause data corruption.
523
524	  The workaround promotes data cache clean instructions to
525	  data cache clean-and-invalidate.
526	  Please note that this does not necessarily enable the workaround,
527	  as it depends on the alternative framework, which will only patch
528	  the kernel if an affected CPU is detected.
529
530	  If unsure, say Y.
531
532config ARM64_ERRATUM_832075
533	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
534	default y
535	help
536	  This option adds an alternative code sequence to work around ARM
537	  erratum 832075 on Cortex-A57 parts up to r1p2.
538
539	  Affected Cortex-A57 parts might deadlock when exclusive load/store
540	  instructions to Write-Back memory are mixed with Device loads.
541
542	  The workaround is to promote device loads to use Load-Acquire
543	  semantics.
544	  Please note that this does not necessarily enable the workaround,
545	  as it depends on the alternative framework, which will only patch
546	  the kernel if an affected CPU is detected.
547
548	  If unsure, say Y.
549
550config ARM64_ERRATUM_834220
551	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
552	depends on KVM
553	help
554	  This option adds an alternative code sequence to work around ARM
555	  erratum 834220 on Cortex-A57 parts up to r1p2.
556
557	  Affected Cortex-A57 parts might report a Stage 2 translation
558	  fault as the result of a Stage 1 fault for load crossing a
559	  page boundary when there is a permission or device memory
560	  alignment fault at Stage 1 and a translation fault at Stage 2.
561
562	  The workaround is to verify that the Stage 1 translation
563	  doesn't generate a fault before handling the Stage 2 fault.
564	  Please note that this does not necessarily enable the workaround,
565	  as it depends on the alternative framework, which will only patch
566	  the kernel if an affected CPU is detected.
567
568	  If unsure, say N.
569
570config ARM64_ERRATUM_1742098
571	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
572	depends on COMPAT
573	default y
574	help
575	  This option removes the AES hwcap for aarch32 user-space to
576	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
577
578	  Affected parts may corrupt the AES state if an interrupt is
579	  taken between a pair of AES instructions. These instructions
580	  are only present if the cryptography extensions are present.
581	  All software should have a fallback implementation for CPUs
582	  that don't implement the cryptography extensions.
583
584	  If unsure, say Y.
585
586config ARM64_ERRATUM_845719
587	bool "Cortex-A53: 845719: a load might read incorrect data"
588	depends on COMPAT
589	default y
590	help
591	  This option adds an alternative code sequence to work around ARM
592	  erratum 845719 on Cortex-A53 parts up to r0p4.
593
594	  When running a compat (AArch32) userspace on an affected Cortex-A53
595	  part, a load at EL0 from a virtual address that matches the bottom 32
596	  bits of the virtual address used by a recent load at (AArch64) EL1
597	  might return incorrect data.
598
599	  The workaround is to write the contextidr_el1 register on exception
600	  return to a 32-bit task.
601	  Please note that this does not necessarily enable the workaround,
602	  as it depends on the alternative framework, which will only patch
603	  the kernel if an affected CPU is detected.
604
605	  If unsure, say Y.
606
607config ARM64_ERRATUM_843419
608	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
609	default y
610	help
611	  This option links the kernel with '--fix-cortex-a53-843419' and
612	  enables PLT support to replace certain ADRP instructions, which can
613	  cause subsequent memory accesses to use an incorrect address on
614	  Cortex-A53 parts up to r0p4.
615
616	  If unsure, say Y.
617
618config ARM64_LD_HAS_FIX_ERRATUM_843419
619	def_bool $(ld-option,--fix-cortex-a53-843419)
620
621config ARM64_ERRATUM_1024718
622	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
623	default y
624	help
625	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
626
627	  Affected Cortex-A55 cores (all revisions) could cause incorrect
628	  update of the hardware dirty bit when the DBM/AP bits are updated
629	  without a break-before-make. The workaround is to disable the usage
630	  of hardware DBM locally on the affected cores. CPUs not affected by
631	  this erratum will continue to use the feature.
632
633	  If unsure, say Y.
634
635config ARM64_ERRATUM_1418040
636	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
637	default y
638	depends on COMPAT
639	help
640	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
641	  errata 1188873 and 1418040.
642
643	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
644	  cause register corruption when accessing the timer registers
645	  from AArch32 userspace.
646
647	  If unsure, say Y.
648
649config ARM64_WORKAROUND_SPECULATIVE_AT
650	bool
651
652config ARM64_ERRATUM_1165522
653	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
654	default y
655	select ARM64_WORKAROUND_SPECULATIVE_AT
656	help
657	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
658
659	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
660	  corrupted TLBs by speculating an AT instruction during a guest
661	  context switch.
662
663	  If unsure, say Y.
664
665config ARM64_ERRATUM_1319367
666	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
667	default y
668	select ARM64_WORKAROUND_SPECULATIVE_AT
669	help
670	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
671	  and A72 erratum 1319367
672
673	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
674	  speculating an AT instruction during a guest context switch.
675
676	  If unsure, say Y.
677
678config ARM64_ERRATUM_1530923
679	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
680	default y
681	select ARM64_WORKAROUND_SPECULATIVE_AT
682	help
683	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
684
685	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
686	  corrupted TLBs by speculating an AT instruction during a guest
687	  context switch.
688
689	  If unsure, say Y.
690
691config ARM64_WORKAROUND_REPEAT_TLBI
692	bool
693
694config ARM64_ERRATUM_2441007
695	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
696	select ARM64_WORKAROUND_REPEAT_TLBI
697	help
698	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
699
700	  Under very rare circumstances, affected Cortex-A55 CPUs
701	  may not handle a race between a break-before-make sequence on one
702	  CPU, and another CPU accessing the same page. This could allow a
703	  store to a page that has been unmapped.
704
705	  Work around this by adding the affected CPUs to the list that needs
706	  TLB sequences to be done twice.
707
708	  If unsure, say N.
709
710config ARM64_ERRATUM_1286807
711	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
712	select ARM64_WORKAROUND_REPEAT_TLBI
713	help
714	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
715
716	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
717	  address for a cacheable mapping of a location is being
718	  accessed by a core while another core is remapping the virtual
719	  address to a new physical page using the recommended
720	  break-before-make sequence, then under very rare circumstances
721	  TLBI+DSB completes before a read using the translation being
722	  invalidated has been observed by other observers. The
723	  workaround repeats the TLBI+DSB operation.
724
725	  If unsure, say N.
726
727config ARM64_ERRATUM_1463225
728	bool "Cortex-A76: Software Step might prevent interrupt recognition"
729	default y
730	help
731	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
732
733	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
734	  of a system call instruction (SVC) can prevent recognition of
735	  subsequent interrupts when software stepping is disabled in the
736	  exception handler of the system call and either kernel debugging
737	  is enabled or VHE is in use.
738
739	  Work around the erratum by triggering a dummy step exception
740	  when handling a system call from a task that is being stepped
741	  in a VHE configuration of the kernel.
742
743	  If unsure, say Y.
744
745config ARM64_ERRATUM_1542419
746	bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
747	help
748	  This option adds a workaround for ARM Neoverse-N1 erratum
749	  1542419.
750
751	  Affected Neoverse-N1 cores could execute a stale instruction when
752	  modified by another CPU. The workaround depends on a firmware
753	  counterpart.
754
755	  Workaround the issue by hiding the DIC feature from EL0. This
756	  forces user-space to perform cache maintenance.
757
758	  If unsure, say N.
759
760config ARM64_ERRATUM_1508412
761	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
762	default y
763	help
764	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
765
766	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
767	  of a store-exclusive or read of PAR_EL1 and a load with device or
768	  non-cacheable memory attributes. The workaround depends on a firmware
769	  counterpart.
