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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_HAS_DEBUG_VIRTUAL
15	select ARCH_HAS_DEBUG_VM_PGTABLE
16	select ARCH_HAS_DEVMEM_IS_ALLOWED
17	select ARCH_HAS_DMA_PREP_COHERENT
18	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
19	select ARCH_HAS_FAST_MULTIPLIER
20	select ARCH_HAS_FORTIFY_SOURCE
21	select ARCH_HAS_GCOV_PROFILE_ALL
22	select ARCH_HAS_GIGANTIC_PAGE
23	select ARCH_HAS_KCOV
24	select ARCH_HAS_KEEPINITRD
25	select ARCH_HAS_MEMBARRIER_SYNC_CORE
26	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
27	select ARCH_HAS_PTE_DEVMAP
28	select ARCH_HAS_PTE_SPECIAL
29	select ARCH_HAS_SETUP_DMA_OPS
30	select ARCH_HAS_SET_DIRECT_MAP
31	select ARCH_HAS_SET_MEMORY
32	select ARCH_STACKWALK
33	select ARCH_HAS_STRICT_KERNEL_RWX
34	select ARCH_HAS_STRICT_MODULE_RWX
35	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
36	select ARCH_HAS_SYNC_DMA_FOR_CPU
37	select ARCH_HAS_SYSCALL_WRAPPER
38	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
39	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
40	select ARCH_HAVE_ELF_PROT
41	select ARCH_HAVE_NMI_SAFE_CMPXCHG
42	select ARCH_INLINE_READ_LOCK if !PREEMPTION
43	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
44	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
45	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
46	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
47	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
48	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
49	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
50	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
51	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
52	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
53	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
54	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
55	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
56	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
57	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
58	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
59	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
60	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
61	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
62	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
63	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
64	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
65	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
66	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
67	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
68	select ARCH_KEEP_MEMBLOCK
69	select ARCH_USE_CMPXCHG_LOCKREF
70	select ARCH_USE_GNU_PROPERTY
71	select ARCH_USE_QUEUED_RWLOCKS
72	select ARCH_USE_QUEUED_SPINLOCKS
73	select ARCH_USE_SYM_ANNOTATIONS
74	select ARCH_SUPPORTS_MEMORY_FAILURE
75	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
76	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
77	select ARCH_SUPPORTS_LTO_CLANG_THIN
78	select ARCH_SUPPORTS_ATOMIC_RMW
79	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG)
80	select ARCH_SUPPORTS_NUMA_BALANCING
81	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
82	select ARCH_WANT_DEFAULT_BPF_JIT
83	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
84	select ARCH_WANT_FRAME_POINTERS
85	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
86	select ARCH_WANT_LD_ORPHAN_WARN
87	select ARCH_HAS_UBSAN_SANITIZE_ALL
88	select ARM_AMBA
89	select ARM_ARCH_TIMER
90	select ARM_GIC
91	select AUDIT_ARCH_COMPAT_GENERIC
92	select ARM_GIC_V2M if PCI
93	select ARM_GIC_V3
94	select ARM_GIC_V3_ITS if PCI
95	select ARM_PSCI_FW
96	select BUILDTIME_TABLE_SORT
97	select CLONE_BACKWARDS
98	select COMMON_CLK
99	select CPU_PM if (SUSPEND || CPU_IDLE)
100	select CRC32
101	select DCACHE_WORD_ACCESS
102	select DMA_DIRECT_REMAP
103	select EDAC_SUPPORT
104	select FRAME_POINTER
105	select GENERIC_ALLOCATOR
106	select GENERIC_ARCH_TOPOLOGY
107	select GENERIC_CLOCKEVENTS
108	select GENERIC_CLOCKEVENTS_BROADCAST
109	select GENERIC_CPU_AUTOPROBE
110	select GENERIC_CPU_VULNERABILITIES
111	select GENERIC_EARLY_IOREMAP
112	select GENERIC_IDLE_POLL_SETUP
113	select GENERIC_IRQ_IPI
114	select ARCH_WANTS_IRQ_RAW
115	select GENERIC_IRQ_MULTI_HANDLER
116	select GENERIC_IRQ_PROBE
117	select GENERIC_IRQ_SHOW
118	select GENERIC_IRQ_SHOW_LEVEL
119	select GENERIC_PCI_IOMAP
120	select GENERIC_PTDUMP
121	select GENERIC_SCHED_CLOCK
122	select GENERIC_SMP_IDLE_THREAD
123	select GENERIC_STRNCPY_FROM_USER
124	select GENERIC_STRNLEN_USER
125	select GENERIC_TIME_VSYSCALL
126	select GENERIC_GETTIMEOFDAY
127	select GENERIC_VDSO_TIME_NS
128	select HANDLE_DOMAIN_IRQ
129	select HARDIRQS_SW_RESEND
130	select HAVE_MOVE_PMD
131	select HAVE_MOVE_PUD
132	select HAVE_PCI
133	select HAVE_ACPI_APEI if (ACPI && EFI)
134	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
135	select HAVE_ARCH_AUDITSYSCALL
136	select HAVE_ARCH_BITREVERSE
137	select HAVE_ARCH_COMPILER_H
138	select HAVE_ARCH_HUGE_VMAP
139	select HAVE_ARCH_JUMP_LABEL
140	select HAVE_ARCH_JUMP_LABEL_RELATIVE
141	select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
142	select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
143	select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
144	select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
145	select HAVE_ARCH_KFENCE
146	select HAVE_ARCH_KGDB
147	select HAVE_ARCH_MMAP_RND_BITS
148	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
149	select HAVE_ARCH_PREL32_RELOCATIONS
150	select HAVE_ARCH_SECCOMP_FILTER
151	select HAVE_ARCH_STACKLEAK
152	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
153	select HAVE_ARCH_TRACEHOOK
154	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
155	select HAVE_ARCH_VMAP_STACK
156	select HAVE_ARM_SMCCC
157	select HAVE_ASM_MODVERSIONS
158	select HAVE_EBPF_JIT
159	select HAVE_C_RECORDMCOUNT
160	select HAVE_CMPXCHG_DOUBLE
161	select HAVE_CMPXCHG_LOCAL
162	select HAVE_CONTEXT_TRACKING
163	select HAVE_DEBUG_BUGVERBOSE
164	select HAVE_DEBUG_KMEMLEAK
165	select HAVE_DMA_CONTIGUOUS
166	select HAVE_DYNAMIC_FTRACE
167	select HAVE_DYNAMIC_FTRACE_WITH_REGS \
168		if $(cc-option,-fpatchable-function-entry=2)
169	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
170		if DYNAMIC_FTRACE_WITH_REGS
171	select HAVE_EFFICIENT_UNALIGNED_ACCESS
172	select HAVE_FAST_GUP
173	select HAVE_FTRACE_MCOUNT_RECORD
174	select HAVE_FUNCTION_TRACER
175	select HAVE_FUNCTION_ERROR_INJECTION
176	select HAVE_FUNCTION_GRAPH_TRACER
177	select HAVE_GCC_PLUGINS
178	select HAVE_HW_BREAKPOINT if PERF_EVENTS
179	select HAVE_IRQ_TIME_ACCOUNTING
180	select HAVE_NMI
181	select HAVE_PATA_PLATFORM
182	select HAVE_PERF_EVENTS
183	select HAVE_PERF_REGS
184	select HAVE_PERF_USER_STACK_DUMP
185	select HAVE_REGS_AND_STACK_ACCESS_API
186	select HAVE_FUNCTION_ARG_ACCESS_API
187	select HAVE_FUTEX_CMPXCHG if FUTEX
188	select MMU_GATHER_RCU_TABLE_FREE
189	select HAVE_RSEQ
190	select HAVE_STACKPROTECTOR
191	select HAVE_SYSCALL_TRACEPOINTS
192	select HAVE_KPROBES
193	select HAVE_KRETPROBES
194	select HAVE_GENERIC_VDSO
195	select IOMMU_DMA if IOMMU_SUPPORT
196	select IRQ_DOMAIN
197	select IRQ_FORCED_THREADING
198	select KASAN_VMALLOC if KASAN_GENERIC
199	select MODULES_USE_ELF_RELA
200	select NEED_DMA_MAP_STATE
201	select NEED_SG_DMA_LENGTH
202	select OF
203	select OF_EARLY_FLATTREE
204	select PCI_DOMAINS_GENERIC if PCI
205	select PCI_ECAM if (ACPI && PCI)
