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1config 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
9	select ACPI_SPCR_TABLE if ACPI
10	select ARCH_CLOCKSOURCE_DATA
11	select ARCH_HAS_DEBUG_VIRTUAL
12	select ARCH_HAS_DEVMEM_IS_ALLOWED
13	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
14	select ARCH_HAS_ELF_RANDOMIZE
15	select ARCH_HAS_FORTIFY_SOURCE
16	select ARCH_HAS_GCOV_PROFILE_ALL
17	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
18	select ARCH_HAS_KCOV
19	select ARCH_HAS_SET_MEMORY
20	select ARCH_HAS_SG_CHAIN
21	select ARCH_HAS_STRICT_KERNEL_RWX
22	select ARCH_HAS_STRICT_MODULE_RWX
23	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
24	select ARCH_HAVE_NMI_SAFE_CMPXCHG if ACPI_APEI_SEA
25	select ARCH_USE_CMPXCHG_LOCKREF
26	select ARCH_SUPPORTS_MEMORY_FAILURE
27	select ARCH_SUPPORTS_LTO_CLANG
28	select ARCH_SUPPORTS_ATOMIC_RMW
29	select ARCH_SUPPORTS_NUMA_BALANCING
30	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
31	select ARCH_WANT_FRAME_POINTERS
32	select ARCH_HAS_UBSAN_SANITIZE_ALL
33	select ARM_AMBA
34	select ARM_ARCH_TIMER
35	select ARM_GIC
36	select AUDIT_ARCH_COMPAT_GENERIC
37	select ARM_GIC_V2M if PCI
38	select ARM_GIC_V3
39	select ARM_GIC_V3_ITS if PCI
40	select ARM_PSCI_FW
41	select BUILDTIME_EXTABLE_SORT
42	select CLONE_BACKWARDS
43	select COMMON_CLK
44	select CPU_PM if (SUSPEND || CPU_IDLE)
45	select DCACHE_WORD_ACCESS
46	select EDAC_SUPPORT
47	select FRAME_POINTER
48	select GENERIC_ALLOCATOR
49	select GENERIC_ARCH_TOPOLOGY
50	select GENERIC_CLOCKEVENTS
51	select GENERIC_CLOCKEVENTS_BROADCAST
52	select GENERIC_CPU_AUTOPROBE
53	select GENERIC_CPU_VULNERABILITIES
54	select GENERIC_EARLY_IOREMAP
55	select GENERIC_IDLE_POLL_SETUP
56	select GENERIC_IRQ_PROBE
57	select GENERIC_IRQ_SHOW
58	select GENERIC_IRQ_SHOW_LEVEL
59	select GENERIC_PCI_IOMAP
60	select GENERIC_SCHED_CLOCK
61	select GENERIC_SMP_IDLE_THREAD
62	select GENERIC_STRNCPY_FROM_USER
63	select GENERIC_STRNLEN_USER
64	select GENERIC_TIME_VSYSCALL
65	select HANDLE_DOMAIN_IRQ
66	select HARDIRQS_SW_RESEND
67	select HAVE_ACPI_APEI if (ACPI && EFI)
68	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
69	select HAVE_ARCH_AUDITSYSCALL
70	select HAVE_ARCH_BITREVERSE
71	select HAVE_ARCH_HUGE_VMAP
72	select HAVE_ARCH_JUMP_LABEL
73	select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP && !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
