xref: /openbmc/linux/arch/arm64/Kconfig (revision dfc66bef)
1# SPDX-License-Identifier: GPL-2.0-only
2config ARM64
3	def_bool y
4	select ACPI_CCA_REQUIRED if ACPI
5	select ACPI_GENERIC_GSI if ACPI
6	select ACPI_GTDT if ACPI
7	select ACPI_IORT if ACPI
8	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
9	select ACPI_MCFG if (ACPI && PCI)
10	select ACPI_SPCR_TABLE if ACPI
11	select ACPI_PPTT if ACPI
12	select ARCH_HAS_DEBUG_WX
13	select ARCH_BINFMT_ELF_STATE
14	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
15	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
16	select ARCH_ENABLE_MEMORY_HOTPLUG
17	select ARCH_ENABLE_MEMORY_HOTREMOVE
18	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
19	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
20	select ARCH_HAS_CACHE_LINE_SIZE
21	select ARCH_HAS_DEBUG_VIRTUAL
22	select ARCH_HAS_DEBUG_VM_PGTABLE
23	select ARCH_HAS_DMA_PREP_COHERENT
24	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
25	select ARCH_HAS_FAST_MULTIPLIER
26	select ARCH_HAS_FORTIFY_SOURCE
27	select ARCH_HAS_GCOV_PROFILE_ALL
28	select ARCH_HAS_GIGANTIC_PAGE
29	select ARCH_HAS_KCOV
30	select ARCH_HAS_KEEPINITRD
31	select ARCH_HAS_MEMBARRIER_SYNC_CORE
32	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
33	select ARCH_HAS_PTE_DEVMAP
34	select ARCH_HAS_PTE_SPECIAL
35	select ARCH_HAS_SETUP_DMA_OPS
36	select ARCH_HAS_SET_DIRECT_MAP
37	select ARCH_HAS_SET_MEMORY
38	select ARCH_STACKWALK
39	select ARCH_HAS_STRICT_KERNEL_RWX
40	select ARCH_HAS_STRICT_MODULE_RWX
41	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
42	select ARCH_HAS_SYNC_DMA_FOR_CPU
43	select ARCH_HAS_SYSCALL_WRAPPER
44	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
45	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
46	select ARCH_HAS_ZONE_DMA_SET if EXPERT
47	select ARCH_HAVE_ELF_PROT
48	select ARCH_HAVE_NMI_SAFE_CMPXCHG
49	select ARCH_INLINE_READ_LOCK if !PREEMPTION
50	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
51	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
52	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
53	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
54	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
55	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
56	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
57	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
58	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
59	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
60	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
61	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
62	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
63	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
64	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
65	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
66	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
67	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
68	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
69	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
70	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
71	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
72	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
73	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
74	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
75	select ARCH_KEEP_MEMBLOCK
76	select ARCH_USE_CMPXCHG_LOCKREF
77	select ARCH_USE_GNU_PROPERTY
78	select ARCH_USE_MEMTEST
79	select ARCH_USE_QUEUED_RWLOCKS
80	select ARCH_USE_QUEUED_SPINLOCKS
81	select ARCH_USE_SYM_ANNOTATIONS
82	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
83	select ARCH_SUPPORTS_HUGETLBFS
84	select ARCH_SUPPORTS_MEMORY_FAILURE
85	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
86	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
87	select ARCH_SUPPORTS_LTO_CLANG_THIN
88	select ARCH_SUPPORTS_CFI_CLANG
89	select ARCH_SUPPORTS_ATOMIC_RMW
90	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
91	select ARCH_SUPPORTS_NUMA_BALANCING
92	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
93	select ARCH_WANT_DEFAULT_BPF_JIT
94	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
95	select ARCH_WANT_FRAME_POINTERS
96	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
97	select ARCH_WANT_LD_ORPHAN_WARN
98	select ARCH_WANTS_NO_INSTR
99	select ARCH_HAS_UBSAN_SANITIZE_ALL
100	select ARM_AMBA
101	select ARM_ARCH_TIMER
102	select ARM_GIC
103	select AUDIT_ARCH_COMPAT_GENERIC
104	select ARM_GIC_V2M if PCI
105	select ARM_GIC_V3
106	select ARM_GIC_V3_ITS if PCI
107	select ARM_PSCI_FW
108	select BUILDTIME_TABLE_SORT
109	select CLONE_BACKWARDS
110	select COMMON_CLK
111	select CPU_PM if (SUSPEND || CPU_IDLE)
112	select CRC32
113	select DCACHE_WORD_ACCESS
114	select DMA_DIRECT_REMAP
115	select EDAC_SUPPORT
116	select FRAME_POINTER
117	select GENERIC_ALLOCATOR
118	select GENERIC_ARCH_TOPOLOGY
119	select GENERIC_CLOCKEVENTS_BROADCAST
120	select GENERIC_CPU_AUTOPROBE
121	select GENERIC_CPU_VULNERABILITIES
122	select GENERIC_EARLY_IOREMAP
123	select GENERIC_FIND_FIRST_BIT
124	select GENERIC_IDLE_POLL_SETUP
125	select GENERIC_IRQ_IPI
126	select GENERIC_IRQ_PROBE
127	select GENERIC_IRQ_SHOW
128	select GENERIC_IRQ_SHOW_LEVEL
129	select GENERIC_LIB_DEVMEM_IS_ALLOWED
130	select GENERIC_PCI_IOMAP
131	select GENERIC_PTDUMP
132	select GENERIC_SCHED_CLOCK
133	select GENERIC_SMP_IDLE_THREAD
134	select GENERIC_TIME_VSYSCALL
135	select GENERIC_GETTIMEOFDAY
136	select GENERIC_VDSO_TIME_NS
137	select HARDIRQS_SW_RESEND
138	select HAVE_MOVE_PMD
139	select HAVE_MOVE_PUD
140	select HAVE_PCI
141	select HAVE_ACPI_APEI if (ACPI && EFI)
142	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
143	select HAVE_ARCH_AUDITSYSCALL
144	select HAVE_ARCH_BITREVERSE
145	select HAVE_ARCH_COMPILER_H
146	select HAVE_ARCH_HUGE_VMAP
147	select HAVE_ARCH_JUMP_LABEL
148	select HAVE_ARCH_JUMP_LABEL_RELATIVE
149	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
150	select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
151	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
152	select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
153	# Some instrumentation may be unsound, hence EXPERT
154	select HAVE_ARCH_KCSAN if EXPERT
155	select HAVE_ARCH_KFENCE
156	select HAVE_ARCH_KGDB
157	select HAVE_ARCH_MMAP_RND_BITS
158	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
159	select HAVE_ARCH_PREL32_RELOCATIONS
160	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
161	select HAVE_ARCH_SECCOMP_FILTER
162	select HAVE_ARCH_STACKLEAK
163	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
164	select HAVE_ARCH_TRACEHOOK
165	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
166	select HAVE_ARCH_VMAP_STACK
167	select HAVE_ARM_SMCCC
168	select HAVE_ASM_MODVERSIONS
169	select HAVE_EBPF_JIT
170	select HAVE_C_RECORDMCOUNT
171	select HAVE_CMPXCHG_DOUBLE
172	select HAVE_CMPXCHG_LOCAL
173	select HAVE_CONTEXT_TRACKING
174	select HAVE_DEBUG_KMEMLEAK
175	select HAVE_DMA_CONTIGUOUS
176	select HAVE_DYNAMIC_FTRACE
177	select HAVE_DYNAMIC_FTRACE_WITH_REGS \
178		if $(cc-option,-fpatchable-function-entry=2)
179	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
180		if DYNAMIC_FTRACE_WITH_REGS
181	select HAVE_EFFICIENT_UNALIGNED_ACCESS
182	select HAVE_FAST_GUP
183	select HAVE_FTRACE_MCOUNT_RECORD
184	select HAVE_FUNCTION_TRACER
185	select HAVE_FUNCTION_ERROR_INJECTION
186	select HAVE_FUNCTION_GRAPH_TRACER
187	select HAVE_GCC_PLUGINS
188	select HAVE_HW_BREAKPOINT if PERF_EVENTS
189	select HAVE_IRQ_TIME_ACCOUNTING
190	select HAVE_KVM
191	select HAVE_NMI
192	select HAVE_PATA_PLATFORM
193	select HAVE_PERF_EVENTS
194	select HAVE_PERF_REGS
195	select HAVE_PERF_USER_STACK_DUMP
196	select HAVE_REGS_AND_STACK_ACCESS_API
197	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
198	select HAVE_FUNCTION_ARG_ACCESS_API
199	select HAVE_FUTEX_CMPXCHG if FUTEX
200	select MMU_GATHER_RCU_TABLE_FREE
201	select HAVE_RSEQ
202	select HAVE_STACKPROTECTOR
203	select HAVE_SYSCALL_TRACEPOINTS
204	select HAVE_KPROBES
205	select HAVE_KRETPROBES
206	select HAVE_GENERIC_VDSO
207	select IOMMU_DMA if IOMMU_SUPPORT
208	select IRQ_DOMAIN
209	select IRQ_FORCED_THREADING
210	select KASAN_VMALLOC if KASAN_GENERIC
211	select MODULES_USE_ELF_RELA
212	select NEED_DMA_MAP_STATE
213	select NEED_SG_DMA_LENGTH
214	select OF
215	select OF_EARLY_FLATTREE
216	select PCI_DOMAINS_GENERIC if PCI
217	select PCI_ECAM if (ACPI && PCI)
