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Merge branch 'akpm' (patches from Andrew)
[mirror_ubuntu-eoan-kernel.git] / arch / arm64 / Kconfig
1 config ARM64
2 def_bool y
3 select ACPI_CCA_REQUIRED if ACPI
4 select ACPI_GENERIC_GSI if ACPI
5 select ACPI_GTDT if ACPI
6 select ACPI_IORT if ACPI
7 select ACPI_REDUCED_HARDWARE_ONLY if ACPI
8 select ACPI_MCFG if (ACPI && PCI)
9 select ACPI_SPCR_TABLE if ACPI
10 select ACPI_PPTT if ACPI
11 select ARCH_CLOCKSOURCE_DATA
12 select ARCH_HAS_DEBUG_VIRTUAL
13 select ARCH_HAS_DEVMEM_IS_ALLOWED
14 select ARCH_HAS_DMA_COHERENT_TO_PFN
15 select ARCH_HAS_DMA_MMAP_PGPROT
16 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
17 select ARCH_HAS_ELF_RANDOMIZE
18 select ARCH_HAS_FAST_MULTIPLIER
19 select ARCH_HAS_FORTIFY_SOURCE
20 select ARCH_HAS_GCOV_PROFILE_ALL
21 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
22 select ARCH_HAS_KCOV
23 select ARCH_HAS_MEMBARRIER_SYNC_CORE
24 select ARCH_HAS_PTE_SPECIAL
25 select ARCH_HAS_SET_MEMORY
26 select ARCH_HAS_STRICT_KERNEL_RWX
27 select ARCH_HAS_STRICT_MODULE_RWX
28 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
29 select ARCH_HAS_SYNC_DMA_FOR_CPU
30 select ARCH_HAS_SYSCALL_WRAPPER
31 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
32 select ARCH_HAVE_NMI_SAFE_CMPXCHG
33 select ARCH_INLINE_READ_LOCK if !PREEMPT
34 select ARCH_INLINE_READ_LOCK_BH if !PREEMPT
35 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT
36 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT
37 select ARCH_INLINE_READ_UNLOCK if !PREEMPT
38 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT
39 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT
40 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT
41 select ARCH_INLINE_WRITE_LOCK if !PREEMPT
42 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT
43 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT
44 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT
45 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT
46 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT
47 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT
48 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT
49 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPT
50 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPT
51 select ARCH_INLINE_SPIN_LOCK if !PREEMPT
52 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPT
53 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPT
54 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPT
55 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPT
56 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT
57 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT
58 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT
59 select ARCH_USE_CMPXCHG_LOCKREF
60 select ARCH_USE_QUEUED_RWLOCKS
61 select ARCH_USE_QUEUED_SPINLOCKS
62 select ARCH_SUPPORTS_MEMORY_FAILURE
63 select ARCH_SUPPORTS_ATOMIC_RMW
64 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG
65 select ARCH_SUPPORTS_NUMA_BALANCING
66 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
67 select ARCH_WANT_FRAME_POINTERS
68 select ARCH_HAS_UBSAN_SANITIZE_ALL
69 select ARM_AMBA
70 select ARM_ARCH_TIMER
71 select ARM_GIC
72 select AUDIT_ARCH_COMPAT_GENERIC
73 select ARM_GIC_V2M if PCI
74 select ARM_GIC_V3
75 select ARM_GIC_V3_ITS if PCI
76 select ARM_PSCI_FW
77 select BUILDTIME_EXTABLE_SORT
78 select CLONE_BACKWARDS
79 select COMMON_CLK
80 select CPU_PM if (SUSPEND || CPU_IDLE)
81 select CRC32
82 select DCACHE_WORD_ACCESS
83 select DMA_DIRECT_REMAP
84 select EDAC_SUPPORT
85 select FRAME_POINTER
86 select GENERIC_ALLOCATOR
87 select GENERIC_ARCH_TOPOLOGY
88 select GENERIC_CLOCKEVENTS
89 select GENERIC_CLOCKEVENTS_BROADCAST
90 select GENERIC_CPU_AUTOPROBE
91 select GENERIC_EARLY_IOREMAP
92 select GENERIC_IDLE_POLL_SETUP
93 select GENERIC_IRQ_MULTI_HANDLER
94 select GENERIC_IRQ_PROBE
95 select GENERIC_IRQ_SHOW
96 select GENERIC_IRQ_SHOW_LEVEL
97 select GENERIC_PCI_IOMAP
98 select GENERIC_SCHED_CLOCK
99 select GENERIC_SMP_IDLE_THREAD
100 select GENERIC_STRNCPY_FROM_USER
101 select GENERIC_STRNLEN_USER
102 select GENERIC_TIME_VSYSCALL
103 select HANDLE_DOMAIN_IRQ
104 select HARDIRQS_SW_RESEND
105 select HAVE_ACPI_APEI if (ACPI && EFI)
106 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
107 select HAVE_ARCH_AUDITSYSCALL
108 select HAVE_ARCH_BITREVERSE
109 select HAVE_ARCH_HUGE_VMAP
110 select HAVE_ARCH_JUMP_LABEL
111 select HAVE_ARCH_JUMP_LABEL_RELATIVE
112 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
113 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
114 select HAVE_ARCH_KGDB
115 select HAVE_ARCH_MMAP_RND_BITS
116 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
117 select HAVE_ARCH_PREL32_RELOCATIONS
118 select HAVE_ARCH_SECCOMP_FILTER
119 select HAVE_ARCH_STACKLEAK
120 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
121 select HAVE_ARCH_TRACEHOOK
122 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
123 select HAVE_ARCH_VMAP_STACK
124 select HAVE_ARM_SMCCC
125 select HAVE_EBPF_JIT
126 select HAVE_C_RECORDMCOUNT
127 select HAVE_CMPXCHG_DOUBLE
128 select HAVE_CMPXCHG_LOCAL
129 select HAVE_CONTEXT_TRACKING
130 select HAVE_DEBUG_BUGVERBOSE
131 select HAVE_DEBUG_KMEMLEAK
132 select HAVE_DMA_CONTIGUOUS
133 select HAVE_DYNAMIC_FTRACE
134 select HAVE_EFFICIENT_UNALIGNED_ACCESS
135 select HAVE_FTRACE_MCOUNT_RECORD
136 select HAVE_FUNCTION_TRACER
137 select HAVE_FUNCTION_GRAPH_TRACER
138 select HAVE_GCC_PLUGINS
139 select HAVE_GENERIC_DMA_COHERENT
140 select HAVE_HW_BREAKPOINT if PERF_EVENTS
141 select HAVE_IRQ_TIME_ACCOUNTING
142 select HAVE_MEMBLOCK_NODE_MAP if NUMA
143 select HAVE_NMI
144 select HAVE_PATA_PLATFORM
145 select HAVE_PERF_EVENTS
146 select HAVE_PERF_REGS
147 select HAVE_PERF_USER_STACK_DUMP
148 select HAVE_REGS_AND_STACK_ACCESS_API
149 select HAVE_RCU_TABLE_FREE
150 select HAVE_RCU_TABLE_INVALIDATE
151 select HAVE_RSEQ
152 select HAVE_STACKPROTECTOR
153 select HAVE_SYSCALL_TRACEPOINTS
154 select HAVE_KPROBES
155 select HAVE_KRETPROBES
156 select IOMMU_DMA if IOMMU_SUPPORT
157 select IRQ_DOMAIN
158 select IRQ_FORCED_THREADING
159 select MODULES_USE_ELF_RELA
160 select MULTI_IRQ_HANDLER
161 select NEED_DMA_MAP_STATE
162 select NEED_SG_DMA_LENGTH
163 select OF
164 select OF_EARLY_FLATTREE
165 select OF_RESERVED_MEM
166 select PCI_ECAM if (ACPI && PCI)