74	select HAVE_ARCH_KGDB
75	select HAVE_ARCH_MMAP_RND_BITS
76	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
77	select HAVE_ARCH_SECCOMP_FILTER
78	select HAVE_ARCH_TRACEHOOK
79	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
80	select HAVE_ARCH_VMAP_STACK
81	select HAVE_ARM_SMCCC
82	select HAVE_EBPF_JIT
83	select HAVE_C_RECORDMCOUNT
84	select HAVE_CC_STACKPROTECTOR
85	select HAVE_CMPXCHG_DOUBLE
86	select HAVE_CMPXCHG_LOCAL
87	select HAVE_CONTEXT_TRACKING
88	select HAVE_DEBUG_BUGVERBOSE
89	select HAVE_DEBUG_KMEMLEAK
90	select HAVE_DMA_API_DEBUG
91	select HAVE_DMA_CONTIGUOUS
92	select HAVE_DYNAMIC_FTRACE
93	select HAVE_EFFICIENT_UNALIGNED_ACCESS
94	select HAVE_FTRACE_MCOUNT_RECORD
95	select HAVE_FUNCTION_TRACER
96	select HAVE_FUNCTION_GRAPH_TRACER
97	select HAVE_GCC_PLUGINS
98	select HAVE_GENERIC_DMA_COHERENT
99	select HAVE_HW_BREAKPOINT if PERF_EVENTS
100	select HAVE_IRQ_TIME_ACCOUNTING
101	select HAVE_MEMBLOCK
102	select HAVE_MEMBLOCK_NODE_MAP if NUMA
103	select HAVE_NMI if ACPI_APEI_SEA
104	select HAVE_PATA_PLATFORM
105	select HAVE_PERF_EVENTS
106	select HAVE_PERF_REGS
107	select HAVE_PERF_USER_STACK_DUMP
108	select HAVE_REGS_AND_STACK_ACCESS_API
109	select HAVE_RCU_TABLE_FREE
110	select HAVE_SYSCALL_TRACEPOINTS
111	select HAVE_KPROBES
112	select HAVE_KRETPROBES
113	select IOMMU_DMA if IOMMU_SUPPORT
114	select IRQ_DOMAIN
115	select IRQ_FORCED_THREADING
116	select MODULES_USE_ELF_RELA
117	select NO_BOOTMEM
118	select OF
119	select OF_EARLY_FLATTREE
120	select OF_RESERVED_MEM
121	select PCI_ECAM if ACPI
122	select POWER_RESET
123	select POWER_SUPPLY
124	select SPARSE_IRQ
125	select SYSCTL_EXCEPTION_TRACE
126	select THREAD_INFO_IN_TASK
127	help
128	  ARM 64-bit (AArch64) Linux support.
129
130config 64BIT
131	def_bool y
132
133config ARCH_PHYS_ADDR_T_64BIT
134	def_bool y
135
136config MMU
137	def_bool y
138
139config ARM64_PAGE_SHIFT
140	int
141	default 16 if ARM64_64K_PAGES
142	default 14 if ARM64_16K_PAGES
143	default 12
144
145config ARM64_CONT_SHIFT
146	int
147	default 5 if ARM64_64K_PAGES
148	default 7 if ARM64_16K_PAGES
149	default 4
150
151config ARCH_MMAP_RND_BITS_MIN
152       default 14 if ARM64_64K_PAGES
153       default 16 if ARM64_16K_PAGES
154       default 18
155
156# max bits determined by the following formula:
157#  VA_BITS - PAGE_SHIFT - 3
158config ARCH_MMAP_RND_BITS_MAX
159       default 19 if ARM64_VA_BITS=36
160       default 24 if ARM64_VA_BITS=39
161       default 27 if ARM64_VA_BITS=42
162       default 30 if ARM64_VA_BITS=47
163       default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
164       default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
165       default 33 if ARM64_VA_BITS=48
166       default 14 if ARM64_64K_PAGES
167       default 16 if ARM64_16K_PAGES
168       default 18
169
170config ARCH_MMAP_RND_COMPAT_BITS_MIN
171       default 7 if ARM64_64K_PAGES
172       default 9 if ARM64_16K_PAGES
173       default 11
174
175config ARCH_MMAP_RND_COMPAT_BITS_MAX
176       default 16
177
178config NO_IOPORT_MAP
179	def_bool y if !PCI
180
181config STACKTRACE_SUPPORT
182	def_bool y
183
184config ILLEGAL_POINTER_VALUE
185	hex
186	default 0xdead000000000000
187
188config LOCKDEP_SUPPORT
189	def_bool y
190
191config TRACE_IRQFLAGS_SUPPORT
192	def_bool y
193
194config RWSEM_XCHGADD_ALGORITHM
195	def_bool y
196
197config GENERIC_BUG
198	def_bool y
199	depends on BUG
200
201config GENERIC_BUG_RELATIVE_POINTERS
202	def_bool y
203	depends on GENERIC_BUG
204
205config GENERIC_HWEIGHT
206	def_bool y
207
208config GENERIC_CSUM
209        def_bool y
210
211config GENERIC_CALIBRATE_DELAY
212	def_bool y
213
214config ZONE_DMA
215	def_bool y
216
217config HAVE_GENERIC_GUP
218	def_bool y
219
220config ARCH_DMA_ADDR_T_64BIT
221	def_bool y
222
223config NEED_DMA_MAP_STATE
224	def_bool y
225
226config NEED_SG_DMA_LENGTH
227	def_bool y
228
229config SMP
230	def_bool y
231
232config SWIOTLB
233	def_bool y
234
235config IOMMU_HELPER
236	def_bool SWIOTLB
237
238config KERNEL_MODE_NEON
239	def_bool y
240
241config FIX_EARLYCON_MEM
242	def_bool y
243
244config PGTABLE_LEVELS
245	int
246	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
247	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
248	default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48
249	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
250	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
251	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
252
253config ARCH_SUPPORTS_UPROBES
254	def_bool y
255
256config ARCH_PROC_KCORE_TEXT
257	def_bool y
258
259source "init/Kconfig"
260
261source "kernel/Kconfig.freezer"
262
263source "arch/arm64/Kconfig.platforms"
264
265menu "Bus support"
266
267config PCI
268	bool "PCI support"
269	help
270	  This feature enables support for PCI bus system. If you say Y
271	  here, the kernel will include drivers and infrastructure code
272	  to support PCI bus devices.
273
274config PCI_DOMAINS
275	def_bool PCI
276
277config PCI_DOMAINS_GENERIC
278	def_bool PCI
279
280config PCI_SYSCALL
281	def_bool PCI
282
283source "drivers/pci/Kconfig"
284
285endmenu
286
287menu "Kernel Features"
288
289menu "ARM errata workarounds via the alternatives framework"
290
291config ARM64_ERRATUM_826319
292	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
293	default y
294	help
295	  This option adds an alternative code sequence to work around ARM
296	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
297	  AXI master interface and an L2 cache.
298
299	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
300	  and is unable to accept a certain write via this interface, it will
301	  not progress on read data presented on the read data channel and the
302	  system can deadlock.
303
304	  The workaround promotes data cache clean instructions to
305	  data cache clean-and-invalidate.
306	  Please note that this does not necessarily enable the workaround,
307	  as it depends on the alternative framework, which will only patch
308	  the kernel if an affected CPU is detected.
309
310	  If unsure, say Y.
311
312config ARM64_ERRATUM_827319
313	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
314	default y
315	help
316	  This option adds an alternative code sequence to work around ARM
317	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
318	  master interface and an L2 cache.