770
771	  KVM guests must also have the workaround implemented or they can
772	  deadlock the system.
773
774	  Work around the issue by inserting DMB SY barriers around PAR_EL1
775	  register reads and warning KVM users. The DMB barrier is sufficient
776	  to prevent a speculative PAR_EL1 read.
777
778	  If unsure, say Y.
779
780config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
781	bool
782
783config ARM64_ERRATUM_2051678
784	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
785	default y
786	help
787	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
788	  Affected Cortex-A510 might not respect the ordering rules for
789	  hardware update of the page table's dirty bit. The workaround
790	  is to not enable the feature on affected CPUs.
791
792	  If unsure, say Y.
793
794config ARM64_ERRATUM_2077057
795	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
796	default y
797	help
798	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
799	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
800	  expected, but a Pointer Authentication trap is taken instead. The
801	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
802	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
803
804	  This can only happen when EL2 is stepping EL1.
805
806	  When these conditions occur, the SPSR_EL2 value is unchanged from the
807	  previous guest entry, and can be restored from the in-memory copy.
808
809	  If unsure, say Y.
810
811config ARM64_ERRATUM_2658417
812	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
813	default y
814	help
815	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
816	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
817	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
818	  A510 CPUs are using shared neon hardware. As the sharing is not
819	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
820	  user-space should not be using these instructions.
821
822	  If unsure, say Y.
823
824config ARM64_ERRATUM_2119858
825	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
826	default y
827	depends on CORESIGHT_TRBE
828	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
829	help
830	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
831
832	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
833	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
834	  the event of a WRAP event.
835
836	  Work around the issue by always making sure we move the TRBPTR_EL1 by
837	  256 bytes before enabling the buffer and filling the first 256 bytes of
838	  the buffer with ETM ignore packets upon disabling.
839
840	  If unsure, say Y.
841
842config ARM64_ERRATUM_2139208
843	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
844	default y
845	depends on CORESIGHT_TRBE
846	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
847	help
848	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
849
850	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
851	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
852	  the event of a WRAP event.
853
854	  Work around the issue by always making sure we move the TRBPTR_EL1 by
855	  256 bytes before enabling the buffer and filling the first 256 bytes of
856	  the buffer with ETM ignore packets upon disabling.
857
858	  If unsure, say Y.
859
860config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
861	bool
862
863config ARM64_ERRATUM_2054223
864	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
865	default y
866	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
867	help
868	  Enable workaround for ARM Cortex-A710 erratum 2054223
869
870	  Affected cores may fail to flush the trace data on a TSB instruction, when
871	  the PE is in trace prohibited state. This will cause losing a few bytes
872	  of the trace cached.
873
874	  Workaround is to issue two TSB consecutively on affected cores.
875
876	  If unsure, say Y.
877
878config ARM64_ERRATUM_2067961
879	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
880	default y
881	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
882	help
883	  Enable workaround for ARM Neoverse-N2 erratum 2067961
884
885	  Affected cores may fail to flush the trace data on a TSB instruction, when
886	  the PE is in trace prohibited state. This will cause losing a few bytes
887	  of the trace cached.
888
889	  Workaround is to issue two TSB consecutively on affected cores.
890
891	  If unsure, say Y.
892
893config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
894	bool
895
896config ARM64_ERRATUM_2253138
897	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
898	depends on CORESIGHT_TRBE
899	default y
900	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
901	help
902	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
903
904	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
905	  for TRBE. Under some conditions, the TRBE might generate a write to the next
906	  virtually addressed page following the last page of the TRBE address space
907	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
908
909	  Work around this in the driver by always making sure that there is a
910	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
911
912	  If unsure, say Y.
913
914config ARM64_ERRATUM_2224489
915	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
916	depends on CORESIGHT_TRBE
917	default y
918	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
919	help
920	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
921
922	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
923	  for TRBE. Under some conditions, the TRBE might generate a write to the next
924	  virtually addressed page following the last page of the TRBE address space
925	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
926
927	  Work around this in the driver by always making sure that there is a
928	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
929
930	  If unsure, say Y.
931
932config ARM64_ERRATUM_2441009
933	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
934	select ARM64_WORKAROUND_REPEAT_TLBI
935	help
936	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
937
938	  Under very rare circumstances, affected Cortex-A510 CPUs
939	  may not handle a race between a break-before-make sequence on one
940	  CPU, and another CPU accessing the same page. This could allow a
941	  store to a page that has been unmapped.
942
943	  Work around this by adding the affected CPUs to the list that needs
944	  TLB sequences to be done twice.
945
946	  If unsure, say N.
947
948config ARM64_ERRATUM_2064142
949	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
950	depends on CORESIGHT_TRBE
951	default y
952	help
953	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
954
955	  Affected Cortex-A510 core might fail to write into system registers after the
956	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
957	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
958	  and TRBTRG_EL1 will be ignored and will not be effected.
959
960	  Work around this in the driver by executing TSB CSYNC and DSB after collection
961	  is stopped and before performing a system register write to one of the affected
962	  registers.
963
964	  If unsure, say Y.
965
966config ARM64_ERRATUM_2038923
967	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
968	depends on CORESIGHT_TRBE
969	default y
970	help
971	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
972
973	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
974	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
975	  might be corrupted. This happens after TRBE buffer has been enabled by setting
976	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
977	  execution changes from a context, in which trace is prohibited to one where it
978	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
979	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
980	  the trace buffer state might be corrupted.
981
982	  Work around this in the driver by preventing an inconsistent view of whether the
983	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
984	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
985	  two ISB instructions if no ERET is to take place.
986
987	  If unsure, say Y.
988
989config ARM64_ERRATUM_1902691
990	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
991	depends on CORESIGHT_TRBE
992	default y
993	help
994	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
995
996	  Affected Cortex-A510 core might cause trace data corruption, when being written
997	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
998	  trace data.
999
1000	  Work around this problem in the driver by just preventing TRBE initialization on
1001	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1002	  on such implementations. This will cover the kernel for any firmware that doesn't
1003	  do this already.
1004
1005	  If unsure, say Y.
1006
1007config ARM64_ERRATUM_2457168
1008	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1009	depends on ARM64_AMU_EXTN
1010	default y
1011	help
1012	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1013
1014	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1015	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1016	  incorrectly giving a significantly higher output value.
1017
1018	  Work around this problem by returning 0 when reading the affected counter in
1019	  key locations that results in disabling all users of this counter. This effect
1020	  is the same to firmware disabling affected counters.
1021
1022	  If unsure, say Y.
1023
1024config ARM64_ERRATUM_2645198
1025	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1026	default y
1027	help
1028	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1029
1030	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1031	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1032	  next instruction abort caused by permission fault.
1033
1034	  Only user-space does executable to non-executable permission transition via
1035	  mprotect() system call. Workaround the problem by doing a break-before-make
1036	  TLB invalidation, for all changes to executable user space mappings.
1037
1038	  If unsure, say Y.
1039
1040config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1041	bool
1042
1043config ARM64_ERRATUM_2966298
1044	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1045	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1046	default y
1047	help
1048	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1049
1050	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1051	  load might leak data from a privileged level via a cache side channel.
1052
1053	  Work around this problem by executing a TLBI before returning to EL0.
1054
1055	  If unsure, say Y.
1056
1057config ARM64_ERRATUM_3117295
1058	bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1059	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1060	default y
1061	help
1062	  This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1063
1064	  On an affected Cortex-A510 core, a speculatively executed unprivileged
1065	  load might leak data from a privileged level via a cache side channel.