167 select POWER_RESET
168 select POWER_SUPPLY
169 select REFCOUNT_FULL
170 select SPARSE_IRQ
171 select SWIOTLB
172 select SYSCTL_EXCEPTION_TRACE
173 select THREAD_INFO_IN_TASK
174 help
175 ARM 64-bit (AArch64) Linux support.
176
177 config 64BIT
178 def_bool y
179
180 config MMU
181 def_bool y
182
183 config ARM64_PAGE_SHIFT
184 int
185 default 16 if ARM64_64K_PAGES
186 default 14 if ARM64_16K_PAGES
187 default 12
188
189 config ARM64_CONT_SHIFT
190 int
191 default 5 if ARM64_64K_PAGES
192 default 7 if ARM64_16K_PAGES
193 default 4
194
195 config ARCH_MMAP_RND_BITS_MIN
196 default 14 if ARM64_64K_PAGES
197 default 16 if ARM64_16K_PAGES
198 default 18
199
200 # max bits determined by the following formula:
201 # VA_BITS - PAGE_SHIFT - 3
202 config ARCH_MMAP_RND_BITS_MAX
203 default 19 if ARM64_VA_BITS=36
204 default 24 if ARM64_VA_BITS=39
205 default 27 if ARM64_VA_BITS=42
206 default 30 if ARM64_VA_BITS=47
207 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
208 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
209 default 33 if ARM64_VA_BITS=48
210 default 14 if ARM64_64K_PAGES
211 default 16 if ARM64_16K_PAGES
212 default 18
213
214 config ARCH_MMAP_RND_COMPAT_BITS_MIN
215 default 7 if ARM64_64K_PAGES
216 default 9 if ARM64_16K_PAGES
217 default 11
218
219 config ARCH_MMAP_RND_COMPAT_BITS_MAX
220 default 16
221
222 config NO_IOPORT_MAP
223 def_bool y if !PCI
224
225 config STACKTRACE_SUPPORT
226 def_bool y
227
228 config ILLEGAL_POINTER_VALUE
229 hex
230 default 0xdead000000000000
231
232 config LOCKDEP_SUPPORT
233 def_bool y
234
235 config TRACE_IRQFLAGS_SUPPORT
236 def_bool y
237
238 config RWSEM_XCHGADD_ALGORITHM
239 def_bool y
240
241 config GENERIC_BUG
242 def_bool y
243 depends on BUG
244
245 config GENERIC_BUG_RELATIVE_POINTERS
246 def_bool y
247 depends on GENERIC_BUG
248
249 config GENERIC_HWEIGHT
250 def_bool y
251
252 config GENERIC_CSUM
253 def_bool y
254
255 config GENERIC_CALIBRATE_DELAY
256 def_bool y
257
258 config ZONE_DMA32
259 def_bool y
260
261 config HAVE_GENERIC_GUP
262 def_bool y
263
264 config ARCH_ENABLE_MEMORY_HOTPLUG
265 def_bool y
266
267 config SMP
268 def_bool y
269
270 config KERNEL_MODE_NEON
271 def_bool y
272
273 config FIX_EARLYCON_MEM
274 def_bool y
275
276 config PGTABLE_LEVELS
277 int
278 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
279 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
280 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52)
281 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
282 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
283 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
284
285 config ARCH_SUPPORTS_UPROBES
286 def_bool y
287
288 config ARCH_PROC_KCORE_TEXT
289 def_bool y
290
291 source "arch/arm64/Kconfig.platforms"
292
293 menu "Bus support"
294
295 config PCI
296 bool "PCI support"
297 help
298 This feature enables support for PCI bus system. If you say Y
299 here, the kernel will include drivers and infrastructure code
300 to support PCI bus devices.
301
302 config PCI_DOMAINS
303 def_bool PCI
304
305 config PCI_DOMAINS_GENERIC
306 def_bool PCI
307
308 config PCI_SYSCALL
309 def_bool PCI
310
311 source "drivers/pci/Kconfig"
312
313 endmenu
314
315 menu "Kernel Features"
316
317 menu "ARM errata workarounds via the alternatives framework"
318
319 config ARM64_WORKAROUND_CLEAN_CACHE
320 def_bool n
321
322 config ARM64_ERRATUM_826319
323 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
324 default y
325 select ARM64_WORKAROUND_CLEAN_CACHE
326 help
327 This option adds an alternative code sequence to work around ARM
328 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
329 AXI master interface and an L2 cache.
330
331 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
332 and is unable to accept a certain write via this interface, it will
333 not progress on read data presented on the read data channel and the
334 system can deadlock.
335
336 The workaround promotes data cache clean instructions to
337 data cache clean-and-invalidate.
338 Please note that this does not necessarily enable the workaround,
339 as it depends on the alternative framework, which will only patch
340 the kernel if an affected CPU is detected.
341
342 If unsure, say Y.
343
344 config ARM64_ERRATUM_827319
345 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
346 default y
347 select ARM64_WORKAROUND_CLEAN_CACHE
348 help
349 This option adds an alternative code sequence to work around ARM
350 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
351 master interface and an L2 cache.
352
353 Under certain conditions this erratum can cause a clean line eviction
354 to occur at the same time as another transaction to the same address
355 on the AMBA 5 CHI interface, which can cause data corruption if the
356 interconnect reorders the two transactions.
357
358 The workaround promotes data cache clean instructions to
359 data cache clean-and-invalidate.
360 Please note that this does not necessarily enable the workaround,
361 as it depends on the alternative framework, which will only patch
362 the kernel if an affected CPU is detected.