319
320	  Under certain conditions this erratum can cause a clean line eviction
321	  to occur at the same time as another transaction to the same address
322	  on the AMBA 5 CHI interface, which can cause data corruption if the
323	  interconnect reorders the two transactions.
324
325	  The workaround promotes data cache clean instructions to
326	  data cache clean-and-invalidate.
327	  Please note that this does not necessarily enable the workaround,
328	  as it depends on the alternative framework, which will only patch
329	  the kernel if an affected CPU is detected.
330
331	  If unsure, say Y.
332
333config ARM64_ERRATUM_824069
334	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
335	default y
336	help
337	  This option adds an alternative code sequence to work around ARM
338	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
339	  to a coherent interconnect.
340
341	  If a Cortex-A53 processor is executing a store or prefetch for
342	  write instruction at the same time as a processor in another
343	  cluster is executing a cache maintenance operation to the same
344	  address, then this erratum might cause a clean cache line to be
345	  incorrectly marked as dirty.
346
347	  The workaround promotes data cache clean instructions to
348	  data cache clean-and-invalidate.
349	  Please note that this option does not necessarily enable the
350	  workaround, as it depends on the alternative framework, which will
351	  only patch the kernel if an affected CPU is detected.
352
353	  If unsure, say Y.
354
355config ARM64_ERRATUM_819472
356	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
357	default y
358	help
359	  This option adds an alternative code sequence to work around ARM
360	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
361	  present when it is connected to a coherent interconnect.
362
363	  If the processor is executing a load and store exclusive sequence at
364	  the same time as a processor in another cluster is executing a cache
365	  maintenance operation to the same address, then this erratum might
366	  cause data corruption.
367
368	  The workaround promotes data cache clean instructions to
369	  data cache clean-and-invalidate.
370	  Please note that this does not necessarily enable the workaround,
371	  as it depends on the alternative framework, which will only patch
372	  the kernel if an affected CPU is detected.
373
374	  If unsure, say Y.
375
376config ARM64_ERRATUM_832075
377	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
378	default y
379	help
380	  This option adds an alternative code sequence to work around ARM
381	  erratum 832075 on Cortex-A57 parts up to r1p2.
382
383	  Affected Cortex-A57 parts might deadlock when exclusive load/store
384	  instructions to Write-Back memory are mixed with Device loads.
385
386	  The workaround is to promote device loads to use Load-Acquire
387	  semantics.
388	  Please note that this does not necessarily enable the workaround,
389	  as it depends on the alternative framework, which will only patch
390	  the kernel if an affected CPU is detected.
391
392	  If unsure, say Y.
393
394config ARM64_ERRATUM_834220
395	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
396	depends on KVM
397	default y
398	help
399	  This option adds an alternative code sequence to work around ARM
400	  erratum 834220 on Cortex-A57 parts up to r1p2.
401
402	  Affected Cortex-A57 parts might report a Stage 2 translation
403	  fault as the result of a Stage 1 fault for load crossing a
404	  page boundary when there is a permission or device memory
405	  alignment fault at Stage 1 and a translation fault at Stage 2.
406
407	  The workaround is to verify that the Stage 1 translation
408	  doesn't generate a fault before handling the Stage 2 fault.
409	  Please note that this does not necessarily enable the workaround,
410	  as it depends on the alternative framework, which will only patch
411	  the kernel if an affected CPU is detected.
412
413	  If unsure, say Y.
414
415config ARM64_ERRATUM_845719
416	bool "Cortex-A53: 845719: a load might read incorrect data"
417	depends on COMPAT
418	default y
419	help
420	  This option adds an alternative code sequence to work around ARM
421	  erratum 845719 on Cortex-A53 parts up to r0p4.
422
423	  When running a compat (AArch32) userspace on an affected Cortex-A53
424	  part, a load at EL0 from a virtual address that matches the bottom 32
425	  bits of the virtual address used by a recent load at (AArch64) EL1
426	  might return incorrect data.
427
428	  The workaround is to write the contextidr_el1 register on exception
429	  return to a 32-bit task.
430	  Please note that this does not necessarily enable the workaround,
431	  as it depends on the alternative framework, which will only patch
432	  the kernel if an affected CPU is detected.
433
434	  If unsure, say Y.
435
436config ARM64_ERRATUM_843419
437	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
438	default y if !LTO_CLANG
439	select ARM64_MODULE_CMODEL_LARGE if MODULES
440	help
441	  This option links the kernel with '--fix-cortex-a53-843419' and
442	  builds modules using the large memory model in order to avoid the use
443	  of the ADRP instruction, which can cause a subsequent memory access
444	  to use an incorrect address on Cortex-A53 parts up to r0p4.
445
446	  If unsure, say Y.
447
448config ARM64_ERRATUM_1024718
449	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
450	default y
451	help
452	  This option adds work around for Arm Cortex-A55 Erratum 1024718.
453
454	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
455	  update of the hardware dirty bit when the DBM/AP bits are updated
456	  without a break-before-make. The work around is to disable the usage
457	  of hardware DBM locally on the affected cores. CPUs not affected by
458	  erratum will continue to use the feature.
459
460	  If unsure, say Y.
461
462config CAVIUM_ERRATUM_22375
463	bool "Cavium erratum 22375, 24313"
464	default y
465	help
466	  Enable workaround for erratum 22375, 24313.
467
468	  This implements two gicv3-its errata workarounds for ThunderX. Both
469	  with small impact affecting only ITS table allocation.