218	select PCI_SYSCALL if PCI
219	select POWER_RESET
220	select POWER_SUPPLY
221	select SPARSE_IRQ
222	select SWIOTLB
223	select SYSCTL_EXCEPTION_TRACE
224	select THREAD_INFO_IN_TASK
225	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
226	select TRACE_IRQFLAGS_SUPPORT
227	help
228	  ARM 64-bit (AArch64) Linux support.
229
230config 64BIT
231	def_bool y
232
233config MMU
234	def_bool y
235
236config ARM64_PAGE_SHIFT
237	int
238	default 16 if ARM64_64K_PAGES
239	default 14 if ARM64_16K_PAGES
240	default 12
241
242config ARM64_CONT_PTE_SHIFT
243	int
244	default 5 if ARM64_64K_PAGES
245	default 7 if ARM64_16K_PAGES
246	default 4
247
248config ARM64_CONT_PMD_SHIFT
249	int
250	default 5 if ARM64_64K_PAGES
251	default 5 if ARM64_16K_PAGES
252	default 4
253
254config ARCH_MMAP_RND_BITS_MIN
255       default 14 if ARM64_64K_PAGES
256       default 16 if ARM64_16K_PAGES
257       default 18
258
259# max bits determined by the following formula:
260#  VA_BITS - PAGE_SHIFT - 3
261config ARCH_MMAP_RND_BITS_MAX
262       default 19 if ARM64_VA_BITS=36
263       default 24 if ARM64_VA_BITS=39
264       default 27 if ARM64_VA_BITS=42
265       default 30 if ARM64_VA_BITS=47
266       default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
267       default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
268       default 33 if ARM64_VA_BITS=48
269       default 14 if ARM64_64K_PAGES
270       default 16 if ARM64_16K_PAGES
271       default 18
272
273config ARCH_MMAP_RND_COMPAT_BITS_MIN
274       default 7 if ARM64_64K_PAGES
275       default 9 if ARM64_16K_PAGES
276       default 11
277
278config ARCH_MMAP_RND_COMPAT_BITS_MAX
279       default 16
280
281config NO_IOPORT_MAP
282	def_bool y if !PCI
283
284config STACKTRACE_SUPPORT
285	def_bool y
286
287config ILLEGAL_POINTER_VALUE
288	hex
289	default 0xdead000000000000
290
291config LOCKDEP_SUPPORT
292	def_bool y
293
294config GENERIC_BUG
295	def_bool y
296	depends on BUG
297
298config GENERIC_BUG_RELATIVE_POINTERS
299	def_bool y
300	depends on GENERIC_BUG
301
302config GENERIC_HWEIGHT
303	def_bool y
304
305config GENERIC_CSUM
306        def_bool y
307
308config GENERIC_CALIBRATE_DELAY
309	def_bool y
310
311config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
312	def_bool y
313
314config SMP
315	def_bool y
316
317config KERNEL_MODE_NEON
318	def_bool y
319
320config FIX_EARLYCON_MEM
321	def_bool y
322
323config PGTABLE_LEVELS
324	int
325	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
326	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
327	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
328	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
329	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
330	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
331
332config ARCH_SUPPORTS_UPROBES
333	def_bool y
334
335config ARCH_PROC_KCORE_TEXT
336	def_bool y
337
338config BROKEN_GAS_INST
339	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
340
341config KASAN_SHADOW_OFFSET
342	hex
343	depends on KASAN_GENERIC || KASAN_SW_TAGS
344	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
345	default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
346	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
347	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
348	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
349	default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
350	default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
351	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
352	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
353	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
354	default 0xffffffffffffffff
355
356source "arch/arm64/Kconfig.platforms"
357
358menu "Kernel Features"
359
360menu "ARM errata workarounds via the alternatives framework"
361
362config ARM64_WORKAROUND_CLEAN_CACHE
363	bool
364
365config ARM64_ERRATUM_826319
366	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
367	default y
368	select ARM64_WORKAROUND_CLEAN_CACHE
369	help
370	  This option adds an alternative code sequence to work around ARM
371	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
372	  AXI master interface and an L2 cache.
373
374	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
375	  and is unable to accept a certain write via this interface, it will
376	  not progress on read data presented on the read data channel and the
377	  system can deadlock.
378
379	  The workaround promotes data cache clean instructions to
380	  data cache clean-and-invalidate.
381	  Please note that this does not necessarily enable the workaround,
382	  as it depends on the alternative framework, which will only patch
383	  the kernel if an affected CPU is detected.
384
385	  If unsure, say Y.
386
387config ARM64_ERRATUM_827319
388	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
389	default y
390	select ARM64_WORKAROUND_CLEAN_CACHE
391	help
392	  This option adds an alternative code sequence to work around ARM
393	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
394	  master interface and an L2 cache.
395
396	  Under certain conditions this erratum can cause a clean line eviction
397	  to occur at the same time as another transaction to the same address
398	  on the AMBA 5 CHI interface, which can cause data corruption if the
399	  interconnect reorders the two transactions.
400
401	  The workaround promotes data cache clean instructions to
402	  data cache clean-and-invalidate.
403	  Please note that this does not necessarily enable the workaround,
404	  as it depends on the alternative framework, which will only patch
405	  the kernel if an affected CPU is detected.
406
407	  If unsure, say Y.
408
409config ARM64_ERRATUM_824069
410	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
411	default y
412	select ARM64_WORKAROUND_CLEAN_CACHE
413	help
414	  This option adds an alternative code sequence to work around ARM
415	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
416	  to a coherent interconnect.
417
418	  If a Cortex-A53 processor is executing a store or prefetch for
419	  write instruction at the same time as a processor in another
420	  cluster is executing a cache maintenance operation to the same
421	  address, then this erratum might cause a clean cache line to be
422	  incorrectly marked as dirty.
423
424	  The workaround promotes data cache clean instructions to
425	  data cache clean-and-invalidate.
426	  Please note that this option does not necessarily enable the
427	  workaround, as it depends on the alternative framework, which will
428	  only patch the kernel if an affected CPU is detected.
429
430	  If unsure, say Y.
431
432config ARM64_ERRATUM_819472
433	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
434	default y
435	select ARM64_WORKAROUND_CLEAN_CACHE
436	help
437	  This option adds an alternative code sequence to work around ARM
438	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
439	  present when it is connected to a coherent interconnect.
440
441	  If the processor is executing a load and store exclusive sequence at
442	  the same time as a processor in another cluster is executing a cache
443	  maintenance operation to the same address, then this erratum might
444	  cause data corruption.
445
446	  The workaround promotes data cache clean instructions to
447	  data cache clean-and-invalidate.
448	  Please note that this does not necessarily enable the workaround,
449	  as it depends on the alternative framework, which will only patch
450	  the kernel if an affected CPU is detected.
451
452	  If unsure, say Y.
453
454config ARM64_ERRATUM_832075
455	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
456	default y
457	help
458	  This option adds an alternative code sequence to work around ARM
459	  erratum 832075 on Cortex-A57 parts up to r1p2.
460
461	  Affected Cortex-A57 parts might deadlock when exclusive load/store
462	  instructions to Write-Back memory are mixed with Device loads.
463
464	  The workaround is to promote device loads to use Load-Acquire
465	  semantics.
466	  Please note that this does not necessarily enable the workaround,
467	  as it depends on the alternative framework, which will only patch
468	  the kernel if an affected CPU is detected.
469
470	  If unsure, say Y.
471
472config ARM64_ERRATUM_834220
473	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
474	depends on KVM
475	default y
476	help
477	  This option adds an alternative code sequence to work around ARM
478	  erratum 834220 on Cortex-A57 parts up to r1p2.
479
480	  Affected Cortex-A57 parts might report a Stage 2 translation
481	  fault as the result of a Stage 1 fault for load crossing a
482	  page boundary when there is a permission or device memory
483	  alignment fault at Stage 1 and a translation fault at Stage 2.
484
485	  The workaround is to verify that the Stage 1 translation
486	  doesn't generate a fault before handling the Stage 2 fault.
487	  Please note that this does not necessarily enable the workaround,
488	  as it depends on the alternative framework, which will only patch
489	  the kernel if an affected CPU is detected.
490
491	  If unsure, say Y.
492
493config ARM64_ERRATUM_845719
494	bool "Cortex-A53: 845719: a load might read incorrect data"
495	depends on COMPAT
496	default y
497	help
498	  This option adds an alternative code sequence to work around ARM
499	  erratum 845719 on Cortex-A53 parts up to r0p4.
