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
19 select ARCH_HAS_MEMBARRIER_SYNC_CORE
20 select ARCH_HAS_SET_MEMORY
21 select ARCH_HAS_SG_CHAIN
22 select ARCH_HAS_STRICT_KERNEL_RWX
23 select ARCH_HAS_STRICT_MODULE_RWX
24 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
25 select ARCH_HAVE_NMI_SAFE_CMPXCHG
26 select ARCH_INLINE_READ_LOCK if !PREEMPT
27 select ARCH_INLINE_READ_LOCK_BH if !PREEMPT
28 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT
29 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT
30 select ARCH_INLINE_READ_UNLOCK if !PREEMPT
31 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT
32 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT
33 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT
34 select ARCH_INLINE_WRITE_LOCK if !PREEMPT
35 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT
36 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT
37 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT
38 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT
39 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT
40 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT
41 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT
42 select ARCH_USE_CMPXCHG_LOCKREF
43 select ARCH_USE_QUEUED_RWLOCKS
44 select ARCH_SUPPORTS_MEMORY_FAILURE
45 select ARCH_SUPPORTS_ATOMIC_RMW
46 select ARCH_SUPPORTS_NUMA_BALANCING
47 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
48 select ARCH_WANT_FRAME_POINTERS
49 select ARCH_HAS_UBSAN_SANITIZE_ALL
53 select AUDIT_ARCH_COMPAT_GENERIC
54 select ARM_GIC_V2M if PCI
56 select ARM_GIC_V3_ITS if PCI
58 select BUILDTIME_EXTABLE_SORT
59 select CLONE_BACKWARDS
61 select CPU_PM if (SUSPEND || CPU_IDLE)
62 select DCACHE_WORD_ACCESS
66 select GENERIC_ALLOCATOR
67 select GENERIC_ARCH_TOPOLOGY
68 select GENERIC_CLOCKEVENTS
69 select GENERIC_CLOCKEVENTS_BROADCAST
70 select GENERIC_CPU_AUTOPROBE
71 select GENERIC_EARLY_IOREMAP
72 select GENERIC_IDLE_POLL_SETUP
73 select GENERIC_IRQ_PROBE
74 select GENERIC_IRQ_SHOW
75 select GENERIC_IRQ_SHOW_LEVEL
76 select GENERIC_PCI_IOMAP
77 select GENERIC_SCHED_CLOCK
78 select GENERIC_SMP_IDLE_THREAD
79 select GENERIC_STRNCPY_FROM_USER
80 select GENERIC_STRNLEN_USER
81 select GENERIC_TIME_VSYSCALL
82 select HANDLE_DOMAIN_IRQ
83 select HARDIRQS_SW_RESEND
84 select HAVE_ACPI_APEI if (ACPI && EFI)