470
471	    erratum 22375: only alloc 8MB table size
472	    erratum 24313: ignore memory access type
473
474	  The fixes are in ITS initialization and basically ignore memory access
475	  type and table size provided by the TYPER and BASER registers.
476
477	  If unsure, say Y.
478
479config CAVIUM_ERRATUM_23144
480	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
481	depends on NUMA
482	default y
483	help
484	  ITS SYNC command hang for cross node io and collections/cpu mapping.
485
486	  If unsure, say Y.
487
488config CAVIUM_ERRATUM_23154
489	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
490	default y
491	help
492	  The gicv3 of ThunderX requires a modified version for
493	  reading the IAR status to ensure data synchronization
494	  (access to icc_iar1_el1 is not sync'ed before and after).
495
496	  If unsure, say Y.
497
498config CAVIUM_ERRATUM_27456
499	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
500	default y
501	help
502	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
503	  instructions may cause the icache to become corrupted if it
504	  contains data for a non-current ASID.  The fix is to
505	  invalidate the icache when changing the mm context.
506
507	  If unsure, say Y.
508
509config CAVIUM_ERRATUM_30115
510	bool "Cavium erratum 30115: Guest may disable interrupts in host"
511	default y
512	help
513	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
514	  1.2, and T83 Pass 1.0, KVM guest execution may disable
515	  interrupts in host. Trapping both GICv3 group-0 and group-1
516	  accesses sidesteps the issue.
517
518	  If unsure, say Y.
519
520config QCOM_FALKOR_ERRATUM_1003
521	bool "Falkor E1003: Incorrect translation due to ASID change"
522	default y
523	help
524	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
525	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
526	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
527	  then only for entries in the walk cache, since the leaf translation
528	  is unchanged. Work around the erratum by invalidating the walk cache
529	  entries for the trampoline before entering the kernel proper.
530
531config QCOM_FALKOR_ERRATUM_1009
532	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
533	default y
534	help
535	  On Falkor v1, the CPU may prematurely complete a DSB following a
536	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
537	  one more time to fix the issue.
538
539	  If unsure, say Y.
540
541config QCOM_QDF2400_ERRATUM_0065
542	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
543	default y
544	help
545	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
546	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
547	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
548
549	  If unsure, say Y.
550
551config QCOM_FALKOR_ERRATUM_E1041
552	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
553	default y
554	help
555	  Falkor CPU may speculatively fetch instructions from an improper
556	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
557	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
558
559	  If unsure, say Y.
560
561endmenu
562
563
564choice
565	prompt "Page size"
566	default ARM64_4K_PAGES
567	help
568	  Page size (translation granule) configuration.
569
570config ARM64_4K_PAGES
571	bool "4KB"
572	help
573	  This feature enables 4KB pages support.
574
575config ARM64_16K_PAGES
576	bool "16KB"
577	help
578	  The system will use 16KB pages support. AArch32 emulation
579	  requires applications compiled with 16K (or a multiple of 16K)
580	  aligned segments.
581
582config ARM64_64K_PAGES
583	bool "64KB"
584	help
585	  This feature enables 64KB pages support (4KB by default)
586	  allowing only two levels of page tables and faster TLB
587	  look-up. AArch32 emulation requires applications compiled
588	  with 64K aligned segments.
589
590endchoice
591
592choice
593	prompt "Virtual address space size"
594	default ARM64_VA_BITS_39 if ARM64_4K_PAGES
595	default ARM64_VA_BITS_47 if ARM64_16K_PAGES
596	default ARM64_VA_BITS_42 if ARM64_64K_PAGES
597	help
598	  Allows choosing one of multiple possible virtual address
599	  space sizes. The level of translation table is determined by
600	  a combination of page size and virtual address space size.
601
602config ARM64_VA_BITS_36
603	bool "36-bit" if EXPERT
604	depends on ARM64_16K_PAGES
605
606config ARM64_VA_BITS_39
607	bool "39-bit"
608	depends on ARM64_4K_PAGES
609
610config ARM64_VA_BITS_42
611	bool "42-bit"
612	depends on ARM64_64K_PAGES
613
614config ARM64_VA_BITS_47
615	bool "47-bit"
616	depends on ARM64_16K_PAGES
617
618config ARM64_VA_BITS_48
619	bool "48-bit"
620
621endchoice
622
623config ARM64_VA_BITS
624	int
625	default 36 if ARM64_VA_BITS_36
626	default 39 if ARM64_VA_BITS_39
627	default 42 if ARM64_VA_BITS_42
628	default 47 if ARM64_VA_BITS_47
629	default 48 if ARM64_VA_BITS_48
630
631config CPU_BIG_ENDIAN
632       bool "Build big-endian kernel"
633       help
634         Say Y if you plan on running a kernel in big-endian mode.
635
636config SCHED_MC
637	bool "Multi-core scheduler support"
638	help
639	  Multi-core scheduler support improves the CPU scheduler's decision
640	  making when dealing with multi-core CPU chips at a cost of slightly
641	  increased overhead in some places. If unsure say N here.
642
643config SCHED_SMT
644	bool "SMT scheduler support"
645	help
646	  Improves the CPU scheduler's decision making when dealing with
647	  MultiThreading at a cost of slightly increased overhead in some
648	  places. If unsure say N here.