500
501	  When running a compat (AArch32) userspace on an affected Cortex-A53
502	  part, a load at EL0 from a virtual address that matches the bottom 32
503	  bits of the virtual address used by a recent load at (AArch64) EL1
504	  might return incorrect data.
505
506	  The workaround is to write the contextidr_el1 register on exception
507	  return to a 32-bit task.
508	  Please note that this does not necessarily enable the workaround,
509	  as it depends on the alternative framework, which will only patch
510	  the kernel if an affected CPU is detected.
511
512	  If unsure, say Y.
513
514config ARM64_ERRATUM_843419
515	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
516	default y
517	select ARM64_MODULE_PLTS if MODULES
518	help
519	  This option links the kernel with '--fix-cortex-a53-843419' and
520	  enables PLT support to replace certain ADRP instructions, which can
521	  cause subsequent memory accesses to use an incorrect address on
522	  Cortex-A53 parts up to r0p4.
523
524	  If unsure, say Y.
525
526config ARM64_LD_HAS_FIX_ERRATUM_843419
527	def_bool $(ld-option,--fix-cortex-a53-843419)
528
529config ARM64_ERRATUM_1024718
530	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
531	default y
532	help
533	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
534
535	  Affected Cortex-A55 cores (all revisions) could cause incorrect
536	  update of the hardware dirty bit when the DBM/AP bits are updated
537	  without a break-before-make. The workaround is to disable the usage
538	  of hardware DBM locally on the affected cores. CPUs not affected by
539	  this erratum will continue to use the feature.
540
541	  If unsure, say Y.
542
543config ARM64_ERRATUM_1418040
544	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
545	default y
546	depends on COMPAT
547	help
548	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
549	  errata 1188873 and 1418040.
550
551	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
552	  cause register corruption when accessing the timer registers
553	  from AArch32 userspace.
554
555	  If unsure, say Y.
556
557config ARM64_WORKAROUND_SPECULATIVE_AT
558	bool
559
560config ARM64_ERRATUM_1165522
561	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
562	default y
563	select ARM64_WORKAROUND_SPECULATIVE_AT
564	help
565	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
566
567	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
568	  corrupted TLBs by speculating an AT instruction during a guest
569	  context switch.
570
571	  If unsure, say Y.
572
573config ARM64_ERRATUM_1319367
574	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
575	default y
576	select ARM64_WORKAROUND_SPECULATIVE_AT
577	help
578	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
579	  and A72 erratum 1319367
580
581	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
582	  speculating an AT instruction during a guest context switch.
583
584	  If unsure, say Y.
585
586config ARM64_ERRATUM_1530923
587	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
588	default y
589	select ARM64_WORKAROUND_SPECULATIVE_AT
590	help
591	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
592
593	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
594	  corrupted TLBs by speculating an AT instruction during a guest
595	  context switch.
596
597	  If unsure, say Y.
598
599config ARM64_WORKAROUND_REPEAT_TLBI
600	bool
601
602config ARM64_ERRATUM_1286807
603	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
604	default y
605	select ARM64_WORKAROUND_REPEAT_TLBI
606	help
607	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
608
609	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
610	  address for a cacheable mapping of a location is being
611	  accessed by a core while another core is remapping the virtual
612	  address to a new physical page using the recommended
613	  break-before-make sequence, then under very rare circumstances
614	  TLBI+DSB completes before a read using the translation being
615	  invalidated has been observed by other observers. The
616	  workaround repeats the TLBI+DSB operation.
617
618config ARM64_ERRATUM_1463225
619	bool "Cortex-A76: Software Step might prevent interrupt recognition"
620	default y
621	help
622	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
623
624	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
625	  of a system call instruction (SVC) can prevent recognition of
626	  subsequent interrupts when software stepping is disabled in the
627	  exception handler of the system call and either kernel debugging
628	  is enabled or VHE is in use.
629
630	  Work around the erratum by triggering a dummy step exception
631	  when handling a system call from a task that is being stepped
632	  in a VHE configuration of the kernel.
633
634	  If unsure, say Y.
635
636config ARM64_ERRATUM_1542419
637	bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
638	default y
639	help
640	  This option adds a workaround for ARM Neoverse-N1 erratum
641	  1542419.
642
643	  Affected Neoverse-N1 cores could execute a stale instruction when
644	  modified by another CPU. The workaround depends on a firmware
645	  counterpart.
646
647	  Workaround the issue by hiding the DIC feature from EL0. This
648	  forces user-space to perform cache maintenance.
649
650	  If unsure, say Y.
651
652config ARM64_ERRATUM_1508412
653	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
654	default y
655	help
656	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
657
658	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
659	  of a store-exclusive or read of PAR_EL1 and a load with device or
660	  non-cacheable memory attributes. The workaround depends on a firmware
661	  counterpart.
662
663	  KVM guests must also have the workaround implemented or they can
664	  deadlock the system.
665
666	  Work around the issue by inserting DMB SY barriers around PAR_EL1
667	  register reads and warning KVM users. The DMB barrier is sufficient
668	  to prevent a speculative PAR_EL1 read.
669
670	  If unsure, say Y.
671
672config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
673	bool
674
675config ARM64_ERRATUM_2119858
676	bool "Cortex-A710: 2119858: workaround TRBE overwriting trace data in FILL mode"
677	default y
678	depends on CORESIGHT_TRBE
679	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
680	help
681	  This option adds the workaround for ARM Cortex-A710 erratum 2119858.
682
683	  Affected Cortex-A710 cores could overwrite up to 3 cache lines of trace
684	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
685	  the event of a WRAP event.
686
687	  Work around the issue by always making sure we move the TRBPTR_EL1 by
688	  256 bytes before enabling the buffer and filling the first 256 bytes of
689	  the buffer with ETM ignore packets upon disabling.
690
691	  If unsure, say Y.
692
693config ARM64_ERRATUM_2139208
694	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
695	default y
696	depends on CORESIGHT_TRBE
697	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
698	help
699	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
700
701	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
702	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
703	  the event of a WRAP event.
704
705	  Work around the issue by always making sure we move the TRBPTR_EL1 by
706	  256 bytes before enabling the buffer and filling the first 256 bytes of
707	  the buffer with ETM ignore packets upon disabling.
708
709	  If unsure, say Y.
710
711config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
712	bool
713
714config ARM64_ERRATUM_2054223
715	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
716	default y
717	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
718	help
719	  Enable workaround for ARM Cortex-A710 erratum 2054223
720
721	  Affected cores may fail to flush the trace data on a TSB instruction, when
722	  the PE is in trace prohibited state. This will cause losing a few bytes
723	  of the trace cached.
724
725	  Workaround is to issue two TSB consecutively on affected cores.
726
727	  If unsure, say Y.
728
729config ARM64_ERRATUM_2067961
730	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
731	default y
732	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
733	help
734	  Enable workaround for ARM Neoverse-N2 erratum 2067961
735
736	  Affected cores may fail to flush the trace data on a TSB instruction, when
737	  the PE is in trace prohibited state. This will cause losing a few bytes
738	  of the trace cached.
739
740	  Workaround is to issue two TSB consecutively on affected cores.
741
742	  If unsure, say Y.
743
744config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
745	bool
746
747config ARM64_ERRATUM_2253138
748	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
749	depends on CORESIGHT_TRBE
750	default y
751	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
752	help
753	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
754
755	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
756	  for TRBE. Under some conditions, the TRBE might generate a write to the next
757	  virtually addressed page following the last page of the TRBE address space
758	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
759
760	  Work around this in the driver by always making sure that there is a
761	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
762
763	  If unsure, say Y.
764
765config ARM64_ERRATUM_2224489
766	bool "Cortex-A710: 2224489: workaround TRBE writing to address out-of-range"
767	depends on CORESIGHT_TRBE
768	default y
769	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
770	help
771	  This option adds the workaround for ARM Cortex-A710 erratum 2224489.
772
773	  Affected Cortex-A710 cores might write to an out-of-range address, not reserved
774	  for TRBE. Under some conditions, the TRBE might generate a write to the next
775	  virtually addressed page following the last page of the TRBE address space
776	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
777
778	  Work around this in the driver by always making sure that there is a
779	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
780
781	  If unsure, say Y.
782
783config CAVIUM_ERRATUM_22375
784	bool "Cavium erratum 22375, 24313"
785	default y
786	help
787	  Enable workaround for errata 22375 and 24313.
788
789	  This implements two gicv3-its errata workarounds for ThunderX. Both
790	  with a small impact affecting only ITS table allocation.
791
792	    erratum 22375: only alloc 8MB table size
793	    erratum 24313: ignore memory access type
794
795	  The fixes are in ITS initialization and basically ignore memory access
796	  type and table size provided by the TYPER and BASER registers.