363
364 If unsure, say Y.
365
366 config ARM64_ERRATUM_824069
367 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
368 default y
369 select ARM64_WORKAROUND_CLEAN_CACHE
370 help
371 This option adds an alternative code sequence to work around ARM
372 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
373 to a coherent interconnect.
374
375 If a Cortex-A53 processor is executing a store or prefetch for
376 write instruction at the same time as a processor in another
377 cluster is executing a cache maintenance operation to the same
378 address, then this erratum might cause a clean cache line to be
379 incorrectly marked as dirty.
380
381 The workaround promotes data cache clean instructions to
382 data cache clean-and-invalidate.
383 Please note that this option does not necessarily enable the
384 workaround, as it depends on the alternative framework, which will
385 only patch the kernel if an affected CPU is detected.
386
387 If unsure, say Y.
388
389 config ARM64_ERRATUM_819472
390 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
391 default y
392 select ARM64_WORKAROUND_CLEAN_CACHE
393 help
394 This option adds an alternative code sequence to work around ARM
395 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
396 present when it is connected to a coherent interconnect.
397
398 If the processor is executing a load and store exclusive sequence at
399 the same time as a processor in another cluster is executing a cache
400 maintenance operation to the same address, then this erratum might
401 cause data corruption.
402
403 The workaround promotes data cache clean instructions to
404 data cache clean-and-invalidate.
405 Please note that this does not necessarily enable the workaround,
406 as it depends on the alternative framework, which will only patch
407 the kernel if an affected CPU is detected.
408
409 If unsure, say Y.
410
411 config ARM64_ERRATUM_832075
412 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
413 default y
414 help
415 This option adds an alternative code sequence to work around ARM
416 erratum 832075 on Cortex-A57 parts up to r1p2.
417
418 Affected Cortex-A57 parts might deadlock when exclusive load/store
419 instructions to Write-Back memory are mixed with Device loads.
420
421 The workaround is to promote device loads to use Load-Acquire
422 semantics.
423 Please note that this does not necessarily enable the workaround,
424 as it depends on the alternative framework, which will only patch
425 the kernel if an affected CPU is detected.
426
427 If unsure, say Y.
428
429 config ARM64_ERRATUM_834220
430 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
431 depends on KVM
432 default y
433 help
434 This option adds an alternative code sequence to work around ARM
435 erratum 834220 on Cortex-A57 parts up to r1p2.
436
437 Affected Cortex-A57 parts might report a Stage 2 translation
438 fault as the result of a Stage 1 fault for load crossing a
439 page boundary when there is a permission or device memory
440 alignment fault at Stage 1 and a translation fault at Stage 2.
441
442 The workaround is to verify that the Stage 1 translation
443 doesn't generate a fault before handling the Stage 2 fault.
444 Please note that this does not necessarily enable the workaround,
445 as it depends on the alternative framework, which will only patch
446 the kernel if an affected CPU is detected.
447
448 If unsure, say Y.
449
450 config ARM64_ERRATUM_845719
451 bool "Cortex-A53: 845719: a load might read incorrect data"
452 depends on COMPAT
453 default y
454 help
455 This option adds an alternative code sequence to work around ARM
456 erratum 845719 on Cortex-A53 parts up to r0p4.
457
458 When running a compat (AArch32) userspace on an affected Cortex-A53
459 part, a load at EL0 from a virtual address that matches the bottom 32
460 bits of the virtual address used by a recent load at (AArch64) EL1
461 might return incorrect data.
462
463 The workaround is to write the contextidr_el1 register on exception
464 return to a 32-bit task.
465 Please note that this does not necessarily enable the workaround,
466 as it depends on the alternative framework, which will only patch
467 the kernel if an affected CPU is detected.
468
469 If unsure, say Y.
470
471 config ARM64_ERRATUM_843419
472 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
473 default y
474 select ARM64_MODULE_PLTS if MODULES
475 help
476 This option links the kernel with '--fix-cortex-a53-843419' and
477 enables PLT support to replace certain ADRP instructions, which can
478 cause subsequent memory accesses to use an incorrect address on
479 Cortex-A53 parts up to r0p4.
480
481 If unsure, say Y.
482
483 config ARM64_ERRATUM_1024718
484 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
485 default y
486 help
487 This option adds work around for Arm Cortex-A55 Erratum 1024718.
488
489 Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
490 update of the hardware dirty bit when the DBM/AP bits are updated
491 without a break-before-make. The work around is to disable the usage
492 of hardware DBM locally on the affected cores. CPUs not affected by
493 erratum will continue to use the feature.
494
495 If unsure, say Y.
496
497 config ARM64_ERRATUM_1188873
498 bool "Cortex-A76: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
499 default y
500 select ARM_ARCH_TIMER_OOL_WORKAROUND
501 help
502 This option adds work arounds for ARM Cortex-A76 erratum 1188873
503
504 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could cause
505 register corruption when accessing the timer registers from
506 AArch32 userspace.
507
508 If unsure, say Y.
509
510 config ARM64_ERRATUM_1165522
511 bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
512 default y
513 help
514 This option adds work arounds for ARM Cortex-A76 erratum 1165522
515
516 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
517 corrupted TLBs by speculating an AT instruction during a guest
518 context switch.
519
520 If unsure, say Y.
521
522 config ARM64_ERRATUM_1286807
523 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
524 default y
525 select ARM64_WORKAROUND_REPEAT_TLBI
526 help
527 This option adds workaround for ARM Cortex-A76 erratum 1286807
528
529 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
530 address for a cacheable mapping of a location is being
531 accessed by a core while another core is remapping the virtual
532 address to a new physical page using the recommended
533 break-before-make sequence, then under very rare circumstances
534 TLBI+DSB completes before a read using the translation being
535 invalidated has been observed by other observers. The
536 workaround repeats the TLBI+DSB operation.
537
538 If unsure, say Y.
539
540 config CAVIUM_ERRATUM_22375
541 bool "Cavium erratum 22375, 24313"
542 default y
543 help
544 Enable workaround for erratum 22375, 24313.
545
546 This implements two gicv3-its errata workarounds for ThunderX. Both
547 with small impact affecting only ITS table allocation.
548
549 erratum 22375: only alloc 8MB table size
550 erratum 24313: ignore memory access type
551
552 The fixes are in ITS initialization and basically ignore memory access
553 type and table size provided by the TYPER and BASER registers.