649
650config NR_CPUS
651	int "Maximum number of CPUs (2-4096)"
652	range 2 4096
653	# These have to remain sorted largest to smallest
654	default "64"
655
656config HOTPLUG_CPU
657	bool "Support for hot-pluggable CPUs"
658	select GENERIC_IRQ_MIGRATION
659	help
660	  Say Y here to experiment with turning CPUs off and on.  CPUs
661	  can be controlled through /sys/devices/system/cpu.
662
663# Common NUMA Features
664config NUMA
665	bool "Numa Memory Allocation and Scheduler Support"
666	select ACPI_NUMA if ACPI
667	select OF_NUMA
668	help
669	  Enable NUMA (Non Uniform Memory Access) support.
670
671	  The kernel will try to allocate memory used by a CPU on the
672	  local memory of the CPU and add some more
673	  NUMA awareness to the kernel.
674
675config NODES_SHIFT
676	int "Maximum NUMA Nodes (as a power of 2)"
677	range 1 10
678	default "2"
679	depends on NEED_MULTIPLE_NODES
680	help
681	  Specify the maximum number of NUMA Nodes available on the target
682	  system.  Increases memory reserved to accommodate various tables.
683
684config USE_PERCPU_NUMA_NODE_ID
685	def_bool y
686	depends on NUMA
687
688config HAVE_SETUP_PER_CPU_AREA
689	def_bool y
690	depends on NUMA
691
692config NEED_PER_CPU_EMBED_FIRST_CHUNK
693	def_bool y
694	depends on NUMA
695
696config HOLES_IN_ZONE
697	def_bool y
698
699source kernel/Kconfig.preempt
700source kernel/Kconfig.hz
701
702config ARCH_SUPPORTS_DEBUG_PAGEALLOC
703	def_bool y
704
705config ARCH_HAS_HOLES_MEMORYMODEL
706	def_bool y if SPARSEMEM
707
708config ARCH_SPARSEMEM_ENABLE
709	def_bool y
710	select SPARSEMEM_VMEMMAP_ENABLE
711
712config ARCH_SPARSEMEM_DEFAULT
713	def_bool ARCH_SPARSEMEM_ENABLE
714
715config ARCH_SELECT_MEMORY_MODEL
716	def_bool ARCH_SPARSEMEM_ENABLE
717
718config HAVE_ARCH_PFN_VALID
719	def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
720
721config HW_PERF_EVENTS
722	def_bool y
723	depends on ARM_PMU
724
725config SYS_SUPPORTS_HUGETLBFS
726	def_bool y
727
728config ARCH_WANT_HUGE_PMD_SHARE
729	def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
730
731config ARCH_HAS_CACHE_LINE_SIZE
732	def_bool y
733
734source "mm/Kconfig"
735
736config SECCOMP
737	bool "Enable seccomp to safely compute untrusted bytecode"
738	---help---
739	  This kernel feature is useful for number crunching applications
740	  that may need to compute untrusted bytecode during their
741	  execution. By using pipes or other transports made available to
742	  the process as file descriptors supporting the read/write
743	  syscalls, it's possible to isolate those applications in
744	  their own address space using seccomp. Once seccomp is
745	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
746	  and the task is only allowed to execute a few safe syscalls
747	  defined by each seccomp mode.
748
749config PARAVIRT
750	bool "Enable paravirtualization code"
751	help
752	  This changes the kernel so it can modify itself when it is run
753	  under a hypervisor, potentially improving performance significantly
754	  over full virtualization.
755
756config PARAVIRT_TIME_ACCOUNTING
757	bool "Paravirtual steal time accounting"
758	select PARAVIRT
759	default n
760	help
761	  Select this option to enable fine granularity task steal time
762	  accounting. Time spent executing other tasks in parallel with
763	  the current vCPU is discounted from the vCPU power. To account for
764	  that, there can be a small performance impact.
765
766	  If in doubt, say N here.
767
768config KEXEC
769	depends on PM_SLEEP_SMP
770	select KEXEC_CORE
771	bool "kexec system call"
772	---help---
773	  kexec is a system call that implements the ability to shutdown your
774	  current kernel, and to start another kernel.  It is like a reboot
775	  but it is independent of the system firmware.   And like a reboot
776	  you can start any kernel with it, not just Linux.
777
778config CRASH_DUMP
779	bool "Build kdump crash kernel"
780	help
781	  Generate crash dump after being started by kexec. This should
782	  be normally only set in special crash dump kernels which are
783	  loaded in the main kernel with kexec-tools into a specially
784	  reserved region and then later executed after a crash by
785	  kdump/kexec.
786
787	  For more details see Documentation/kdump/kdump.txt
788
789config XEN_DOM0
790	def_bool y
791	depends on XEN
792
793config XEN
794	bool "Xen guest support on ARM64"
795	depends on ARM64 && OF
796	select SWIOTLB_XEN
797	select PARAVIRT
798	help
799	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
800
801config FORCE_MAX_ZONEORDER
802	int
803	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
804	default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
805	default "11"
806	help
807	  The kernel memory allocator divides physically contiguous memory
808	  blocks into "zones", where each zone is a power of two number of
809	  pages.  This option selects the largest power of two that the kernel
810	  keeps in the memory allocator.  If you need to allocate very large
811	  blocks of physically contiguous memory, then you may need to
812	  increase this value.
813
814	  This config option is actually maximum order plus one. For example,
815	  a value of 11 means that the largest free memory block is 2^10 pages.
816
817	  We make sure that we can allocate upto a HugePage size for each configuration.
818	  Hence we have :
819		MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
820
821	  However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
822	  4M allocations matching the default size used by generic code.