85 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
86 select HAVE_ARCH_AUDITSYSCALL
87 select HAVE_ARCH_BITREVERSE
88 select HAVE_ARCH_HUGE_VMAP
89 select HAVE_ARCH_JUMP_LABEL
90 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
92 select HAVE_ARCH_MMAP_RND_BITS
93 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
94 select HAVE_ARCH_SECCOMP_FILTER
95 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
96 select HAVE_ARCH_TRACEHOOK
97 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
98 select HAVE_ARCH_VMAP_STACK
101 select HAVE_C_RECORDMCOUNT
102 select HAVE_CC_STACKPROTECTOR
103 select HAVE_CMPXCHG_DOUBLE
104 select HAVE_CMPXCHG_LOCAL
105 select HAVE_CONTEXT_TRACKING
106 select HAVE_DEBUG_BUGVERBOSE
107 select HAVE_DEBUG_KMEMLEAK
108 select HAVE_DMA_API_DEBUG
109 select HAVE_DMA_CONTIGUOUS
110 select HAVE_DYNAMIC_FTRACE
111 select HAVE_EFFICIENT_UNALIGNED_ACCESS
112 select HAVE_FTRACE_MCOUNT_RECORD
113 select HAVE_FUNCTION_TRACER
114 select HAVE_FUNCTION_GRAPH_TRACER
115 select HAVE_GCC_PLUGINS
116 select HAVE_GENERIC_DMA_COHERENT
117 select HAVE_HW_BREAKPOINT if PERF_EVENTS
118 select HAVE_IRQ_TIME_ACCOUNTING
120 select HAVE_MEMBLOCK_NODE_MAP if NUMA
122 select HAVE_PATA_PLATFORM
123 select HAVE_PERF_EVENTS
124 select HAVE_PERF_REGS
125 select HAVE_PERF_USER_STACK_DUMP
126 select HAVE_REGS_AND_STACK_ACCESS_API
127 select HAVE_RCU_TABLE_FREE
128 select HAVE_SYSCALL_TRACEPOINTS
130 select HAVE_KRETPROBES
131 select IOMMU_DMA if IOMMU_SUPPORT
133 select IRQ_FORCED_THREADING
134 select MODULES_USE_ELF_RELA
137 select OF_EARLY_FLATTREE
138 select OF_RESERVED_MEM
139 select PCI_ECAM if ACPI
144 select SYSCTL_EXCEPTION_TRACE
145 select THREAD_INFO_IN_TASK
147 ARM 64-bit (AArch64) Linux support.
152 config ARCH_PHYS_ADDR_T_64BIT
158 config ARM64_PAGE_SHIFT
160 default 16 if ARM64_64K_PAGES
161 default 14 if ARM64_16K_PAGES
164 config ARM64_CONT_SHIFT
166 default 5 if ARM64_64K_PAGES
167 default 7 if ARM64_16K_PAGES
170 config ARCH_MMAP_RND_BITS_MIN
171 default 14 if ARM64_64K_PAGES
172 default 16 if ARM64_16K_PAGES
175 # max bits determined by the following formula:
176 # VA_BITS - PAGE_SHIFT - 3
177 config ARCH_MMAP_RND_BITS_MAX
178 default 19 if ARM64_VA_BITS=36
179 default 24 if ARM64_VA_BITS=39
180 default 27 if ARM64_VA_BITS=42
181 default 30 if ARM64_VA_BITS=47
182 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
183 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
184 default 33 if ARM64_VA_BITS=48
185 default 14 if ARM64_64K_PAGES
186 default 16 if ARM64_16K_PAGES
189 config ARCH_MMAP_RND_COMPAT_BITS_MIN
190 default 7 if ARM64_64K_PAGES
191 default 9 if ARM64_16K_PAGES
194 config ARCH_MMAP_RND_COMPAT_BITS_MAX
200 config STACKTRACE_SUPPORT
203 config ILLEGAL_POINTER_VALUE
205 default 0xdead000000000000
207 config LOCKDEP_SUPPORT
210 config TRACE_IRQFLAGS_SUPPORT
213 config RWSEM_XCHGADD_ALGORITHM
220 config GENERIC_BUG_RELATIVE_POINTERS
222 depends on GENERIC_BUG
224 config GENERIC_HWEIGHT
230 config GENERIC_CALIBRATE_DELAY
236 config HAVE_GENERIC_GUP
239 config ARCH_DMA_ADDR_T_64BIT
242 config NEED_DMA_MAP_STATE
245 config NEED_SG_DMA_LENGTH
257 config KERNEL_MODE_NEON
260 config FIX_EARLYCON_MEM
263 config PGTABLE_LEVELS
265 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
266 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
267 default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48
268 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
269 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
270 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
272 config ARCH_SUPPORTS_UPROBES
275 config ARCH_PROC_KCORE_TEXT
278 source "init/Kconfig"
280 source "kernel/Kconfig.freezer"
282 source "arch/arm64/Kconfig.platforms"
289 This feature enables support for PCI bus system. If you say Y
290 here, the kernel will include drivers and infrastructure code
291 to support PCI bus devices.
296 config PCI_DOMAINS_GENERIC
302 source "drivers/pci/Kconfig"
306 menu "Kernel Features"
308 menu "ARM errata workarounds via the alternatives framework"
310 config ARM64_ERRATUM_826319
311 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
314 This option adds an alternative code sequence to work around ARM
315 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
316 AXI master interface and an L2 cache.
318 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
319 and is unable to accept a certain write via this interface, it will
320 not progress on read data presented on the read data channel and the
323 The workaround promotes data cache clean instructions to
324 data cache clean-and-invalidate.
325 Please note that this does not necessarily enable the workaround,
326 as it depends on the alternative framework, which will only patch
327 the kernel if an affected CPU is detected.
331 config ARM64_ERRATUM_827319
332 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
335 This option adds an alternative code sequence to work around ARM
336 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
337 master interface and an L2 cache.