1066
1067	  Work around this problem by executing a TLBI before returning to EL0.
1068
1069	  If unsure, say Y.
1070
1071config ARM64_ERRATUM_3194386
1072	bool "Cortex-{A720,X4,X925}/Neoverse-V3: workaround for MSR SSBS not self-synchronizing"
1073	default y
1074	help
1075	  This option adds the workaround for the following errata:
1076
1077	  * ARM Cortex-A710 erratam 3324338
1078	  * ARM Cortex-A720 erratum 3456091
1079	  * ARM Cortex-X2 erratum 3324338
1080	  * ARM Cortex-X3 erratum 3324335
1081	  * ARM Cortex-X4 erratum 3194386
1082	  * ARM Cortex-X925 erratum 3324334
1083	  * ARM Neoverse N2 erratum 3324339
1084	  * ARM Neoverse V2 erratum 3324336
1085	  * ARM Neoverse-V3 erratum 3312417
1086
1087	  On affected cores "MSR SSBS, #0" instructions may not affect
1088	  subsequent speculative instructions, which may permit unexepected
1089	  speculative store bypassing.
1090
1091	  Work around this problem by placing a speculation barrier after
1092	  kernel changes to SSBS. The presence of the SSBS special-purpose
1093	  register is hidden from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such
1094	  that userspace will use the PR_SPEC_STORE_BYPASS prctl to change
1095	  SSBS.
1096
1097	  If unsure, say Y.
1098
1099config CAVIUM_ERRATUM_22375
1100	bool "Cavium erratum 22375, 24313"
1101	default y
1102	help
1103	  Enable workaround for errata 22375 and 24313.
1104
1105	  This implements two gicv3-its errata workarounds for ThunderX. Both
1106	  with a small impact affecting only ITS table allocation.
1107
1108	    erratum 22375: only alloc 8MB table size
1109	    erratum 24313: ignore memory access type
1110
1111	  The fixes are in ITS initialization and basically ignore memory access
1112	  type and table size provided by the TYPER and BASER registers.
1113
1114	  If unsure, say Y.
1115
1116config CAVIUM_ERRATUM_23144
1117	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1118	depends on NUMA
1119	default y
1120	help
1121	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1122
1123	  If unsure, say Y.
1124
1125config CAVIUM_ERRATUM_23154
1126	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1127	default y
1128	help
1129	  The ThunderX GICv3 implementation requires a modified version for
1130	  reading the IAR status to ensure data synchronization
1131	  (access to icc_iar1_el1 is not sync'ed before and after).
1132
1133	  It also suffers from erratum 38545 (also present on Marvell's
1134	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1135	  spuriously presented to the CPU interface.
1136
1137	  If unsure, say Y.
1138
1139config CAVIUM_ERRATUM_27456
1140	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1141	default y
1142	help
1143	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1144	  instructions may cause the icache to become corrupted if it
1145	  contains data for a non-current ASID.  The fix is to
1146	  invalidate the icache when changing the mm context.
1147
1148	  If unsure, say Y.
1149
1150config CAVIUM_ERRATUM_30115
1151	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1152	default y
1153	help
1154	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1155	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1156	  interrupts in host. Trapping both GICv3 group-0 and group-1
1157	  accesses sidesteps the issue.
1158
1159	  If unsure, say Y.
1160
1161config CAVIUM_TX2_ERRATUM_219
1162	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1163	default y
1164	help
1165	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1166	  TTBR update and the corresponding context synchronizing operation can
1167	  cause a spurious Data Abort to be delivered to any hardware thread in
1168	  the CPU core.
1169
1170	  Work around the issue by avoiding the problematic code sequence and
1171	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1172	  trap handler performs the corresponding register access, skips the
1173	  instruction and ensures context synchronization by virtue of the
1174	  exception return.
1175
1176	  If unsure, say Y.
1177
1178config FUJITSU_ERRATUM_010001
1179	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1180	default y
1181	help
1182	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1183	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1184	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1185	  This fault occurs under a specific hardware condition when a
1186	  load/store instruction performs an address translation using:
1187	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1188	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1189	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1190	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1191
1192	  The workaround is to ensure these bits are clear in TCR_ELx.
1193	  The workaround only affects the Fujitsu-A64FX.
1194
1195	  If unsure, say Y.
1196
1197config HISILICON_ERRATUM_161600802
1198	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1199	default y
1200	help
1201	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1202	  when issued ITS commands such as VMOVP and VMAPP, and requires
1203	  a 128kB offset to be applied to the target address in this commands.
1204
1205	  If unsure, say Y.
1206
1207config QCOM_FALKOR_ERRATUM_1003
1208	bool "Falkor E1003: Incorrect translation due to ASID change"
1209	default y
1210	help
1211	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1212	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1213	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1214	  then only for entries in the walk cache, since the leaf translation
1215	  is unchanged. Work around the erratum by invalidating the walk cache
1216	  entries for the trampoline before entering the kernel proper.
1217
1218config QCOM_FALKOR_ERRATUM_1009
1219	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1220	default y
1221	select ARM64_WORKAROUND_REPEAT_TLBI
1222	help
1223	  On Falkor v1, the CPU may prematurely complete a DSB following a
1224	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1225	  one more time to fix the issue.
1226
1227	  If unsure, say Y.
1228
1229config QCOM_QDF2400_ERRATUM_0065
1230	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1231	default y
1232	help
1233	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1234	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1235	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1236
1237	  If unsure, say Y.
1238
1239config QCOM_FALKOR_ERRATUM_E1041
1240	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1241	default y
1242	help
1243	  Falkor CPU may speculatively fetch instructions from an improper
1244	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1245	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1246
1247	  If unsure, say Y.
1248
1249config NVIDIA_CARMEL_CNP_ERRATUM
1250	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1251	default y
1252	help
1253	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1254	  invalidate shared TLB entries installed by a different core, as it would
1255	  on standard ARM cores.
1256
1257	  If unsure, say Y.
1258
1259config ROCKCHIP_ERRATUM_3588001
1260	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1261	default y
1262	help
1263	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1264	  This means, that its sharability feature may not be used, even though it
1265	  is supported by the IP itself.
1266
1267	  If unsure, say Y.
1268
1269config SOCIONEXT_SYNQUACER_PREITS
1270	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1271	default y
1272	help
1273	  Socionext Synquacer SoCs implement a separate h/w block to generate
1274	  MSI doorbell writes with non-zero values for the device ID.
1275
1276	  If unsure, say Y.
1277
1278endmenu # "ARM errata workarounds via the alternatives framework"
1279
1280choice
1281	prompt "Page size"
1282	default ARM64_4K_PAGES
1283	help
1284	  Page size (translation granule) configuration.
1285
1286config ARM64_4K_PAGES
1287	bool "4KB"
1288	select HAVE_PAGE_SIZE_4KB
1289	help
1290	  This feature enables 4KB pages support.
1291
1292config ARM64_16K_PAGES
1293	bool "16KB"
1294	select HAVE_PAGE_SIZE_16KB
1295	help
1296	  The system will use 16KB pages support. AArch32 emulation
1297	  requires applications compiled with 16K (or a multiple of 16K)
1298	  aligned segments.
1299
1300config ARM64_64K_PAGES
1301	bool "64KB"
1302	select HAVE_PAGE_SIZE_64KB
1303	help
1304	  This feature enables 64KB pages support (4KB by default)
1305	  allowing only two levels of page tables and faster TLB
1306	  look-up. AArch32 emulation requires applications compiled
1307	  with 64K aligned segments.
1308
1309endchoice
1310
1311choice
1312	prompt "Virtual address space size"
1313	default ARM64_VA_BITS_52
1314	help
1315	  Allows choosing one of multiple possible virtual address
1316	  space sizes. The level of translation table is determined by
1317	  a combination of page size and virtual address space size.