823
824config UNMAP_KERNEL_AT_EL0
825	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
826	default y
827	help
828	  Speculation attacks against some high-performance processors can
829	  be used to bypass MMU permission checks and leak kernel data to
830	  userspace. This can be defended against by unmapping the kernel
831	  when running in userspace, mapping it back in on exception entry
832	  via a trampoline page in the vector table.
833
834	  If unsure, say Y.
835
836config HARDEN_BRANCH_PREDICTOR
837	bool "Harden the branch predictor against aliasing attacks" if EXPERT
838	default y
839	help
840	  Speculation attacks against some high-performance processors rely on
841	  being able to manipulate the branch predictor for a victim context by
842	  executing aliasing branches in the attacker context.  Such attacks
843	  can be partially mitigated against by clearing internal branch
844	  predictor state and limiting the prediction logic in some situations.
845
846	  This config option will take CPU-specific actions to harden the
847	  branch predictor against aliasing attacks and may rely on specific
848	  instruction sequences or control bits being set by the system
849	  firmware.
850
851	  If unsure, say Y.
852
853config ARM64_SSBD
854	bool "Speculative Store Bypass Disable" if EXPERT
855	default y
856	help
857	  This enables mitigation of the bypassing of previous stores
858	  by speculative loads.
859
860	  If unsure, say Y.
861
862menuconfig ARMV8_DEPRECATED
863	bool "Emulate deprecated/obsolete ARMv8 instructions"
864	depends on COMPAT
865	help
866	  Legacy software support may require certain instructions
867	  that have been deprecated or obsoleted in the architecture.
868
869	  Enable this config to enable selective emulation of these
870	  features.
871
872	  If unsure, say Y
873
874if ARMV8_DEPRECATED
875
876config SWP_EMULATION
877	bool "Emulate SWP/SWPB instructions"
878	help
879	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
880	  they are always undefined. Say Y here to enable software
881	  emulation of these instructions for userspace using LDXR/STXR.
882
883	  In some older versions of glibc [<=2.8] SWP is used during futex
884	  trylock() operations with the assumption that the code will not
885	  be preempted. This invalid assumption may be more likely to fail
886	  with SWP emulation enabled, leading to deadlock of the user
887	  application.
888
889	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
890	  on an external transaction monitoring block called a global
891	  monitor to maintain update atomicity. If your system does not
892	  implement a global monitor, this option can cause programs that
893	  perform SWP operations to uncached memory to deadlock.
894
895	  If unsure, say Y
896
897config CP15_BARRIER_EMULATION
898	bool "Emulate CP15 Barrier instructions"
899	help
900	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
901	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
902	  strongly recommended to use the ISB, DSB, and DMB
903	  instructions instead.
904
905	  Say Y here to enable software emulation of these
906	  instructions for AArch32 userspace code. When this option is
907	  enabled, CP15 barrier usage is traced which can help
908	  identify software that needs updating.
909
910	  If unsure, say Y
911
912config SETEND_EMULATION
913	bool "Emulate SETEND instruction"
914	help
915	  The SETEND instruction alters the data-endianness of the
916	  AArch32 EL0, and is deprecated in ARMv8.
917
918	  Say Y here to enable software emulation of the instruction
919	  for AArch32 userspace code.
920
921	  Note: All the cpus on the system must have mixed endian support at EL0
922	  for this feature to be enabled. If a new CPU - which doesn't support mixed
923	  endian - is hotplugged in after this feature has been enabled, there could
924	  be unexpected results in the applications.
925
926	  If unsure, say Y
927endif
928
929config ARM64_SW_TTBR0_PAN
930	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
931	help
932	  Enabling this option prevents the kernel from accessing
933	  user-space memory directly by pointing TTBR0_EL1 to a reserved
934	  zeroed area and reserved ASID. The user access routines
935	  restore the valid TTBR0_EL1 temporarily.
936
937menu "ARMv8.1 architectural features"
938
939config ARM64_HW_AFDBM
940	bool "Support for hardware updates of the Access and Dirty page flags"
941	default y
942	help
943	  The ARMv8.1 architecture extensions introduce support for
944	  hardware updates of the access and dirty information in page
945	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
946	  capable processors, accesses to pages with PTE_AF cleared will
947	  set this bit instead of raising an access flag fault.
948	  Similarly, writes to read-only pages with the DBM bit set will
949	  clear the read-only bit (AP[2]) instead of raising a
950	  permission fault.
951
952	  Kernels built with this configuration option enabled continue
953	  to work on pre-ARMv8.1 hardware and the performance impact is
954	  minimal. If unsure, say Y.
955
956config ARM64_PAN
957	bool "Enable support for Privileged Access Never (PAN)"
958	default y
959	help
960	 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
961	 prevents the kernel or hypervisor from accessing user-space (EL0)
962	 memory directly.
963
964	 Choosing this option will cause any unprotected (not using
965	 copy_to_user et al) memory access to fail with a permission fault.
966
967	 The feature is detected at runtime, and will remain as a 'nop'
968	 instruction if the cpu does not implement the feature.
969
970config ARM64_LSE_ATOMICS
971	bool "Atomic instructions"
972	help
973	  As part of the Large System Extensions, ARMv8.1 introduces new
974	  atomic instructions that are designed specifically to scale in
975	  very large systems.