206	select PCI_SYSCALL if PCI
207	select POWER_RESET
208	select POWER_SUPPLY
209	select SET_FS
210	select SPARSE_IRQ
211	select SWIOTLB
212	select SYSCTL_EXCEPTION_TRACE
213	select THREAD_INFO_IN_TASK
214	select ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT
215	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
216	help
217	  ARM 64-bit (AArch64) Linux support.
218
219config 64BIT
220	def_bool y
221
222config MMU
223	def_bool y
224
225config ARM64_PAGE_SHIFT
226	int
227	default 16 if ARM64_64K_PAGES
228	default 14 if ARM64_16K_PAGES
229	default 12
230
231config ARM64_CONT_PTE_SHIFT
232	int
233	default 5 if ARM64_64K_PAGES
234	default 7 if ARM64_16K_PAGES
235	default 4
236
237config ARM64_CONT_PMD_SHIFT
238	int
239	default 5 if ARM64_64K_PAGES
240	default 5 if ARM64_16K_PAGES
241	default 4
242
243config ARCH_MMAP_RND_BITS_MIN
244       default 14 if ARM64_64K_PAGES
245       default 16 if ARM64_16K_PAGES
246       default 18
247
248# max bits determined by the following formula:
249#  VA_BITS - PAGE_SHIFT - 3
250config ARCH_MMAP_RND_BITS_MAX
251       default 19 if ARM64_VA_BITS=36
252       default 24 if ARM64_VA_BITS=39
253       default 27 if ARM64_VA_BITS=42
254       default 30 if ARM64_VA_BITS=47
255       default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
256       default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
257       default 33 if ARM64_VA_BITS=48
258       default 14 if ARM64_64K_PAGES
259       default 16 if ARM64_16K_PAGES
260       default 18
261
262config ARCH_MMAP_RND_COMPAT_BITS_MIN
263       default 7 if ARM64_64K_PAGES
264       default 9 if ARM64_16K_PAGES
265       default 11
266
267config ARCH_MMAP_RND_COMPAT_BITS_MAX
268       default 16
269
270config NO_IOPORT_MAP
271	def_bool y if !PCI
272
273config STACKTRACE_SUPPORT
274	def_bool y
275
276config ILLEGAL_POINTER_VALUE
277	hex
278	default 0xdead000000000000
279
280config LOCKDEP_SUPPORT
281	def_bool y
282
283config TRACE_IRQFLAGS_SUPPORT
284	def_bool y
285
286config GENERIC_BUG
287	def_bool y
288	depends on BUG
289
290config GENERIC_BUG_RELATIVE_POINTERS
291	def_bool y
292	depends on GENERIC_BUG
293
294config GENERIC_HWEIGHT
295	def_bool y
296
297config GENERIC_CSUM
298        def_bool y
299
300config GENERIC_CALIBRATE_DELAY
301	def_bool y
302
303config ZONE_DMA
304	bool "Support DMA zone" if EXPERT
305	default y
306
307config ZONE_DMA32
308	bool "Support DMA32 zone" if EXPERT
309	default y
310
311config ARCH_ENABLE_MEMORY_HOTPLUG
312	def_bool y
313
314config ARCH_ENABLE_MEMORY_HOTREMOVE
315	def_bool y
316
317config SMP
318	def_bool y
319
320config KERNEL_MODE_NEON
321	def_bool y
322
323config FIX_EARLYCON_MEM
324	def_bool y
325
326config PGTABLE_LEVELS
327	int
328	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
329	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
330	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
331	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
332	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
333	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
334
335config ARCH_SUPPORTS_UPROBES
336	def_bool y
337
338config ARCH_PROC_KCORE_TEXT
339	def_bool y
340
341config BROKEN_GAS_INST
342	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
343
344config KASAN_SHADOW_OFFSET
345	hex
346	depends on KASAN_GENERIC || KASAN_SW_TAGS
347	default 0xdfffa00000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
348	default 0xdfffd00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
349	default 0xdffffe8000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
350	default 0xdfffffd000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
351	default 0xdffffffa00000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
352	default 0xefff900000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
353	default 0xefffc80000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
354	default 0xeffffe4000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
355	default 0xefffffc800000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
356	default 0xeffffff900000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
357	default 0xffffffffffffffff
358
359source "arch/arm64/Kconfig.platforms"
360
361menu "Kernel Features"
362
363menu "ARM errata workarounds via the alternatives framework"
364
365config ARM64_WORKAROUND_CLEAN_CACHE
366	bool
367
368config ARM64_ERRATUM_826319
369	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
370	default y
371	select ARM64_WORKAROUND_CLEAN_CACHE
372	help
373	  This option adds an alternative code sequence to work around ARM
374	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
375	  AXI master interface and an L2 cache.
376
377	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
378	  and is unable to accept a certain write via this interface, it will
379	  not progress on read data presented on the read data channel and the
380	  system can deadlock.
381
382	  The workaround promotes data cache clean instructions to
383	  data cache clean-and-invalidate.
384	  Please note that this does not necessarily enable the workaround,
385	  as it depends on the alternative framework, which will only patch
386	  the kernel if an affected CPU is detected.
387
388	  If unsure, say Y.
389
390config ARM64_ERRATUM_827319
391	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
392	default y
393	select ARM64_WORKAROUND_CLEAN_CACHE
394	help
395	  This option adds an alternative code sequence to work around ARM
396	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
397	  master interface and an L2 cache.
398
399	  Under certain conditions this erratum can cause a clean line eviction
400	  to occur at the same time as another transaction to the same address
401	  on the AMBA 5 CHI interface, which can cause data corruption if the
402	  interconnect reorders the two transactions.
403
404	  The workaround promotes data cache clean instructions to
405	  data cache clean-and-invalidate.
406	  Please note that this does not necessarily enable the workaround,
407	  as it depends on the alternative framework, which will only patch
408	  the kernel if an affected CPU is detected.
409
410	  If unsure, say Y.
411
412config ARM64_ERRATUM_824069
413	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
414	default y
415	select ARM64_WORKAROUND_CLEAN_CACHE
416	help
417	  This option adds an alternative code sequence to work around ARM
418	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
419	  to a coherent interconnect.
420
421	  If a Cortex-A53 processor is executing a store or prefetch for
422	  write instruction at the same time as a processor in another
423	  cluster is executing a cache maintenance operation to the same
424	  address, then this erratum might cause a clean cache line to be
425	  incorrectly marked as dirty.
426
427	  The workaround promotes data cache clean instructions to
428	  data cache clean-and-invalidate.
429	  Please note that this option does not necessarily enable the
430	  workaround, as it depends on the alternative framework, which will
431	  only patch the kernel if an affected CPU is detected.
432
433	  If unsure, say Y.
434
435config ARM64_ERRATUM_819472
436	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
437	default y
438	select ARM64_WORKAROUND_CLEAN_CACHE
439	help
440	  This option adds an alternative code sequence to work around ARM
441	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
442	  present when it is connected to a coherent interconnect.
443
444	  If the processor is executing a load and store exclusive sequence at
445	  the same time as a processor in another cluster is executing a cache
446	  maintenance operation to the same address, then this erratum might
447	  cause data corruption.
448
449	  The workaround promotes data cache clean instructions to
450	  data cache clean-and-invalidate.
451	  Please note that this does not necessarily enable the workaround,
452	  as it depends on the alternative framework, which will only patch
453	  the kernel if an affected CPU is detected.
454
455	  If unsure, say Y.
456
457config ARM64_ERRATUM_832075
458	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
459	default y
460	help
461	  This option adds an alternative code sequence to work around ARM
462	  erratum 832075 on Cortex-A57 parts up to r1p2.
463
464	  Affected Cortex-A57 parts might deadlock when exclusive load/store
465	  instructions to Write-Back memory are mixed with Device loads.
466
467	  The workaround is to promote device loads to use Load-Acquire
468	  semantics.
469	  Please note that this does not necessarily enable the workaround,
470	  as it depends on the alternative framework, which will only patch
471	  the kernel if an affected CPU is detected.
472
473	  If unsure, say Y.
474
475config ARM64_ERRATUM_834220
476	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
477	depends on KVM
478	default y
479	help
480	  This option adds an alternative code sequence to work around ARM
481	  erratum 834220 on Cortex-A57 parts up to r1p2.
482
483	  Affected Cortex-A57 parts might report a Stage 2 translation
484	  fault as the result of a Stage 1 fault for load crossing a
485	  page boundary when there is a permission or device memory
486	  alignment fault at Stage 1 and a translation fault at Stage 2.
487
488	  The workaround is to verify that the Stage 1 translation
489	  doesn't generate a fault before handling the Stage 2 fault.
490	  Please note that this does not necessarily enable the workaround,
491	  as it depends on the alternative framework, which will only patch
492	  the kernel if an affected CPU is detected.
493
494	  If unsure, say Y.
495
496config ARM64_ERRATUM_1742098
497	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
498	depends on COMPAT
499	default y
500	help
501	  This option removes the AES hwcap for aarch32 user-space to
502	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
503
504	  Affected parts may corrupt the AES state if an interrupt is
505	  taken between a pair of AES instructions. These instructions
506	  are only present if the cryptography extensions are present.
507	  All software should have a fallback implementation for CPUs
508	  that don't implement the cryptography extensions.
509
510	  If unsure, say Y.
511
512config ARM64_ERRATUM_845719
513	bool "Cortex-A53: 845719: a load might read incorrect data"
514	depends on COMPAT
515	default y
516	help
517	  This option adds an alternative code sequence to work around ARM
518	  erratum 845719 on Cortex-A53 parts up to r0p4.