1318
1319config ARM64_VA_BITS_36
1320	bool "36-bit" if EXPERT
1321	depends on PAGE_SIZE_16KB
1322
1323config ARM64_VA_BITS_39
1324	bool "39-bit"
1325	depends on PAGE_SIZE_4KB
1326
1327config ARM64_VA_BITS_42
1328	bool "42-bit"
1329	depends on PAGE_SIZE_64KB
1330
1331config ARM64_VA_BITS_47
1332	bool "47-bit"
1333	depends on PAGE_SIZE_16KB
1334
1335config ARM64_VA_BITS_48
1336	bool "48-bit"
1337
1338config ARM64_VA_BITS_52
1339	bool "52-bit"
1340	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1341	help
1342	  Enable 52-bit virtual addressing for userspace when explicitly
1343	  requested via a hint to mmap(). The kernel will also use 52-bit
1344	  virtual addresses for its own mappings (provided HW support for
1345	  this feature is available, otherwise it reverts to 48-bit).
1346
1347	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1348	  ARMv8.3 Pointer Authentication will result in the PAC being
1349	  reduced from 7 bits to 3 bits, which may have a significant
1350	  impact on its susceptibility to brute-force attacks.
1351
1352	  If unsure, select 48-bit virtual addressing instead.
1353
1354endchoice
1355
1356config ARM64_FORCE_52BIT
1357	bool "Force 52-bit virtual addresses for userspace"
1358	depends on ARM64_VA_BITS_52 && EXPERT
1359	help
1360	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1361	  to maintain compatibility with older software by providing 48-bit VAs
1362	  unless a hint is supplied to mmap.
1363
1364	  This configuration option disables the 48-bit compatibility logic, and
1365	  forces all userspace addresses to be 52-bit on HW that supports it. One
1366	  should only enable this configuration option for stress testing userspace
1367	  memory management code. If unsure say N here.
1368
1369config ARM64_VA_BITS
1370	int
1371	default 36 if ARM64_VA_BITS_36
1372	default 39 if ARM64_VA_BITS_39
1373	default 42 if ARM64_VA_BITS_42
1374	default 47 if ARM64_VA_BITS_47
1375	default 48 if ARM64_VA_BITS_48
1376	default 52 if ARM64_VA_BITS_52
1377
1378choice
1379	prompt "Physical address space size"
1380	default ARM64_PA_BITS_48
1381	help
1382	  Choose the maximum physical address range that the kernel will
1383	  support.
1384
1385config ARM64_PA_BITS_48
1386	bool "48-bit"
1387	depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1388
1389config ARM64_PA_BITS_52
1390	bool "52-bit"
1391	depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1392	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1393	help
1394	  Enable support for a 52-bit physical address space, introduced as
1395	  part of the ARMv8.2-LPA extension.
1396
1397	  With this enabled, the kernel will also continue to work on CPUs that
1398	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1399	  minor performance overhead).
1400
1401endchoice
1402
1403config ARM64_PA_BITS
1404	int
1405	default 48 if ARM64_PA_BITS_48
1406	default 52 if ARM64_PA_BITS_52
1407
1408config ARM64_LPA2
1409	def_bool y
1410	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1411
1412choice
1413	prompt "Endianness"
1414	default CPU_LITTLE_ENDIAN
1415	help
1416	  Select the endianness of data accesses performed by the CPU. Userspace
1417	  applications will need to be compiled and linked for the endianness
1418	  that is selected here.
1419
1420config CPU_BIG_ENDIAN
1421	bool "Build big-endian kernel"
1422	# https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1423	depends on AS_IS_GNU || AS_VERSION >= 150000
1424	help
1425	  Say Y if you plan on running a kernel with a big-endian userspace.
1426
1427config CPU_LITTLE_ENDIAN
1428	bool "Build little-endian kernel"
1429	help
1430	  Say Y if you plan on running a kernel with a little-endian userspace.
1431	  This is usually the case for distributions targeting arm64.
1432
1433endchoice
1434
1435config SCHED_MC
1436	bool "Multi-core scheduler support"
1437	help
1438	  Multi-core scheduler support improves the CPU scheduler's decision
1439	  making when dealing with multi-core CPU chips at a cost of slightly
1440	  increased overhead in some places. If unsure say N here.
1441
1442config SCHED_CLUSTER
1443	bool "Cluster scheduler support"
1444	help
1445	  Cluster scheduler support improves the CPU scheduler's decision
1446	  making when dealing with machines that have clusters of CPUs.
1447	  Cluster usually means a couple of CPUs which are placed closely
1448	  by sharing mid-level caches, last-level cache tags or internal
1449	  busses.
1450
1451config SCHED_SMT
1452	bool "SMT scheduler support"
1453	help
1454	  Improves the CPU scheduler's decision making when dealing with
1455	  MultiThreading at a cost of slightly increased overhead in some
1456	  places. If unsure say N here.
1457
1458config NR_CPUS
1459	int "Maximum number of CPUs (2-4096)"
1460	range 2 4096
1461	default "512"
1462
1463config HOTPLUG_CPU
1464	bool "Support for hot-pluggable CPUs"
1465	select GENERIC_IRQ_MIGRATION
1466	help
1467	  Say Y here to experiment with turning CPUs off and on.  CPUs
1468	  can be controlled through /sys/devices/system/cpu.
1469
1470# Common NUMA Features
1471config NUMA
1472	bool "NUMA Memory Allocation and Scheduler Support"
1473	select GENERIC_ARCH_NUMA
1474	select OF_NUMA
1475	select HAVE_SETUP_PER_CPU_AREA
1476	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1477	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1478	select USE_PERCPU_NUMA_NODE_ID
1479	help
1480	  Enable NUMA (Non-Uniform Memory Access) support.
1481
1482	  The kernel will try to allocate memory used by a CPU on the
1483	  local memory of the CPU and add some more
1484	  NUMA awareness to the kernel.
1485
1486config NODES_SHIFT
1487	int "Maximum NUMA Nodes (as a power of 2)"
1488	range 1 10
1489	default "4"
1490	depends on NUMA
1491	help
1492	  Specify the maximum number of NUMA Nodes available on the target
1493	  system.  Increases memory reserved to accommodate various tables.
1494
1495source "kernel/Kconfig.hz"
1496
1497config ARCH_SPARSEMEM_ENABLE
1498	def_bool y
1499	select SPARSEMEM_VMEMMAP_ENABLE
1500	select SPARSEMEM_VMEMMAP
1501
1502config HW_PERF_EVENTS
1503	def_bool y
1504	depends on ARM_PMU
1505
1506# Supported by clang >= 7.0 or GCC >= 12.0.0
1507config CC_HAVE_SHADOW_CALL_STACK
1508	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1509
1510config PARAVIRT
1511	bool "Enable paravirtualization code"
1512	help
1513	  This changes the kernel so it can modify itself when it is run
1514	  under a hypervisor, potentially improving performance significantly
1515	  over full virtualization.
1516
1517config PARAVIRT_TIME_ACCOUNTING
1518	bool "Paravirtual steal time accounting"
1519	select PARAVIRT
1520	help
1521	  Select this option to enable fine granularity task steal time
1522	  accounting. Time spent executing other tasks in parallel with
1523	  the current vCPU is discounted from the vCPU power. To account for
1524	  that, there can be a small performance impact.