797
798	  If unsure, say Y.
799
800config CAVIUM_ERRATUM_23144
801	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
802	depends on NUMA
803	default y
804	help
805	  ITS SYNC command hang for cross node io and collections/cpu mapping.
806
807	  If unsure, say Y.
808
809config CAVIUM_ERRATUM_23154
810	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
811	default y
812	help
813	  The gicv3 of ThunderX requires a modified version for
814	  reading the IAR status to ensure data synchronization
815	  (access to icc_iar1_el1 is not sync'ed before and after).
816
817	  If unsure, say Y.
818
819config CAVIUM_ERRATUM_27456
820	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
821	default y
822	help
823	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
824	  instructions may cause the icache to become corrupted if it
825	  contains data for a non-current ASID.  The fix is to
826	  invalidate the icache when changing the mm context.
827
828	  If unsure, say Y.
829
830config CAVIUM_ERRATUM_30115
831	bool "Cavium erratum 30115: Guest may disable interrupts in host"
832	default y
833	help
834	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
835	  1.2, and T83 Pass 1.0, KVM guest execution may disable
836	  interrupts in host. Trapping both GICv3 group-0 and group-1
837	  accesses sidesteps the issue.
838
839	  If unsure, say Y.
840
841config CAVIUM_TX2_ERRATUM_219
842	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
843	default y
844	help
845	  On Cavium ThunderX2, a load, store or prefetch instruction between a
846	  TTBR update and the corresponding context synchronizing operation can
847	  cause a spurious Data Abort to be delivered to any hardware thread in
848	  the CPU core.
849
850	  Work around the issue by avoiding the problematic code sequence and
851	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
852	  trap handler performs the corresponding register access, skips the
853	  instruction and ensures context synchronization by virtue of the
854	  exception return.
855
856	  If unsure, say Y.
857
858config FUJITSU_ERRATUM_010001
859	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
860	default y
861	help
862	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
863	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
864	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
865	  This fault occurs under a specific hardware condition when a
866	  load/store instruction performs an address translation using:
867	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
868	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
869	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
870	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
871
872	  The workaround is to ensure these bits are clear in TCR_ELx.
873	  The workaround only affects the Fujitsu-A64FX.
874
875	  If unsure, say Y.
876
877config HISILICON_ERRATUM_161600802
878	bool "Hip07 161600802: Erroneous redistributor VLPI base"
879	default y
880	help
881	  The HiSilicon Hip07 SoC uses the wrong redistributor base
882	  when issued ITS commands such as VMOVP and VMAPP, and requires
883	  a 128kB offset to be applied to the target address in this commands.
884
885	  If unsure, say Y.
886
887config QCOM_FALKOR_ERRATUM_1003
888	bool "Falkor E1003: Incorrect translation due to ASID change"
889	default y
890	help
891	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
892	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
893	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
894	  then only for entries in the walk cache, since the leaf translation
895	  is unchanged. Work around the erratum by invalidating the walk cache
896	  entries for the trampoline before entering the kernel proper.
897
898config QCOM_FALKOR_ERRATUM_1009
899	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
900	default y
901	select ARM64_WORKAROUND_REPEAT_TLBI
902	help
903	  On Falkor v1, the CPU may prematurely complete a DSB following a
904	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
905	  one more time to fix the issue.
906
907	  If unsure, say Y.
908
909config QCOM_QDF2400_ERRATUM_0065
910	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
911	default y
912	help
913	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
914	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
915	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
916
917	  If unsure, say Y.
918
919config QCOM_FALKOR_ERRATUM_E1041
920	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
921	default y
922	help
923	  Falkor CPU may speculatively fetch instructions from an improper
924	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
925	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
926
927	  If unsure, say Y.
928
929config NVIDIA_CARMEL_CNP_ERRATUM
930	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
931	default y
932	help
933	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
934	  invalidate shared TLB entries installed by a different core, as it would
935	  on standard ARM cores.
936
937	  If unsure, say Y.
938
939config SOCIONEXT_SYNQUACER_PREITS
940	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
941	default y
942	help
943	  Socionext Synquacer SoCs implement a separate h/w block to generate
944	  MSI doorbell writes with non-zero values for the device ID.
945
946	  If unsure, say Y.
947
948endmenu
949
950
951choice
952	prompt "Page size"
953	default ARM64_4K_PAGES
954	help
955	  Page size (translation granule) configuration.
956
957config ARM64_4K_PAGES
958	bool "4KB"
959	help
960	  This feature enables 4KB pages support.
961
962config ARM64_16K_PAGES
963	bool "16KB"
964	help
965	  The system will use 16KB pages support. AArch32 emulation
966	  requires applications compiled with 16K (or a multiple of 16K)
967	  aligned segments.
968
969config ARM64_64K_PAGES
970	bool "64KB"
971	help
972	  This feature enables 64KB pages support (4KB by default)
973	  allowing only two levels of page tables and faster TLB
974	  look-up. AArch32 emulation requires applications compiled
975	  with 64K aligned segments.
976
977endchoice
978
979choice
980	prompt "Virtual address space size"
981	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
982	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
983	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
984	help
985	  Allows choosing one of multiple possible virtual address
986	  space sizes. The level of translation table is determined by
987	  a combination of page size and virtual address space size.
988
989config ARM64_VA_BITS_36
990	bool "36-bit" if EXPERT
991	depends on ARM64_16K_PAGES
992
993config ARM64_VA_BITS_39
994	bool "39-bit"
995	depends on ARM64_4K_PAGES
996
997config ARM64_VA_BITS_42
998	bool "42-bit"
999	depends on ARM64_64K_PAGES
1000
1001config ARM64_VA_BITS_47
1002	bool "47-bit"
1003	depends on ARM64_16K_PAGES
1004
1005config ARM64_VA_BITS_48
1006	bool "48-bit"
1007
1008config ARM64_VA_BITS_52
1009	bool "52-bit"
1010	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1011	help
1012	  Enable 52-bit virtual addressing for userspace when explicitly
1013	  requested via a hint to mmap(). The kernel will also use 52-bit
1014	  virtual addresses for its own mappings (provided HW support for
1015	  this feature is available, otherwise it reverts to 48-bit).
1016
1017	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1018	  ARMv8.3 Pointer Authentication will result in the PAC being
1019	  reduced from 7 bits to 3 bits, which may have a significant
1020	  impact on its susceptibility to brute-force attacks.
1021
1022	  If unsure, select 48-bit virtual addressing instead.
1023
1024endchoice
1025
1026config ARM64_FORCE_52BIT
1027	bool "Force 52-bit virtual addresses for userspace"
1028	depends on ARM64_VA_BITS_52 && EXPERT
1029	help
1030	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1031	  to maintain compatibility with older software by providing 48-bit VAs
1032	  unless a hint is supplied to mmap.
1033
1034	  This configuration option disables the 48-bit compatibility logic, and
1035	  forces all userspace addresses to be 52-bit on HW that supports it. One
1036	  should only enable this configuration option for stress testing userspace
1037	  memory management code. If unsure say N here.
1038
1039config ARM64_VA_BITS
1040	int
1041	default 36 if ARM64_VA_BITS_36
1042	default 39 if ARM64_VA_BITS_39
1043	default 42 if ARM64_VA_BITS_42
1044	default 47 if ARM64_VA_BITS_47
1045	default 48 if ARM64_VA_BITS_48
1046	default 52 if ARM64_VA_BITS_52
1047
1048choice
1049	prompt "Physical address space size"
1050	default ARM64_PA_BITS_48
1051	help
1052	  Choose the maximum physical address range that the kernel will
1053	  support.
1054
1055config ARM64_PA_BITS_48
1056	bool "48-bit"
1057
1058config ARM64_PA_BITS_52
1059	bool "52-bit (ARMv8.2)"
1060	depends on ARM64_64K_PAGES
1061	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1062	help
1063	  Enable support for a 52-bit physical address space, introduced as
1064	  part of the ARMv8.2-LPA extension.
1065
1066	  With this enabled, the kernel will also continue to work on CPUs that
1067	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1068	  minor performance overhead).
1069
1070endchoice
1071
1072config ARM64_PA_BITS
1073	int
1074	default 48 if ARM64_PA_BITS_48
1075	default 52 if ARM64_PA_BITS_52
1076
1077choice
1078	prompt "Endianness"
1079	default CPU_LITTLE_ENDIAN
1080	help
1081	  Select the endianness of data accesses performed by the CPU. Userspace
1082	  applications will need to be compiled and linked for the endianness
1083	  that is selected here.
1084
1085config CPU_BIG_ENDIAN
1086	bool "Build big-endian kernel"
1087	depends on !LD_IS_LLD || LLD_VERSION >= 130000
1088	help
1089	  Say Y if you plan on running a kernel with a big-endian userspace.
1090
1091config CPU_LITTLE_ENDIAN
1092	bool "Build little-endian kernel"
1093	help
1094	  Say Y if you plan on running a kernel with a little-endian userspace.
1095	  This is usually the case for distributions targeting arm64.
1096
1097endchoice
1098
1099config SCHED_MC
1100	bool "Multi-core scheduler support"
1101	help
1102	  Multi-core scheduler support improves the CPU scheduler's decision
1103	  making when dealing with multi-core CPU chips at a cost of slightly
1104	  increased overhead in some places. If unsure say N here.