554
555 If unsure, say Y.
556
557 config CAVIUM_ERRATUM_23144
558 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
559 depends on NUMA
560 default y
561 help
562 ITS SYNC command hang for cross node io and collections/cpu mapping.
563
564 If unsure, say Y.
565
566 config CAVIUM_ERRATUM_23154
567 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
568 default y
569 help
570 The gicv3 of ThunderX requires a modified version for
571 reading the IAR status to ensure data synchronization
572 (access to icc_iar1_el1 is not sync'ed before and after).
573
574 If unsure, say Y.
575
576 config CAVIUM_ERRATUM_27456
577 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
578 default y
579 help
580 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
581 instructions may cause the icache to become corrupted if it
582 contains data for a non-current ASID. The fix is to
583 invalidate the icache when changing the mm context.
584
585 If unsure, say Y.
586
587 config CAVIUM_ERRATUM_30115
588 bool "Cavium erratum 30115: Guest may disable interrupts in host"
589 default y
590 help
591 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
592 1.2, and T83 Pass 1.0, KVM guest execution may disable
593 interrupts in host. Trapping both GICv3 group-0 and group-1
594 accesses sidesteps the issue.
595
596 If unsure, say Y.
597
598 config QCOM_FALKOR_ERRATUM_1003
599 bool "Falkor E1003: Incorrect translation due to ASID change"
600 default y
601 help
602 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
603 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
604 in TTBR1_EL1, this situation only occurs in the entry trampoline and
605 then only for entries in the walk cache, since the leaf translation
606 is unchanged. Work around the erratum by invalidating the walk cache
607 entries for the trampoline before entering the kernel proper.
608
609 config ARM64_WORKAROUND_REPEAT_TLBI
610 bool
611 help
612 Enable the repeat TLBI workaround for Falkor erratum 1009 and
613 Cortex-A76 erratum 1286807.
614
615 config QCOM_FALKOR_ERRATUM_1009
616 bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
617 default y
618 select ARM64_WORKAROUND_REPEAT_TLBI
619 help
620 On Falkor v1, the CPU may prematurely complete a DSB following a
621 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
622 one more time to fix the issue.
623
624 If unsure, say Y.
625
626 config QCOM_QDF2400_ERRATUM_0065
627 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
628 default y
629 help
630 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
631 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
632 been indicated as 16Bytes (0xf), not 8Bytes (0x7).
633
634 If unsure, say Y.
635
636 config SOCIONEXT_SYNQUACER_PREITS
637 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
638 default y
639 help
640 Socionext Synquacer SoCs implement a separate h/w block to generate
641 MSI doorbell writes with non-zero values for the device ID.
642
643 If unsure, say Y.
644
645 config HISILICON_ERRATUM_161600802
646 bool "Hip07 161600802: Erroneous redistributor VLPI base"
647 default y
648 help
649 The HiSilicon Hip07 SoC usees the wrong redistributor base
650 when issued ITS commands such as VMOVP and VMAPP, and requires
651 a 128kB offset to be applied to the target address in this commands.
652
653 If unsure, say Y.
654
655 config QCOM_FALKOR_ERRATUM_E1041
656 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
657 default y
658 help
659 Falkor CPU may speculatively fetch instructions from an improper
660 memory location when MMU translation is changed from SCTLR_ELn[M]=1
661 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
662
663 If unsure, say Y.
664
665 endmenu
666
667
668 choice
669 prompt "Page size"
670 default ARM64_4K_PAGES
671 help
672 Page size (translation granule) configuration.
673
674 config ARM64_4K_PAGES
675 bool "4KB"
676 help
677 This feature enables 4KB pages support.
678
679 config ARM64_16K_PAGES
680 bool "16KB"
681 help
682 The system will use 16KB pages support. AArch32 emulation
683 requires applications compiled with 16K (or a multiple of 16K)
684 aligned segments.
685
686 config ARM64_64K_PAGES
687 bool "64KB"
688 help
689 This feature enables 64KB pages support (4KB by default)
690 allowing only two levels of page tables and faster TLB
691 look-up. AArch32 emulation requires applications compiled
692 with 64K aligned segments.
693
694 endchoice
695
696 choice
697 prompt "Virtual address space size"
698 default ARM64_VA_BITS_39 if ARM64_4K_PAGES
699 default ARM64_VA_BITS_47 if ARM64_16K_PAGES
700 default ARM64_VA_BITS_42 if ARM64_64K_PAGES
701 help
702 Allows choosing one of multiple possible virtual address
703 space sizes. The level of translation table is determined by
704 a combination of page size and virtual address space size.
705
706 config ARM64_VA_BITS_36
707 bool "36-bit" if EXPERT
708 depends on ARM64_16K_PAGES
709
710 config ARM64_VA_BITS_39
711 bool "39-bit"
712 depends on ARM64_4K_PAGES
713
714 config ARM64_VA_BITS_42
715 bool "42-bit"
716 depends on ARM64_64K_PAGES
717
718 config ARM64_VA_BITS_47
719 bool "47-bit"
720 depends on ARM64_16K_PAGES
721
722 config ARM64_VA_BITS_48
723 bool "48-bit"
724
725 config ARM64_USER_VA_BITS_52
726 bool "52-bit (user)"
727 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
728 help
729 Enable 52-bit virtual addressing for userspace when explicitly
730 requested via a hint to mmap(). The kernel will continue to
731 use 48-bit virtual addresses for its own mappings.
732
733 NOTE: Enabling 52-bit virtual addressing in conjunction with
734 ARMv8.3 Pointer Authentication will result in the PAC being
735 reduced from 7 bits to 3 bits, which may have a significant
736 impact on its susceptibility to brute-force attacks.
737
738 If unsure, select 48-bit virtual addressing instead.
739
740 endchoice
741
742 config ARM64_FORCE_52BIT
743 bool "Force 52-bit virtual addresses for userspace"
744 depends on ARM64_USER_VA_BITS_52 && EXPERT
745 help
746 For systems with 52-bit userspace VAs enabled, the kernel will attempt
747 to maintain compatibility with older software by providing 48-bit VAs
748 unless a hint is supplied to mmap.
749
750 This configuration option disables the 48-bit compatibility logic, and
751 forces all userspace addresses to be 52-bit on HW that supports it. One
752 should only enable this configuration option for stress testing userspace
753 memory management code. If unsure say N here.
754
755 config ARM64_VA_BITS
756 int
757 default 36 if ARM64_VA_BITS_36
758 default 39 if ARM64_VA_BITS_39
759 default 42 if ARM64_VA_BITS_42
760 default 47 if ARM64_VA_BITS_47
761 default 48 if ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52
762
763 choice
764 prompt "Physical address space size"
765 default ARM64_PA_BITS_48
766 help
767 Choose the maximum physical address range that the kernel will
768 support.