339 Under certain conditions this erratum can cause a clean line eviction
340 to occur at the same time as another transaction to the same address
341 on the AMBA 5 CHI interface, which can cause data corruption if the
342 interconnect reorders the two transactions.
344 The workaround promotes data cache clean instructions to
345 data cache clean-and-invalidate.
346 Please note that this does not necessarily enable the workaround,
347 as it depends on the alternative framework, which will only patch
348 the kernel if an affected CPU is detected.
352 config ARM64_ERRATUM_824069
353 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
356 This option adds an alternative code sequence to work around ARM
357 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
358 to a coherent interconnect.
360 If a Cortex-A53 processor is executing a store or prefetch for
361 write instruction at the same time as a processor in another
362 cluster is executing a cache maintenance operation to the same
363 address, then this erratum might cause a clean cache line to be
364 incorrectly marked as dirty.
366 The workaround promotes data cache clean instructions to
367 data cache clean-and-invalidate.
368 Please note that this option does not necessarily enable the
369 workaround, as it depends on the alternative framework, which will
370 only patch the kernel if an affected CPU is detected.
374 config ARM64_ERRATUM_819472
375 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
378 This option adds an alternative code sequence to work around ARM
379 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
380 present when it is connected to a coherent interconnect.
382 If the processor is executing a load and store exclusive sequence at
383 the same time as a processor in another cluster is executing a cache
384 maintenance operation to the same address, then this erratum might
385 cause data corruption.
387 The workaround promotes data cache clean instructions to
388 data cache clean-and-invalidate.
389 Please note that this does not necessarily enable the workaround,
390 as it depends on the alternative framework, which will only patch
391 the kernel if an affected CPU is detected.
395 config ARM64_ERRATUM_832075
396 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
399 This option adds an alternative code sequence to work around ARM
400 erratum 832075 on Cortex-A57 parts up to r1p2.
402 Affected Cortex-A57 parts might deadlock when exclusive load/store
403 instructions to Write-Back memory are mixed with Device loads.
405 The workaround is to promote device loads to use Load-Acquire
407 Please note that this does not necessarily enable the workaround,
408 as it depends on the alternative framework, which will only patch
409 the kernel if an affected CPU is detected.
413 config ARM64_ERRATUM_834220
414 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
418 This option adds an alternative code sequence to work around ARM
419 erratum 834220 on Cortex-A57 parts up to r1p2.
421 Affected Cortex-A57 parts might report a Stage 2 translation
422 fault as the result of a Stage 1 fault for load crossing a
423 page boundary when there is a permission or device memory
424 alignment fault at Stage 1 and a translation fault at Stage 2.
426 The workaround is to verify that the Stage 1 translation
427 doesn't generate a fault before handling the Stage 2 fault.
428 Please note that this does not necessarily enable the workaround,
429 as it depends on the alternative framework, which will only patch
430 the kernel if an affected CPU is detected.
434 config ARM64_ERRATUM_845719
435 bool "Cortex-A53: 845719: a load might read incorrect data"
439 This option adds an alternative code sequence to work around ARM
440 erratum 845719 on Cortex-A53 parts up to r0p4.
442 When running a compat (AArch32) userspace on an affected Cortex-A53
443 part, a load at EL0 from a virtual address that matches the bottom 32
444 bits of the virtual address used by a recent load at (AArch64) EL1
445 might return incorrect data.
447 The workaround is to write the contextidr_el1 register on exception
448 return to a 32-bit task.
449 Please note that this does not necessarily enable the workaround,
450 as it depends on the alternative framework, which will only patch
451 the kernel if an affected CPU is detected.
455 config ARM64_ERRATUM_843419
456 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
458 select ARM64_MODULE_CMODEL_LARGE if MODULES
460 This option links the kernel with '--fix-cortex-a53-843419' and
461 builds modules using the large memory model in order to avoid the use
462 of the ADRP instruction, which can cause a subsequent memory access
463 to use an incorrect address on Cortex-A53 parts up to r0p4.
467 config CAVIUM_ERRATUM_22375
468 bool "Cavium erratum 22375, 24313"
471 Enable workaround for erratum 22375, 24313.
473 This implements two gicv3-its errata workarounds for ThunderX. Both
474 with small impact affecting only ITS table allocation.
476 erratum 22375: only alloc 8MB table size
477 erratum 24313: ignore memory access type
479 The fixes are in ITS initialization and basically ignore memory access
480 type and table size provided by the TYPER and BASER registers.