1105
1106config SCHED_CLUSTER
1107	bool "Cluster scheduler support"
1108	help
1109	  Cluster scheduler support improves the CPU scheduler's decision
1110	  making when dealing with machines that have clusters of CPUs.
1111	  Cluster usually means a couple of CPUs which are placed closely
1112	  by sharing mid-level caches, last-level cache tags or internal
1113	  busses.
1114
1115config SCHED_SMT
1116	bool "SMT scheduler support"
1117	help
1118	  Improves the CPU scheduler's decision making when dealing with
1119	  MultiThreading at a cost of slightly increased overhead in some
1120	  places. If unsure say N here.
1121
1122config NR_CPUS
1123	int "Maximum number of CPUs (2-4096)"
1124	range 2 4096
1125	default "256"
1126
1127config HOTPLUG_CPU
1128	bool "Support for hot-pluggable CPUs"
1129	select GENERIC_IRQ_MIGRATION
1130	help
1131	  Say Y here to experiment with turning CPUs off and on.  CPUs
1132	  can be controlled through /sys/devices/system/cpu.
1133
1134# Common NUMA Features
1135config NUMA
1136	bool "NUMA Memory Allocation and Scheduler Support"
1137	select GENERIC_ARCH_NUMA
1138	select ACPI_NUMA if ACPI
1139	select OF_NUMA
1140	help
1141	  Enable NUMA (Non-Uniform Memory Access) support.
1142
1143	  The kernel will try to allocate memory used by a CPU on the
1144	  local memory of the CPU and add some more
1145	  NUMA awareness to the kernel.
1146
1147config NODES_SHIFT
1148	int "Maximum NUMA Nodes (as a power of 2)"
1149	range 1 10
1150	default "4"
1151	depends on NUMA
1152	help
1153	  Specify the maximum number of NUMA Nodes available on the target
1154	  system.  Increases memory reserved to accommodate various tables.
1155
1156config USE_PERCPU_NUMA_NODE_ID
1157	def_bool y
1158	depends on NUMA
1159
1160config HAVE_SETUP_PER_CPU_AREA
1161	def_bool y
1162	depends on NUMA
1163
1164config NEED_PER_CPU_EMBED_FIRST_CHUNK
1165	def_bool y
1166	depends on NUMA
1167
1168config NEED_PER_CPU_PAGE_FIRST_CHUNK
1169	def_bool y
1170	depends on NUMA
1171
1172source "kernel/Kconfig.hz"
1173
1174config ARCH_SPARSEMEM_ENABLE
1175	def_bool y
1176	select SPARSEMEM_VMEMMAP_ENABLE
1177	select SPARSEMEM_VMEMMAP
1178
1179config HW_PERF_EVENTS
1180	def_bool y
1181	depends on ARM_PMU
1182
1183config ARCH_HAS_FILTER_PGPROT
1184	def_bool y
1185
1186# Supported by clang >= 7.0
1187config CC_HAVE_SHADOW_CALL_STACK
1188	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1189
1190config PARAVIRT
1191	bool "Enable paravirtualization code"
1192	help
1193	  This changes the kernel so it can modify itself when it is run
1194	  under a hypervisor, potentially improving performance significantly
1195	  over full virtualization.
1196
1197config PARAVIRT_TIME_ACCOUNTING
1198	bool "Paravirtual steal time accounting"
1199	select PARAVIRT
1200	help
1201	  Select this option to enable fine granularity task steal time
1202	  accounting. Time spent executing other tasks in parallel with
1203	  the current vCPU is discounted from the vCPU power. To account for
1204	  that, there can be a small performance impact.
1205
1206	  If in doubt, say N here.
1207
1208config KEXEC
1209	depends on PM_SLEEP_SMP
1210	select KEXEC_CORE
1211	bool "kexec system call"
1212	help
1213	  kexec is a system call that implements the ability to shutdown your
1214	  current kernel, and to start another kernel.  It is like a reboot
1215	  but it is independent of the system firmware.   And like a reboot
1216	  you can start any kernel with it, not just Linux.
1217
1218config KEXEC_FILE
1219	bool "kexec file based system call"
1220	select KEXEC_CORE
1221	select HAVE_IMA_KEXEC if IMA
1222	help
1223	  This is new version of kexec system call. This system call is
1224	  file based and takes file descriptors as system call argument
1225	  for kernel and initramfs as opposed to list of segments as
1226	  accepted by previous system call.
1227
1228config KEXEC_SIG
1229	bool "Verify kernel signature during kexec_file_load() syscall"
1230	depends on KEXEC_FILE
1231	help
1232	  Select this option to verify a signature with loaded kernel
1233	  image. If configured, any attempt of loading a image without
1234	  valid signature will fail.
1235
1236	  In addition to that option, you need to enable signature
1237	  verification for the corresponding kernel image type being
1238	  loaded in order for this to work.
1239
1240config KEXEC_IMAGE_VERIFY_SIG
1241	bool "Enable Image signature verification support"
1242	default y
1243	depends on KEXEC_SIG
1244	depends on EFI && SIGNED_PE_FILE_VERIFICATION
1245	help
1246	  Enable Image signature verification support.
1247
1248comment "Support for PE file signature verification disabled"
1249	depends on KEXEC_SIG
1250	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
1251
1252config CRASH_DUMP
1253	bool "Build kdump crash kernel"
1254	help
1255	  Generate crash dump after being started by kexec. This should
1256	  be normally only set in special crash dump kernels which are
1257	  loaded in the main kernel with kexec-tools into a specially
1258	  reserved region and then later executed after a crash by
1259	  kdump/kexec.
1260
1261	  For more details see Documentation/admin-guide/kdump/kdump.rst
1262
1263config TRANS_TABLE
1264	def_bool y
1265	depends on HIBERNATION || KEXEC_CORE
1266
1267config XEN_DOM0
1268	def_bool y
1269	depends on XEN
1270
1271config XEN
1272	bool "Xen guest support on ARM64"
1273	depends on ARM64 && OF
1274	select SWIOTLB_XEN
1275	select PARAVIRT
1276	help
1277	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1278
1279config FORCE_MAX_ZONEORDER
1280	int
1281	default "14" if ARM64_64K_PAGES
1282	default "12" if ARM64_16K_PAGES
1283	default "11"
1284	help
1285	  The kernel memory allocator divides physically contiguous memory
1286	  blocks into "zones", where each zone is a power of two number of
1287	  pages.  This option selects the largest power of two that the kernel
1288	  keeps in the memory allocator.  If you need to allocate very large
1289	  blocks of physically contiguous memory, then you may need to
1290	  increase this value.
1291
1292	  This config option is actually maximum order plus one. For example,
1293	  a value of 11 means that the largest free memory block is 2^10 pages.
1294
1295	  We make sure that we can allocate upto a HugePage size for each configuration.
1296	  Hence we have :
1297		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1298
1299	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1300	  4M allocations matching the default size used by generic code.
1301
1302config UNMAP_KERNEL_AT_EL0
1303	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1304	default y
1305	help
1306	  Speculation attacks against some high-performance processors can
1307	  be used to bypass MMU permission checks and leak kernel data to
1308	  userspace. This can be defended against by unmapping the kernel
1309	  when running in userspace, mapping it back in on exception entry
1310	  via a trampoline page in the vector table.
1311
1312	  If unsure, say Y.
1313
1314config RODATA_FULL_DEFAULT_ENABLED
1315	bool "Apply r/o permissions of VM areas also to their linear aliases"
1316	default y
1317	help
1318	  Apply read-only attributes of VM areas to the linear alias of
1319	  the backing pages as well. This prevents code or read-only data
1320	  from being modified (inadvertently or intentionally) via another
1321	  mapping of the same memory page. This additional enhancement can
1322	  be turned off at runtime by passing rodata=[off|on] (and turned on
1323	  with rodata=full if this option is set to 'n')
1324
1325	  This requires the linear region to be mapped down to pages,
1326	  which may adversely affect performance in some cases.
1327
1328config ARM64_SW_TTBR0_PAN
1329	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1330	help
1331	  Enabling this option prevents the kernel from accessing
1332	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1333	  zeroed area and reserved ASID. The user access routines
1334	  restore the valid TTBR0_EL1 temporarily.