519
520	  When running a compat (AArch32) userspace on an affected Cortex-A53
521	  part, a load at EL0 from a virtual address that matches the bottom 32
522	  bits of the virtual address used by a recent load at (AArch64) EL1
523	  might return incorrect data.
524
525	  The workaround is to write the contextidr_el1 register on exception
526	  return to a 32-bit task.
527	  Please note that this does not necessarily enable the workaround,
528	  as it depends on the alternative framework, which will only patch
529	  the kernel if an affected CPU is detected.
530
531	  If unsure, say Y.
532
533config ARM64_ERRATUM_843419
534	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
535	default y
536	select ARM64_MODULE_PLTS if MODULES
537	help
538	  This option links the kernel with '--fix-cortex-a53-843419' and
539	  enables PLT support to replace certain ADRP instructions, which can
540	  cause subsequent memory accesses to use an incorrect address on
541	  Cortex-A53 parts up to r0p4.
542
543	  If unsure, say Y.
544
545config ARM64_ERRATUM_1024718
546	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
547	default y
548	help
549	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
550
551	  Affected Cortex-A55 cores (all revisions) could cause incorrect
552	  update of the hardware dirty bit when the DBM/AP bits are updated
553	  without a break-before-make. The workaround is to disable the usage
554	  of hardware DBM locally on the affected cores. CPUs not affected by
555	  this erratum will continue to use the feature.
556
557	  If unsure, say Y.
558
559config ARM64_ERRATUM_1418040
560	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
561	default y
562	depends on COMPAT
563	help
564	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
565	  errata 1188873 and 1418040.
566
567	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
568	  cause register corruption when accessing the timer registers
569	  from AArch32 userspace.
570
571	  If unsure, say Y.
572
573config ARM64_WORKAROUND_SPECULATIVE_AT
574	bool
575
576config ARM64_ERRATUM_1165522
577	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
578	default y
579	select ARM64_WORKAROUND_SPECULATIVE_AT
580	help
581	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
582
583	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
584	  corrupted TLBs by speculating an AT instruction during a guest
585	  context switch.
586
587	  If unsure, say Y.
588
589config ARM64_ERRATUM_1319367
590	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
591	default y
592	select ARM64_WORKAROUND_SPECULATIVE_AT
593	help
594	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
595	  and A72 erratum 1319367
596
597	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
598	  speculating an AT instruction during a guest context switch.
599
600	  If unsure, say Y.
601
602config ARM64_ERRATUM_1530923
603	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
604	default y
605	select ARM64_WORKAROUND_SPECULATIVE_AT
606	help
607	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
608
609	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
610	  corrupted TLBs by speculating an AT instruction during a guest
611	  context switch.
612
613	  If unsure, say Y.
614
615config ARM64_WORKAROUND_REPEAT_TLBI
616	bool
617
618config ARM64_ERRATUM_1286807
619	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
620	default y
621	select ARM64_WORKAROUND_REPEAT_TLBI
622	help
623	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
624
625	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
626	  address for a cacheable mapping of a location is being
627	  accessed by a core while another core is remapping the virtual
628	  address to a new physical page using the recommended
629	  break-before-make sequence, then under very rare circumstances
630	  TLBI+DSB completes before a read using the translation being
631	  invalidated has been observed by other observers. The
632	  workaround repeats the TLBI+DSB operation.
633
634config ARM64_ERRATUM_1463225
635	bool "Cortex-A76: Software Step might prevent interrupt recognition"
636	default y
637	help
638	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
639
640	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
641	  of a system call instruction (SVC) can prevent recognition of
642	  subsequent interrupts when software stepping is disabled in the
643	  exception handler of the system call and either kernel debugging
644	  is enabled or VHE is in use.
645
646	  Work around the erratum by triggering a dummy step exception
647	  when handling a system call from a task that is being stepped
648	  in a VHE configuration of the kernel.
649
650	  If unsure, say Y.
651
652config ARM64_ERRATUM_1542419
653	bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
654	default y
655	help
656	  This option adds a workaround for ARM Neoverse-N1 erratum
657	  1542419.
658
659	  Affected Neoverse-N1 cores could execute a stale instruction when
660	  modified by another CPU. The workaround depends on a firmware
661	  counterpart.
662
663	  Workaround the issue by hiding the DIC feature from EL0. This
664	  forces user-space to perform cache maintenance.
665
666	  If unsure, say Y.
667
668config ARM64_ERRATUM_1508412
669	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
670	default y
671	help
672	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
673
674	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
675	  of a store-exclusive or read of PAR_EL1 and a load with device or
676	  non-cacheable memory attributes. The workaround depends on a firmware
677	  counterpart.
678
679	  KVM guests must also have the workaround implemented or they can
680	  deadlock the system.
681
682	  Work around the issue by inserting DMB SY barriers around PAR_EL1
683	  register reads and warning KVM users. The DMB barrier is sufficient
684	  to prevent a speculative PAR_EL1 read.
685
686	  If unsure, say Y.
687
688config ARM64_ERRATUM_2051678
689	bool "Cortex-A510: 2051678: disable Hardware Update of the page table's dirty bit"
690	default y
691	help
692	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
693	  Affected Coretex-A510 might not respect the ordering rules for
694	  hardware update of the page table's dirty bit. The workaround
695	  is to not enable the feature on affected CPUs.
696
697	  If unsure, say Y.
698
699config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
700	bool
701
702config ARM64_ERRATUM_2054223
703	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
704	default y
705	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
706	help
707	  Enable workaround for ARM Cortex-A710 erratum 2054223
708
709	  Affected cores may fail to flush the trace data on a TSB instruction, when
710	  the PE is in trace prohibited state. This will cause losing a few bytes
711	  of the trace cached.
712
713	  Workaround is to issue two TSB consecutively on affected cores.
714
715	  If unsure, say Y.
716
717config ARM64_ERRATUM_2067961
718	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
719	default y
720	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
721	help
722	  Enable workaround for ARM Neoverse-N2 erratum 2067961
723
724	  Affected cores may fail to flush the trace data on a TSB instruction, when
725	  the PE is in trace prohibited state. This will cause losing a few bytes
726	  of the trace cached.
727
728	  Workaround is to issue two TSB consecutively on affected cores.
729
730	  If unsure, say Y.
731
732config ARM64_ERRATUM_2454944
733	bool "Cortex-A510: 2454944: Unmodified cache line might be written back to memory"
734	select ARCH_HAS_TEARDOWN_DMA_OPS
735	select RODATA_FULL_DEFAULT_ENABLED
736	help
737	  This option adds the workaround for ARM Cortex-A510 erratum 2454944.
738
739	  Affected Cortex-A510 core might write unmodified cache lines back to
740	  memory, which breaks the assumptions upon which software coherency
741	  management for non-coherent DMA relies. If a cache line is
742	  speculatively fetched while a non-coherent device is writing directly
743	  to DRAM, and subsequently written back by natural eviction, data
744	  written by the device in the intervening period can be lost.
745
746	  The workaround is to enforce as far as reasonably possible that all
747	  non-coherent DMA transfers are bounced and/or remapped to minimise
748	  the chance that any Cacheable alias exists through which speculative
749	  cache fills could occur. To further improve effectiveness of
750	  the workaround, lazy TLB flushing should be disabled.
751
752	  This is quite involved and has unavoidable performance impact on
753	  affected systems.
754
755config ARM64_ERRATUM_2457168
756	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
757	depends on ARM64_AMU_EXTN
758	default y
759	help
760	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
761
762	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
763	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
764	  incorrectly giving a significantly higher output value.
765
766	  Work around this problem by keeping the reference values of affected counters
767	  to 0 thus signaling an error case. This effect is the same to firmware disabling
768	  affected counters, in which case 0 will be returned when reading the disabled
769	  counters.
770
771	  If unsure, say Y.
772
773config CAVIUM_ERRATUM_22375
774	bool "Cavium erratum 22375, 24313"
775	default y
776	help
777	  Enable workaround for errata 22375 and 24313.
778
779	  This implements two gicv3-its errata workarounds for ThunderX. Both
780	  with a small impact affecting only ITS table allocation.
781
782	    erratum 22375: only alloc 8MB table size
783	    erratum 24313: ignore memory access type
784
785	  The fixes are in ITS initialization and basically ignore memory access
786	  type and table size provided by the TYPER and BASER registers.
787
788	  If unsure, say Y.
789
790config CAVIUM_ERRATUM_23144
791	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
792	depends on NUMA
793	default y
794	help
795	  ITS SYNC command hang for cross node io and collections/cpu mapping.
796
797	  If unsure, say Y.
798
799config CAVIUM_ERRATUM_23154
800	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
801	default y
802	help
803	  The gicv3 of ThunderX requires a modified version for
804	  reading the IAR status to ensure data synchronization
805	  (access to icc_iar1_el1 is not sync'ed before and after).
806
807	  If unsure, say Y.
808
809config CAVIUM_ERRATUM_27456
810	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
811	default y
812	help
813	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
814	  instructions may cause the icache to become corrupted if it
815	  contains data for a non-current ASID.  The fix is to
816	  invalidate the icache when changing the mm context.