1525
1526	  If in doubt, say N here.
1527
1528config ARCH_SUPPORTS_KEXEC
1529	def_bool PM_SLEEP_SMP
1530
1531config ARCH_SUPPORTS_KEXEC_FILE
1532	def_bool y
1533
1534config ARCH_SELECTS_KEXEC_FILE
1535	def_bool y
1536	depends on KEXEC_FILE
1537	select HAVE_IMA_KEXEC if IMA
1538
1539config ARCH_SUPPORTS_KEXEC_SIG
1540	def_bool y
1541
1542config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1543	def_bool y
1544
1545config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1546	def_bool y
1547
1548config ARCH_SUPPORTS_CRASH_DUMP
1549	def_bool y
1550
1551config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1552	def_bool CRASH_RESERVE
1553
1554config TRANS_TABLE
1555	def_bool y
1556	depends on HIBERNATION || KEXEC_CORE
1557
1558config XEN_DOM0
1559	def_bool y
1560	depends on XEN
1561
1562config XEN
1563	bool "Xen guest support on ARM64"
1564	depends on ARM64 && OF
1565	select SWIOTLB_XEN
1566	select PARAVIRT
1567	help
1568	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1569
1570# include/linux/mmzone.h requires the following to be true:
1571#
1572#   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1573#
1574# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1575#
1576#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1577# ----+-------------------+--------------+----------------------+-------------------------+
1578# 4K  |       27          |      12      |       15             |         10              |
1579# 16K |       27          |      14      |       13             |         11              |
1580# 64K |       29          |      16      |       13             |         13              |
1581config ARCH_FORCE_MAX_ORDER
1582	int
1583	default "13" if ARM64_64K_PAGES
1584	default "11" if ARM64_16K_PAGES
1585	default "10"
1586	help
1587	  The kernel page allocator limits the size of maximal physically
1588	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1589	  defines the maximal power of two of number of pages that can be
1590	  allocated as a single contiguous block. This option allows
1591	  overriding the default setting when ability to allocate very
1592	  large blocks of physically contiguous memory is required.
1593
1594	  The maximal size of allocation cannot exceed the size of the
1595	  section, so the value of MAX_PAGE_ORDER should satisfy
1596
1597	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1598
1599	  Don't change if unsure.
1600
1601config UNMAP_KERNEL_AT_EL0
1602	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1603	default y
1604	help
1605	  Speculation attacks against some high-performance processors can
1606	  be used to bypass MMU permission checks and leak kernel data to
1607	  userspace. This can be defended against by unmapping the kernel
1608	  when running in userspace, mapping it back in on exception entry
1609	  via a trampoline page in the vector table.
1610
1611	  If unsure, say Y.
1612
1613config MITIGATE_SPECTRE_BRANCH_HISTORY
1614	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1615	default y
1616	help
1617	  Speculation attacks against some high-performance processors can
1618	  make use of branch history to influence future speculation.
1619	  When taking an exception from user-space, a sequence of branches
1620	  or a firmware call overwrites the branch history.
1621
1622config RODATA_FULL_DEFAULT_ENABLED
1623	bool "Apply r/o permissions of VM areas also to their linear aliases"
1624	default y
1625	help
1626	  Apply read-only attributes of VM areas to the linear alias of
1627	  the backing pages as well. This prevents code or read-only data
1628	  from being modified (inadvertently or intentionally) via another
1629	  mapping of the same memory page. This additional enhancement can
1630	  be turned off at runtime by passing rodata=[off|on] (and turned on
1631	  with rodata=full if this option is set to 'n')
1632
1633	  This requires the linear region to be mapped down to pages,
1634	  which may adversely affect performance in some cases.
1635
1636config ARM64_SW_TTBR0_PAN
1637	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1638	depends on !KCSAN
1639	help
1640	  Enabling this option prevents the kernel from accessing
1641	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1642	  zeroed area and reserved ASID. The user access routines
1643	  restore the valid TTBR0_EL1 temporarily.
1644
1645config ARM64_TAGGED_ADDR_ABI
1646	bool "Enable the tagged user addresses syscall ABI"
1647	default y
1648	help
1649	  When this option is enabled, user applications can opt in to a
1650	  relaxed ABI via prctl() allowing tagged addresses to be passed
1651	  to system calls as pointer arguments. For details, see
1652	  Documentation/arch/arm64/tagged-address-abi.rst.
1653
1654menuconfig COMPAT
1655	bool "Kernel support for 32-bit EL0"
1656	depends on ARM64_4K_PAGES || EXPERT
1657	select HAVE_UID16
1658	select OLD_SIGSUSPEND3
1659	select COMPAT_OLD_SIGACTION
1660	help
1661	  This option enables support for a 32-bit EL0 running under a 64-bit
1662	  kernel at EL1. AArch32-specific components such as system calls,
1663	  the user helper functions, VFP support and the ptrace interface are
1664	  handled appropriately by the kernel.
1665
1666	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1667	  that you will only be able to execute AArch32 binaries that were compiled
1668	  with page size aligned segments.
1669
1670	  If you want to execute 32-bit userspace applications, say Y.
1671
1672if COMPAT
1673
1674config KUSER_HELPERS
1675	bool "Enable kuser helpers page for 32-bit applications"
1676	default y
1677	help
1678	  Warning: disabling this option may break 32-bit user programs.
1679
1680	  Provide kuser helpers to compat tasks. The kernel provides
1681	  helper code to userspace in read only form at a fixed location
1682	  to allow userspace to be independent of the CPU type fitted to
1683	  the system. This permits binaries to be run on ARMv4 through
1684	  to ARMv8 without modification.
1685
1686	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1687
1688	  However, the fixed address nature of these helpers can be used
1689	  by ROP (return orientated programming) authors when creating
1690	  exploits.
1691
1692	  If all of the binaries and libraries which run on your platform
1693	  are built specifically for your platform, and make no use of
1694	  these helpers, then you can turn this option off to hinder
1695	  such exploits. However, in that case, if a binary or library
1696	  relying on those helpers is run, it will not function correctly.
1697
1698	  Say N here only if you are absolutely certain that you do not
1699	  need these helpers; otherwise, the safe option is to say Y.
1700
1701config COMPAT_VDSO
1702	bool "Enable vDSO for 32-bit applications"
1703	depends on !CPU_BIG_ENDIAN
1704	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1705	select GENERIC_COMPAT_VDSO
1706	default y
1707	help
1708	  Place in the process address space of 32-bit applications an
1709	  ELF shared object providing fast implementations of gettimeofday
1710	  and clock_gettime.
1711
1712	  You must have a 32-bit build of glibc 2.22 or later for programs
1713	  to seamlessly take advantage of this.
1714
1715config THUMB2_COMPAT_VDSO
1716	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1717	depends on COMPAT_VDSO
1718	default y
1719	help
1720	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1721	  otherwise with '-marm'.
1722
1723config COMPAT_ALIGNMENT_FIXUPS
1724	bool "Fix up misaligned multi-word loads and stores in user space"
1725
1726menuconfig ARMV8_DEPRECATED
1727	bool "Emulate deprecated/obsolete ARMv8 instructions"
1728	depends on SYSCTL
1729	help
1730	  Legacy software support may require certain instructions
1731	  that have been deprecated or obsoleted in the architecture.
1732
1733	  Enable this config to enable selective emulation of these
1734	  features.
1735
1736	  If unsure, say Y
1737
1738if ARMV8_DEPRECATED
1739
1740config SWP_EMULATION
1741	bool "Emulate SWP/SWPB instructions"
1742	help
1743	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1744	  they are always undefined. Say Y here to enable software
1745	  emulation of these instructions for userspace using LDXR/STXR.
1746	  This feature can be controlled at runtime with the abi.swp
1747	  sysctl which is disabled by default.
1748
1749	  In some older versions of glibc [<=2.8] SWP is used during futex
1750	  trylock() operations with the assumption that the code will not
1751	  be preempted. This invalid assumption may be more likely to fail
1752	  with SWP emulation enabled, leading to deadlock of the user
1753	  application.
