1 # SPDX-License-Identifier: GPL-2.0-only
4 select ACPI_CCA_REQUIRED if ACPI
5 select ACPI_GENERIC_GSI if ACPI
6 select ACPI_GTDT if ACPI
7 select ACPI_IORT if ACPI
8 select ACPI_REDUCED_HARDWARE_ONLY if ACPI
9 select ACPI_MCFG if (ACPI && PCI)
10 select ACPI_SPCR_TABLE if ACPI
11 select ACPI_PPTT if ACPI
12 select ARCH_HAS_DEBUG_WX
13 select ARCH_BINFMT_ELF_STATE
14 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
15 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
16 select ARCH_ENABLE_MEMORY_HOTPLUG
17 select ARCH_ENABLE_MEMORY_HOTREMOVE
18 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
19 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
20 select ARCH_HAS_CACHE_LINE_SIZE
21 select ARCH_HAS_DEBUG_VIRTUAL
22 select ARCH_HAS_DEBUG_VM_PGTABLE
23 select ARCH_HAS_DMA_PREP_COHERENT
24 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
25 select ARCH_HAS_FAST_MULTIPLIER
26 select ARCH_HAS_FORTIFY_SOURCE
27 select ARCH_HAS_GCOV_PROFILE_ALL
28 select ARCH_HAS_GIGANTIC_PAGE
30 select ARCH_HAS_KEEPINITRD
31 select ARCH_HAS_MEMBARRIER_SYNC_CORE
32 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
33 select ARCH_HAS_PTE_DEVMAP
34 select ARCH_HAS_PTE_SPECIAL
35 select ARCH_HAS_SETUP_DMA_OPS
36 select ARCH_HAS_SET_DIRECT_MAP
37 select ARCH_HAS_SET_MEMORY
39 select ARCH_HAS_STRICT_KERNEL_RWX
40 select ARCH_HAS_STRICT_MODULE_RWX
41 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
42 select ARCH_HAS_SYNC_DMA_FOR_CPU
43 select ARCH_HAS_SYSCALL_WRAPPER
44 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
45 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
46 select ARCH_HAS_ZONE_DMA_SET if EXPERT
47 select ARCH_HAVE_ELF_PROT
48 select ARCH_HAVE_NMI_SAFE_CMPXCHG
49 select ARCH_INLINE_READ_LOCK if !PREEMPTION
50 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
51 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
52 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
53 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
54 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
55 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
56 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
57 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
58 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
59 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
60 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
61 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
62 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
63 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
64 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
65 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
66 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
67 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
68 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
69 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
70 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
71 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
72 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
73 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
74 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
75 select ARCH_KEEP_MEMBLOCK
76 select ARCH_USE_CMPXCHG_LOCKREF
77 select ARCH_USE_GNU_PROPERTY
78 select ARCH_USE_MEMTEST
79 select ARCH_USE_QUEUED_RWLOCKS
80 select ARCH_USE_QUEUED_SPINLOCKS
81 select ARCH_USE_SYM_ANNOTATIONS
82 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
83 select ARCH_SUPPORTS_HUGETLBFS
84 select ARCH_SUPPORTS_MEMORY_FAILURE
85 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
86 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
87 select ARCH_SUPPORTS_LTO_CLANG_THIN
88 select ARCH_SUPPORTS_CFI_CLANG
89 select ARCH_SUPPORTS_ATOMIC_RMW
90 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
91 select ARCH_SUPPORTS_NUMA_BALANCING
92 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
93 select ARCH_WANT_DEFAULT_BPF_JIT
94 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
95 select ARCH_WANT_FRAME_POINTERS
96 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
97 select ARCH_WANT_LD_ORPHAN_WARN
98 select ARCH_WANTS_NO_INSTR
99 select ARCH_HAS_UBSAN_SANITIZE_ALL
101 select ARM_ARCH_TIMER
103 select AUDIT_ARCH_COMPAT_GENERIC
104 select ARM_GIC_V2M if PCI
106 select ARM_GIC_V3_ITS if PCI
108 select BUILDTIME_TABLE_SORT
109 select CLONE_BACKWARDS
111 select CPU_PM if (SUSPEND || CPU_IDLE)
113 select DCACHE_WORD_ACCESS
114 select DMA_DIRECT_REMAP
117 select GENERIC_ALLOCATOR
118 select GENERIC_ARCH_TOPOLOGY
119 select GENERIC_CLOCKEVENTS_BROADCAST
120 select GENERIC_CPU_AUTOPROBE
121 select GENERIC_CPU_VULNERABILITIES
122 select GENERIC_EARLY_IOREMAP
123 select GENERIC_IDLE_POLL_SETUP
124 select GENERIC_IRQ_IPI
125 select GENERIC_IRQ_PROBE
126 select GENERIC_IRQ_SHOW
127 select GENERIC_IRQ_SHOW_LEVEL
128 select GENERIC_LIB_DEVMEM_IS_ALLOWED
129 select GENERIC_PCI_IOMAP
130 select GENERIC_PTDUMP
131 select GENERIC_SCHED_CLOCK
132 select GENERIC_SMP_IDLE_THREAD
133 select GENERIC_TIME_VSYSCALL
134 select GENERIC_GETTIMEOFDAY
135 select GENERIC_VDSO_TIME_NS
136 select HARDIRQS_SW_RESEND
140 select HAVE_ACPI_APEI if (ACPI && EFI)
141 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
142 select HAVE_ARCH_AUDITSYSCALL
143 select HAVE_ARCH_BITREVERSE
144 select HAVE_ARCH_COMPILER_H
145 select HAVE_ARCH_HUGE_VMAP
146 select HAVE_ARCH_JUMP_LABEL
147 select HAVE_ARCH_JUMP_LABEL_RELATIVE
148 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
149 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
150 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
151 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
152 # Some instrumentation may be unsound, hence EXPERT
153 select HAVE_ARCH_KCSAN if EXPERT
154 select HAVE_ARCH_KFENCE
155 select HAVE_ARCH_KGDB
156 select HAVE_ARCH_MMAP_RND_BITS
157 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
158 select HAVE_ARCH_PREL32_RELOCATIONS
159 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
160 select HAVE_ARCH_SECCOMP_FILTER
161 select HAVE_ARCH_STACKLEAK
162 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
163 select HAVE_ARCH_TRACEHOOK
164 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
165 select HAVE_ARCH_VMAP_STACK
166 select HAVE_ARM_SMCCC
167 select HAVE_ASM_MODVERSIONS
169 select HAVE_C_RECORDMCOUNT
170 select HAVE_CMPXCHG_DOUBLE
171 select HAVE_CMPXCHG_LOCAL
172 select HAVE_CONTEXT_TRACKING
173 select HAVE_DEBUG_KMEMLEAK
174 select HAVE_DMA_CONTIGUOUS
175 select HAVE_DYNAMIC_FTRACE
176 select HAVE_DYNAMIC_FTRACE_WITH_REGS \
177 if $(cc-option,-fpatchable-function-entry=2)
178 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
179 if DYNAMIC_FTRACE_WITH_REGS
180 select HAVE_EFFICIENT_UNALIGNED_ACCESS
182 select HAVE_FTRACE_MCOUNT_RECORD
183 select HAVE_FUNCTION_TRACER
184 select HAVE_FUNCTION_ERROR_INJECTION
185 select HAVE_FUNCTION_GRAPH_TRACER
186 select HAVE_GCC_PLUGINS
187 select HAVE_HW_BREAKPOINT if PERF_EVENTS
188 select HAVE_IRQ_TIME_ACCOUNTING
191 select HAVE_PATA_PLATFORM
192 select HAVE_PERF_EVENTS
193 select HAVE_PERF_REGS
194 select HAVE_PERF_USER_STACK_DUMP
195 select HAVE_REGS_AND_STACK_ACCESS_API
196 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
197 select HAVE_FUNCTION_ARG_ACCESS_API
198 select MMU_GATHER_RCU_TABLE_FREE
200 select HAVE_STACKPROTECTOR
201 select HAVE_SYSCALL_TRACEPOINTS
203 select HAVE_KRETPROBES
204 select HAVE_GENERIC_VDSO
205 select IOMMU_DMA if IOMMU_SUPPORT
207 select IRQ_FORCED_THREADING
208 select KASAN_VMALLOC if KASAN_GENERIC
209 select MODULES_USE_ELF_RELA
210 select NEED_DMA_MAP_STATE
211 select NEED_SG_DMA_LENGTH
213 select OF_EARLY_FLATTREE
214 select PCI_DOMAINS_GENERIC if PCI
215 select PCI_ECAM if (ACPI && PCI)