484 config CAVIUM_ERRATUM_23144
485 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
489 ITS SYNC command hang for cross node io and collections/cpu mapping.
493 config CAVIUM_ERRATUM_23154
494 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
497 The gicv3 of ThunderX requires a modified version for
498 reading the IAR status to ensure data synchronization
499 (access to icc_iar1_el1 is not sync'ed before and after).
503 config CAVIUM_ERRATUM_27456
504 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
507 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
508 instructions may cause the icache to become corrupted if it
509 contains data for a non-current ASID. The fix is to
510 invalidate the icache when changing the mm context.
514 config CAVIUM_ERRATUM_30115
515 bool "Cavium erratum 30115: Guest may disable interrupts in host"
518 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
519 1.2, and T83 Pass 1.0, KVM guest execution may disable
520 interrupts in host. Trapping both GICv3 group-0 and group-1
521 accesses sidesteps the issue.
525 config QCOM_FALKOR_ERRATUM_1003
526 bool "Falkor E1003: Incorrect translation due to ASID change"
529 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
530 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
531 in TTBR1_EL1, this situation only occurs in the entry trampoline and
532 then only for entries in the walk cache, since the leaf translation
533 is unchanged. Work around the erratum by invalidating the walk cache
534 entries for the trampoline before entering the kernel proper.
536 config QCOM_FALKOR_ERRATUM_1009
537 bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
540 On Falkor v1, the CPU may prematurely complete a DSB following a
541 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
542 one more time to fix the issue.
546 config QCOM_QDF2400_ERRATUM_0065
547 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
550 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
551 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
552 been indicated as 16Bytes (0xf), not 8Bytes (0x7).
556 config SOCIONEXT_SYNQUACER_PREITS
557 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
560 Socionext Synquacer SoCs implement a separate h/w block to generate
561 MSI doorbell writes with non-zero values for the device ID.
565 config HISILICON_ERRATUM_161600802
566 bool "Hip07 161600802: Erroneous redistributor VLPI base"
569 The HiSilicon Hip07 SoC usees the wrong redistributor base
570 when issued ITS commands such as VMOVP and VMAPP, and requires
571 a 128kB offset to be applied to the target address in this commands.
575 config QCOM_FALKOR_ERRATUM_E1041
576 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
579 Falkor CPU may speculatively fetch instructions from an improper
580 memory location when MMU translation is changed from SCTLR_ELn[M]=1
581 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
590 default ARM64_4K_PAGES
592 Page size (translation granule) configuration.
594 config ARM64_4K_PAGES
597 This feature enables 4KB pages support.
599 config ARM64_16K_PAGES
602 The system will use 16KB pages support. AArch32 emulation
603 requires applications compiled with 16K (or a multiple of 16K)
606 config ARM64_64K_PAGES
609 This feature enables 64KB pages support (4KB by default)
610 allowing only two levels of page tables and faster TLB
611 look-up. AArch32 emulation requires applications compiled
612 with 64K aligned segments.
617 prompt "Virtual address space size"
618 default ARM64_VA_BITS_39 if ARM64_4K_PAGES
619 default ARM64_VA_BITS_47 if ARM64_16K_PAGES
620 default ARM64_VA_BITS_42 if ARM64_64K_PAGES
622 Allows choosing one of multiple possible virtual address
623 space sizes. The level of translation table is determined by
624 a combination of page size and virtual address space size.
626 config ARM64_VA_BITS_36
627 bool "36-bit" if EXPERT
628 depends on ARM64_16K_PAGES
630 config ARM64_VA_BITS_39
632 depends on ARM64_4K_PAGES
634 config ARM64_VA_BITS_42
636 depends on ARM64_64K_PAGES
638 config ARM64_VA_BITS_47
640 depends on ARM64_16K_PAGES
642 config ARM64_VA_BITS_48
649 default 36 if ARM64_VA_BITS_36
650 default 39 if ARM64_VA_BITS_39
651 default 42 if ARM64_VA_BITS_42
652 default 47 if ARM64_VA_BITS_47
653 default 48 if ARM64_VA_BITS_48
656 prompt "Physical address space size"
657 default ARM64_PA_BITS_48
659 Choose the maximum physical address range that the kernel will
662 config ARM64_PA_BITS_48
665 config ARM64_PA_BITS_52
666 bool "52-bit (ARMv8.2)"
667 depends on ARM64_64K_PAGES
668 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
670 Enable support for a 52-bit physical address space, introduced as
671 part of the ARMv8.2-LPA extension.