1335
1336config ARM64_TAGGED_ADDR_ABI
1337	bool "Enable the tagged user addresses syscall ABI"
1338	default y
1339	help
1340	  When this option is enabled, user applications can opt in to a
1341	  relaxed ABI via prctl() allowing tagged addresses to be passed
1342	  to system calls as pointer arguments. For details, see
1343	  Documentation/arm64/tagged-address-abi.rst.
1344
1345menuconfig COMPAT
1346	bool "Kernel support for 32-bit EL0"
1347	depends on ARM64_4K_PAGES || EXPERT
1348	select HAVE_UID16
1349	select OLD_SIGSUSPEND3
1350	select COMPAT_OLD_SIGACTION
1351	help
1352	  This option enables support for a 32-bit EL0 running under a 64-bit
1353	  kernel at EL1. AArch32-specific components such as system calls,
1354	  the user helper functions, VFP support and the ptrace interface are
1355	  handled appropriately by the kernel.
1356
1357	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1358	  that you will only be able to execute AArch32 binaries that were compiled
1359	  with page size aligned segments.
1360
1361	  If you want to execute 32-bit userspace applications, say Y.
1362
1363if COMPAT
1364
1365config KUSER_HELPERS
1366	bool "Enable kuser helpers page for 32-bit applications"
1367	default y
1368	help
1369	  Warning: disabling this option may break 32-bit user programs.
1370
1371	  Provide kuser helpers to compat tasks. The kernel provides
1372	  helper code to userspace in read only form at a fixed location
1373	  to allow userspace to be independent of the CPU type fitted to
1374	  the system. This permits binaries to be run on ARMv4 through
1375	  to ARMv8 without modification.
1376
1377	  See Documentation/arm/kernel_user_helpers.rst for details.
1378
1379	  However, the fixed address nature of these helpers can be used
1380	  by ROP (return orientated programming) authors when creating
1381	  exploits.
1382
1383	  If all of the binaries and libraries which run on your platform
1384	  are built specifically for your platform, and make no use of
1385	  these helpers, then you can turn this option off to hinder
1386	  such exploits. However, in that case, if a binary or library
1387	  relying on those helpers is run, it will not function correctly.
1388
1389	  Say N here only if you are absolutely certain that you do not
1390	  need these helpers; otherwise, the safe option is to say Y.
1391
1392config COMPAT_VDSO
1393	bool "Enable vDSO for 32-bit applications"
1394	depends on !CPU_BIG_ENDIAN
1395	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1396	select GENERIC_COMPAT_VDSO
1397	default y
1398	help
1399	  Place in the process address space of 32-bit applications an
1400	  ELF shared object providing fast implementations of gettimeofday
1401	  and clock_gettime.
1402
1403	  You must have a 32-bit build of glibc 2.22 or later for programs
1404	  to seamlessly take advantage of this.
1405
1406config THUMB2_COMPAT_VDSO
1407	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1408	depends on COMPAT_VDSO
1409	default y
1410	help
1411	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1412	  otherwise with '-marm'.
1413
1414menuconfig ARMV8_DEPRECATED
1415	bool "Emulate deprecated/obsolete ARMv8 instructions"
1416	depends on SYSCTL
1417	help
1418	  Legacy software support may require certain instructions
1419	  that have been deprecated or obsoleted in the architecture.
1420
1421	  Enable this config to enable selective emulation of these
1422	  features.
1423
1424	  If unsure, say Y
1425
1426if ARMV8_DEPRECATED
1427
1428config SWP_EMULATION
1429	bool "Emulate SWP/SWPB instructions"
1430	help
1431	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1432	  they are always undefined. Say Y here to enable software
1433	  emulation of these instructions for userspace using LDXR/STXR.
1434	  This feature can be controlled at runtime with the abi.swp
1435	  sysctl which is disabled by default.
1436
1437	  In some older versions of glibc [<=2.8] SWP is used during futex
1438	  trylock() operations with the assumption that the code will not
1439	  be preempted. This invalid assumption may be more likely to fail
1440	  with SWP emulation enabled, leading to deadlock of the user
1441	  application.
1442
1443	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1444	  on an external transaction monitoring block called a global
1445	  monitor to maintain update atomicity. If your system does not
1446	  implement a global monitor, this option can cause programs that
1447	  perform SWP operations to uncached memory to deadlock.
1448
1449	  If unsure, say Y
1450
1451config CP15_BARRIER_EMULATION
1452	bool "Emulate CP15 Barrier instructions"
1453	help
1454	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1455	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1456	  strongly recommended to use the ISB, DSB, and DMB
1457	  instructions instead.
1458
1459	  Say Y here to enable software emulation of these
1460	  instructions for AArch32 userspace code. When this option is
1461	  enabled, CP15 barrier usage is traced which can help
1462	  identify software that needs updating. This feature can be
1463	  controlled at runtime with the abi.cp15_barrier sysctl.
1464
1465	  If unsure, say Y
1466
1467config SETEND_EMULATION
1468	bool "Emulate SETEND instruction"
1469	help
1470	  The SETEND instruction alters the data-endianness of the
1471	  AArch32 EL0, and is deprecated in ARMv8.
1472
1473	  Say Y here to enable software emulation of the instruction
1474	  for AArch32 userspace code. This feature can be controlled
1475	  at runtime with the abi.setend sysctl.
1476
1477	  Note: All the cpus on the system must have mixed endian support at EL0
1478	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1479	  endian - is hotplugged in after this feature has been enabled, there could
1480	  be unexpected results in the applications.
1481
1482	  If unsure, say Y
1483endif
1484
1485endif
1486
1487menu "ARMv8.1 architectural features"
1488
1489config ARM64_HW_AFDBM
1490	bool "Support for hardware updates of the Access and Dirty page flags"
1491	default y
1492	help
1493	  The ARMv8.1 architecture extensions introduce support for
1494	  hardware updates of the access and dirty information in page
1495	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1496	  capable processors, accesses to pages with PTE_AF cleared will
1497	  set this bit instead of raising an access flag fault.
1498	  Similarly, writes to read-only pages with the DBM bit set will
1499	  clear the read-only bit (AP[2]) instead of raising a
1500	  permission fault.
1501
1502	  Kernels built with this configuration option enabled continue
1503	  to work on pre-ARMv8.1 hardware and the performance impact is
1504	  minimal. If unsure, say Y.
1505
1506config ARM64_PAN
1507	bool "Enable support for Privileged Access Never (PAN)"
1508	default y
1509	help
1510	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1511	 prevents the kernel or hypervisor from accessing user-space (EL0)
1512	 memory directly.
1513
1514	 Choosing this option will cause any unprotected (not using
1515	 copy_to_user et al) memory access to fail with a permission fault.
1516
1517	 The feature is detected at runtime, and will remain as a 'nop'
1518	 instruction if the cpu does not implement the feature.
1519
1520config AS_HAS_LDAPR
1521	def_bool $(as-instr,.arch_extension rcpc)
1522
1523config AS_HAS_LSE_ATOMICS
1524	def_bool $(as-instr,.arch_extension lse)
1525
1526config ARM64_LSE_ATOMICS
1527	bool
1528	default ARM64_USE_LSE_ATOMICS
1529	depends on AS_HAS_LSE_ATOMICS
1530
1531config ARM64_USE_LSE_ATOMICS
1532	bool "Atomic instructions"
1533	depends on JUMP_LABEL
1534	default y
1535	help
1536	  As part of the Large System Extensions, ARMv8.1 introduces new
1537	  atomic instructions that are designed specifically to scale in
1538	  very large systems.
1539
1540	  Say Y here to make use of these instructions for the in-kernel
1541	  atomic routines. This incurs a small overhead on CPUs that do
1542	  not support these instructions and requires the kernel to be
1543	  built with binutils >= 2.25 in order for the new instructions
1544	  to be used.
1545
1546endmenu
1547
1548menu "ARMv8.2 architectural features"
1549
1550config AS_HAS_ARMV8_2
1551       def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1552
1553config AS_HAS_SHA3
1554       def_bool $(as-instr,.arch armv8.2-a+sha3)
1555
1556config ARM64_PMEM
1557	bool "Enable support for persistent memory"
1558	select ARCH_HAS_PMEM_API
1559	select ARCH_HAS_UACCESS_FLUSHCACHE
1560	help
1561	  Say Y to enable support for the persistent memory API based on the
1562	  ARMv8.2 DCPoP feature.
1563
1564	  The feature is detected at runtime, and the kernel will use DC CVAC
1565	  operations if DC CVAP is not supported (following the behaviour of
1566	  DC CVAP itself if the system does not define a point of persistence).
1567
1568config ARM64_RAS_EXTN
1569	bool "Enable support for RAS CPU Extensions"
1570	default y
1571	help
1572	  CPUs that support the Reliability, Availability and Serviceability
1573	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1574	  errors, classify them and report them to software.
1575
1576	  On CPUs with these extensions system software can use additional
1577	  barriers to determine if faults are pending and read the
1578	  classification from a new set of registers.
1579
1580	  Selecting this feature will allow the kernel to use these barriers
1581	  and access the new registers if the system supports the extension.