216 select PCI_SYSCALL if PCI
221 select SYSCTL_EXCEPTION_TRACE
222 select THREAD_INFO_IN_TASK
223 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
224 select TRACE_IRQFLAGS_SUPPORT
226 ARM 64-bit (AArch64) Linux support.
234 config ARM64_PAGE_SHIFT
236 default 16 if ARM64_64K_PAGES
237 default 14 if ARM64_16K_PAGES
240 config ARM64_CONT_PTE_SHIFT
242 default 5 if ARM64_64K_PAGES
243 default 7 if ARM64_16K_PAGES
246 config ARM64_CONT_PMD_SHIFT
248 default 5 if ARM64_64K_PAGES
249 default 5 if ARM64_16K_PAGES
252 config ARCH_MMAP_RND_BITS_MIN
253 default 14 if ARM64_64K_PAGES
254 default 16 if ARM64_16K_PAGES
257 # max bits determined by the following formula:
258 # VA_BITS - PAGE_SHIFT - 3
259 config ARCH_MMAP_RND_BITS_MAX
260 default 19 if ARM64_VA_BITS=36
261 default 24 if ARM64_VA_BITS=39
262 default 27 if ARM64_VA_BITS=42
263 default 30 if ARM64_VA_BITS=47
264 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
265 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
266 default 33 if ARM64_VA_BITS=48
267 default 14 if ARM64_64K_PAGES
268 default 16 if ARM64_16K_PAGES
271 config ARCH_MMAP_RND_COMPAT_BITS_MIN
272 default 7 if ARM64_64K_PAGES
273 default 9 if ARM64_16K_PAGES
276 config ARCH_MMAP_RND_COMPAT_BITS_MAX
282 config STACKTRACE_SUPPORT
285 config ILLEGAL_POINTER_VALUE
287 default 0xdead000000000000
289 config LOCKDEP_SUPPORT
296 config GENERIC_BUG_RELATIVE_POINTERS
298 depends on GENERIC_BUG
300 config GENERIC_HWEIGHT
306 config GENERIC_CALIBRATE_DELAY
309 config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
315 config KERNEL_MODE_NEON
318 config FIX_EARLYCON_MEM
321 config PGTABLE_LEVELS
323 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
324 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
325 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
326 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
327 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
328 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
330 config ARCH_SUPPORTS_UPROBES
333 config ARCH_PROC_KCORE_TEXT
336 config BROKEN_GAS_INST
337 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
339 config KASAN_SHADOW_OFFSET
341 depends on KASAN_GENERIC || KASAN_SW_TAGS
342 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
343 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
344 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
345 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
346 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
347 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
348 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
349 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
350 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
351 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
352 default 0xffffffffffffffff
354 source "arch/arm64/Kconfig.platforms"
356 menu "Kernel Features"
358 menu "ARM errata workarounds via the alternatives framework"
360 config ARM64_WORKAROUND_CLEAN_CACHE
363 config ARM64_ERRATUM_826319
364 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
366 select ARM64_WORKAROUND_CLEAN_CACHE
368 This option adds an alternative code sequence to work around ARM
369 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
370 AXI master interface and an L2 cache.
372 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
373 and is unable to accept a certain write via this interface, it will
374 not progress on read data presented on the read data channel and the
377 The workaround promotes data cache clean instructions to
378 data cache clean-and-invalidate.
379 Please note that this does not necessarily enable the workaround,
380 as it depends on the alternative framework, which will only patch
381 the kernel if an affected CPU is detected.
385 config ARM64_ERRATUM_827319
386 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
388 select ARM64_WORKAROUND_CLEAN_CACHE
390 This option adds an alternative code sequence to work around ARM
391 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
392 master interface and an L2 cache.
394 Under certain conditions this erratum can cause a clean line eviction
395 to occur at the same time as another transaction to the same address
396 on the AMBA 5 CHI interface, which can cause data corruption if the
397 interconnect reorders the two transactions.
399 The workaround promotes data cache clean instructions to
400 data cache clean-and-invalidate.
401 Please note that this does not necessarily enable the workaround,
402 as it depends on the alternative framework, which will only patch
403 the kernel if an affected CPU is detected.
407 config ARM64_ERRATUM_824069
408 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
410 select ARM64_WORKAROUND_CLEAN_CACHE
412 This option adds an alternative code sequence to work around ARM
413 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
414 to a coherent interconnect.
416 If a Cortex-A53 processor is executing a store or prefetch for
417 write instruction at the same time as a processor in another
418 cluster is executing a cache maintenance operation to the same
419 address, then this erratum might cause a clean cache line to be
420 incorrectly marked as dirty.
422 The workaround promotes data cache clean instructions to
423 data cache clean-and-invalidate.
424 Please note that this option does not necessarily enable the
425 workaround, as it depends on the alternative framework, which will
426 only patch the kernel if an affected CPU is detected.
430 config ARM64_ERRATUM_819472
431 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
433 select ARM64_WORKAROUND_CLEAN_CACHE
435 This option adds an alternative code sequence to work around ARM
436 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
437 present when it is connected to a coherent interconnect.