673 With this enabled, the kernel will also continue to work on CPUs that
674 do not support ARMv8.2-LPA, but with some added memory overhead (and
675 minor performance overhead).
681 default 48 if ARM64_PA_BITS_48
682 default 52 if ARM64_PA_BITS_52
684 config CPU_BIG_ENDIAN
685 bool "Build big-endian kernel"
687 Say Y if you plan on running a kernel in big-endian mode.
690 bool "Multi-core scheduler support"
692 Multi-core scheduler support improves the CPU scheduler's decision
693 making when dealing with multi-core CPU chips at a cost of slightly
694 increased overhead in some places. If unsure say N here.
697 bool "SMT scheduler support"
699 Improves the CPU scheduler's decision making when dealing with
700 MultiThreading at a cost of slightly increased overhead in some
701 places. If unsure say N here.
704 int "Maximum number of CPUs (2-4096)"
706 # These have to remain sorted largest to smallest
710 bool "Support for hot-pluggable CPUs"
711 select GENERIC_IRQ_MIGRATION
713 Say Y here to experiment with turning CPUs off and on. CPUs
714 can be controlled through /sys/devices/system/cpu.
716 # Common NUMA Features
718 bool "Numa Memory Allocation and Scheduler Support"
719 select ACPI_NUMA if ACPI
722 Enable NUMA (Non Uniform Memory Access) support.
724 The kernel will try to allocate memory used by a CPU on the
725 local memory of the CPU and add some more
726 NUMA awareness to the kernel.
729 int "Maximum NUMA Nodes (as a power of 2)"
732 depends on NEED_MULTIPLE_NODES
734 Specify the maximum number of NUMA Nodes available on the target
735 system. Increases memory reserved to accommodate various tables.
737 config USE_PERCPU_NUMA_NODE_ID
741 config HAVE_SETUP_PER_CPU_AREA
745 config NEED_PER_CPU_EMBED_FIRST_CHUNK
753 source kernel/Kconfig.preempt
754 source kernel/Kconfig.hz
756 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
759 config ARCH_HAS_HOLES_MEMORYMODEL
760 def_bool y if SPARSEMEM
762 config ARCH_SPARSEMEM_ENABLE
764 select SPARSEMEM_VMEMMAP_ENABLE
766 config ARCH_SPARSEMEM_DEFAULT
767 def_bool ARCH_SPARSEMEM_ENABLE
769 config ARCH_SELECT_MEMORY_MODEL
770 def_bool ARCH_SPARSEMEM_ENABLE
772 config HAVE_ARCH_PFN_VALID
773 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
775 config HW_PERF_EVENTS
779 config SYS_SUPPORTS_HUGETLBFS
782 config ARCH_WANT_HUGE_PMD_SHARE
783 def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
785 config ARCH_HAS_CACHE_LINE_SIZE
791 bool "Enable seccomp to safely compute untrusted bytecode"
793 This kernel feature is useful for number crunching applications
794 that may need to compute untrusted bytecode during their
795 execution. By using pipes or other transports made available to
796 the process as file descriptors supporting the read/write
797 syscalls, it's possible to isolate those applications in
798 their own address space using seccomp. Once seccomp is
799 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
800 and the task is only allowed to execute a few safe syscalls
801 defined by each seccomp mode.
804 bool "Enable paravirtualization code"
806 This changes the kernel so it can modify itself when it is run
807 under a hypervisor, potentially improving performance significantly
808 over full virtualization.
810 config PARAVIRT_TIME_ACCOUNTING
811 bool "Paravirtual steal time accounting"
815 Select this option to enable fine granularity task steal time
816 accounting. Time spent executing other tasks in parallel with
817 the current vCPU is discounted from the vCPU power. To account for
818 that, there can be a small performance impact.
820 If in doubt, say N here.
823 depends on PM_SLEEP_SMP
825 bool "kexec system call"
827 kexec is a system call that implements the ability to shutdown your
828 current kernel, and to start another kernel. It is like a reboot
829 but it is independent of the system firmware. And like a reboot
830 you can start any kernel with it, not just Linux.