817
818	  If unsure, say Y.
819
820config CAVIUM_ERRATUM_30115
821	bool "Cavium erratum 30115: Guest may disable interrupts in host"
822	default y
823	help
824	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
825	  1.2, and T83 Pass 1.0, KVM guest execution may disable
826	  interrupts in host. Trapping both GICv3 group-0 and group-1
827	  accesses sidesteps the issue.
828
829	  If unsure, say Y.
830
831config CAVIUM_TX2_ERRATUM_219
832	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
833	default y
834	help
835	  On Cavium ThunderX2, a load, store or prefetch instruction between a
836	  TTBR update and the corresponding context synchronizing operation can
837	  cause a spurious Data Abort to be delivered to any hardware thread in
838	  the CPU core.
839
840	  Work around the issue by avoiding the problematic code sequence and
841	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
842	  trap handler performs the corresponding register access, skips the
843	  instruction and ensures context synchronization by virtue of the
844	  exception return.
845
846	  If unsure, say Y.
847
848config FUJITSU_ERRATUM_010001
849	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
850	default y
851	help
852	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
853	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
854	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
855	  This fault occurs under a specific hardware condition when a
856	  load/store instruction performs an address translation using:
857	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
858	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
859	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
860	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
861
862	  The workaround is to ensure these bits are clear in TCR_ELx.
863	  The workaround only affects the Fujitsu-A64FX.
864
865	  If unsure, say Y.
866
867config HISILICON_ERRATUM_161600802
868	bool "Hip07 161600802: Erroneous redistributor VLPI base"
869	default y
870	help
871	  The HiSilicon Hip07 SoC uses the wrong redistributor base
872	  when issued ITS commands such as VMOVP and VMAPP, and requires
873	  a 128kB offset to be applied to the target address in this commands.
874
875	  If unsure, say Y.
876
877config QCOM_FALKOR_ERRATUM_1003
878	bool "Falkor E1003: Incorrect translation due to ASID change"
879	default y
880	help
881	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
882	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
883	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
884	  then only for entries in the walk cache, since the leaf translation
885	  is unchanged. Work around the erratum by invalidating the walk cache
886	  entries for the trampoline before entering the kernel proper.
887
888config QCOM_FALKOR_ERRATUM_1009
889	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
890	default y
891	select ARM64_WORKAROUND_REPEAT_TLBI
892	help
893	  On Falkor v1, the CPU may prematurely complete a DSB following a
894	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
895	  one more time to fix the issue.
896
897	  If unsure, say Y.
898
899config QCOM_QDF2400_ERRATUM_0065
900	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
901	default y
902	help
903	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
904	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
905	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
906
907	  If unsure, say Y.
908
909config QCOM_FALKOR_ERRATUM_E1041
910	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
911	default y
912	help
913	  Falkor CPU may speculatively fetch instructions from an improper
914	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
915	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
916
917	  If unsure, say Y.
918
919config SOCIONEXT_SYNQUACER_PREITS
920	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
921	default y
922	help
923	  Socionext Synquacer SoCs implement a separate h/w block to generate
924	  MSI doorbell writes with non-zero values for the device ID.
925
926	  If unsure, say Y.
927
928endmenu
929
930
931choice
932	prompt "Page size"
933	default ARM64_4K_PAGES
934	help
935	  Page size (translation granule) configuration.
936
937config ARM64_4K_PAGES
938	bool "4KB"
939	help
940	  This feature enables 4KB pages support.
941
942config ARM64_16K_PAGES
943	bool "16KB"
944	help
945	  The system will use 16KB pages support. AArch32 emulation
946	  requires applications compiled with 16K (or a multiple of 16K)
947	  aligned segments.
948
949config ARM64_64K_PAGES
950	bool "64KB"
951	help
952	  This feature enables 64KB pages support (4KB by default)
953	  allowing only two levels of page tables and faster TLB
954	  look-up. AArch32 emulation requires applications compiled
955	  with 64K aligned segments.
956
957endchoice
958
959choice
960	prompt "Virtual address space size"
961	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
962	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
963	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
964	help
965	  Allows choosing one of multiple possible virtual address
966	  space sizes. The level of translation table is determined by
967	  a combination of page size and virtual address space size.
968
969config ARM64_VA_BITS_36
970	bool "36-bit" if EXPERT
971	depends on ARM64_16K_PAGES
972
973config ARM64_VA_BITS_39
974	bool "39-bit"
975	depends on ARM64_4K_PAGES
976
977config ARM64_VA_BITS_42
978	bool "42-bit"
979	depends on ARM64_64K_PAGES
980
981config ARM64_VA_BITS_47
982	bool "47-bit"
983	depends on ARM64_16K_PAGES
984
985config ARM64_VA_BITS_48
986	bool "48-bit"
987
988config ARM64_VA_BITS_52
989	bool "52-bit"
990	depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
991	help
992	  Enable 52-bit virtual addressing for userspace when explicitly
993	  requested via a hint to mmap(). The kernel will also use 52-bit
994	  virtual addresses for its own mappings (provided HW support for
995	  this feature is available, otherwise it reverts to 48-bit).
996
997	  NOTE: Enabling 52-bit virtual addressing in conjunction with
998	  ARMv8.3 Pointer Authentication will result in the PAC being
999	  reduced from 7 bits to 3 bits, which may have a significant
1000	  impact on its susceptibility to brute-force attacks.
1001
1002	  If unsure, select 48-bit virtual addressing instead.
1003
1004endchoice
1005
1006config ARM64_FORCE_52BIT
1007	bool "Force 52-bit virtual addresses for userspace"
1008	depends on ARM64_VA_BITS_52 && EXPERT
1009	help
1010	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1011	  to maintain compatibility with older software by providing 48-bit VAs
1012	  unless a hint is supplied to mmap.
1013
1014	  This configuration option disables the 48-bit compatibility logic, and
1015	  forces all userspace addresses to be 52-bit on HW that supports it. One
1016	  should only enable this configuration option for stress testing userspace
1017	  memory management code. If unsure say N here.
1018
1019config ARM64_VA_BITS
1020	int
1021	default 36 if ARM64_VA_BITS_36
1022	default 39 if ARM64_VA_BITS_39
1023	default 42 if ARM64_VA_BITS_42
1024	default 47 if ARM64_VA_BITS_47
1025	default 48 if ARM64_VA_BITS_48
1026	default 52 if ARM64_VA_BITS_52
1027
1028choice
1029	prompt "Physical address space size"
1030	default ARM64_PA_BITS_48
1031	help
1032	  Choose the maximum physical address range that the kernel will
1033	  support.
1034
1035config ARM64_PA_BITS_48
1036	bool "48-bit"
1037
1038config ARM64_PA_BITS_52
1039	bool "52-bit (ARMv8.2)"
1040	depends on ARM64_64K_PAGES
1041	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1042	help
1043	  Enable support for a 52-bit physical address space, introduced as
1044	  part of the ARMv8.2-LPA extension.
1045
1046	  With this enabled, the kernel will also continue to work on CPUs that
1047	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1048	  minor performance overhead).
1049
1050endchoice
1051
1052config ARM64_PA_BITS
1053	int
1054	default 48 if ARM64_PA_BITS_48
1055	default 52 if ARM64_PA_BITS_52
1056
1057choice
1058	prompt "Endianness"
1059	default CPU_LITTLE_ENDIAN
1060	help
1061	  Select the endianness of data accesses performed by the CPU. Userspace
1062	  applications will need to be compiled and linked for the endianness
1063	  that is selected here.
1064
1065config CPU_BIG_ENDIAN
1066	bool "Build big-endian kernel"
1067	depends on !LD_IS_LLD || LLD_VERSION >= 130000
1068	# https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1069	depends on AS_IS_GNU || AS_VERSION >= 150000
1070	help
1071	  Say Y if you plan on running a kernel with a big-endian userspace.
1072
1073config CPU_LITTLE_ENDIAN
1074	bool "Build little-endian kernel"
1075	help
1076	  Say Y if you plan on running a kernel with a little-endian userspace.
1077	  This is usually the case for distributions targeting arm64.
1078
1079endchoice
1080
1081config SCHED_MC
1082	bool "Multi-core scheduler support"
1083	help
1084	  Multi-core scheduler support improves the CPU scheduler's decision
1085	  making when dealing with multi-core CPU chips at a cost of slightly
1086	  increased overhead in some places. If unsure say N here.
1087
1088config SCHED_SMT
1089	bool "SMT scheduler support"
1090	help
1091	  Improves the CPU scheduler's decision making when dealing with
1092	  MultiThreading at a cost of slightly increased overhead in some
1093	  places. If unsure say N here.
1094
1095config NR_CPUS
1096	int "Maximum number of CPUs (2-4096)"
1097	range 2 4096
1098	default "256"
1099
1100config HOTPLUG_CPU
1101	bool "Support for hot-pluggable CPUs"
1102	select GENERIC_IRQ_MIGRATION
1103	help
1104	  Say Y here to experiment with turning CPUs off and on.  CPUs
1105	  can be controlled through /sys/devices/system/cpu.