439 If the processor is executing a load and store exclusive sequence at
440 the same time as a processor in another cluster is executing a cache
441 maintenance operation to the same address, then this erratum might
442 cause data corruption.
444 The workaround promotes data cache clean instructions to
445 data cache clean-and-invalidate.
446 Please note that this does not necessarily enable the workaround,
447 as it depends on the alternative framework, which will only patch
448 the kernel if an affected CPU is detected.
452 config ARM64_ERRATUM_832075
453 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
456 This option adds an alternative code sequence to work around ARM
457 erratum 832075 on Cortex-A57 parts up to r1p2.
459 Affected Cortex-A57 parts might deadlock when exclusive load/store
460 instructions to Write-Back memory are mixed with Device loads.
462 The workaround is to promote device loads to use Load-Acquire
464 Please note that this does not necessarily enable the workaround,
465 as it depends on the alternative framework, which will only patch
466 the kernel if an affected CPU is detected.
470 config ARM64_ERRATUM_834220
471 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
475 This option adds an alternative code sequence to work around ARM
476 erratum 834220 on Cortex-A57 parts up to r1p2.
478 Affected Cortex-A57 parts might report a Stage 2 translation
479 fault as the result of a Stage 1 fault for load crossing a
480 page boundary when there is a permission or device memory
481 alignment fault at Stage 1 and a translation fault at Stage 2.
483 The workaround is to verify that the Stage 1 translation
484 doesn't generate a fault before handling the Stage 2 fault.
485 Please note that this does not necessarily enable the workaround,
486 as it depends on the alternative framework, which will only patch
487 the kernel if an affected CPU is detected.
491 config ARM64_ERRATUM_845719
492 bool "Cortex-A53: 845719: a load might read incorrect data"
496 This option adds an alternative code sequence to work around ARM
497 erratum 845719 on Cortex-A53 parts up to r0p4.
499 When running a compat (AArch32) userspace on an affected Cortex-A53
500 part, a load at EL0 from a virtual address that matches the bottom 32
501 bits of the virtual address used by a recent load at (AArch64) EL1
502 might return incorrect data.
504 The workaround is to write the contextidr_el1 register on exception
505 return to a 32-bit task.
506 Please note that this does not necessarily enable the workaround,
507 as it depends on the alternative framework, which will only patch
508 the kernel if an affected CPU is detected.
512 config ARM64_ERRATUM_843419
513 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
515 select ARM64_MODULE_PLTS if MODULES
517 This option links the kernel with '--fix-cortex-a53-843419' and
518 enables PLT support to replace certain ADRP instructions, which can
519 cause subsequent memory accesses to use an incorrect address on
520 Cortex-A53 parts up to r0p4.
524 config ARM64_LD_HAS_FIX_ERRATUM_843419
525 def_bool $(ld-option,--fix-cortex-a53-843419)
527 config ARM64_ERRATUM_1024718
528 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
531 This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
533 Affected Cortex-A55 cores (all revisions) could cause incorrect
534 update of the hardware dirty bit when the DBM/AP bits are updated
535 without a break-before-make. The workaround is to disable the usage
536 of hardware DBM locally on the affected cores. CPUs not affected by
537 this erratum will continue to use the feature.
541 config ARM64_ERRATUM_1418040
542 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
546 This option adds a workaround for ARM Cortex-A76/Neoverse-N1
547 errata 1188873 and 1418040.
549 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
550 cause register corruption when accessing the timer registers
551 from AArch32 userspace.
555 config ARM64_WORKAROUND_SPECULATIVE_AT
558 config ARM64_ERRATUM_1165522
559 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
561 select ARM64_WORKAROUND_SPECULATIVE_AT
563 This option adds a workaround for ARM Cortex-A76 erratum 1165522.
565 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
566 corrupted TLBs by speculating an AT instruction during a guest
571 config ARM64_ERRATUM_1319367
572 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
574 select ARM64_WORKAROUND_SPECULATIVE_AT
576 This option adds work arounds for ARM Cortex-A57 erratum 1319537
577 and A72 erratum 1319367
579 Cortex-A57 and A72 cores could end-up with corrupted TLBs by
580 speculating an AT instruction during a guest context switch.
584 config ARM64_ERRATUM_1530923
585 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
587 select ARM64_WORKAROUND_SPECULATIVE_AT
589 This option adds a workaround for ARM Cortex-A55 erratum 1530923.
591 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
592 corrupted TLBs by speculating an AT instruction during a guest
597 config ARM64_WORKAROUND_REPEAT_TLBI
600 config ARM64_ERRATUM_1286807
601 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
603 select ARM64_WORKAROUND_REPEAT_TLBI
605 This option adds a workaround for ARM Cortex-A76 erratum 1286807.
607 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
608 address for a cacheable mapping of a location is being
609 accessed by a core while another core is remapping the virtual
610 address to a new physical page using the recommended
611 break-before-make sequence, then under very rare circumstances
612 TLBI+DSB completes before a read using the translation being
613 invalidated has been observed by other observers. The
614 workaround repeats the TLBI+DSB operation.
616 config ARM64_ERRATUM_1463225
617 bool "Cortex-A76: Software Step might prevent interrupt recognition"
620 This option adds a workaround for Arm Cortex-A76 erratum 1463225.
622 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
623 of a system call instruction (SVC) can prevent recognition of
624 subsequent interrupts when software stepping is disabled in the
625 exception handler of the system call and either kernel debugging
626 is enabled or VHE is in use.
628 Work around the erratum by triggering a dummy step exception
629 when handling a system call from a task that is being stepped
630 in a VHE configuration of the kernel.
634 config ARM64_ERRATUM_1542419
635 bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
638 This option adds a workaround for ARM Neoverse-N1 erratum
641 Affected Neoverse-N1 cores could execute a stale instruction when
642 modified by another CPU. The workaround depends on a firmware
645 Workaround the issue by hiding the DIC feature from EL0. This
646 forces user-space to perform cache maintenance.
650 config ARM64_ERRATUM_1508412
651 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
654 This option adds a workaround for Arm Cortex-A77 erratum 1508412.
656 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
657 of a store-exclusive or read of PAR_EL1 and a load with device or
658 non-cacheable memory attributes. The workaround depends on a firmware
661 KVM guests must also have the workaround implemented or they can
664 Work around the issue by inserting DMB SY barriers around PAR_EL1
665 register reads and warning KVM users. The DMB barrier is sufficient
666 to prevent a speculative PAR_EL1 read.
670 config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
673 config ARM64_ERRATUM_2051678
674 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
676 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
677 Affected Coretex-A510 might not respect the ordering rules for
678 hardware update of the page table's dirty bit. The workaround
679 is to not enable the feature on affected CPUs.
683 config ARM64_ERRATUM_2119858
684 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
686 depends on CORESIGHT_TRBE
687 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
689 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
691 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
692 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
693 the event of a WRAP event.