833 bool "Build kdump crash kernel"
835 Generate crash dump after being started by kexec. This should
836 be normally only set in special crash dump kernels which are
837 loaded in the main kernel with kexec-tools into a specially
838 reserved region and then later executed after a crash by
841 For more details see Documentation/kdump/kdump.txt
848 bool "Xen guest support on ARM64"
849 depends on ARM64 && OF
853 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
855 config FORCE_MAX_ZONEORDER
857 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
858 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
861 The kernel memory allocator divides physically contiguous memory
862 blocks into "zones", where each zone is a power of two number of
863 pages. This option selects the largest power of two that the kernel
864 keeps in the memory allocator. If you need to allocate very large
865 blocks of physically contiguous memory, then you may need to
868 This config option is actually maximum order plus one. For example,
869 a value of 11 means that the largest free memory block is 2^10 pages.
871 We make sure that we can allocate upto a HugePage size for each configuration.
873 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
875 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
876 4M allocations matching the default size used by generic code.
878 config UNMAP_KERNEL_AT_EL0
879 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
882 Speculation attacks against some high-performance processors can
883 be used to bypass MMU permission checks and leak kernel data to
884 userspace. This can be defended against by unmapping the kernel
885 when running in userspace, mapping it back in on exception entry
886 via a trampoline page in the vector table.
890 config HARDEN_BRANCH_PREDICTOR
891 bool "Harden the branch predictor against aliasing attacks" if EXPERT
894 Speculation attacks against some high-performance processors rely on
895 being able to manipulate the branch predictor for a victim context by
896 executing aliasing branches in the attacker context. Such attacks
897 can be partially mitigated against by clearing internal branch
898 predictor state and limiting the prediction logic in some situations.
900 This config option will take CPU-specific actions to harden the
901 branch predictor against aliasing attacks and may rely on specific
902 instruction sequences or control bits being set by the system
907 menuconfig ARMV8_DEPRECATED
908 bool "Emulate deprecated/obsolete ARMv8 instructions"
912 Legacy software support may require certain instructions
913 that have been deprecated or obsoleted in the architecture.
915 Enable this config to enable selective emulation of these
923 bool "Emulate SWP/SWPB instructions"
925 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
926 they are always undefined. Say Y here to enable software
927 emulation of these instructions for userspace using LDXR/STXR.
929 In some older versions of glibc [<=2.8] SWP is used during futex
930 trylock() operations with the assumption that the code will not
931 be preempted. This invalid assumption may be more likely to fail
932 with SWP emulation enabled, leading to deadlock of the user
935 NOTE: when accessing uncached shared regions, LDXR/STXR rely
936 on an external transaction monitoring block called a global
937 monitor to maintain update atomicity. If your system does not
938 implement a global monitor, this option can cause programs that
939 perform SWP operations to uncached memory to deadlock.
943 config CP15_BARRIER_EMULATION
944 bool "Emulate CP15 Barrier instructions"
946 The CP15 barrier instructions - CP15ISB, CP15DSB, and
947 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
948 strongly recommended to use the ISB, DSB, and DMB
949 instructions instead.
951 Say Y here to enable software emulation of these
952 instructions for AArch32 userspace code. When this option is
953 enabled, CP15 barrier usage is traced which can help
954 identify software that needs updating.
958 config SETEND_EMULATION
959 bool "Emulate SETEND instruction"
961 The SETEND instruction alters the data-endianness of the
962 AArch32 EL0, and is deprecated in ARMv8.
964 Say Y here to enable software emulation of the instruction
965 for AArch32 userspace code.
967 Note: All the cpus on the system must have mixed endian support at EL0
968 for this feature to be enabled. If a new CPU - which doesn't support mixed
969 endian - is hotplugged in after this feature has been enabled, there could
970 be unexpected results in the applications.
975 config ARM64_SW_TTBR0_PAN
976 bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
978 Enabling this option prevents the kernel from accessing
979 user-space memory directly by pointing TTBR0_EL1 to a reserved
980 zeroed area and reserved ASID. The user access routines
981 restore the valid TTBR0_EL1 temporarily.
983 menu "ARMv8.1 architectural features"
985 config ARM64_HW_AFDBM
986 bool "Support for hardware updates of the Access and Dirty page flags"
989 The ARMv8.1 architecture extensions introduce support for
990 hardware updates of the access and dirty information in page
991 table entries. When enabled in TCR_EL1 (HA and HD bits) on
992 capable processors, accesses to pages with PTE_AF cleared will
993 set this bit instead of raising an access flag fault.