1106
1107# Common NUMA Features
1108config NUMA
1109	bool "NUMA Memory Allocation and Scheduler Support"
1110	select ACPI_NUMA if ACPI
1111	select OF_NUMA
1112	help
1113	  Enable NUMA (Non-Uniform Memory Access) support.
1114
1115	  The kernel will try to allocate memory used by a CPU on the
1116	  local memory of the CPU and add some more
1117	  NUMA awareness to the kernel.
1118
1119config NODES_SHIFT
1120	int "Maximum NUMA Nodes (as a power of 2)"
1121	range 1 10
1122	default "4"
1123	depends on NEED_MULTIPLE_NODES
1124	help
1125	  Specify the maximum number of NUMA Nodes available on the target
1126	  system.  Increases memory reserved to accommodate various tables.
1127
1128config USE_PERCPU_NUMA_NODE_ID
1129	def_bool y
1130	depends on NUMA
1131
1132config HAVE_SETUP_PER_CPU_AREA
1133	def_bool y
1134	depends on NUMA
1135
1136config NEED_PER_CPU_EMBED_FIRST_CHUNK
1137	def_bool y
1138	depends on NUMA
1139
1140config HOLES_IN_ZONE
1141	def_bool y
1142
1143source "kernel/Kconfig.hz"
1144
1145config ARCH_SUPPORTS_DEBUG_PAGEALLOC
1146	def_bool y
1147
1148config ARCH_SPARSEMEM_ENABLE
1149	def_bool y
1150	select SPARSEMEM_VMEMMAP_ENABLE
1151
1152config ARCH_SPARSEMEM_DEFAULT
1153	def_bool ARCH_SPARSEMEM_ENABLE
1154
1155config ARCH_SELECT_MEMORY_MODEL
1156	def_bool ARCH_SPARSEMEM_ENABLE
1157
1158config ARCH_FLATMEM_ENABLE
1159	def_bool !NUMA
1160
1161config HAVE_ARCH_PFN_VALID
1162	def_bool y
1163
1164config HW_PERF_EVENTS
1165	def_bool y
1166	depends on ARM_PMU
1167
1168config SYS_SUPPORTS_HUGETLBFS
1169	def_bool y
1170
1171config ARCH_WANT_HUGE_PMD_SHARE
1172
1173config ARCH_HAS_CACHE_LINE_SIZE
1174	def_bool y
1175
1176config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1177	def_bool y if PGTABLE_LEVELS > 2
1178
1179# Supported by clang >= 7.0
1180config CC_HAVE_SHADOW_CALL_STACK
1181	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1182
1183config PARAVIRT
1184	bool "Enable paravirtualization code"
1185	help
1186	  This changes the kernel so it can modify itself when it is run
1187	  under a hypervisor, potentially improving performance significantly
1188	  over full virtualization.
1189
1190config PARAVIRT_TIME_ACCOUNTING
1191	bool "Paravirtual steal time accounting"
1192	select PARAVIRT
1193	help
1194	  Select this option to enable fine granularity task steal time
1195	  accounting. Time spent executing other tasks in parallel with
1196	  the current vCPU is discounted from the vCPU power. To account for
1197	  that, there can be a small performance impact.
1198
1199	  If in doubt, say N here.
1200
1201config KEXEC
1202	depends on PM_SLEEP_SMP
1203	select KEXEC_CORE
1204	bool "kexec system call"
1205	help
1206	  kexec is a system call that implements the ability to shutdown your
1207	  current kernel, and to start another kernel.  It is like a reboot
1208	  but it is independent of the system firmware.   And like a reboot
1209	  you can start any kernel with it, not just Linux.
1210
1211config KEXEC_FILE
1212	bool "kexec file based system call"
1213	select KEXEC_CORE
1214	help
1215	  This is new version of kexec system call. This system call is
1216	  file based and takes file descriptors as system call argument
1217	  for kernel and initramfs as opposed to list of segments as
1218	  accepted by previous system call.
1219
1220config KEXEC_SIG
1221	bool "Verify kernel signature during kexec_file_load() syscall"
1222	depends on KEXEC_FILE
1223	help
1224	  Select this option to verify a signature with loaded kernel
1225	  image. If configured, any attempt of loading a image without
1226	  valid signature will fail.
1227
1228	  In addition to that option, you need to enable signature
1229	  verification for the corresponding kernel image type being
1230	  loaded in order for this to work.
1231
1232config KEXEC_IMAGE_VERIFY_SIG
1233	bool "Enable Image signature verification support"
1234	default y
1235	depends on KEXEC_SIG
1236	depends on EFI && SIGNED_PE_FILE_VERIFICATION
1237	help
1238	  Enable Image signature verification support.
1239
1240comment "Support for PE file signature verification disabled"
1241	depends on KEXEC_SIG
1242	depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
1243
1244config CRASH_DUMP
1245	bool "Build kdump crash kernel"
1246	help
1247	  Generate crash dump after being started by kexec. This should
1248	  be normally only set in special crash dump kernels which are
1249	  loaded in the main kernel with kexec-tools into a specially
1250	  reserved region and then later executed after a crash by
1251	  kdump/kexec.
1252
1253	  For more details see Documentation/admin-guide/kdump/kdump.rst
1254
1255config XEN_DOM0
1256	def_bool y
1257	depends on XEN
1258
1259config XEN
1260	bool "Xen guest support on ARM64"
1261	depends on ARM64 && OF
1262	select SWIOTLB_XEN
1263	select PARAVIRT
1264	help
1265	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1266
1267config FORCE_MAX_ZONEORDER
1268	int
1269	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
1270	default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
1271	default "11"
1272	help
1273	  The kernel memory allocator divides physically contiguous memory
1274	  blocks into "zones", where each zone is a power of two number of
1275	  pages.  This option selects the largest power of two that the kernel
1276	  keeps in the memory allocator.  If you need to allocate very large
1277	  blocks of physically contiguous memory, then you may need to
1278	  increase this value.
1279
1280	  This config option is actually maximum order plus one. For example,
1281	  a value of 11 means that the largest free memory block is 2^10 pages.
1282
1283	  We make sure that we can allocate upto a HugePage size for each configuration.
1284	  Hence we have :
1285		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1286
1287	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1288	  4M allocations matching the default size used by generic code.
1289
1290config UNMAP_KERNEL_AT_EL0
1291	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1292	default y
1293	help
1294	  Speculation attacks against some high-performance processors can
1295	  be used to bypass MMU permission checks and leak kernel data to
1296	  userspace. This can be defended against by unmapping the kernel
1297	  when running in userspace, mapping it back in on exception entry
1298	  via a trampoline page in the vector table.
1299
1300	  If unsure, say Y.
1301
1302config MITIGATE_SPECTRE_BRANCH_HISTORY
1303	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1304	default y
1305	help
1306	  Speculation attacks against some high-performance processors can
1307	  make use of branch history to influence future speculation.
1308	  When taking an exception from user-space, a sequence of branches
1309	  or a firmware call overwrites the branch history.
1310
1311config RODATA_FULL_DEFAULT_ENABLED
1312	bool "Apply r/o permissions of VM areas also to their linear aliases"
1313	default y
1314	help
1315	  Apply read-only attributes of VM areas to the linear alias of
1316	  the backing pages as well. This prevents code or read-only data
1317	  from being modified (inadvertently or intentionally) via another
1318	  mapping of the same memory page. This additional enhancement can
1319	  be turned off at runtime by passing rodata=[off|on] (and turned on
1320	  with rodata=full if this option is set to 'n')
1321
1322	  This requires the linear region to be mapped down to pages,
1323	  which may adversely affect performance in some cases.
1324
1325config ARM64_SW_TTBR0_PAN
1326	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1327	help
1328	  Enabling this option prevents the kernel from accessing
1329	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1330	  zeroed area and reserved ASID. The user access routines
1331	  restore the valid TTBR0_EL1 temporarily.
1332
1333config ARM64_TAGGED_ADDR_ABI
1334	bool "Enable the tagged user addresses syscall ABI"
1335	default y
1336	help
1337	  When this option is enabled, user applications can opt in to a
1338	  relaxed ABI via prctl() allowing tagged addresses to be passed
1339	  to system calls as pointer arguments. For details, see
1340	  Documentation/arm64/tagged-address-abi.rst.
1341
1342menuconfig COMPAT
1343	bool "Kernel support for 32-bit EL0"
1344	depends on ARM64_4K_PAGES || EXPERT
1345	select COMPAT_BINFMT_ELF if BINFMT_ELF
1346	select HAVE_UID16
1347	select OLD_SIGSUSPEND3
1348	select COMPAT_OLD_SIGACTION
1349	help
1350	  This option enables support for a 32-bit EL0 running under a 64-bit
1351	  kernel at EL1. AArch32-specific components such as system calls,
1352	  the user helper functions, VFP support and the ptrace interface are
1353	  handled appropriately by the kernel.
1354
1355	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1356	  that you will only be able to execute AArch32 binaries that were compiled
1357	  with page size aligned segments.