695 Work around the issue by always making sure we move the TRBPTR_EL1 by
696 256 bytes before enabling the buffer and filling the first 256 bytes of
697 the buffer with ETM ignore packets upon disabling.
701 config ARM64_ERRATUM_2139208
702 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
704 depends on CORESIGHT_TRBE
705 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
707 This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
709 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
710 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
711 the event of a WRAP event.
713 Work around the issue by always making sure we move the TRBPTR_EL1 by
714 256 bytes before enabling the buffer and filling the first 256 bytes of
715 the buffer with ETM ignore packets upon disabling.
719 config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
722 config ARM64_ERRATUM_2054223
723 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
725 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
727 Enable workaround for ARM Cortex-A710 erratum 2054223
729 Affected cores may fail to flush the trace data on a TSB instruction, when
730 the PE is in trace prohibited state. This will cause losing a few bytes
733 Workaround is to issue two TSB consecutively on affected cores.
737 config ARM64_ERRATUM_2067961
738 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
740 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
742 Enable workaround for ARM Neoverse-N2 erratum 2067961
744 Affected cores may fail to flush the trace data on a TSB instruction, when
745 the PE is in trace prohibited state. This will cause losing a few bytes
748 Workaround is to issue two TSB consecutively on affected cores.
752 config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
755 config ARM64_ERRATUM_2253138
756 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
757 depends on CORESIGHT_TRBE
759 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
761 This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
763 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
764 for TRBE. Under some conditions, the TRBE might generate a write to the next
765 virtually addressed page following the last page of the TRBE address space
766 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
768 Work around this in the driver by always making sure that there is a
769 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
773 config ARM64_ERRATUM_2224489
774 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
775 depends on CORESIGHT_TRBE
777 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
779 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
781 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
782 for TRBE. Under some conditions, the TRBE might generate a write to the next
783 virtually addressed page following the last page of the TRBE address space
784 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
786 Work around this in the driver by always making sure that there is a
787 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
791 config ARM64_ERRATUM_2064142
792 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
793 depends on COMPILE_TEST # Until the CoreSight TRBE driver changes are in
796 This option adds the workaround for ARM Cortex-A510 erratum 2064142.
798 Affected Cortex-A510 core might fail to write into system registers after the
799 TRBE has been disabled. Under some conditions after the TRBE has been disabled
800 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
801 and TRBTRG_EL1 will be ignored and will not be effected.
803 Work around this in the driver by executing TSB CSYNC and DSB after collection
804 is stopped and before performing a system register write to one of the affected
809 config ARM64_ERRATUM_2038923
810 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
811 depends on COMPILE_TEST # Until the CoreSight TRBE driver changes are in
814 This option adds the workaround for ARM Cortex-A510 erratum 2038923.
816 Affected Cortex-A510 core might cause an inconsistent view on whether trace is
817 prohibited within the CPU. As a result, the trace buffer or trace buffer state
818 might be corrupted. This happens after TRBE buffer has been enabled by setting
819 TRBLIMITR_EL1.E, followed by just a single context synchronization event before
820 execution changes from a context, in which trace is prohibited to one where it
821 isn't, or vice versa. In these mentioned conditions, the view of whether trace
822 is prohibited is inconsistent between parts of the CPU, and the trace buffer or
823 the trace buffer state might be corrupted.
825 Work around this in the driver by preventing an inconsistent view of whether the
826 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
827 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
828 two ISB instructions if no ERET is to take place.
832 config ARM64_ERRATUM_1902691
833 bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
834 depends on COMPILE_TEST # Until the CoreSight TRBE driver changes are in
837 This option adds the workaround for ARM Cortex-A510 erratum 1902691.
839 Affected Cortex-A510 core might cause trace data corruption, when being written
840 into the memory. Effectively TRBE is broken and hence cannot be used to capture
843 Work around this problem in the driver by just preventing TRBE initialization on
844 affected cpus. The firmware must have disabled the access to TRBE for the kernel
845 on such implementations. This will cover the kernel for any firmware that doesn't
850 config CAVIUM_ERRATUM_22375
851 bool "Cavium erratum 22375, 24313"
854 Enable workaround for errata 22375 and 24313.
856 This implements two gicv3-its errata workarounds for ThunderX. Both
857 with a small impact affecting only ITS table allocation.
859 erratum 22375: only alloc 8MB table size
860 erratum 24313: ignore memory access type
862 The fixes are in ITS initialization and basically ignore memory access
863 type and table size provided by the TYPER and BASER registers.
867 config CAVIUM_ERRATUM_23144
868 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
872 ITS SYNC command hang for cross node io and collections/cpu mapping.
876 config CAVIUM_ERRATUM_23154
877 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
880 The gicv3 of ThunderX requires a modified version for
881 reading the IAR status to ensure data synchronization
882 (access to icc_iar1_el1 is not sync'ed before and after).
886 config CAVIUM_ERRATUM_27456
887 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
890 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
891 instructions may cause the icache to become corrupted if it
892 contains data for a non-current ASID. The fix is to
893 invalidate the icache when changing the mm context.
897 config CAVIUM_ERRATUM_30115
898 bool "Cavium erratum 30115: Guest may disable interrupts in host"
901 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
902 1.2, and T83 Pass 1.0, KVM guest execution may disable
903 interrupts in host. Trapping both GICv3 group-0 and group-1
904 accesses sidesteps the issue.
908 config CAVIUM_TX2_ERRATUM_219
909 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
912 On Cavium ThunderX2, a load, store or prefetch instruction between a
913 TTBR update and the corresponding context synchronizing operation can
914 cause a spurious Data Abort to be delivered to any hardware thread in
917 Work around the issue by avoiding the problematic code sequence and
918 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
919 trap handler performs the corresponding register access, skips the
920 instruction and ensures context synchronization by virtue of the
925 config FUJITSU_ERRATUM_010001
926 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
929 This option adds a workaround for Fujitsu-A64FX erratum E#010001.
930 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
931 accesses may cause undefined fault (Data abort, DFSC=0b111111).
932 This fault occurs under a specific hardware condition when a
933 load/store instruction performs an address translation using:
934 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1.
935 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1.
936 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1.
937 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1.
939 The workaround is to ensure these bits are clear in TCR_ELx.
940 The workaround only affects the Fujitsu-A64FX.
944 config HISILICON_ERRATUM_161600802
945 bool "Hip07 161600802: Erroneous redistributor VLPI base"
948 The HiSilicon Hip07 SoC uses the wrong redistributor base
949 when issued ITS commands such as VMOVP and VMAPP, and requires
950 a 128kB offset to be applied to the target address in this commands.
954 config QCOM_FALKOR_ERRATUM_1003
955 bool "Falkor E1003: Incorrect translation due to ASID change"
958 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
959 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
960 in TTBR1_EL1, this situation only occurs in the entry trampoline and
961 then only for entries in the walk cache, since the leaf translation
962 is unchanged. Work around the erratum by invalidating the walk cache
963 entries for the trampoline before entering the kernel proper.