994 Similarly, writes to read-only pages with the DBM bit set will
995 clear the read-only bit (AP[2]) instead of raising a
998 Kernels built with this configuration option enabled continue
999 to work on pre-ARMv8.1 hardware and the performance impact is
1000 minimal. If unsure, say Y.
1003 bool "Enable support for Privileged Access Never (PAN)"
1006 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1007 prevents the kernel or hypervisor from accessing user-space (EL0)
1010 Choosing this option will cause any unprotected (not using
1011 copy_to_user et al) memory access to fail with a permission fault.
1013 The feature is detected at runtime, and will remain as a 'nop'
1014 instruction if the cpu does not implement the feature.
1016 config ARM64_LSE_ATOMICS
1017 bool "Atomic instructions"
1019 As part of the Large System Extensions, ARMv8.1 introduces new
1020 atomic instructions that are designed specifically to scale in
1023 Say Y here to make use of these instructions for the in-kernel
1024 atomic routines. This incurs a small overhead on CPUs that do
1025 not support these instructions and requires the kernel to be
1026 built with binutils >= 2.25.
1029 bool "Enable support for Virtualization Host Extensions (VHE)"
1032 Virtualization Host Extensions (VHE) allow the kernel to run
1033 directly at EL2 (instead of EL1) on processors that support
1034 it. This leads to better performance for KVM, as they reduce
1035 the cost of the world switch.
1037 Selecting this option allows the VHE feature to be detected
1038 at runtime, and does not affect processors that do not
1039 implement this feature.
1043 menu "ARMv8.2 architectural features"
1046 bool "Enable support for User Access Override (UAO)"
1049 User Access Override (UAO; part of the ARMv8.2 Extensions)
1050 causes the 'unprivileged' variant of the load/store instructions to
1051 be overridden to be privileged.
1053 This option changes get_user() and friends to use the 'unprivileged'
1054 variant of the load/store instructions. This ensures that user-space
1055 really did have access to the supplied memory. When addr_limit is
1056 set to kernel memory the UAO bit will be set, allowing privileged
1057 access to kernel memory.
1059 Choosing this option will cause copy_to_user() et al to use user-space
1062 The feature is detected at runtime, the kernel will use the
1063 regular load/store instructions if the cpu does not implement the
1067 bool "Enable support for persistent memory"
1068 select ARCH_HAS_PMEM_API
1069 select ARCH_HAS_UACCESS_FLUSHCACHE
1071 Say Y to enable support for the persistent memory API based on the
1072 ARMv8.2 DCPoP feature.
1074 The feature is detected at runtime, and the kernel will use DC CVAC
1075 operations if DC CVAP is not supported (following the behaviour of
1076 DC CVAP itself if the system does not define a point of persistence).
1078 config ARM64_RAS_EXTN
1079 bool "Enable support for RAS CPU Extensions"
1082 CPUs that support the Reliability, Availability and Serviceability
1083 (RAS) Extensions, part of ARMv8.2 are able to track faults and
1084 errors, classify them and report them to software.
1086 On CPUs with these extensions system software can use additional
1087 barriers to determine if faults are pending and read the
1088 classification from a new set of registers.
1090 Selecting this feature will allow the kernel to use these barriers
1091 and access the new registers if the system supports the extension.
1092 Platform RAS features may additionally depend on firmware support.
1097 bool "ARM Scalable Vector Extension support"
1100 The Scalable Vector Extension (SVE) is an extension to the AArch64
1101 execution state which complements and extends the SIMD functionality
1102 of the base architecture to support much larger vectors and to enable
1103 additional vectorisation opportunities.
1105 To enable use of this extension on CPUs that implement it, say Y.
1107 config ARM64_MODULE_CMODEL_LARGE
1110 config ARM64_MODULE_PLTS
1112 select ARM64_MODULE_CMODEL_LARGE
1113 select HAVE_MOD_ARCH_SPECIFIC
1118 This builds the kernel as a Position Independent Executable (PIE),
1119 which retains all relocation metadata required to relocate the
1120 kernel binary at runtime to a different virtual address than the
1121 address it was linked at.
1122 Since AArch64 uses the RELA relocation format, this requires a
1123 relocation pass at runtime even if the kernel is loaded at the
1124 same address it was linked at.
1126 config RANDOMIZE_BASE
1127 bool "Randomize the address of the kernel image"
1128 select ARM64_MODULE_PLTS if MODULES
1131 Randomizes the virtual address at which the kernel image is
1132 loaded, as a security feature that deters exploit attempts
1133 relying on knowledge of the location of kernel internals.