1754
1755	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1756	  on an external transaction monitoring block called a global
1757	  monitor to maintain update atomicity. If your system does not
1758	  implement a global monitor, this option can cause programs that
1759	  perform SWP operations to uncached memory to deadlock.
1760
1761	  If unsure, say Y
1762
1763config CP15_BARRIER_EMULATION
1764	bool "Emulate CP15 Barrier instructions"
1765	help
1766	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1767	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1768	  strongly recommended to use the ISB, DSB, and DMB
1769	  instructions instead.
1770
1771	  Say Y here to enable software emulation of these
1772	  instructions for AArch32 userspace code. When this option is
1773	  enabled, CP15 barrier usage is traced which can help
1774	  identify software that needs updating. This feature can be
1775	  controlled at runtime with the abi.cp15_barrier sysctl.
1776
1777	  If unsure, say Y
1778
1779config SETEND_EMULATION
1780	bool "Emulate SETEND instruction"
1781	help
1782	  The SETEND instruction alters the data-endianness of the
1783	  AArch32 EL0, and is deprecated in ARMv8.
1784
1785	  Say Y here to enable software emulation of the instruction
1786	  for AArch32 userspace code. This feature can be controlled
1787	  at runtime with the abi.setend sysctl.
1788
1789	  Note: All the cpus on the system must have mixed endian support at EL0
1790	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1791	  endian - is hotplugged in after this feature has been enabled, there could
1792	  be unexpected results in the applications.
1793
1794	  If unsure, say Y
1795endif # ARMV8_DEPRECATED
1796
1797endif # COMPAT
1798
1799menu "ARMv8.1 architectural features"
1800
1801config ARM64_HW_AFDBM
1802	bool "Support for hardware updates of the Access and Dirty page flags"
1803	default y
1804	help
1805	  The ARMv8.1 architecture extensions introduce support for
1806	  hardware updates of the access and dirty information in page
1807	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1808	  capable processors, accesses to pages with PTE_AF cleared will
1809	  set this bit instead of raising an access flag fault.
1810	  Similarly, writes to read-only pages with the DBM bit set will
1811	  clear the read-only bit (AP[2]) instead of raising a
1812	  permission fault.
1813
1814	  Kernels built with this configuration option enabled continue
1815	  to work on pre-ARMv8.1 hardware and the performance impact is
1816	  minimal. If unsure, say Y.
1817
1818config ARM64_PAN
1819	bool "Enable support for Privileged Access Never (PAN)"
1820	default y
1821	help
1822	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1823	  prevents the kernel or hypervisor from accessing user-space (EL0)
1824	  memory directly.
1825
1826	  Choosing this option will cause any unprotected (not using
1827	  copy_to_user et al) memory access to fail with a permission fault.
1828
1829	  The feature is detected at runtime, and will remain as a 'nop'
1830	  instruction if the cpu does not implement the feature.
1831
1832config AS_HAS_LSE_ATOMICS
1833	def_bool $(as-instr,.arch_extension lse)
1834
1835config ARM64_LSE_ATOMICS
1836	bool
1837	default ARM64_USE_LSE_ATOMICS
1838	depends on AS_HAS_LSE_ATOMICS
1839
1840config ARM64_USE_LSE_ATOMICS
1841	bool "Atomic instructions"
1842	default y
1843	help
1844	  As part of the Large System Extensions, ARMv8.1 introduces new
1845	  atomic instructions that are designed specifically to scale in
1846	  very large systems.
1847
1848	  Say Y here to make use of these instructions for the in-kernel
1849	  atomic routines. This incurs a small overhead on CPUs that do
1850	  not support these instructions and requires the kernel to be
1851	  built with binutils >= 2.25 in order for the new instructions
1852	  to be used.
1853
1854endmenu # "ARMv8.1 architectural features"
1855
1856menu "ARMv8.2 architectural features"
1857
1858config AS_HAS_ARMV8_2
1859	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1860
1861config AS_HAS_SHA3
1862	def_bool $(as-instr,.arch armv8.2-a+sha3)
1863
1864config ARM64_PMEM
1865	bool "Enable support for persistent memory"
1866	select ARCH_HAS_PMEM_API
1867	select ARCH_HAS_UACCESS_FLUSHCACHE
1868	help
1869	  Say Y to enable support for the persistent memory API based on the
1870	  ARMv8.2 DCPoP feature.
1871
1872	  The feature is detected at runtime, and the kernel will use DC CVAC
1873	  operations if DC CVAP is not supported (following the behaviour of
1874	  DC CVAP itself if the system does not define a point of persistence).
1875
1876config ARM64_RAS_EXTN
1877	bool "Enable support for RAS CPU Extensions"
1878	default y
1879	help
1880	  CPUs that support the Reliability, Availability and Serviceability
1881	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1882	  errors, classify them and report them to software.
1883
1884	  On CPUs with these extensions system software can use additional
1885	  barriers to determine if faults are pending and read the
1886	  classification from a new set of registers.
1887
1888	  Selecting this feature will allow the kernel to use these barriers
1889	  and access the new registers if the system supports the extension.
1890	  Platform RAS features may additionally depend on firmware support.
1891
1892config ARM64_CNP
1893	bool "Enable support for Common Not Private (CNP) translations"
1894	default y
1895	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1896	help
1897	  Common Not Private (CNP) allows translation table entries to
1898	  be shared between different PEs in the same inner shareable
1899	  domain, so the hardware can use this fact to optimise the
1900	  caching of such entries in the TLB.
1901
1902	  Selecting this option allows the CNP feature to be detected
1903	  at runtime, and does not affect PEs that do not implement
1904	  this feature.
1905
1906endmenu # "ARMv8.2 architectural features"
1907
1908menu "ARMv8.3 architectural features"
1909
1910config ARM64_PTR_AUTH
1911	bool "Enable support for pointer authentication"
1912	default y
1913	help
1914	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1915	  instructions for signing and authenticating pointers against secret
1916	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1917	  and other attacks.
1918
1919	  This option enables these instructions at EL0 (i.e. for userspace).
1920	  Choosing this option will cause the kernel to initialise secret keys
1921	  for each process at exec() time, with these keys being
1922	  context-switched along with the process.
1923
1924	  The feature is detected at runtime. If the feature is not present in
1925	  hardware it will not be advertised to userspace/KVM guest nor will it
1926	  be enabled.
1927
1928	  If the feature is present on the boot CPU but not on a late CPU, then
1929	  the late CPU will be parked. Also, if the boot CPU does not have
1930	  address auth and the late CPU has then the late CPU will still boot
1931	  but with the feature disabled. On such a system, this option should
1932	  not be selected.
1933
1934config ARM64_PTR_AUTH_KERNEL
1935	bool "Use pointer authentication for kernel"
1936	default y
1937	depends on ARM64_PTR_AUTH
1938	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1939	# Modern compilers insert a .note.gnu.property section note for PAC
1940	# which is only understood by binutils starting with version 2.33.1.
1941	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1942	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1943	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1944	help
1945	  If the compiler supports the -mbranch-protection or
1946	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1947	  will cause the kernel itself to be compiled with return address
1948	  protection. In this case, and if the target hardware is known to
1949	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1950	  disabled with minimal loss of protection.
1951
1952	  This feature works with FUNCTION_GRAPH_TRACER option only if
1953	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
1954
1955config CC_HAS_BRANCH_PROT_PAC_RET
1956	# GCC 9 or later, clang 8 or later
1957	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1958
1959config CC_HAS_SIGN_RETURN_ADDRESS
1960	# GCC 7, 8
1961	def_bool $(cc-option,-msign-return-address=all)
1962
1963config AS_HAS_ARMV8_3
1964	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1965
1966config AS_HAS_CFI_NEGATE_RA_STATE
1967	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1968
1969config AS_HAS_LDAPR
1970	def_bool $(as-instr,.arch_extension rcpc)
1971
1972endmenu # "ARMv8.3 architectural features"
1973
1974menu "ARMv8.4 architectural features"
1975
1976config ARM64_AMU_EXTN
1977	bool "Enable support for the Activity Monitors Unit CPU extension"
1978	default y
1979	help
1980	  The activity monitors extension is an optional extension introduced
1981	  by the ARMv8.4 CPU architecture. This enables support for version 1
1982	  of the activity monitors architecture, AMUv1.