965 config QCOM_FALKOR_ERRATUM_1009
966 bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
968 select ARM64_WORKAROUND_REPEAT_TLBI
970 On Falkor v1, the CPU may prematurely complete a DSB following a
971 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
972 one more time to fix the issue.
976 config QCOM_QDF2400_ERRATUM_0065
977 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
980 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
981 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
982 been indicated as 16Bytes (0xf), not 8Bytes (0x7).
986 config QCOM_FALKOR_ERRATUM_E1041
987 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
990 Falkor CPU may speculatively fetch instructions from an improper
991 memory location when MMU translation is changed from SCTLR_ELn[M]=1
992 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
996 config NVIDIA_CARMEL_CNP_ERRATUM
997 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1000 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1001 invalidate shared TLB entries installed by a different core, as it would
1002 on standard ARM cores.
1006 config SOCIONEXT_SYNQUACER_PREITS
1007 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1010 Socionext Synquacer SoCs implement a separate h/w block to generate
1011 MSI doorbell writes with non-zero values for the device ID.
1020 default ARM64_4K_PAGES
1022 Page size (translation granule) configuration.
1024 config ARM64_4K_PAGES
1027 This feature enables 4KB pages support.
1029 config ARM64_16K_PAGES
1032 The system will use 16KB pages support. AArch32 emulation
1033 requires applications compiled with 16K (or a multiple of 16K)
1036 config ARM64_64K_PAGES
1039 This feature enables 64KB pages support (4KB by default)
1040 allowing only two levels of page tables and faster TLB
1041 look-up. AArch32 emulation requires applications compiled
1042 with 64K aligned segments.
1047 prompt "Virtual address space size"
1048 default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1049 default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1050 default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1052 Allows choosing one of multiple possible virtual address
1053 space sizes. The level of translation table is determined by
1054 a combination of page size and virtual address space size.
1056 config ARM64_VA_BITS_36
1057 bool "36-bit" if EXPERT
1058 depends on ARM64_16K_PAGES
1060 config ARM64_VA_BITS_39
1062 depends on ARM64_4K_PAGES
1064 config ARM64_VA_BITS_42
1066 depends on ARM64_64K_PAGES
1068 config ARM64_VA_BITS_47
1070 depends on ARM64_16K_PAGES
1072 config ARM64_VA_BITS_48
1075 config ARM64_VA_BITS_52
1077 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1079 Enable 52-bit virtual addressing for userspace when explicitly
1080 requested via a hint to mmap(). The kernel will also use 52-bit
1081 virtual addresses for its own mappings (provided HW support for
1082 this feature is available, otherwise it reverts to 48-bit).
1084 NOTE: Enabling 52-bit virtual addressing in conjunction with
1085 ARMv8.3 Pointer Authentication will result in the PAC being
1086 reduced from 7 bits to 3 bits, which may have a significant
1087 impact on its susceptibility to brute-force attacks.
1089 If unsure, select 48-bit virtual addressing instead.
1093 config ARM64_FORCE_52BIT
1094 bool "Force 52-bit virtual addresses for userspace"
1095 depends on ARM64_VA_BITS_52 && EXPERT
1097 For systems with 52-bit userspace VAs enabled, the kernel will attempt
1098 to maintain compatibility with older software by providing 48-bit VAs
1099 unless a hint is supplied to mmap.
1101 This configuration option disables the 48-bit compatibility logic, and
1102 forces all userspace addresses to be 52-bit on HW that supports it. One
1103 should only enable this configuration option for stress testing userspace
1104 memory management code. If unsure say N here.
1106 config ARM64_VA_BITS
1108 default 36 if ARM64_VA_BITS_36
1109 default 39 if ARM64_VA_BITS_39
1110 default 42 if ARM64_VA_BITS_42
1111 default 47 if ARM64_VA_BITS_47
1112 default 48 if ARM64_VA_BITS_48
1113 default 52 if ARM64_VA_BITS_52
1116 prompt "Physical address space size"
1117 default ARM64_PA_BITS_48
1119 Choose the maximum physical address range that the kernel will
1122 config ARM64_PA_BITS_48
1125 config ARM64_PA_BITS_52
1126 bool "52-bit (ARMv8.2)"
1127 depends on ARM64_64K_PAGES
1128 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1130 Enable support for a 52-bit physical address space, introduced as
1131 part of the ARMv8.2-LPA extension.
1133 With this enabled, the kernel will also continue to work on CPUs that
1134 do not support ARMv8.2-LPA, but with some added memory overhead (and
1135 minor performance overhead).
1139 config ARM64_PA_BITS
1141 default 48 if ARM64_PA_BITS_48
1142 default 52 if ARM64_PA_BITS_52
1146 default CPU_LITTLE_ENDIAN
1148 Select the endianness of data accesses performed by the CPU. Userspace
1149 applications will need to be compiled and linked for the endianness
1150 that is selected here.
1152 config CPU_BIG_ENDIAN
1153 bool "Build big-endian kernel"
1154 depends on !LD_IS_LLD || LLD_VERSION >= 130000
1156 Say Y if you plan on running a kernel with a big-endian userspace.
1158 config CPU_LITTLE_ENDIAN
1159 bool "Build little-endian kernel"
1161 Say Y if you plan on running a kernel with a little-endian userspace.
1162 This is usually the case for distributions targeting arm64.
1167 bool "Multi-core scheduler support"
1169 Multi-core scheduler support improves the CPU scheduler's decision
1170 making when dealing with multi-core CPU chips at a cost of slightly
1171 increased overhead in some places. If unsure say N here.
1173 config SCHED_CLUSTER
1174 bool "Cluster scheduler support"
1176 Cluster scheduler support improves the CPU scheduler's decision
1177 making when dealing with machines that have clusters of CPUs.
1178 Cluster usually means a couple of CPUs which are placed closely
1179 by sharing mid-level caches, last-level cache tags or internal
1183 bool "SMT scheduler support"
1185 Improves the CPU scheduler's decision making when dealing with
1186 MultiThreading at a cost of slightly increased overhead in some
1187 places. If unsure say N here.
1190 int "Maximum number of CPUs (2-4096)"
1195 bool "Support for hot-pluggable CPUs"
1196 select GENERIC_IRQ_MIGRATION
1198 Say Y here to experiment with turning CPUs off and on. CPUs
1199 can be controlled through /sys/devices/system/cpu.
1201 # Common NUMA Features
1203 bool "NUMA Memory Allocation and Scheduler Support"
1204 select GENERIC_ARCH_NUMA
1205 select ACPI_NUMA if ACPI
1207 select HAVE_SETUP_PER_CPU_AREA
1208 select NEED_PER_CPU_EMBED_FIRST_CHUNK
1209 select NEED_PER_CPU_PAGE_FIRST_CHUNK
1210 select USE_PERCPU_NUMA_NODE_ID
1212 Enable NUMA (Non-Uniform Memory Access) support.
1214 The kernel will try to allocate memory used by a CPU on the
1215 local memory of the CPU and add some more
1216 NUMA awareness to the kernel.
1219 int "Maximum NUMA Nodes (as a power of 2)"
1224 Specify the maximum number of NUMA Nodes available on the target
1225 system. Increases memory reserved to accommodate various tables.