1582	  Platform RAS features may additionally depend on firmware support.
1583
1584config ARM64_CNP
1585	bool "Enable support for Common Not Private (CNP) translations"
1586	default y
1587	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1588	help
1589	  Common Not Private (CNP) allows translation table entries to
1590	  be shared between different PEs in the same inner shareable
1591	  domain, so the hardware can use this fact to optimise the
1592	  caching of such entries in the TLB.
1593
1594	  Selecting this option allows the CNP feature to be detected
1595	  at runtime, and does not affect PEs that do not implement
1596	  this feature.
1597
1598endmenu
1599
1600menu "ARMv8.3 architectural features"
1601
1602config ARM64_PTR_AUTH
1603	bool "Enable support for pointer authentication"
1604	default y
1605	help
1606	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1607	  instructions for signing and authenticating pointers against secret
1608	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1609	  and other attacks.
1610
1611	  This option enables these instructions at EL0 (i.e. for userspace).
1612	  Choosing this option will cause the kernel to initialise secret keys
1613	  for each process at exec() time, with these keys being
1614	  context-switched along with the process.
1615
1616	  The feature is detected at runtime. If the feature is not present in
1617	  hardware it will not be advertised to userspace/KVM guest nor will it
1618	  be enabled.
1619
1620	  If the feature is present on the boot CPU but not on a late CPU, then
1621	  the late CPU will be parked. Also, if the boot CPU does not have
1622	  address auth and the late CPU has then the late CPU will still boot
1623	  but with the feature disabled. On such a system, this option should
1624	  not be selected.
1625
1626config ARM64_PTR_AUTH_KERNEL
1627	bool "Use pointer authentication for kernel"
1628	default y
1629	depends on ARM64_PTR_AUTH
1630	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC
1631	# Modern compilers insert a .note.gnu.property section note for PAC
1632	# which is only understood by binutils starting with version 2.33.1.
1633	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1634	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1635	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
1636	help
1637	  If the compiler supports the -mbranch-protection or
1638	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1639	  will cause the kernel itself to be compiled with return address
1640	  protection. In this case, and if the target hardware is known to
1641	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1642	  disabled with minimal loss of protection.
1643
1644	  This feature works with FUNCTION_GRAPH_TRACER option only if
1645	  DYNAMIC_FTRACE_WITH_REGS is enabled.
1646
1647config CC_HAS_BRANCH_PROT_PAC_RET
1648	# GCC 9 or later, clang 8 or later
1649	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1650
1651config CC_HAS_SIGN_RETURN_ADDRESS
1652	# GCC 7, 8
1653	def_bool $(cc-option,-msign-return-address=all)
1654
1655config AS_HAS_PAC
1656	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1657
1658config AS_HAS_CFI_NEGATE_RA_STATE
1659	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1660
1661endmenu
1662
1663menu "ARMv8.4 architectural features"
1664
1665config ARM64_AMU_EXTN
1666	bool "Enable support for the Activity Monitors Unit CPU extension"
1667	default y
1668	help
1669	  The activity monitors extension is an optional extension introduced
1670	  by the ARMv8.4 CPU architecture. This enables support for version 1
1671	  of the activity monitors architecture, AMUv1.
1672
1673	  To enable the use of this extension on CPUs that implement it, say Y.
1674
1675	  Note that for architectural reasons, firmware _must_ implement AMU
1676	  support when running on CPUs that present the activity monitors
1677	  extension. The required support is present in:
1678	    * Version 1.5 and later of the ARM Trusted Firmware
1679
1680	  For kernels that have this configuration enabled but boot with broken
1681	  firmware, you may need to say N here until the firmware is fixed.
1682	  Otherwise you may experience firmware panics or lockups when
1683	  accessing the counter registers. Even if you are not observing these
1684	  symptoms, the values returned by the register reads might not
1685	  correctly reflect reality. Most commonly, the value read will be 0,
1686	  indicating that the counter is not enabled.
1687
1688config AS_HAS_ARMV8_4
1689	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1690
1691config ARM64_TLB_RANGE
1692	bool "Enable support for tlbi range feature"
1693	default y
1694	depends on AS_HAS_ARMV8_4
1695	help
1696	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1697	  range of input addresses.
1698
1699	  The feature introduces new assembly instructions, and they were
1700	  support when binutils >= 2.30.
1701
1702endmenu
1703
1704menu "ARMv8.5 architectural features"
1705
1706config AS_HAS_ARMV8_5
1707	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1708
1709config ARM64_BTI
1710	bool "Branch Target Identification support"
1711	default y
1712	help
1713	  Branch Target Identification (part of the ARMv8.5 Extensions)
1714	  provides a mechanism to limit the set of locations to which computed
1715	  branch instructions such as BR or BLR can jump.
1716
1717	  To make use of BTI on CPUs that support it, say Y.
1718
1719	  BTI is intended to provide complementary protection to other control
1720	  flow integrity protection mechanisms, such as the Pointer
1721	  authentication mechanism provided as part of the ARMv8.3 Extensions.
1722	  For this reason, it does not make sense to enable this option without
1723	  also enabling support for pointer authentication.  Thus, when
1724	  enabling this option you should also select ARM64_PTR_AUTH=y.
1725
1726	  Userspace binaries must also be specifically compiled to make use of
1727	  this mechanism.  If you say N here or the hardware does not support
1728	  BTI, such binaries can still run, but you get no additional
1729	  enforcement of branch destinations.
1730
1731config ARM64_BTI_KERNEL
1732	bool "Use Branch Target Identification for kernel"
1733	default y
1734	depends on ARM64_BTI
1735	depends on ARM64_PTR_AUTH_KERNEL
1736	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1737	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1738	depends on !CC_IS_GCC || GCC_VERSION >= 100100
1739	# https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
1740	depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
1741	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
1742	help
1743	  Build the kernel with Branch Target Identification annotations
1744	  and enable enforcement of this for kernel code. When this option
1745	  is enabled and the system supports BTI all kernel code including
1746	  modular code must have BTI enabled.
1747
1748config CC_HAS_BRANCH_PROT_PAC_RET_BTI
1749	# GCC 9 or later, clang 8 or later
1750	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
1751
1752config ARM64_E0PD
1753	bool "Enable support for E0PD"
1754	default y
1755	help
1756	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
1757	  that EL0 accesses made via TTBR1 always fault in constant time,
1758	  providing similar benefits to KASLR as those provided by KPTI, but
1759	  with lower overhead and without disrupting legitimate access to
1760	  kernel memory such as SPE.
1761
1762	  This option enables E0PD for TTBR1 where available.
1763
1764config ARCH_RANDOM
1765	bool "Enable support for random number generation"
1766	default y
1767	help
1768	  Random number generation (part of the ARMv8.5 Extensions)
1769	  provides a high bandwidth, cryptographically secure
1770	  hardware random number generator.
1771
1772config ARM64_AS_HAS_MTE
1773	# Initial support for MTE went in binutils 2.32.0, checked with
1774	# ".arch armv8.5-a+memtag" below. However, this was incomplete
1775	# as a late addition to the final architecture spec (LDGM/STGM)
1776	# is only supported in the newer 2.32.x and 2.33 binutils
1777	# versions, hence the extra "stgm" instruction check below.
1778	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
1779
1780config ARM64_MTE
1781	bool "Memory Tagging Extension support"
1782	default y
1783	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
1784	depends on AS_HAS_ARMV8_5
1785	depends on AS_HAS_LSE_ATOMICS
1786	# Required for tag checking in the uaccess routines
1787	depends on ARM64_PAN
1788	select ARCH_USES_HIGH_VMA_FLAGS
1789	help
1790	  Memory Tagging (part of the ARMv8.5 Extensions) provides
1791	  architectural support for run-time, always-on detection of
1792	  various classes of memory error to aid with software debugging
1793	  to eliminate vulnerabilities arising from memory-unsafe
1794	  languages.
1795
1796	  This option enables the support for the Memory Tagging
1797	  Extension at EL0 (i.e. for userspace).
1798
1799	  Selecting this option allows the feature to be detected at
1800	  runtime. Any secondary CPU not implementing this feature will
1801	  not be allowed a late bring-up.
1802
1803	  Userspace binaries that want to use this feature must
1804	  explicitly opt in. The mechanism for the userspace is
1805	  described in:
1806
1807	  Documentation/arm64/memory-tagging-extension.rst.
1808
1809endmenu
1810
1811menu "ARMv8.7 architectural features"
1812
1813config ARM64_EPAN
1814	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
1815	default y
1816	depends on ARM64_PAN
1817	help
1818	 Enhanced Privileged Access Never (EPAN) allows Privileged
1819	 Access Never to be used with Execute-only mappings.
1820
1821	 The feature is detected at runtime, and will remain disabled
1822	 if the cpu does not implement the feature.
1823endmenu
1824
1825config ARM64_SVE
1826	bool "ARM Scalable Vector Extension support"
1827	default y
1828	help
1829	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1830	  execution state which complements and extends the SIMD functionality
1831	  of the base architecture to support much larger vectors and to enable
1832	  additional vectorisation opportunities.