1983
1984	  To enable the use of this extension on CPUs that implement it, say Y.
1985
1986	  Note that for architectural reasons, firmware _must_ implement AMU
1987	  support when running on CPUs that present the activity monitors
1988	  extension. The required support is present in:
1989	    * Version 1.5 and later of the ARM Trusted Firmware
1990
1991	  For kernels that have this configuration enabled but boot with broken
1992	  firmware, you may need to say N here until the firmware is fixed.
1993	  Otherwise you may experience firmware panics or lockups when
1994	  accessing the counter registers. Even if you are not observing these
1995	  symptoms, the values returned by the register reads might not
1996	  correctly reflect reality. Most commonly, the value read will be 0,
1997	  indicating that the counter is not enabled.
1998
1999config AS_HAS_ARMV8_4
2000	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
2001
2002config ARM64_TLB_RANGE
2003	bool "Enable support for tlbi range feature"
2004	default y
2005	depends on AS_HAS_ARMV8_4
2006	help
2007	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2008	  range of input addresses.
2009
2010	  The feature introduces new assembly instructions, and they were
2011	  support when binutils >= 2.30.
2012
2013endmenu # "ARMv8.4 architectural features"
2014
2015menu "ARMv8.5 architectural features"
2016
2017config AS_HAS_ARMV8_5
2018	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2019
2020config ARM64_BTI
2021	bool "Branch Target Identification support"
2022	default y
2023	help
2024	  Branch Target Identification (part of the ARMv8.5 Extensions)
2025	  provides a mechanism to limit the set of locations to which computed
2026	  branch instructions such as BR or BLR can jump.
2027
2028	  To make use of BTI on CPUs that support it, say Y.
2029
2030	  BTI is intended to provide complementary protection to other control
2031	  flow integrity protection mechanisms, such as the Pointer
2032	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2033	  For this reason, it does not make sense to enable this option without
2034	  also enabling support for pointer authentication.  Thus, when
2035	  enabling this option you should also select ARM64_PTR_AUTH=y.
2036
2037	  Userspace binaries must also be specifically compiled to make use of
2038	  this mechanism.  If you say N here or the hardware does not support
2039	  BTI, such binaries can still run, but you get no additional
2040	  enforcement of branch destinations.
2041
2042config ARM64_BTI_KERNEL
2043	bool "Use Branch Target Identification for kernel"
2044	default y
2045	depends on ARM64_BTI
2046	depends on ARM64_PTR_AUTH_KERNEL
2047	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2048	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2049	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2050	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2051	depends on !CC_IS_GCC
2052	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2053	help
2054	  Build the kernel with Branch Target Identification annotations
2055	  and enable enforcement of this for kernel code. When this option
2056	  is enabled and the system supports BTI all kernel code including
2057	  modular code must have BTI enabled.
2058
2059config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2060	# GCC 9 or later, clang 8 or later
2061	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2062
2063config ARM64_E0PD
2064	bool "Enable support for E0PD"
2065	default y
2066	help
2067	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2068	  that EL0 accesses made via TTBR1 always fault in constant time,
2069	  providing similar benefits to KASLR as those provided by KPTI, but
2070	  with lower overhead and without disrupting legitimate access to
2071	  kernel memory such as SPE.
2072
2073	  This option enables E0PD for TTBR1 where available.
2074
2075config ARM64_AS_HAS_MTE
2076	# Initial support for MTE went in binutils 2.32.0, checked with
2077	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2078	# as a late addition to the final architecture spec (LDGM/STGM)
2079	# is only supported in the newer 2.32.x and 2.33 binutils
2080	# versions, hence the extra "stgm" instruction check below.
2081	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2082
2083config ARM64_MTE
2084	bool "Memory Tagging Extension support"
2085	default y
2086	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2087	depends on AS_HAS_ARMV8_5
2088	depends on AS_HAS_LSE_ATOMICS
2089	# Required for tag checking in the uaccess routines
2090	depends on ARM64_PAN
2091	select ARCH_HAS_SUBPAGE_FAULTS
2092	select ARCH_USES_HIGH_VMA_FLAGS
2093	select ARCH_USES_PG_ARCH_X
2094	help
2095	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2096	  architectural support for run-time, always-on detection of
2097	  various classes of memory error to aid with software debugging
2098	  to eliminate vulnerabilities arising from memory-unsafe
2099	  languages.
2100
2101	  This option enables the support for the Memory Tagging
2102	  Extension at EL0 (i.e. for userspace).
2103
2104	  Selecting this option allows the feature to be detected at
2105	  runtime. Any secondary CPU not implementing this feature will
2106	  not be allowed a late bring-up.
2107
2108	  Userspace binaries that want to use this feature must
2109	  explicitly opt in. The mechanism for the userspace is
2110	  described in:
2111
2112	  Documentation/arch/arm64/memory-tagging-extension.rst.
2113
2114endmenu # "ARMv8.5 architectural features"
2115
2116menu "ARMv8.7 architectural features"
2117
2118config ARM64_EPAN
2119	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2120	default y
2121	depends on ARM64_PAN
2122	help
2123	  Enhanced Privileged Access Never (EPAN) allows Privileged
2124	  Access Never to be used with Execute-only mappings.
2125
2126	  The feature is detected at runtime, and will remain disabled
2127	  if the cpu does not implement the feature.
2128endmenu # "ARMv8.7 architectural features"
2129
2130config ARM64_SVE
2131	bool "ARM Scalable Vector Extension support"
2132	default y
2133	help
2134	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2135	  execution state which complements and extends the SIMD functionality
2136	  of the base architecture to support much larger vectors and to enable
2137	  additional vectorisation opportunities.
2138
2139	  To enable use of this extension on CPUs that implement it, say Y.
2140
2141	  On CPUs that support the SVE2 extensions, this option will enable
2142	  those too.
2143
2144	  Note that for architectural reasons, firmware _must_ implement SVE
2145	  support when running on SVE capable hardware.  The required support
2146	  is present in:
2147
2148	    * version 1.5 and later of the ARM Trusted Firmware
2149	    * the AArch64 boot wrapper since commit 5e1261e08abf
2150	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2151
2152	  For other firmware implementations, consult the firmware documentation
2153	  or vendor.
2154
2155	  If you need the kernel to boot on SVE-capable hardware with broken
2156	  firmware, you may need to say N here until you get your firmware
2157	  fixed.  Otherwise, you may experience firmware panics or lockups when
2158	  booting the kernel.  If unsure and you are not observing these
2159	  symptoms, you should assume that it is safe to say Y.
2160
2161config ARM64_SME
2162	bool "ARM Scalable Matrix Extension support"
2163	default y
2164	depends on ARM64_SVE
2165	help
2166	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2167	  execution state which utilises a substantial subset of the SVE
2168	  instruction set, together with the addition of new architectural
2169	  register state capable of holding two dimensional matrix tiles to
2170	  enable various matrix operations.
2171
2172config ARM64_PSEUDO_NMI
2173	bool "Support for NMI-like interrupts"
2174	select ARM_GIC_V3
2175	help
2176	  Adds support for mimicking Non-Maskable Interrupts through the use of
2177	  GIC interrupt priority. This support requires version 3 or later of
2178	  ARM GIC.
2179
2180	  This high priority configuration for interrupts needs to be
2181	  explicitly enabled by setting the kernel parameter
2182	  "irqchip.gicv3_pseudo_nmi" to 1.