1227 source "kernel/Kconfig.hz"
1229 config ARCH_SPARSEMEM_ENABLE
1231 select SPARSEMEM_VMEMMAP_ENABLE
1232 select SPARSEMEM_VMEMMAP
1234 config HW_PERF_EVENTS
1238 config ARCH_HAS_FILTER_PGPROT
1241 # Supported by clang >= 7.0
1242 config CC_HAVE_SHADOW_CALL_STACK
1243 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1246 bool "Enable paravirtualization code"
1248 This changes the kernel so it can modify itself when it is run
1249 under a hypervisor, potentially improving performance significantly
1250 over full virtualization.
1252 config PARAVIRT_TIME_ACCOUNTING
1253 bool "Paravirtual steal time accounting"
1256 Select this option to enable fine granularity task steal time
1257 accounting. Time spent executing other tasks in parallel with
1258 the current vCPU is discounted from the vCPU power. To account for
1259 that, there can be a small performance impact.
1261 If in doubt, say N here.
1264 depends on PM_SLEEP_SMP
1266 bool "kexec system call"
1268 kexec is a system call that implements the ability to shutdown your
1269 current kernel, and to start another kernel. It is like a reboot
1270 but it is independent of the system firmware. And like a reboot
1271 you can start any kernel with it, not just Linux.
1274 bool "kexec file based system call"
1276 select HAVE_IMA_KEXEC if IMA
1278 This is new version of kexec system call. This system call is
1279 file based and takes file descriptors as system call argument
1280 for kernel and initramfs as opposed to list of segments as
1281 accepted by previous system call.
1284 bool "Verify kernel signature during kexec_file_load() syscall"
1285 depends on KEXEC_FILE
1287 Select this option to verify a signature with loaded kernel
1288 image. If configured, any attempt of loading a image without
1289 valid signature will fail.
1291 In addition to that option, you need to enable signature
1292 verification for the corresponding kernel image type being
1293 loaded in order for this to work.
1295 config KEXEC_IMAGE_VERIFY_SIG
1296 bool "Enable Image signature verification support"
1298 depends on KEXEC_SIG
1299 depends on EFI && SIGNED_PE_FILE_VERIFICATION
1301 Enable Image signature verification support.
1303 comment "Support for PE file signature verification disabled"
1304 depends on KEXEC_SIG
1305 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
1308 bool "Build kdump crash kernel"
1310 Generate crash dump after being started by kexec. This should
1311 be normally only set in special crash dump kernels which are
1312 loaded in the main kernel with kexec-tools into a specially
1313 reserved region and then later executed after a crash by
1316 For more details see Documentation/admin-guide/kdump/kdump.rst
1320 depends on HIBERNATION || KEXEC_CORE
1327 bool "Xen guest support on ARM64"
1328 depends on ARM64 && OF
1332 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1334 config FORCE_MAX_ZONEORDER
1336 default "14" if ARM64_64K_PAGES
1337 default "12" if ARM64_16K_PAGES
1340 The kernel memory allocator divides physically contiguous memory
1341 blocks into "zones", where each zone is a power of two number of
1342 pages. This option selects the largest power of two that the kernel
1343 keeps in the memory allocator. If you need to allocate very large
1344 blocks of physically contiguous memory, then you may need to
1345 increase this value.
1347 This config option is actually maximum order plus one. For example,
1348 a value of 11 means that the largest free memory block is 2^10 pages.
1350 We make sure that we can allocate upto a HugePage size for each configuration.
1352 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1354 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1355 4M allocations matching the default size used by generic code.
1357 config UNMAP_KERNEL_AT_EL0
1358 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1361 Speculation attacks against some high-performance processors can
1362 be used to bypass MMU permission checks and leak kernel data to
1363 userspace. This can be defended against by unmapping the kernel
1364 when running in userspace, mapping it back in on exception entry
1365 via a trampoline page in the vector table.
1369 config RODATA_FULL_DEFAULT_ENABLED
1370 bool "Apply r/o permissions of VM areas also to their linear aliases"
1373 Apply read-only attributes of VM areas to the linear alias of
1374 the backing pages as well. This prevents code or read-only data
1375 from being modified (inadvertently or intentionally) via another
1376 mapping of the same memory page. This additional enhancement can
1377 be turned off at runtime by passing rodata=[off|on] (and turned on
1378 with rodata=full if this option is set to 'n')
1380 This requires the linear region to be mapped down to pages,
1381 which may adversely affect performance in some cases.
1383 config ARM64_SW_TTBR0_PAN
1384 bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1386 Enabling this option prevents the kernel from accessing
1387 user-space memory directly by pointing TTBR0_EL1 to a reserved
1388 zeroed area and reserved ASID. The user access routines
1389 restore the valid TTBR0_EL1 temporarily.
1391 config ARM64_TAGGED_ADDR_ABI
1392 bool "Enable the tagged user addresses syscall ABI"
1395 When this option is enabled, user applications can opt in to a
1396 relaxed ABI via prctl() allowing tagged addresses to be passed
1397 to system calls as pointer arguments. For details, see
1398 Documentation/arm64/tagged-address-abi.rst.
1401 bool "Kernel support for 32-bit EL0"
1402 depends on ARM64_4K_PAGES || EXPERT
1404 select OLD_SIGSUSPEND3
1405 select COMPAT_OLD_SIGACTION
1407 This option enables support for a 32-bit EL0 running under a 64-bit
1408 kernel at EL1. AArch32-specific components such as system calls,
1409 the user helper functions, VFP support and the ptrace interface are
1410 handled appropriately by the kernel.
1412 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1413 that you will only be able to execute AArch32 binaries that were compiled
1414 with page size aligned segments.
1416 If you want to execute 32-bit userspace applications, say Y.
1420 config KUSER_HELPERS
1421 bool "Enable kuser helpers page for 32-bit applications"
1424 Warning: disabling this option may break 32-bit user programs.
1426 Provide kuser helpers to compat tasks. The kernel provides
1427 helper code to userspace in read only form at a fixed location
1428 to allow userspace to be independent of the CPU type fitted to
1429 the system. This permits binaries to be run on ARMv4 through
1430 to ARMv8 without modification.
1432 See Documentation/arm/kernel_user_helpers.rst for details.
1434 However, the fixed address nature of these helpers can be used
1435 by ROP (return orientated programming) authors when creating
1438 If all of the binaries and libraries which run on your platform
1439 are built specifically for your platform, and make no use of
1440 these helpers, then you can turn this option off to hinder
1441 such exploits. However, in that case, if a binary or library
1442 relying on those helpers is run, it will not function correctly.