1358
1359	  If you want to execute 32-bit userspace applications, say Y.
1360
1361if COMPAT
1362
1363config KUSER_HELPERS
1364	bool "Enable kuser helpers page for 32-bit applications"
1365	default y
1366	help
1367	  Warning: disabling this option may break 32-bit user programs.
1368
1369	  Provide kuser helpers to compat tasks. The kernel provides
1370	  helper code to userspace in read only form at a fixed location
1371	  to allow userspace to be independent of the CPU type fitted to
1372	  the system. This permits binaries to be run on ARMv4 through
1373	  to ARMv8 without modification.
1374
1375	  See Documentation/arm/kernel_user_helpers.rst for details.
1376
1377	  However, the fixed address nature of these helpers can be used
1378	  by ROP (return orientated programming) authors when creating
1379	  exploits.
1380
1381	  If all of the binaries and libraries which run on your platform
1382	  are built specifically for your platform, and make no use of
1383	  these helpers, then you can turn this option off to hinder
1384	  such exploits. However, in that case, if a binary or library
1385	  relying on those helpers is run, it will not function correctly.
1386
1387	  Say N here only if you are absolutely certain that you do not
1388	  need these helpers; otherwise, the safe option is to say Y.
1389
1390config COMPAT_VDSO
1391	bool "Enable vDSO for 32-bit applications"
1392	depends on !CPU_BIG_ENDIAN
1393	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1394	select GENERIC_COMPAT_VDSO
1395	default y
1396	help
1397	  Place in the process address space of 32-bit applications an
1398	  ELF shared object providing fast implementations of gettimeofday
1399	  and clock_gettime.
1400
1401	  You must have a 32-bit build of glibc 2.22 or later for programs
1402	  to seamlessly take advantage of this.
1403
1404config THUMB2_COMPAT_VDSO
1405	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1406	depends on COMPAT_VDSO
1407	default y
1408	help
1409	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1410	  otherwise with '-marm'.
1411
1412menuconfig ARMV8_DEPRECATED
1413	bool "Emulate deprecated/obsolete ARMv8 instructions"
1414	depends on SYSCTL
1415	help
1416	  Legacy software support may require certain instructions
1417	  that have been deprecated or obsoleted in the architecture.
1418
1419	  Enable this config to enable selective emulation of these
1420	  features.
1421
1422	  If unsure, say Y
1423
1424if ARMV8_DEPRECATED
1425
1426config SWP_EMULATION
1427	bool "Emulate SWP/SWPB instructions"
1428	help
1429	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1430	  they are always undefined. Say Y here to enable software
1431	  emulation of these instructions for userspace using LDXR/STXR.
1432	  This feature can be controlled at runtime with the abi.swp
1433	  sysctl which is disabled by default.
1434
1435	  In some older versions of glibc [<=2.8] SWP is used during futex
1436	  trylock() operations with the assumption that the code will not
1437	  be preempted. This invalid assumption may be more likely to fail
1438	  with SWP emulation enabled, leading to deadlock of the user
1439	  application.
1440
1441	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1442	  on an external transaction monitoring block called a global
1443	  monitor to maintain update atomicity. If your system does not
1444	  implement a global monitor, this option can cause programs that
1445	  perform SWP operations to uncached memory to deadlock.
1446
1447	  If unsure, say Y
1448
1449config CP15_BARRIER_EMULATION
1450	bool "Emulate CP15 Barrier instructions"
1451	help
1452	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1453	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1454	  strongly recommended to use the ISB, DSB, and DMB
1455	  instructions instead.
1456
1457	  Say Y here to enable software emulation of these
1458	  instructions for AArch32 userspace code. When this option is
1459	  enabled, CP15 barrier usage is traced which can help
1460	  identify software that needs updating. This feature can be
1461	  controlled at runtime with the abi.cp15_barrier sysctl.
1462
1463	  If unsure, say Y
1464
1465config SETEND_EMULATION
1466	bool "Emulate SETEND instruction"
1467	help
1468	  The SETEND instruction alters the data-endianness of the
1469	  AArch32 EL0, and is deprecated in ARMv8.
1470
1471	  Say Y here to enable software emulation of the instruction
1472	  for AArch32 userspace code. This feature can be controlled
1473	  at runtime with the abi.setend sysctl.
1474
1475	  Note: All the cpus on the system must have mixed endian support at EL0
1476	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1477	  endian - is hotplugged in after this feature has been enabled, there could
1478	  be unexpected results in the applications.
1479
1480	  If unsure, say Y
1481endif
1482
1483endif
1484
1485menu "ARMv8.1 architectural features"
1486
1487config ARM64_HW_AFDBM
1488	bool "Support for hardware updates of the Access and Dirty page flags"
1489	default y
1490	help
1491	  The ARMv8.1 architecture extensions introduce support for
1492	  hardware updates of the access and dirty information in page
1493	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1494	  capable processors, accesses to pages with PTE_AF cleared will
1495	  set this bit instead of raising an access flag fault.
1496	  Similarly, writes to read-only pages with the DBM bit set will
1497	  clear the read-only bit (AP[2]) instead of raising a
1498	  permission fault.
1499
1500	  Kernels built with this configuration option enabled continue
1501	  to work on pre-ARMv8.1 hardware and the performance impact is
1502	  minimal. If unsure, say Y.
1503
1504config ARM64_PAN
1505	bool "Enable support for Privileged Access Never (PAN)"
1506	default y
1507	help
1508	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1509	 prevents the kernel or hypervisor from accessing user-space (EL0)
1510	 memory directly.
1511
1512	 Choosing this option will cause any unprotected (not using
1513	 copy_to_user et al) memory access to fail with a permission fault.
1514
1515	 The feature is detected at runtime, and will remain as a 'nop'
1516	 instruction if the cpu does not implement the feature.
1517
1518config AS_HAS_LDAPR
1519	def_bool $(as-instr,.arch_extension rcpc)
1520
1521config AS_HAS_LSE_ATOMICS
1522	def_bool $(as-instr,.arch_extension lse)
1523
1524config ARM64_LSE_ATOMICS
1525	bool
1526	default ARM64_USE_LSE_ATOMICS
1527	depends on AS_HAS_LSE_ATOMICS
1528
1529config ARM64_USE_LSE_ATOMICS
1530	bool "Atomic instructions"
1531	depends on JUMP_LABEL
1532	default y
1533	help
1534	  As part of the Large System Extensions, ARMv8.1 introduces new
1535	  atomic instructions that are designed specifically to scale in
1536	  very large systems.
1537
1538	  Say Y here to make use of these instructions for the in-kernel
1539	  atomic routines. This incurs a small overhead on CPUs that do
1540	  not support these instructions and requires the kernel to be
1541	  built with binutils >= 2.25 in order for the new instructions
1542	  to be used.
1543
1544config ARM64_VHE
1545	bool "Enable support for Virtualization Host Extensions (VHE)"
1546	default y
1547	help
1548	  Virtualization Host Extensions (VHE) allow the kernel to run
1549	  directly at EL2 (instead of EL1) on processors that support
1550	  it. This leads to better performance for KVM, as they reduce
1551	  the cost of the world switch.
1552
1553	  Selecting this option allows the VHE feature to be detected
1554	  at runtime, and does not affect processors that do not
1555	  implement this feature.
1556
1557endmenu
1558
1559menu "ARMv8.2 architectural features"
1560
1561config ARM64_UAO
1562	bool "Enable support for User Access Override (UAO)"
1563	default y
1564	help
1565	  User Access Override (UAO; part of the ARMv8.2 Extensions)
1566	  causes the 'unprivileged' variant of the load/store instructions to
1567	  be overridden to be privileged.
1568
1569	  This option changes get_user() and friends to use the 'unprivileged'
1570	  variant of the load/store instructions. This ensures that user-space
1571	  really did have access to the supplied memory. When addr_limit is
1572	  set to kernel memory the UAO bit will be set, allowing privileged
1573	  access to kernel memory.
1574
1575	  Choosing this option will cause copy_to_user() et al to use user-space
1576	  memory permissions.
1577
1578	  The feature is detected at runtime, the kernel will use the
1579	  regular load/store instructions if the cpu does not implement the
1580	  feature.
1581
1582config ARM64_PMEM
1583	bool "Enable support for persistent memory"
1584	select ARCH_HAS_PMEM_API
1585	select ARCH_HAS_UACCESS_FLUSHCACHE
1586	help
1587	  Say Y to enable support for the persistent memory API based on the
1588	  ARMv8.2 DCPoP feature.
1589
1590	  The feature is detected at runtime, and the kernel will use DC CVAC
1591	  operations if DC CVAP is not supported (following the behaviour of
1592	  DC CVAP itself if the system does not define a point of persistence).
1593
1594config ARM64_RAS_EXTN
1595	bool "Enable support for RAS CPU Extensions"
1596	default y
1597	help
1598	  CPUs that support the Reliability, Availability and Serviceability
1599	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1600	  errors, classify them and report them to software.
1601
1602	  On CPUs with these extensions system software can use additional
1603	  barriers to determine if faults are pending and read the
1604	  classification from a new set of registers.