769
770 config ARM64_PA_BITS_48
771 bool "48-bit"
772
773 config ARM64_PA_BITS_52
774 bool "52-bit (ARMv8.2)"
775 depends on ARM64_64K_PAGES
776 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
777 help
778 Enable support for a 52-bit physical address space, introduced as
779 part of the ARMv8.2-LPA extension.
780
781 With this enabled, the kernel will also continue to work on CPUs that
782 do not support ARMv8.2-LPA, but with some added memory overhead (and
783 minor performance overhead).
784
785 endchoice
786
787 config ARM64_PA_BITS
788 int
789 default 48 if ARM64_PA_BITS_48
790 default 52 if ARM64_PA_BITS_52
791
792 config CPU_BIG_ENDIAN
793 bool "Build big-endian kernel"
794 help
795 Say Y if you plan on running a kernel in big-endian mode.
796
797 config SCHED_MC
798 bool "Multi-core scheduler support"
799 help
800 Multi-core scheduler support improves the CPU scheduler's decision
801 making when dealing with multi-core CPU chips at a cost of slightly
802 increased overhead in some places. If unsure say N here.
803
804 config SCHED_SMT
805 bool "SMT scheduler support"
806 help
807 Improves the CPU scheduler's decision making when dealing with
808 MultiThreading at a cost of slightly increased overhead in some
809 places. If unsure say N here.
810
811 config NR_CPUS
812 int "Maximum number of CPUs (2-4096)"
813 range 2 4096
814 # These have to remain sorted largest to smallest
815 default "64"
816
817 config HOTPLUG_CPU
818 bool "Support for hot-pluggable CPUs"
819 select GENERIC_IRQ_MIGRATION
820 help
821 Say Y here to experiment with turning CPUs off and on. CPUs
822 can be controlled through /sys/devices/system/cpu.
823
824 # Common NUMA Features
825 config NUMA
826 bool "Numa Memory Allocation and Scheduler Support"
827 select ACPI_NUMA if ACPI
828 select OF_NUMA
829 help
830 Enable NUMA (Non Uniform Memory Access) support.
831
832 The kernel will try to allocate memory used by a CPU on the
833 local memory of the CPU and add some more
834 NUMA awareness to the kernel.
835
836 config NODES_SHIFT
837 int "Maximum NUMA Nodes (as a power of 2)"
838 range 1 10
839 default "2"
840 depends on NEED_MULTIPLE_NODES
841 help
842 Specify the maximum number of NUMA Nodes available on the target
843 system. Increases memory reserved to accommodate various tables.
844
845 config USE_PERCPU_NUMA_NODE_ID
846 def_bool y
847 depends on NUMA
848
849 config HAVE_SETUP_PER_CPU_AREA
850 def_bool y
851 depends on NUMA
852
853 config NEED_PER_CPU_EMBED_FIRST_CHUNK
854 def_bool y
855 depends on NUMA
856
857 config HOLES_IN_ZONE
858 def_bool y
859
860 source kernel/Kconfig.hz
861
862 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
863 def_bool y
864
865 config ARCH_SPARSEMEM_ENABLE
866 def_bool y
867 select SPARSEMEM_VMEMMAP_ENABLE
868
869 config ARCH_SPARSEMEM_DEFAULT
870 def_bool ARCH_SPARSEMEM_ENABLE
871
872 config ARCH_SELECT_MEMORY_MODEL
873 def_bool ARCH_SPARSEMEM_ENABLE
874
875 config ARCH_FLATMEM_ENABLE
876 def_bool !NUMA
877
878 config HAVE_ARCH_PFN_VALID
879 def_bool y
880
881 config HW_PERF_EVENTS
882 def_bool y
883 depends on ARM_PMU
884
885 config SYS_SUPPORTS_HUGETLBFS
886 def_bool y
887
888 config ARCH_WANT_HUGE_PMD_SHARE
889 def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
890
891 config ARCH_HAS_CACHE_LINE_SIZE
892 def_bool y
893
894 config SECCOMP
895 bool "Enable seccomp to safely compute untrusted bytecode"
896 ---help---
897 This kernel feature is useful for number crunching applications
898 that may need to compute untrusted bytecode during their
899 execution. By using pipes or other transports made available to
900 the process as file descriptors supporting the read/write
901 syscalls, it's possible to isolate those applications in
902 their own address space using seccomp. Once seccomp is
903 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
904 and the task is only allowed to execute a few safe syscalls
905 defined by each seccomp mode.
906
907 config PARAVIRT
908 bool "Enable paravirtualization code"
909 help
910 This changes the kernel so it can modify itself when it is run
911 under a hypervisor, potentially improving performance significantly
912 over full virtualization.
913
914 config PARAVIRT_TIME_ACCOUNTING
915 bool "Paravirtual steal time accounting"
916 select PARAVIRT
917 default n
918 help
919 Select this option to enable fine granularity task steal time
920 accounting. Time spent executing other tasks in parallel with
921 the current vCPU is discounted from the vCPU power. To account for
922 that, there can be a small performance impact.
923
924 If in doubt, say N here.
925
926 config KEXEC
927 depends on PM_SLEEP_SMP
928 select KEXEC_CORE
929 bool "kexec system call"
930 ---help---
931 kexec is a system call that implements the ability to shutdown your
932 current kernel, and to start another kernel. It is like a reboot
933 but it is independent of the system firmware. And like a reboot
934 you can start any kernel with it, not just Linux.
935
936 config KEXEC_FILE
937 bool "kexec file based system call"
938 select KEXEC_CORE
939 help
940 This is new version of kexec system call. This system call is
941 file based and takes file descriptors as system call argument
942 for kernel and initramfs as opposed to list of segments as
943 accepted by previous system call.
944
945 config KEXEC_VERIFY_SIG
946 bool "Verify kernel signature during kexec_file_load() syscall"
947 depends on KEXEC_FILE
948 help
949 Select this option to verify a signature with loaded kernel
950 image. If configured, any attempt of loading a image without
951 valid signature will fail.
952
953 In addition to that option, you need to enable signature
954 verification for the corresponding kernel image type being
955 loaded in order for this to work.
956
957 config KEXEC_IMAGE_VERIFY_SIG
958 bool "Enable Image signature verification support"
959 default y
960 depends on KEXEC_VERIFY_SIG
961 depends on EFI && SIGNED_PE_FILE_VERIFICATION
962 help
963 Enable Image signature verification support.
964
965 comment "Support for PE file signature verification disabled"
966 depends on KEXEC_VERIFY_SIG
967 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
968
969 config CRASH_DUMP
970 bool "Build kdump crash kernel"
971 help
972 Generate crash dump after being started by kexec. This should
973 be normally only set in special crash dump kernels which are
974 loaded in the main kernel with kexec-tools into a specially
975 reserved region and then later executed after a crash by
976 kdump/kexec.