1833
1834	  To enable use of this extension on CPUs that implement it, say Y.
1835
1836	  On CPUs that support the SVE2 extensions, this option will enable
1837	  those too.
1838
1839	  Note that for architectural reasons, firmware _must_ implement SVE
1840	  support when running on SVE capable hardware.  The required support
1841	  is present in:
1842
1843	    * version 1.5 and later of the ARM Trusted Firmware
1844	    * the AArch64 boot wrapper since commit 5e1261e08abf
1845	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1846
1847	  For other firmware implementations, consult the firmware documentation
1848	  or vendor.
1849
1850	  If you need the kernel to boot on SVE-capable hardware with broken
1851	  firmware, you may need to say N here until you get your firmware
1852	  fixed.  Otherwise, you may experience firmware panics or lockups when
1853	  booting the kernel.  If unsure and you are not observing these
1854	  symptoms, you should assume that it is safe to say Y.
1855
1856config ARM64_MODULE_PLTS
1857	bool "Use PLTs to allow module memory to spill over into vmalloc area"
1858	depends on MODULES
1859	select HAVE_MOD_ARCH_SPECIFIC
1860	help
1861	  Allocate PLTs when loading modules so that jumps and calls whose
1862	  targets are too far away for their relative offsets to be encoded
1863	  in the instructions themselves can be bounced via veneers in the
1864	  module's PLT. This allows modules to be allocated in the generic
1865	  vmalloc area after the dedicated module memory area has been
1866	  exhausted.
1867
1868	  When running with address space randomization (KASLR), the module
1869	  region itself may be too far away for ordinary relative jumps and
1870	  calls, and so in that case, module PLTs are required and cannot be
1871	  disabled.
1872
1873	  Specific errata workaround(s) might also force module PLTs to be
1874	  enabled (ARM64_ERRATUM_843419).
1875
1876config ARM64_PSEUDO_NMI
1877	bool "Support for NMI-like interrupts"
1878	select ARM_GIC_V3
1879	help
1880	  Adds support for mimicking Non-Maskable Interrupts through the use of
1881	  GIC interrupt priority. This support requires version 3 or later of
1882	  ARM GIC.
1883
1884	  This high priority configuration for interrupts needs to be
1885	  explicitly enabled by setting the kernel parameter
1886	  "irqchip.gicv3_pseudo_nmi" to 1.
1887
1888	  If unsure, say N
1889
1890if ARM64_PSEUDO_NMI
1891config ARM64_DEBUG_PRIORITY_MASKING
1892	bool "Debug interrupt priority masking"
1893	help
1894	  This adds runtime checks to functions enabling/disabling
1895	  interrupts when using priority masking. The additional checks verify
1896	  the validity of ICC_PMR_EL1 when calling concerned functions.
1897
1898	  If unsure, say N
1899endif
1900
1901config RELOCATABLE
1902	bool "Build a relocatable kernel image" if EXPERT
1903	select ARCH_HAS_RELR
1904	default y
1905	help
1906	  This builds the kernel as a Position Independent Executable (PIE),
1907	  which retains all relocation metadata required to relocate the
1908	  kernel binary at runtime to a different virtual address than the
1909	  address it was linked at.
1910	  Since AArch64 uses the RELA relocation format, this requires a
1911	  relocation pass at runtime even if the kernel is loaded at the
1912	  same address it was linked at.
1913
1914config RANDOMIZE_BASE
1915	bool "Randomize the address of the kernel image"
1916	select ARM64_MODULE_PLTS if MODULES
1917	select RELOCATABLE
1918	help
1919	  Randomizes the virtual address at which the kernel image is
1920	  loaded, as a security feature that deters exploit attempts
1921	  relying on knowledge of the location of kernel internals.
1922
1923	  It is the bootloader's job to provide entropy, by passing a
1924	  random u64 value in /chosen/kaslr-seed at kernel entry.
1925
1926	  When booting via the UEFI stub, it will invoke the firmware's
1927	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1928	  to the kernel proper. In addition, it will randomise the physical
1929	  location of the kernel Image as well.
1930
1931	  If unsure, say N.
1932
1933config RANDOMIZE_MODULE_REGION_FULL
1934	bool "Randomize the module region over a 2 GB range"
1935	depends on RANDOMIZE_BASE
1936	default y
1937	help
1938	  Randomizes the location of the module region inside a 2 GB window
1939	  covering the core kernel. This way, it is less likely for modules
1940	  to leak information about the location of core kernel data structures
1941	  but it does imply that function calls between modules and the core
1942	  kernel will need to be resolved via veneers in the module PLT.
1943
1944	  When this option is not set, the module region will be randomized over
1945	  a limited range that contains the [_stext, _etext] interval of the
1946	  core kernel, so branch relocations are almost always in range unless
1947	  ARM64_MODULE_PLTS is enabled and the region is exhausted. In this
1948	  particular case of region exhaustion, modules might be able to fall
1949	  back to a larger 2GB area.
1950
1951config CC_HAVE_STACKPROTECTOR_SYSREG
1952	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1953
1954config STACKPROTECTOR_PER_TASK
1955	def_bool y
1956	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1957
1958endmenu
1959
1960menu "Boot options"
1961
1962config ARM64_ACPI_PARKING_PROTOCOL
1963	bool "Enable support for the ARM64 ACPI parking protocol"
1964	depends on ACPI
1965	help
1966	  Enable support for the ARM64 ACPI parking protocol. If disabled
1967	  the kernel will not allow booting through the ARM64 ACPI parking
1968	  protocol even if the corresponding data is present in the ACPI
1969	  MADT table.
1970
1971config CMDLINE
1972	string "Default kernel command string"
1973	default ""
1974	help
1975	  Provide a set of default command-line options at build time by
1976	  entering them here. As a minimum, you should specify the the
1977	  root device (e.g. root=/dev/nfs).
1978
1979choice
1980	prompt "Kernel command line type" if CMDLINE != ""
1981	default CMDLINE_FROM_BOOTLOADER
1982	help
1983	  Choose how the kernel will handle the provided default kernel
1984	  command line string.
1985
1986config CMDLINE_FROM_BOOTLOADER
1987	bool "Use bootloader kernel arguments if available"
1988	help
1989	  Uses the command-line options passed by the boot loader. If
1990	  the boot loader doesn't provide any, the default kernel command
1991	  string provided in CMDLINE will be used.
1992
1993config CMDLINE_FORCE
1994	bool "Always use the default kernel command string"
1995	help
1996	  Always use the default kernel command string, even if the boot
1997	  loader passes other arguments to the kernel.
1998	  This is useful if you cannot or don't want to change the
1999	  command-line options your boot loader passes to the kernel.
2000
2001endchoice
2002
2003config EFI_STUB
2004	bool
2005
2006config EFI
2007	bool "UEFI runtime support"
2008	depends on OF && !CPU_BIG_ENDIAN
2009	depends on KERNEL_MODE_NEON
2010	select ARCH_SUPPORTS_ACPI
2011	select LIBFDT
2012	select UCS2_STRING
2013	select EFI_PARAMS_FROM_FDT
2014	select EFI_RUNTIME_WRAPPERS
2015	select EFI_STUB
2016	select EFI_GENERIC_STUB
2017	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2018	default y
2019	help
2020	  This option provides support for runtime services provided
2021	  by UEFI firmware (such as non-volatile variables, realtime
2022          clock, and platform reset). A UEFI stub is also provided to
2023	  allow the kernel to be booted as an EFI application. This
2024	  is only useful on systems that have UEFI firmware.
2025
2026config DMI
2027	bool "Enable support for SMBIOS (DMI) tables"
2028	depends on EFI
2029	default y
2030	help
2031	  This enables SMBIOS/DMI feature for systems.
2032
2033	  This option is only useful on systems that have UEFI firmware.
2034	  However, even with this option, the resultant kernel should
2035	  continue to boot on existing non-UEFI platforms.
2036
2037endmenu
2038
2039config SYSVIPC_COMPAT
2040	def_bool y
2041	depends on COMPAT && SYSVIPC
2042
2043menu "Power management options"
2044
2045source "kernel/power/Kconfig"
2046
2047config ARCH_HIBERNATION_POSSIBLE
2048	def_bool y
2049	depends on CPU_PM
2050
2051config ARCH_HIBERNATION_HEADER
2052	def_bool y
2053	depends on HIBERNATION
2054
2055config ARCH_SUSPEND_POSSIBLE
2056	def_bool y
2057
2058endmenu
2059
2060menu "CPU Power Management"
2061
2062source "drivers/cpuidle/Kconfig"
2063
2064source "drivers/cpufreq/Kconfig"
2065
2066endmenu
2067
2068source "drivers/acpi/Kconfig"
2069
2070source "arch/arm64/kvm/Kconfig"
2071
2072if CRYPTO
2073source "arch/arm64/crypto/Kconfig"
2074endif
2075