1605
1606	  Selecting this feature will allow the kernel to use these barriers
1607	  and access the new registers if the system supports the extension.
1608	  Platform RAS features may additionally depend on firmware support.
1609
1610config ARM64_CNP
1611	bool "Enable support for Common Not Private (CNP) translations"
1612	default y
1613	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1614	help
1615	  Common Not Private (CNP) allows translation table entries to
1616	  be shared between different PEs in the same inner shareable
1617	  domain, so the hardware can use this fact to optimise the
1618	  caching of such entries in the TLB.
1619
1620	  Selecting this option allows the CNP feature to be detected
1621	  at runtime, and does not affect PEs that do not implement
1622	  this feature.
1623
1624endmenu
1625
1626menu "ARMv8.3 architectural features"
1627
1628config ARM64_PTR_AUTH
1629	bool "Enable support for pointer authentication"
1630	default y
1631	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC
1632	# Modern compilers insert a .note.gnu.property section note for PAC
1633	# which is only understood by binutils starting with version 2.33.1.
1634	depends on LD_IS_LLD || LD_VERSION >= 233010000 || (CC_IS_GCC && GCC_VERSION < 90100)
1635	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1636	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
1637	help
1638	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1639	  instructions for signing and authenticating pointers against secret
1640	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1641	  and other attacks.
1642
1643	  This option enables these instructions at EL0 (i.e. for userspace).
1644	  Choosing this option will cause the kernel to initialise secret keys
1645	  for each process at exec() time, with these keys being
1646	  context-switched along with the process.
1647
1648	  If the compiler supports the -mbranch-protection or
1649	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1650	  will also cause the kernel itself to be compiled with return address
1651	  protection. In this case, and if the target hardware is known to
1652	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1653	  disabled with minimal loss of protection.
1654
1655	  The feature is detected at runtime. If the feature is not present in
1656	  hardware it will not be advertised to userspace/KVM guest nor will it
1657	  be enabled.
1658
1659	  If the feature is present on the boot CPU but not on a late CPU, then
1660	  the late CPU will be parked. Also, if the boot CPU does not have
1661	  address auth and the late CPU has then the late CPU will still boot
1662	  but with the feature disabled. On such a system, this option should
1663	  not be selected.
1664
1665	  This feature works with FUNCTION_GRAPH_TRACER option only if
1666	  DYNAMIC_FTRACE_WITH_REGS is enabled.
1667
1668config CC_HAS_BRANCH_PROT_PAC_RET
1669	# GCC 9 or later, clang 8 or later
1670	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1671
1672config CC_HAS_SIGN_RETURN_ADDRESS
1673	# GCC 7, 8
1674	def_bool $(cc-option,-msign-return-address=all)
1675
1676config AS_HAS_PAC
1677	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1678
1679config AS_HAS_CFI_NEGATE_RA_STATE
1680	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1681
1682endmenu
1683
1684menu "ARMv8.4 architectural features"
1685
1686config ARM64_AMU_EXTN
1687	bool "Enable support for the Activity Monitors Unit CPU extension"
1688	default y
1689	help
1690	  The activity monitors extension is an optional extension introduced
1691	  by the ARMv8.4 CPU architecture. This enables support for version 1
1692	  of the activity monitors architecture, AMUv1.
1693
1694	  To enable the use of this extension on CPUs that implement it, say Y.
1695
1696	  Note that for architectural reasons, firmware _must_ implement AMU
1697	  support when running on CPUs that present the activity monitors
1698	  extension. The required support is present in:
1699	    * Version 1.5 and later of the ARM Trusted Firmware
1700
1701	  For kernels that have this configuration enabled but boot with broken
1702	  firmware, you may need to say N here until the firmware is fixed.
1703	  Otherwise you may experience firmware panics or lockups when
1704	  accessing the counter registers. Even if you are not observing these
1705	  symptoms, the values returned by the register reads might not
1706	  correctly reflect reality. Most commonly, the value read will be 0,
1707	  indicating that the counter is not enabled.
1708
1709config AS_HAS_ARMV8_4
1710	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1711
1712config ARM64_TLB_RANGE
1713	bool "Enable support for tlbi range feature"
1714	default y
1715	depends on AS_HAS_ARMV8_4
1716	help
1717	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1718	  range of input addresses.
1719
1720	  The feature introduces new assembly instructions, and they were
1721	  support when binutils >= 2.30.
1722
1723endmenu
1724
1725menu "ARMv8.5 architectural features"
1726
1727config AS_HAS_ARMV8_5
1728	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1729
1730config ARM64_BTI
1731	bool "Branch Target Identification support"
1732	default y
1733	help
1734	  Branch Target Identification (part of the ARMv8.5 Extensions)
1735	  provides a mechanism to limit the set of locations to which computed
1736	  branch instructions such as BR or BLR can jump.
1737
1738	  To make use of BTI on CPUs that support it, say Y.
1739
1740	  BTI is intended to provide complementary protection to other control
1741	  flow integrity protection mechanisms, such as the Pointer
1742	  authentication mechanism provided as part of the ARMv8.3 Extensions.
1743	  For this reason, it does not make sense to enable this option without
1744	  also enabling support for pointer authentication.  Thus, when
1745	  enabling this option you should also select ARM64_PTR_AUTH=y.
1746
1747	  Userspace binaries must also be specifically compiled to make use of
1748	  this mechanism.  If you say N here or the hardware does not support
1749	  BTI, such binaries can still run, but you get no additional
1750	  enforcement of branch destinations.
1751
1752config ARM64_BTI_KERNEL
1753	bool "Use Branch Target Identification for kernel"
1754	default y
1755	depends on ARM64_BTI
1756	depends on ARM64_PTR_AUTH
1757	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1758	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1759	depends on !CC_IS_GCC || GCC_VERSION >= 100100
1760	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
1761	depends on !CC_IS_GCC
1762	# https://bugs.llvm.org/show_bug.cgi?id=46258
1763	depends on !CFI_CLANG || CLANG_VERSION >= 120000
1764	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
1765	help
1766	  Build the kernel with Branch Target Identification annotations
1767	  and enable enforcement of this for kernel code. When this option
1768	  is enabled and the system supports BTI all kernel code including
1769	  modular code must have BTI enabled.
1770
1771config CC_HAS_BRANCH_PROT_PAC_RET_BTI
1772	# GCC 9 or later, clang 8 or later
1773	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
1774
1775config ARM64_E0PD
1776	bool "Enable support for E0PD"
1777	default y
1778	help
1779	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
1780	  that EL0 accesses made via TTBR1 always fault in constant time,
1781	  providing similar benefits to KASLR as those provided by KPTI, but
1782	  with lower overhead and without disrupting legitimate access to
1783	  kernel memory such as SPE.
1784
1785	  This option enables E0PD for TTBR1 where available.
1786
1787config ARCH_RANDOM
1788	bool "Enable support for random number generation"
1789	default y
1790	help
1791	  Random number generation (part of the ARMv8.5 Extensions)
1792	  provides a high bandwidth, cryptographically secure
1793	  hardware random number generator.
1794
1795config ARM64_AS_HAS_MTE
1796	# Initial support for MTE went in binutils 2.32.0, checked with
1797	# ".arch armv8.5-a+memtag" below. However, this was incomplete
1798	# as a late addition to the final architecture spec (LDGM/STGM)
1799	# is only supported in the newer 2.32.x and 2.33 binutils
1800	# versions, hence the extra "stgm" instruction check below.
1801	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
1802
1803config ARM64_MTE
1804	bool "Memory Tagging Extension support"
1805	default y
1806	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
1807	depends on AS_HAS_ARMV8_5
1808	# Required for tag checking in the uaccess routines
1809	depends on ARM64_PAN
1810	depends on AS_HAS_LSE_ATOMICS
1811	select ARCH_USES_HIGH_VMA_FLAGS
1812	help
1813	  Memory Tagging (part of the ARMv8.5 Extensions) provides
1814	  architectural support for run-time, always-on detection of
1815	  various classes of memory error to aid with software debugging
1816	  to eliminate vulnerabilities arising from memory-unsafe
1817	  languages.
1818
1819	  This option enables the support for the Memory Tagging
1820	  Extension at EL0 (i.e. for userspace).
1821
1822	  Selecting this option allows the feature to be detected at
1823	  runtime. Any secondary CPU not implementing this feature will
1824	  not be allowed a late bring-up.
1825
1826	  Userspace binaries that want to use this feature must
1827	  explicitly opt in. The mechanism for the userspace is
1828	  described in:
1829
1830	  Documentation/arm64/memory-tagging-extension.rst.
1831
1832endmenu
1833
1834config ARM64_SVE
1835	bool "ARM Scalable Vector Extension support"
1836	default y
1837	help
1838	  The Scalable Vector Extension (SVE) is an extension to the AArch64
1839	  execution state which complements and extends the SIMD functionality
1840	  of the base architecture to support much larger vectors and to enable
1841	  additional vectorisation opportunities.
1842
1843	  To enable use of this extension on CPUs that implement it, say Y.
1844
1845	  On CPUs that support the SVE2 extensions, this option will enable
1846	  those too.