977
978 For more details see Documentation/kdump/kdump.txt
979
980 config XEN_DOM0
981 def_bool y
982 depends on XEN
983
984 config XEN
985 bool "Xen guest support on ARM64"
986 depends on ARM64 && OF
987 select SWIOTLB_XEN
988 select PARAVIRT
989 help
990 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
991
992 config FORCE_MAX_ZONEORDER
993 int
994 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
995 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
996 default "11"
997 help
998 The kernel memory allocator divides physically contiguous memory
999 blocks into "zones", where each zone is a power of two number of
1000 pages. This option selects the largest power of two that the kernel
1001 keeps in the memory allocator. If you need to allocate very large
1002 blocks of physically contiguous memory, then you may need to
1003 increase this value.
1004
1005 This config option is actually maximum order plus one. For example,
1006 a value of 11 means that the largest free memory block is 2^10 pages.
1007
1008 We make sure that we can allocate upto a HugePage size for each configuration.
1009 Hence we have :
1010 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1011
1012 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1013 4M allocations matching the default size used by generic code.
1014
1015 config UNMAP_KERNEL_AT_EL0
1016 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1017 default y
1018 help
1019 Speculation attacks against some high-performance processors can
1020 be used to bypass MMU permission checks and leak kernel data to
1021 userspace. This can be defended against by unmapping the kernel
1022 when running in userspace, mapping it back in on exception entry
1023 via a trampoline page in the vector table.
1024
1025 If unsure, say Y.
1026
1027 config HARDEN_BRANCH_PREDICTOR
1028 bool "Harden the branch predictor against aliasing attacks" if EXPERT
1029 default y
1030 help
1031 Speculation attacks against some high-performance processors rely on
1032 being able to manipulate the branch predictor for a victim context by
1033 executing aliasing branches in the attacker context. Such attacks
1034 can be partially mitigated against by clearing internal branch
1035 predictor state and limiting the prediction logic in some situations.
1036
1037 This config option will take CPU-specific actions to harden the
1038 branch predictor against aliasing attacks and may rely on specific
1039 instruction sequences or control bits being set by the system
1040 firmware.
1041
1042 If unsure, say Y.
1043
1044 config HARDEN_EL2_VECTORS
1045 bool "Harden EL2 vector mapping against system register leak" if EXPERT
1046 default y
1047 help
1048 Speculation attacks against some high-performance processors can
1049 be used to leak privileged information such as the vector base
1050 register, resulting in a potential defeat of the EL2 layout
1051 randomization.
1052
1053 This config option will map the vectors to a fixed location,
1054 independent of the EL2 code mapping, so that revealing VBAR_EL2
1055 to an attacker does not give away any extra information. This
1056 only gets enabled on affected CPUs.
1057
1058 If unsure, say Y.
1059
1060 config ARM64_SSBD
1061 bool "Speculative Store Bypass Disable" if EXPERT
1062 default y
1063 help
1064 This enables mitigation of the bypassing of previous stores
1065 by speculative loads.
1066
1067 If unsure, say Y.
1068
1069 config RODATA_FULL_DEFAULT_ENABLED
1070 bool "Apply r/o permissions of VM areas also to their linear aliases"
1071 default y
1072 help
1073 Apply read-only attributes of VM areas to the linear alias of
1074 the backing pages as well. This prevents code or read-only data
1075 from being modified (inadvertently or intentionally) via another
1076 mapping of the same memory page. This additional enhancement can
1077 be turned off at runtime by passing rodata=[off|on] (and turned on
1078 with rodata=full if this option is set to 'n')
1079
1080 This requires the linear region to be mapped down to pages,
1081 which may adversely affect performance in some cases.
1082
1083 menuconfig ARMV8_DEPRECATED
1084 bool "Emulate deprecated/obsolete ARMv8 instructions"
1085 depends on COMPAT
1086 depends on SYSCTL
1087 help
1088 Legacy software support may require certain instructions
1089 that have been deprecated or obsoleted in the architecture.
1090
1091 Enable this config to enable selective emulation of these
1092 features.
1093
1094 If unsure, say Y
1095
1096 if ARMV8_DEPRECATED
1097
1098 config SWP_EMULATION
1099 bool "Emulate SWP/SWPB instructions"
1100 help
1101 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1102 they are always undefined. Say Y here to enable software
1103 emulation of these instructions for userspace using LDXR/STXR.
1104
1105 In some older versions of glibc [<=2.8] SWP is used during futex
1106 trylock() operations with the assumption that the code will not
1107 be preempted. This invalid assumption may be more likely to fail
1108 with SWP emulation enabled, leading to deadlock of the user
1109 application.
1110
1111 NOTE: when accessing uncached shared regions, LDXR/STXR rely
1112 on an external transaction monitoring block called a global
1113 monitor to maintain update atomicity. If your system does not
1114 implement a global monitor, this option can cause programs that
1115 perform SWP operations to uncached memory to deadlock.
1116
1117 If unsure, say Y
1118
1119 config CP15_BARRIER_EMULATION
1120 bool "Emulate CP15 Barrier instructions"
1121 help
1122 The CP15 barrier instructions - CP15ISB, CP15DSB, and
1123 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1124 strongly recommended to use the ISB, DSB, and DMB
1125 instructions instead.
1126
1127 Say Y here to enable software emulation of these
1128 instructions for AArch32 userspace code. When this option is
1129 enabled, CP15 barrier usage is traced which can help
1130 identify software that needs updating.
1131
1132 If unsure, say Y
1133
1134 config SETEND_EMULATION
1135 bool "Emulate SETEND instruction"
1136 help
1137 The SETEND instruction alters the data-endianness of the
1138 AArch32 EL0, and is deprecated in ARMv8.
1139
1140 Say Y here to enable software emulation of the instruction
1141 for AArch32 userspace code.
1142
1143 Note: All the cpus on the system must have mixed endian support at EL0
1144 for this feature to be enabled. If a new CPU - which doesn't support mixed
1145 endian - is hotplugged in after this feature has been enabled, there could
1146 be unexpected results in the applications.
1147
1148 If unsure, say Y
1149 endif
1150
1151 config ARM64_SW_TTBR0_PAN
1152 bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1153 help
1154 Enabling this option prevents the kernel from accessing
1155 user-space memory directly by pointing TTBR0_EL1 to a reserved
1156 zeroed area and reserved ASID. The user access routines
1157 restore the valid TTBR0_EL1 temporarily.