1444 Say N here only if you are absolutely certain that you do not
1445 need these helpers; otherwise, the safe option is to say Y.
1448 bool "Enable vDSO for 32-bit applications"
1449 depends on !CPU_BIG_ENDIAN
1450 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1451 select GENERIC_COMPAT_VDSO
1454 Place in the process address space of 32-bit applications an
1455 ELF shared object providing fast implementations of gettimeofday
1458 You must have a 32-bit build of glibc 2.22 or later for programs
1459 to seamlessly take advantage of this.
1461 config THUMB2_COMPAT_VDSO
1462 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1463 depends on COMPAT_VDSO
1466 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1467 otherwise with '-marm'.
1469 menuconfig ARMV8_DEPRECATED
1470 bool "Emulate deprecated/obsolete ARMv8 instructions"
1473 Legacy software support may require certain instructions
1474 that have been deprecated or obsoleted in the architecture.
1476 Enable this config to enable selective emulation of these
1483 config SWP_EMULATION
1484 bool "Emulate SWP/SWPB instructions"
1486 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1487 they are always undefined. Say Y here to enable software
1488 emulation of these instructions for userspace using LDXR/STXR.
1489 This feature can be controlled at runtime with the abi.swp
1490 sysctl which is disabled by default.
1492 In some older versions of glibc [<=2.8] SWP is used during futex
1493 trylock() operations with the assumption that the code will not
1494 be preempted. This invalid assumption may be more likely to fail
1495 with SWP emulation enabled, leading to deadlock of the user
1498 NOTE: when accessing uncached shared regions, LDXR/STXR rely
1499 on an external transaction monitoring block called a global
1500 monitor to maintain update atomicity. If your system does not
1501 implement a global monitor, this option can cause programs that
1502 perform SWP operations to uncached memory to deadlock.
1506 config CP15_BARRIER_EMULATION
1507 bool "Emulate CP15 Barrier instructions"
1509 The CP15 barrier instructions - CP15ISB, CP15DSB, and
1510 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1511 strongly recommended to use the ISB, DSB, and DMB
1512 instructions instead.
1514 Say Y here to enable software emulation of these
1515 instructions for AArch32 userspace code. When this option is
1516 enabled, CP15 barrier usage is traced which can help
1517 identify software that needs updating. This feature can be
1518 controlled at runtime with the abi.cp15_barrier sysctl.
1522 config SETEND_EMULATION
1523 bool "Emulate SETEND instruction"
1525 The SETEND instruction alters the data-endianness of the
1526 AArch32 EL0, and is deprecated in ARMv8.
1528 Say Y here to enable software emulation of the instruction
1529 for AArch32 userspace code. This feature can be controlled
1530 at runtime with the abi.setend sysctl.
1532 Note: All the cpus on the system must have mixed endian support at EL0
1533 for this feature to be enabled. If a new CPU - which doesn't support mixed
1534 endian - is hotplugged in after this feature has been enabled, there could
1535 be unexpected results in the applications.
1542 menu "ARMv8.1 architectural features"
1544 config ARM64_HW_AFDBM
1545 bool "Support for hardware updates of the Access and Dirty page flags"
1548 The ARMv8.1 architecture extensions introduce support for
1549 hardware updates of the access and dirty information in page
1550 table entries. When enabled in TCR_EL1 (HA and HD bits) on
1551 capable processors, accesses to pages with PTE_AF cleared will
1552 set this bit instead of raising an access flag fault.
1553 Similarly, writes to read-only pages with the DBM bit set will
1554 clear the read-only bit (AP[2]) instead of raising a
1557 Kernels built with this configuration option enabled continue
1558 to work on pre-ARMv8.1 hardware and the performance impact is
1559 minimal. If unsure, say Y.
1562 bool "Enable support for Privileged Access Never (PAN)"
1565 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1566 prevents the kernel or hypervisor from accessing user-space (EL0)
1569 Choosing this option will cause any unprotected (not using
1570 copy_to_user et al) memory access to fail with a permission fault.
1572 The feature is detected at runtime, and will remain as a 'nop'
1573 instruction if the cpu does not implement the feature.
1576 def_bool $(as-instr,.arch_extension rcpc)
1578 config AS_HAS_LSE_ATOMICS
1579 def_bool $(as-instr,.arch_extension lse)
1581 config ARM64_LSE_ATOMICS
1583 default ARM64_USE_LSE_ATOMICS
1584 depends on AS_HAS_LSE_ATOMICS
1586 config ARM64_USE_LSE_ATOMICS
1587 bool "Atomic instructions"
1588 depends on JUMP_LABEL
1591 As part of the Large System Extensions, ARMv8.1 introduces new
1592 atomic instructions that are designed specifically to scale in
1595 Say Y here to make use of these instructions for the in-kernel
1596 atomic routines. This incurs a small overhead on CPUs that do
1597 not support these instructions and requires the kernel to be
1598 built with binutils >= 2.25 in order for the new instructions
1603 menu "ARMv8.2 architectural features"
1605 config AS_HAS_ARMV8_2
1606 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1609 def_bool $(as-instr,.arch armv8.2-a+sha3)
1612 bool "Enable support for persistent memory"
1613 select ARCH_HAS_PMEM_API
1614 select ARCH_HAS_UACCESS_FLUSHCACHE
1616 Say Y to enable support for the persistent memory API based on the
1617 ARMv8.2 DCPoP feature.
1619 The feature is detected at runtime, and the kernel will use DC CVAC
1620 operations if DC CVAP is not supported (following the behaviour of
1621 DC CVAP itself if the system does not define a point of persistence).
1623 config ARM64_RAS_EXTN
1624 bool "Enable support for RAS CPU Extensions"
1627 CPUs that support the Reliability, Availability and Serviceability
1628 (RAS) Extensions, part of ARMv8.2 are able to track faults and
1629 errors, classify them and report them to software.
1631 On CPUs with these extensions system software can use additional
1632 barriers to determine if faults are pending and read the
1633 classification from a new set of registers.
1635 Selecting this feature will allow the kernel to use these barriers
1636 and access the new registers if the system supports the extension.
1637 Platform RAS features may additionally depend on firmware support.
1640 bool "Enable support for Common Not Private (CNP) translations"
1642 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1644 Common Not Private (CNP) allows translation table entries to
1645 be shared between different PEs in the same inner shareable
1646 domain, so the hardware can use this fact to optimise the
1647 caching of such entries in the TLB.
1649 Selecting this option allows the CNP feature to be detected
1650 at runtime, and does not affect PEs that do not implement
1655 menu "ARMv8.3 architectural features"
1657 config ARM64_PTR_AUTH
1658 bool "Enable support for pointer authentication"
1661 Pointer authentication (part of the ARMv8.3 Extensions) provides
1662 instructions for signing and authenticating pointers against secret
1663 keys, which can be used to mitigate Return Oriented Programming (ROP)
1666 This option enables these instructions at EL0 (i.e. for userspace).
1667 Choosing this option will cause the kernel to initialise secret keys
1668 for each process at exec() time, with these keys being
1669 context-switched along with the process.