976
977	  Say Y here to make use of these instructions for the in-kernel
978	  atomic routines. This incurs a small overhead on CPUs that do
979	  not support these instructions and requires the kernel to be
980	  built with binutils >= 2.25.
981
982config ARM64_VHE
983	bool "Enable support for Virtualization Host Extensions (VHE)"
984	default y
985	help
986	  Virtualization Host Extensions (VHE) allow the kernel to run
987	  directly at EL2 (instead of EL1) on processors that support
988	  it. This leads to better performance for KVM, as they reduce
989	  the cost of the world switch.
990
991	  Selecting this option allows the VHE feature to be detected
992	  at runtime, and does not affect processors that do not
993	  implement this feature.
994
995endmenu
996
997menu "ARMv8.2 architectural features"
998
999config ARM64_UAO
1000	bool "Enable support for User Access Override (UAO)"
1001	default y
1002	help
1003	  User Access Override (UAO; part of the ARMv8.2 Extensions)
1004	  causes the 'unprivileged' variant of the load/store instructions to
1005	  be overriden to be privileged.
1006
1007	  This option changes get_user() and friends to use the 'unprivileged'
1008	  variant of the load/store instructions. This ensures that user-space
1009	  really did have access to the supplied memory. When addr_limit is
1010	  set to kernel memory the UAO bit will be set, allowing privileged
1011	  access to kernel memory.
1012
1013	  Choosing this option will cause copy_to_user() et al to use user-space
1014	  memory permissions.
1015
1016	  The feature is detected at runtime, the kernel will use the
1017	  regular load/store instructions if the cpu does not implement the
1018	  feature.
1019
1020config ARM64_PMEM
1021	bool "Enable support for persistent memory"
1022	select ARCH_HAS_PMEM_API
1023	select ARCH_HAS_UACCESS_FLUSHCACHE
1024	help
1025	  Say Y to enable support for the persistent memory API based on the
1026	  ARMv8.2 DCPoP feature.
1027
1028	  The feature is detected at runtime, and the kernel will use DC CVAC
1029	  operations if DC CVAP is not supported (following the behaviour of
1030	  DC CVAP itself if the system does not define a point of persistence).
1031
1032endmenu
1033
1034config ARM64_MODULE_CMODEL_LARGE
1035	bool
1036
1037config ARM64_MODULE_PLTS
1038	bool
1039	select ARM64_MODULE_CMODEL_LARGE
1040	select HAVE_MOD_ARCH_SPECIFIC
1041
1042config RELOCATABLE
1043	bool
1044	help
1045	  This builds the kernel as a Position Independent Executable (PIE),
1046	  which retains all relocation metadata required to relocate the
1047	  kernel binary at runtime to a different virtual address than the
1048	  address it was linked at.
1049	  Since AArch64 uses the RELA relocation format, this requires a
1050	  relocation pass at runtime even if the kernel is loaded at the
1051	  same address it was linked at.
1052
1053config RANDOMIZE_BASE
1054	bool "Randomize the address of the kernel image"
1055	select ARM64_MODULE_PLTS if MODULES
1056	select RELOCATABLE
1057	help
1058	  Randomizes the virtual address at which the kernel image is
1059	  loaded, as a security feature that deters exploit attempts
1060	  relying on knowledge of the location of kernel internals.
1061
1062	  It is the bootloader's job to provide entropy, by passing a
1063	  random u64 value in /chosen/kaslr-seed at kernel entry.
1064
1065	  When booting via the UEFI stub, it will invoke the firmware's
1066	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1067	  to the kernel proper. In addition, it will randomise the physical
1068	  location of the kernel Image as well.
1069
1070	  If unsure, say N.
1071
1072config RANDOMIZE_MODULE_REGION_FULL
1073	bool "Randomize the module region independently from the core kernel"
1074	depends on RANDOMIZE_BASE && !LTO_CLANG
1075	default y
1076	help
1077	  Randomizes the location of the module region without considering the
1078	  location of the core kernel. This way, it is impossible for modules
1079	  to leak information about the location of core kernel data structures
1080	  but it does imply that function calls between modules and the core
1081	  kernel will need to be resolved via veneers in the module PLT.
1082
1083	  When this option is not set, the module region will be randomized over
1084	  a limited range that contains the [_stext, _etext] interval of the
1085	  core kernel, so branch relocations are always in range.
1086
1087endmenu
1088
1089menu "Boot options"
1090
1091config ARM64_ACPI_PARKING_PROTOCOL
1092	bool "Enable support for the ARM64 ACPI parking protocol"
1093	depends on ACPI
1094	help
1095	  Enable support for the ARM64 ACPI parking protocol. If disabled
1096	  the kernel will not allow booting through the ARM64 ACPI parking
1097	  protocol even if the corresponding data is present in the ACPI
1098	  MADT table.
1099
1100config CMDLINE
1101	string "Default kernel command string"
1102	default ""
1103	help
1104	  Provide a set of default command-line options at build time by
1105	  entering them here. As a minimum, you should specify the the
1106	  root device (e.g. root=/dev/nfs).
1107
1108choice
1109	prompt "Kernel command line type" if CMDLINE != ""
1110	default CMDLINE_FROM_BOOTLOADER
1111
1112config CMDLINE_FROM_BOOTLOADER
1113	bool "Use bootloader kernel arguments if available"
1114	help
1115	  Uses the command-line options passed by the boot loader. If
1116	  the boot loader doesn't provide any, the default kernel command
1117	  string provided in CMDLINE will be used.