2183
2184	  If unsure, say N
2185
2186if ARM64_PSEUDO_NMI
2187config ARM64_DEBUG_PRIORITY_MASKING
2188	bool "Debug interrupt priority masking"
2189	help
2190	  This adds runtime checks to functions enabling/disabling
2191	  interrupts when using priority masking. The additional checks verify
2192	  the validity of ICC_PMR_EL1 when calling concerned functions.
2193
2194	  If unsure, say N
2195endif # ARM64_PSEUDO_NMI
2196
2197config RELOCATABLE
2198	bool "Build a relocatable kernel image" if EXPERT
2199	select ARCH_HAS_RELR
2200	default y
2201	help
2202	  This builds the kernel as a Position Independent Executable (PIE),
2203	  which retains all relocation metadata required to relocate the
2204	  kernel binary at runtime to a different virtual address than the
2205	  address it was linked at.
2206	  Since AArch64 uses the RELA relocation format, this requires a
2207	  relocation pass at runtime even if the kernel is loaded at the
2208	  same address it was linked at.
2209
2210config RANDOMIZE_BASE
2211	bool "Randomize the address of the kernel image"
2212	select RELOCATABLE
2213	help
2214	  Randomizes the virtual address at which the kernel image is
2215	  loaded, as a security feature that deters exploit attempts
2216	  relying on knowledge of the location of kernel internals.
2217
2218	  It is the bootloader's job to provide entropy, by passing a
2219	  random u64 value in /chosen/kaslr-seed at kernel entry.
2220
2221	  When booting via the UEFI stub, it will invoke the firmware's
2222	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2223	  to the kernel proper. In addition, it will randomise the physical
2224	  location of the kernel Image as well.
2225
2226	  If unsure, say N.
2227
2228config RANDOMIZE_MODULE_REGION_FULL
2229	bool "Randomize the module region over a 2 GB range"
2230	depends on RANDOMIZE_BASE
2231	default y
2232	help
2233	  Randomizes the location of the module region inside a 2 GB window
2234	  covering the core kernel. This way, it is less likely for modules
2235	  to leak information about the location of core kernel data structures
2236	  but it does imply that function calls between modules and the core
2237	  kernel will need to be resolved via veneers in the module PLT.
2238
2239	  When this option is not set, the module region will be randomized over
2240	  a limited range that contains the [_stext, _etext] interval of the
2241	  core kernel, so branch relocations are almost always in range unless
2242	  the region is exhausted. In this particular case of region
2243	  exhaustion, modules might be able to fall back to a larger 2GB area.
2244
2245config CC_HAVE_STACKPROTECTOR_SYSREG
2246	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2247
2248config STACKPROTECTOR_PER_TASK
2249	def_bool y
2250	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2251
2252config UNWIND_PATCH_PAC_INTO_SCS
2253	bool "Enable shadow call stack dynamically using code patching"
2254	# needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated
2255	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2256	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2257	depends on SHADOW_CALL_STACK
2258	select UNWIND_TABLES
2259	select DYNAMIC_SCS
2260
2261config ARM64_CONTPTE
2262	bool "Contiguous PTE mappings for user memory" if EXPERT
2263	depends on TRANSPARENT_HUGEPAGE
2264	default y
2265	help
2266	  When enabled, user mappings are configured using the PTE contiguous
2267	  bit, for any mappings that meet the size and alignment requirements.
2268	  This reduces TLB pressure and improves performance.
2269
2270endmenu # "Kernel Features"
2271
2272menu "Boot options"
2273
2274config ARM64_ACPI_PARKING_PROTOCOL
2275	bool "Enable support for the ARM64 ACPI parking protocol"
2276	depends on ACPI
2277	help
2278	  Enable support for the ARM64 ACPI parking protocol. If disabled
2279	  the kernel will not allow booting through the ARM64 ACPI parking
2280	  protocol even if the corresponding data is present in the ACPI
2281	  MADT table.
2282
2283config CMDLINE
2284	string "Default kernel command string"
2285	default ""
2286	help
2287	  Provide a set of default command-line options at build time by
2288	  entering them here. As a minimum, you should specify the the
2289	  root device (e.g. root=/dev/nfs).
2290
2291choice
2292	prompt "Kernel command line type"
2293	depends on CMDLINE != ""
2294	default CMDLINE_FROM_BOOTLOADER
2295	help
2296	  Choose how the kernel will handle the provided default kernel
2297	  command line string.
2298
2299config CMDLINE_FROM_BOOTLOADER
2300	bool "Use bootloader kernel arguments if available"
2301	help
2302	  Uses the command-line options passed by the boot loader. If
2303	  the boot loader doesn't provide any, the default kernel command
2304	  string provided in CMDLINE will be used.
2305
2306config CMDLINE_FORCE
2307	bool "Always use the default kernel command string"
2308	help
2309	  Always use the default kernel command string, even if the boot
2310	  loader passes other arguments to the kernel.
2311	  This is useful if you cannot or don't want to change the
2312	  command-line options your boot loader passes to the kernel.
2313
2314endchoice
2315
2316config EFI_STUB
2317	bool
2318
2319config EFI
2320	bool "UEFI runtime support"
2321	depends on OF && !CPU_BIG_ENDIAN
2322	depends on KERNEL_MODE_NEON
2323	select ARCH_SUPPORTS_ACPI
2324	select LIBFDT
2325	select UCS2_STRING
2326	select EFI_PARAMS_FROM_FDT
2327	select EFI_RUNTIME_WRAPPERS
2328	select EFI_STUB
2329	select EFI_GENERIC_STUB
2330	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2331	default y
2332	help
2333	  This option provides support for runtime services provided
2334	  by UEFI firmware (such as non-volatile variables, realtime
2335	  clock, and platform reset). A UEFI stub is also provided to
2336	  allow the kernel to be booted as an EFI application. This
2337	  is only useful on systems that have UEFI firmware.
2338
2339config COMPRESSED_INSTALL
2340	bool "Install compressed image by default"
2341	help
2342	  This makes the regular "make install" install the compressed
2343	  image we built, not the legacy uncompressed one.
2344
2345	  You can check that a compressed image works for you by doing
2346	  "make zinstall" first, and verifying that everything is fine
2347	  in your environment before making "make install" do this for
2348	  you.
2349
2350config DMI
2351	bool "Enable support for SMBIOS (DMI) tables"
2352	depends on EFI
2353	default y
2354	help
2355	  This enables SMBIOS/DMI feature for systems.
2356
2357	  This option is only useful on systems that have UEFI firmware.
2358	  However, even with this option, the resultant kernel should
2359	  continue to boot on existing non-UEFI platforms.
2360
2361endmenu # "Boot options"
2362
2363menu "Power management options"
2364
2365source "kernel/power/Kconfig"
2366
2367config ARCH_HIBERNATION_POSSIBLE
2368	def_bool y
2369	depends on CPU_PM
2370
2371config ARCH_HIBERNATION_HEADER
2372	def_bool y
2373	depends on HIBERNATION
2374
2375config ARCH_SUSPEND_POSSIBLE
2376	def_bool y
2377
2378endmenu # "Power management options"
2379
2380menu "CPU Power Management"
2381
2382source "drivers/cpuidle/Kconfig"
2383
2384source "drivers/cpufreq/Kconfig"
2385
2386endmenu # "CPU Power Management"
2387
2388source "drivers/acpi/Kconfig"
2389
2390source "arch/arm64/kvm/Kconfig"
2391
2392