1158
1159 menu "ARMv8.1 architectural features"
1160
1161 config ARM64_HW_AFDBM
1162 bool "Support for hardware updates of the Access and Dirty page flags"
1163 default y
1164 help
1165 The ARMv8.1 architecture extensions introduce support for
1166 hardware updates of the access and dirty information in page
1167 table entries. When enabled in TCR_EL1 (HA and HD bits) on
1168 capable processors, accesses to pages with PTE_AF cleared will
1169 set this bit instead of raising an access flag fault.
1170 Similarly, writes to read-only pages with the DBM bit set will
1171 clear the read-only bit (AP[2]) instead of raising a
1172 permission fault.
1173
1174 Kernels built with this configuration option enabled continue
1175 to work on pre-ARMv8.1 hardware and the performance impact is
1176 minimal. If unsure, say Y.
1177
1178 config ARM64_PAN
1179 bool "Enable support for Privileged Access Never (PAN)"
1180 default y
1181 help
1182 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1183 prevents the kernel or hypervisor from accessing user-space (EL0)
1184 memory directly.
1185
1186 Choosing this option will cause any unprotected (not using
1187 copy_to_user et al) memory access to fail with a permission fault.
1188
1189 The feature is detected at runtime, and will remain as a 'nop'
1190 instruction if the cpu does not implement the feature.
1191
1192 config ARM64_LSE_ATOMICS
1193 bool "Atomic instructions"
1194 default y
1195 help
1196 As part of the Large System Extensions, ARMv8.1 introduces new
1197 atomic instructions that are designed specifically to scale in
1198 very large systems.
1199
1200 Say Y here to make use of these instructions for the in-kernel
1201 atomic routines. This incurs a small overhead on CPUs that do
1202 not support these instructions and requires the kernel to be
1203 built with binutils >= 2.25 in order for the new instructions
1204 to be used.
1205
1206 config ARM64_VHE
1207 bool "Enable support for Virtualization Host Extensions (VHE)"
1208 default y
1209 help
1210 Virtualization Host Extensions (VHE) allow the kernel to run
1211 directly at EL2 (instead of EL1) on processors that support
1212 it. This leads to better performance for KVM, as they reduce
1213 the cost of the world switch.
1214
1215 Selecting this option allows the VHE feature to be detected
1216 at runtime, and does not affect processors that do not
1217 implement this feature.
1218
1219 endmenu
1220
1221 menu "ARMv8.2 architectural features"
1222
1223 config ARM64_UAO
1224 bool "Enable support for User Access Override (UAO)"
1225 default y
1226 help
1227 User Access Override (UAO; part of the ARMv8.2 Extensions)
1228 causes the 'unprivileged' variant of the load/store instructions to
1229 be overridden to be privileged.
1230
1231 This option changes get_user() and friends to use the 'unprivileged'
1232 variant of the load/store instructions. This ensures that user-space
1233 really did have access to the supplied memory. When addr_limit is
1234 set to kernel memory the UAO bit will be set, allowing privileged
1235 access to kernel memory.
1236
1237 Choosing this option will cause copy_to_user() et al to use user-space
1238 memory permissions.
1239
1240 The feature is detected at runtime, the kernel will use the
1241 regular load/store instructions if the cpu does not implement the
1242 feature.
1243
1244 config ARM64_PMEM
1245 bool "Enable support for persistent memory"
1246 select ARCH_HAS_PMEM_API
1247 select ARCH_HAS_UACCESS_FLUSHCACHE
1248 help
1249 Say Y to enable support for the persistent memory API based on the
1250 ARMv8.2 DCPoP feature.
1251
1252 The feature is detected at runtime, and the kernel will use DC CVAC
1253 operations if DC CVAP is not supported (following the behaviour of
1254 DC CVAP itself if the system does not define a point of persistence).
1255
1256 config ARM64_RAS_EXTN
1257 bool "Enable support for RAS CPU Extensions"
1258 default y
1259 help
1260 CPUs that support the Reliability, Availability and Serviceability
1261 (RAS) Extensions, part of ARMv8.2 are able to track faults and
1262 errors, classify them and report them to software.
1263
1264 On CPUs with these extensions system software can use additional
1265 barriers to determine if faults are pending and read the
1266 classification from a new set of registers.
1267
1268 Selecting this feature will allow the kernel to use these barriers
1269 and access the new registers if the system supports the extension.
1270 Platform RAS features may additionally depend on firmware support.
1271
1272 config ARM64_CNP
1273 bool "Enable support for Common Not Private (CNP) translations"
1274 default y
1275 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1276 help
1277 Common Not Private (CNP) allows translation table entries to
1278 be shared between different PEs in the same inner shareable
1279 domain, so the hardware can use this fact to optimise the
1280 caching of such entries in the TLB.
1281
1282 Selecting this option allows the CNP feature to be detected
1283 at runtime, and does not affect PEs that do not implement
1284 this feature.
1285
1286 endmenu
1287
1288 menu "ARMv8.3 architectural features"
1289
1290 config ARM64_PTR_AUTH
1291 bool "Enable support for pointer authentication"
1292 default y
1293 help
1294 Pointer authentication (part of the ARMv8.3 Extensions) provides
1295 instructions for signing and authenticating pointers against secret
1296 keys, which can be used to mitigate Return Oriented Programming (ROP)
1297 and other attacks.
1298
1299 This option enables these instructions at EL0 (i.e. for userspace).
1300
1301 Choosing this option will cause the kernel to initialise secret keys
1302 for each process at exec() time, with these keys being
1303 context-switched along with the process.
1304
1305 The feature is detected at runtime. If the feature is not present in
1306 hardware it will not be advertised to userspace nor will it be
1307 enabled.
1308
1309 endmenu
1310
1311 config ARM64_SVE
1312 bool "ARM Scalable Vector Extension support"
1313 default y
1314 depends on !KVM || ARM64_VHE
1315 help
1316 The Scalable Vector Extension (SVE) is an extension to the AArch64
1317 execution state which complements and extends the SIMD functionality
1318 of the base architecture to support much larger vectors and to enable
1319 additional vectorisation opportunities.
1320
1321 To enable use of this extension on CPUs that implement it, say Y.
1322
1323 Note that for architectural reasons, firmware _must_ implement SVE
1324 support when running on SVE capable hardware. The required support
1325 is present in:
1326
1327 * version 1.5 and later of the ARM Trusted Firmware
1328 * the AArch64 boot wrapper since commit 5e1261e08abf
1329 ("bootwrapper: SVE: Enable SVE for EL2 and below").
1330
1331 For other firmware implementations, consult the firmware documentation
1332 or vendor.