1135 It is the bootloader's job to provide entropy, by passing a
1136 random u64 value in /chosen/kaslr-seed at kernel entry.
1138 When booting via the UEFI stub, it will invoke the firmware's
1139 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1140 to the kernel proper. In addition, it will randomise the physical
1141 location of the kernel Image as well.
1145 config RANDOMIZE_MODULE_REGION_FULL
1146 bool "Randomize the module region independently from the core kernel"
1147 depends on RANDOMIZE_BASE
1150 Randomizes the location of the module region without considering the
1151 location of the core kernel. This way, it is impossible for modules
1152 to leak information about the location of core kernel data structures
1153 but it does imply that function calls between modules and the core
1154 kernel will need to be resolved via veneers in the module PLT.
1156 When this option is not set, the module region will be randomized over
1157 a limited range that contains the [_stext, _etext] interval of the
1158 core kernel, so branch relocations are always in range.
1164 config ARM64_ACPI_PARKING_PROTOCOL
1165 bool "Enable support for the ARM64 ACPI parking protocol"
1168 Enable support for the ARM64 ACPI parking protocol. If disabled
1169 the kernel will not allow booting through the ARM64 ACPI parking
1170 protocol even if the corresponding data is present in the ACPI
1174 string "Default kernel command string"
1177 Provide a set of default command-line options at build time by
1178 entering them here. As a minimum, you should specify the the
1179 root device (e.g. root=/dev/nfs).
1181 config CMDLINE_FORCE
1182 bool "Always use the default kernel command string"
1184 Always use the default kernel command string, even if the boot
1185 loader passes other arguments to the kernel.
1186 This is useful if you cannot or don't want to change the
1187 command-line options your boot loader passes to the kernel.
1193 bool "UEFI runtime support"
1194 depends on OF && !CPU_BIG_ENDIAN
1195 depends on KERNEL_MODE_NEON
1198 select EFI_PARAMS_FROM_FDT
1199 select EFI_RUNTIME_WRAPPERS
1204 This option provides support for runtime services provided
1205 by UEFI firmware (such as non-volatile variables, realtime
1206 clock, and platform reset). A UEFI stub is also provided to
1207 allow the kernel to be booted as an EFI application. This
1208 is only useful on systems that have UEFI firmware.
1211 bool "Enable support for SMBIOS (DMI) tables"
1215 This enables SMBIOS/DMI feature for systems.
1217 This option is only useful on systems that have UEFI firmware.
1218 However, even with this option, the resultant kernel should
1219 continue to boot on existing non-UEFI platforms.
1223 menu "Userspace binary formats"
1225 source "fs/Kconfig.binfmt"
1228 bool "Kernel support for 32-bit EL0"
1229 depends on ARM64_4K_PAGES || EXPERT
1230 select COMPAT_BINFMT_ELF if BINFMT_ELF
1232 select OLD_SIGSUSPEND3
1233 select COMPAT_OLD_SIGACTION
1235 This option enables support for a 32-bit EL0 running under a 64-bit
1236 kernel at EL1. AArch32-specific components such as system calls,
1237 the user helper functions, VFP support and the ptrace interface are
1238 handled appropriately by the kernel.
1240 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1241 that you will only be able to execute AArch32 binaries that were compiled
1242 with page size aligned segments.
1244 If you want to execute 32-bit userspace applications, say Y.
1246 config SYSVIPC_COMPAT
1248 depends on COMPAT && SYSVIPC
1252 menu "Power management options"
1254 source "kernel/power/Kconfig"
1256 config ARCH_HIBERNATION_POSSIBLE
1260 config ARCH_HIBERNATION_HEADER
1262 depends on HIBERNATION
1264 config ARCH_SUSPEND_POSSIBLE
1269 menu "CPU Power Management"
1271 source "drivers/cpuidle/Kconfig"
1273 source "drivers/cpufreq/Kconfig"
1277 source "net/Kconfig"
1279 source "drivers/Kconfig"
1281 source "drivers/firmware/Kconfig"
1283 source "drivers/acpi/Kconfig"
1287 source "arch/arm64/kvm/Kconfig"
1289 source "arch/arm64/Kconfig.debug"
1291 source "security/Kconfig"
1293 source "crypto/Kconfig"
1295 source "arch/arm64/crypto/Kconfig"
1298 source "lib/Kconfig"