1847
1848	  Note that for architectural reasons, firmware _must_ implement SVE
1849	  support when running on SVE capable hardware.  The required support
1850	  is present in:
1851
1852	    * version 1.5 and later of the ARM Trusted Firmware
1853	    * the AArch64 boot wrapper since commit 5e1261e08abf
1854	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
1855
1856	  For other firmware implementations, consult the firmware documentation
1857	  or vendor.
1858
1859	  If you need the kernel to boot on SVE-capable hardware with broken
1860	  firmware, you may need to say N here until you get your firmware
1861	  fixed.  Otherwise, you may experience firmware panics or lockups when
1862	  booting the kernel.  If unsure and you are not observing these
1863	  symptoms, you should assume that it is safe to say Y.
1864
1865config ARM64_MODULE_PLTS
1866	bool "Use PLTs to allow module memory to spill over into vmalloc area"
1867	depends on MODULES
1868	select HAVE_MOD_ARCH_SPECIFIC
1869	help
1870	  Allocate PLTs when loading modules so that jumps and calls whose
1871	  targets are too far away for their relative offsets to be encoded
1872	  in the instructions themselves can be bounced via veneers in the
1873	  module's PLT. This allows modules to be allocated in the generic
1874	  vmalloc area after the dedicated module memory area has been
1875	  exhausted.
1876
1877	  When running with address space randomization (KASLR), the module
1878	  region itself may be too far away for ordinary relative jumps and
1879	  calls, and so in that case, module PLTs are required and cannot be
1880	  disabled.
1881
1882	  Specific errata workaround(s) might also force module PLTs to be
1883	  enabled (ARM64_ERRATUM_843419).
1884
1885config ARM64_PSEUDO_NMI
1886	bool "Support for NMI-like interrupts"
1887	select ARM_GIC_V3
1888	help
1889	  Adds support for mimicking Non-Maskable Interrupts through the use of
1890	  GIC interrupt priority. This support requires version 3 or later of
1891	  ARM GIC.
1892
1893	  This high priority configuration for interrupts needs to be
1894	  explicitly enabled by setting the kernel parameter
1895	  "irqchip.gicv3_pseudo_nmi" to 1.
1896
1897	  If unsure, say N
1898
1899if ARM64_PSEUDO_NMI
1900config ARM64_DEBUG_PRIORITY_MASKING
1901	bool "Debug interrupt priority masking"
1902	help
1903	  This adds runtime checks to functions enabling/disabling
1904	  interrupts when using priority masking. The additional checks verify
1905	  the validity of ICC_PMR_EL1 when calling concerned functions.
1906
1907	  If unsure, say N
1908endif
1909
1910config RELOCATABLE
1911	bool "Build a relocatable kernel image" if EXPERT
1912	select ARCH_HAS_RELR
1913	default y
1914	help
1915	  This builds the kernel as a Position Independent Executable (PIE),
1916	  which retains all relocation metadata required to relocate the
1917	  kernel binary at runtime to a different virtual address than the
1918	  address it was linked at.
1919	  Since AArch64 uses the RELA relocation format, this requires a
1920	  relocation pass at runtime even if the kernel is loaded at the
1921	  same address it was linked at.
1922
1923config RANDOMIZE_BASE
1924	bool "Randomize the address of the kernel image"
1925	select ARM64_MODULE_PLTS if MODULES
1926	select RELOCATABLE
1927	help
1928	  Randomizes the virtual address at which the kernel image is
1929	  loaded, as a security feature that deters exploit attempts
1930	  relying on knowledge of the location of kernel internals.
1931
1932	  It is the bootloader's job to provide entropy, by passing a
1933	  random u64 value in /chosen/kaslr-seed at kernel entry.
1934
1935	  When booting via the UEFI stub, it will invoke the firmware's
1936	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1937	  to the kernel proper. In addition, it will randomise the physical
1938	  location of the kernel Image as well.
1939
1940	  If unsure, say N.
1941
1942config RANDOMIZE_MODULE_REGION_FULL
1943	bool "Randomize the module region over a 4 GB range"
1944	depends on RANDOMIZE_BASE
1945	default y
1946	help
1947	  Randomizes the location of the module region inside a 4 GB window
1948	  covering the core kernel. This way, it is less likely for modules
1949	  to leak information about the location of core kernel data structures
1950	  but it does imply that function calls between modules and the core
1951	  kernel will need to be resolved via veneers in the module PLT.
1952
1953	  When this option is not set, the module region will be randomized over
1954	  a limited range that contains the [_stext, _etext] interval of the
1955	  core kernel, so branch relocations are always in range.
1956
1957config CC_HAVE_STACKPROTECTOR_SYSREG
1958	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1959
1960config STACKPROTECTOR_PER_TASK
1961	def_bool y
1962	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1963
1964endmenu
1965
1966menu "Boot options"
1967
1968config ARM64_ACPI_PARKING_PROTOCOL
1969	bool "Enable support for the ARM64 ACPI parking protocol"
1970	depends on ACPI
1971	help
1972	  Enable support for the ARM64 ACPI parking protocol. If disabled
1973	  the kernel will not allow booting through the ARM64 ACPI parking
1974	  protocol even if the corresponding data is present in the ACPI
1975	  MADT table.
1976
1977config CMDLINE
1978	string "Default kernel command string"
1979	default ""
1980	help
1981	  Provide a set of default command-line options at build time by
1982	  entering them here. As a minimum, you should specify the the
1983	  root device (e.g. root=/dev/nfs).
1984
1985choice
1986	prompt "Kernel command line type" if CMDLINE != ""
1987	default CMDLINE_FROM_BOOTLOADER
1988	help
1989	  Choose how the kernel will handle the provided default kernel
1990	  command line string.
1991
1992config CMDLINE_FROM_BOOTLOADER
1993	bool "Use bootloader kernel arguments if available"
1994	help
1995	  Uses the command-line options passed by the boot loader. If
1996	  the boot loader doesn't provide any, the default kernel command
1997	  string provided in CMDLINE will be used.
1998
1999config CMDLINE_EXTEND
2000	bool "Extend bootloader kernel arguments"
2001	help
2002	  The command-line arguments provided by the boot loader will be
2003	  appended to the default kernel command string.
2004
2005config CMDLINE_FORCE
2006	bool "Always use the default kernel command string"
2007	help
2008	  Always use the default kernel command string, even if the boot
2009	  loader passes other arguments to the kernel.
2010	  This is useful if you cannot or don't want to change the
2011	  command-line options your boot loader passes to the kernel.
2012
2013endchoice
2014
2015config EFI_STUB
2016	bool
2017
2018config EFI
2019	bool "UEFI runtime support"
2020	depends on OF && !CPU_BIG_ENDIAN
2021	depends on KERNEL_MODE_NEON
2022	select ARCH_SUPPORTS_ACPI
2023	select LIBFDT
2024	select UCS2_STRING
2025	select EFI_PARAMS_FROM_FDT
2026	select EFI_RUNTIME_WRAPPERS
2027	select EFI_STUB
2028	select EFI_GENERIC_STUB
2029	default y
2030	help
2031	  This option provides support for runtime services provided
2032	  by UEFI firmware (such as non-volatile variables, realtime
2033          clock, and platform reset). A UEFI stub is also provided to
2034	  allow the kernel to be booted as an EFI application. This
2035	  is only useful on systems that have UEFI firmware.
2036
2037config DMI
2038	bool "Enable support for SMBIOS (DMI) tables"
2039	depends on EFI
2040	default y
2041	help
2042	  This enables SMBIOS/DMI feature for systems.
2043
2044	  This option is only useful on systems that have UEFI firmware.
2045	  However, even with this option, the resultant kernel should
2046	  continue to boot on existing non-UEFI platforms.
2047
2048endmenu
2049
2050config SYSVIPC_COMPAT
2051	def_bool y
2052	depends on COMPAT && SYSVIPC
2053
2054config ARCH_ENABLE_HUGEPAGE_MIGRATION
2055	def_bool y
2056	depends on HUGETLB_PAGE && MIGRATION
2057
2058config ARCH_ENABLE_THP_MIGRATION
2059	def_bool y
2060	depends on TRANSPARENT_HUGEPAGE
2061
2062menu "Power management options"
2063
2064source "kernel/power/Kconfig"
2065
2066config ARCH_HIBERNATION_POSSIBLE
2067	def_bool y
2068	depends on CPU_PM
2069
2070config ARCH_HIBERNATION_HEADER
2071	def_bool y
2072	depends on HIBERNATION
2073
2074config ARCH_SUSPEND_POSSIBLE
2075	def_bool y
2076
2077endmenu
2078
2079menu "CPU Power Management"
2080
2081source "drivers/cpuidle/Kconfig"
2082
2083source "drivers/cpufreq/Kconfig"
2084
2085endmenu
2086
2087source "drivers/firmware/Kconfig"
2088
2089source "drivers/acpi/Kconfig"
2090
2091source "arch/arm64/kvm/Kconfig"
2092
2093if CRYPTO
2094source "arch/arm64/crypto/Kconfig"
2095endif
2096