1333
1334 If you need the kernel to boot on SVE-capable hardware with broken
1335 firmware, you may need to say N here until you get your firmware
1336 fixed. Otherwise, you may experience firmware panics or lockups when
1337 booting the kernel. If unsure and you are not observing these
1338 symptoms, you should assume that it is safe to say Y.
1339
1340 CPUs that support SVE are architecturally required to support the
1341 Virtualization Host Extensions (VHE), so the kernel makes no
1342 provision for supporting SVE alongside KVM without VHE enabled.
1343 Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
1344 KVM in the same kernel image.
1345
1346 config ARM64_MODULE_PLTS
1347 bool
1348 select HAVE_MOD_ARCH_SPECIFIC
1349
1350 config RELOCATABLE
1351 bool
1352 help
1353 This builds the kernel as a Position Independent Executable (PIE),
1354 which retains all relocation metadata required to relocate the
1355 kernel binary at runtime to a different virtual address than the
1356 address it was linked at.
1357 Since AArch64 uses the RELA relocation format, this requires a
1358 relocation pass at runtime even if the kernel is loaded at the
1359 same address it was linked at.
1360
1361 config RANDOMIZE_BASE
1362 bool "Randomize the address of the kernel image"
1363 select ARM64_MODULE_PLTS if MODULES
1364 select RELOCATABLE
1365 help
1366 Randomizes the virtual address at which the kernel image is
1367 loaded, as a security feature that deters exploit attempts
1368 relying on knowledge of the location of kernel internals.
1369
1370 It is the bootloader's job to provide entropy, by passing a
1371 random u64 value in /chosen/kaslr-seed at kernel entry.
1372
1373 When booting via the UEFI stub, it will invoke the firmware's
1374 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1375 to the kernel proper. In addition, it will randomise the physical
1376 location of the kernel Image as well.
1377
1378 If unsure, say N.
1379
1380 config RANDOMIZE_MODULE_REGION_FULL
1381 bool "Randomize the module region over a 4 GB range"
1382 depends on RANDOMIZE_BASE
1383 default y
1384 help
1385 Randomizes the location of the module region inside a 4 GB window
1386 covering the core kernel. This way, it is less likely for modules
1387 to leak information about the location of core kernel data structures
1388 but it does imply that function calls between modules and the core
1389 kernel will need to be resolved via veneers in the module PLT.
1390
1391 When this option is not set, the module region will be randomized over
1392 a limited range that contains the [_stext, _etext] interval of the
1393 core kernel, so branch relocations are always in range.
1394
1395 config CC_HAVE_STACKPROTECTOR_SYSREG
1396 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1397
1398 config STACKPROTECTOR_PER_TASK
1399 def_bool y
1400 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1401
1402 endmenu
1403
1404 menu "Boot options"
1405
1406 config ARM64_ACPI_PARKING_PROTOCOL
1407 bool "Enable support for the ARM64 ACPI parking protocol"
1408 depends on ACPI
1409 help
1410 Enable support for the ARM64 ACPI parking protocol. If disabled
1411 the kernel will not allow booting through the ARM64 ACPI parking
1412 protocol even if the corresponding data is present in the ACPI
1413 MADT table.
1414
1415 config CMDLINE
1416 string "Default kernel command string"
1417 default ""
1418 help
1419 Provide a set of default command-line options at build time by
1420 entering them here. As a minimum, you should specify the the
1421 root device (e.g. root=/dev/nfs).
1422
1423 config CMDLINE_FORCE
1424 bool "Always use the default kernel command string"
1425 help
1426 Always use the default kernel command string, even if the boot
1427 loader passes other arguments to the kernel.
1428 This is useful if you cannot or don't want to change the
1429 command-line options your boot loader passes to the kernel.
1430
1431 config EFI_STUB
1432 bool
1433
1434 config EFI
1435 bool "UEFI runtime support"
1436 depends on OF && !CPU_BIG_ENDIAN
1437 depends on KERNEL_MODE_NEON
1438 select ARCH_SUPPORTS_ACPI
1439 select LIBFDT
1440 select UCS2_STRING
1441 select EFI_PARAMS_FROM_FDT
1442 select EFI_RUNTIME_WRAPPERS
1443 select EFI_STUB
1444 select EFI_ARMSTUB
1445 default y
1446 help
1447 This option provides support for runtime services provided
1448 by UEFI firmware (such as non-volatile variables, realtime
1449 clock, and platform reset). A UEFI stub is also provided to
1450 allow the kernel to be booted as an EFI application. This
1451 is only useful on systems that have UEFI firmware.
1452
1453 config DMI
1454 bool "Enable support for SMBIOS (DMI) tables"
1455 depends on EFI
1456 default y
1457 help
1458 This enables SMBIOS/DMI feature for systems.
1459
1460 This option is only useful on systems that have UEFI firmware.
1461 However, even with this option, the resultant kernel should
1462 continue to boot on existing non-UEFI platforms.
1463
1464 endmenu
1465
1466 config COMPAT
1467 bool "Kernel support for 32-bit EL0"
1468 depends on ARM64_4K_PAGES || EXPERT
1469 select COMPAT_BINFMT_ELF if BINFMT_ELF
1470 select HAVE_UID16
1471 select OLD_SIGSUSPEND3
1472 select COMPAT_OLD_SIGACTION
1473 help
1474 This option enables support for a 32-bit EL0 running under a 64-bit
1475 kernel at EL1. AArch32-specific components such as system calls,
1476 the user helper functions, VFP support and the ptrace interface are
1477 handled appropriately by the kernel.
1478
1479 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1480 that you will only be able to execute AArch32 binaries that were compiled
1481 with page size aligned segments.
1482
1483 If you want to execute 32-bit userspace applications, say Y.
1484
1485 config SYSVIPC_COMPAT
1486 def_bool y
1487 depends on COMPAT && SYSVIPC
1488
1489 menu "Power management options"
1490
1491 source "kernel/power/Kconfig"
1492
1493 config ARCH_HIBERNATION_POSSIBLE
1494 def_bool y
1495 depends on CPU_PM
1496
1497 config ARCH_HIBERNATION_HEADER
1498 def_bool y
1499 depends on HIBERNATION
1500
1501 config ARCH_SUSPEND_POSSIBLE
1502 def_bool y
1503
1504 endmenu
1505
1506 menu "CPU Power Management"
1507
1508 source "drivers/cpuidle/Kconfig"
1509
1510 source "drivers/cpufreq/Kconfig"
1511
1512 endmenu
1513
1514 source "drivers/firmware/Kconfig"
1515
1516 source "drivers/acpi/Kconfig"
1517
1518 source "arch/arm64/kvm/Kconfig"
1519
1520 if CRYPTO
1521 source "arch/arm64/crypto/Kconfig"
1522 endif