1118
1119config CMDLINE_EXTEND
1120	bool "Extend bootloader kernel arguments"
1121	help
1122	  The command-line arguments provided by the boot loader will be
1123	  appended to the default kernel command string.
1124
1125config CMDLINE_FORCE
1126	bool "Always use the default kernel command string"
1127	help
1128	  Always use the default kernel command string, even if the boot
1129	  loader passes other arguments to the kernel.
1130	  This is useful if you cannot or don't want to change the
1131	  command-line options your boot loader passes to the kernel.
1132endchoice
1133
1134config EFI_STUB
1135	bool
1136
1137config EFI
1138	bool "UEFI runtime support"
1139	depends on OF && !CPU_BIG_ENDIAN
1140	select LIBFDT
1141	select UCS2_STRING
1142	select EFI_PARAMS_FROM_FDT
1143	select EFI_RUNTIME_WRAPPERS
1144	select EFI_STUB
1145	select EFI_ARMSTUB
1146	default y
1147	help
1148	  This option provides support for runtime services provided
1149	  by UEFI firmware (such as non-volatile variables, realtime
1150          clock, and platform reset). A UEFI stub is also provided to
1151	  allow the kernel to be booted as an EFI application. This
1152	  is only useful on systems that have UEFI firmware.
1153
1154config DMI
1155	bool "Enable support for SMBIOS (DMI) tables"
1156	depends on EFI
1157	default y
1158	help
1159	  This enables SMBIOS/DMI feature for systems.
1160
1161	  This option is only useful on systems that have UEFI firmware.
1162	  However, even with this option, the resultant kernel should
1163	  continue to boot on existing non-UEFI platforms.
1164
1165config BUILD_ARM64_APPENDED_DTB_IMAGE
1166	bool "Build a concatenated Image.gz/dtb by default"
1167	depends on OF
1168	help
1169	  Enabling this option will cause a concatenated Image.gz and list of
1170	  DTBs to be built by default (instead of a standalone Image.gz.)
1171	  The image will built in arch/arm64/boot/Image.gz-dtb
1172
1173choice
1174	prompt "Appended DTB Kernel Image name"
1175	depends on BUILD_ARM64_APPENDED_DTB_IMAGE
1176	help
1177	  Enabling this option will cause a specific kernel image Image or
1178	  Image.gz to be used for final image creation.
1179	  The image will built in arch/arm64/boot/IMAGE-NAME-dtb
1180
1181	config IMG_GZ_DTB
1182		bool "Image.gz-dtb"
1183	config IMG_DTB
1184		bool "Image-dtb"
1185endchoice
1186
1187config BUILD_ARM64_APPENDED_KERNEL_IMAGE_NAME
1188	string
1189	depends on BUILD_ARM64_APPENDED_DTB_IMAGE
1190	default "Image.gz-dtb" if IMG_GZ_DTB
1191	default "Image-dtb" if IMG_DTB
1192
1193config BUILD_ARM64_APPENDED_DTB_IMAGE_NAMES
1194	string "Default dtb names"
1195	depends on BUILD_ARM64_APPENDED_DTB_IMAGE
1196	help
1197	  Space separated list of names of dtbs to append when
1198	  building a concatenated Image.gz-dtb.
1199
1200endmenu
1201
1202menu "Userspace binary formats"
1203
1204source "fs/Kconfig.binfmt"
1205
1206config COMPAT
1207	bool "Kernel support for 32-bit EL0"
1208	depends on ARM64_4K_PAGES || EXPERT
1209	select COMPAT_BINFMT_ELF if BINFMT_ELF
1210	select HAVE_UID16
1211	select OLD_SIGSUSPEND3
1212	select COMPAT_OLD_SIGACTION
1213	help
1214	  This option enables support for a 32-bit EL0 running under a 64-bit
1215	  kernel at EL1. AArch32-specific components such as system calls,
1216	  the user helper functions, VFP support and the ptrace interface are
1217	  handled appropriately by the kernel.
1218
1219	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1220	  that you will only be able to execute AArch32 binaries that were compiled
1221	  with page size aligned segments.
1222
1223	  If you want to execute 32-bit userspace applications, say Y.
1224
1225config SYSVIPC_COMPAT
1226	def_bool y
1227	depends on COMPAT && SYSVIPC
1228
1229endmenu
1230
1231menu "Power management options"
1232
1233source "kernel/power/Kconfig"
1234
1235config ARCH_HIBERNATION_POSSIBLE
1236	def_bool y
1237	depends on CPU_PM
1238
1239config ARCH_HIBERNATION_HEADER
1240	def_bool y
1241	depends on HIBERNATION
1242
1243config ARCH_SUSPEND_POSSIBLE
1244	def_bool y
1245
1246endmenu
1247
1248menu "CPU Power Management"
1249
1250source "drivers/cpuidle/Kconfig"
1251
1252source "drivers/cpufreq/Kconfig"
1253
1254endmenu
1255
1256source "net/Kconfig"
1257
1258source "drivers/Kconfig"
1259
1260source "drivers/firmware/Kconfig"
1261
1262source "drivers/acpi/Kconfig"
1263
1264source "fs/Kconfig"
1265
1266source "arch/arm64/kvm/Kconfig"
1267
1268source "arch/arm64/Kconfig.debug"
1269
1270source "security/Kconfig"
1271
1272source "crypto/Kconfig"
1273if CRYPTO
1274source "arch/arm64/crypto/Kconfig"
1275endif
1276
1277source "lib/Kconfig"
1278