1671 The feature is detected at runtime. If the feature is not present in
1672 hardware it will not be advertised to userspace/KVM guest nor will it
1675 If the feature is present on the boot CPU but not on a late CPU, then
1676 the late CPU will be parked. Also, if the boot CPU does not have
1677 address auth and the late CPU has then the late CPU will still boot
1678 but with the feature disabled. On such a system, this option should
1681 config ARM64_PTR_AUTH_KERNEL
1682 bool "Use pointer authentication for kernel"
1684 depends on ARM64_PTR_AUTH
1685 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC
1686 # Modern compilers insert a .note.gnu.property section note for PAC
1687 # which is only understood by binutils starting with version 2.33.1.
1688 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1689 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1690 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
1692 If the compiler supports the -mbranch-protection or
1693 -msign-return-address flag (e.g. GCC 7 or later), then this option
1694 will cause the kernel itself to be compiled with return address
1695 protection. In this case, and if the target hardware is known to
1696 support pointer authentication, then CONFIG_STACKPROTECTOR can be
1697 disabled with minimal loss of protection.
1699 This feature works with FUNCTION_GRAPH_TRACER option only if
1700 DYNAMIC_FTRACE_WITH_REGS is enabled.
1702 config CC_HAS_BRANCH_PROT_PAC_RET
1703 # GCC 9 or later, clang 8 or later
1704 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1706 config CC_HAS_SIGN_RETURN_ADDRESS
1708 def_bool $(cc-option,-msign-return-address=all)
1711 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1713 config AS_HAS_CFI_NEGATE_RA_STATE
1714 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1718 menu "ARMv8.4 architectural features"
1720 config ARM64_AMU_EXTN
1721 bool "Enable support for the Activity Monitors Unit CPU extension"
1724 The activity monitors extension is an optional extension introduced
1725 by the ARMv8.4 CPU architecture. This enables support for version 1
1726 of the activity monitors architecture, AMUv1.
1728 To enable the use of this extension on CPUs that implement it, say Y.
1730 Note that for architectural reasons, firmware _must_ implement AMU
1731 support when running on CPUs that present the activity monitors
1732 extension. The required support is present in:
1733 * Version 1.5 and later of the ARM Trusted Firmware
1735 For kernels that have this configuration enabled but boot with broken
1736 firmware, you may need to say N here until the firmware is fixed.
1737 Otherwise you may experience firmware panics or lockups when
1738 accessing the counter registers. Even if you are not observing these
1739 symptoms, the values returned by the register reads might not
1740 correctly reflect reality. Most commonly, the value read will be 0,
1741 indicating that the counter is not enabled.
1743 config AS_HAS_ARMV8_4
1744 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1746 config ARM64_TLB_RANGE
1747 bool "Enable support for tlbi range feature"
1749 depends on AS_HAS_ARMV8_4
1751 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1752 range of input addresses.
1754 The feature introduces new assembly instructions, and they were
1755 support when binutils >= 2.30.
1759 menu "ARMv8.5 architectural features"
1761 config AS_HAS_ARMV8_5
1762 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1765 bool "Branch Target Identification support"
1768 Branch Target Identification (part of the ARMv8.5 Extensions)
1769 provides a mechanism to limit the set of locations to which computed
1770 branch instructions such as BR or BLR can jump.
1772 To make use of BTI on CPUs that support it, say Y.
1774 BTI is intended to provide complementary protection to other control
1775 flow integrity protection mechanisms, such as the Pointer
1776 authentication mechanism provided as part of the ARMv8.3 Extensions.
1777 For this reason, it does not make sense to enable this option without
1778 also enabling support for pointer authentication. Thus, when
1779 enabling this option you should also select ARM64_PTR_AUTH=y.
1781 Userspace binaries must also be specifically compiled to make use of
1782 this mechanism. If you say N here or the hardware does not support
1783 BTI, such binaries can still run, but you get no additional
1784 enforcement of branch destinations.
1786 config ARM64_BTI_KERNEL
1787 bool "Use Branch Target Identification for kernel"
1789 depends on ARM64_BTI
1790 depends on ARM64_PTR_AUTH_KERNEL
1791 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1792 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1793 depends on !CC_IS_GCC || GCC_VERSION >= 100100
1794 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
1795 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
1796 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
1798 Build the kernel with Branch Target Identification annotations
1799 and enable enforcement of this for kernel code. When this option
1800 is enabled and the system supports BTI all kernel code including
1801 modular code must have BTI enabled.
1803 config CC_HAS_BRANCH_PROT_PAC_RET_BTI
1804 # GCC 9 or later, clang 8 or later
1805 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
1808 bool "Enable support for E0PD"
1811 E0PD (part of the ARMv8.5 extensions) allows us to ensure
1812 that EL0 accesses made via TTBR1 always fault in constant time,
1813 providing similar benefits to KASLR as those provided by KPTI, but
1814 with lower overhead and without disrupting legitimate access to
1815 kernel memory such as SPE.
1817 This option enables E0PD for TTBR1 where available.
1820 bool "Enable support for random number generation"
1823 Random number generation (part of the ARMv8.5 Extensions)
1824 provides a high bandwidth, cryptographically secure
1825 hardware random number generator.
1827 config ARM64_AS_HAS_MTE
1828 # Initial support for MTE went in binutils 2.32.0, checked with
1829 # ".arch armv8.5-a+memtag" below. However, this was incomplete
1830 # as a late addition to the final architecture spec (LDGM/STGM)
1831 # is only supported in the newer 2.32.x and 2.33 binutils
1832 # versions, hence the extra "stgm" instruction check below.
1833 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
1836 bool "Memory Tagging Extension support"
1838 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
1839 depends on AS_HAS_ARMV8_5
1840 depends on AS_HAS_LSE_ATOMICS
1841 # Required for tag checking in the uaccess routines
1842 depends on ARM64_PAN
1843 select ARCH_USES_HIGH_VMA_FLAGS
1845 Memory Tagging (part of the ARMv8.5 Extensions) provides
1846 architectural support for run-time, always-on detection of
1847 various classes of memory error to aid with software debugging
1848 to eliminate vulnerabilities arising from memory-unsafe
1851 This option enables the support for the Memory Tagging
1852 Extension at EL0 (i.e. for userspace).
1854 Selecting this option allows the feature to be detected at
1855 runtime. Any secondary CPU not implementing this feature will
1856 not be allowed a late bring-up.
1858 Userspace binaries that want to use this feature must
1859 explicitly opt in. The mechanism for the userspace is
1862 Documentation/arm64/memory-tagging-extension.rst.
1866 menu "ARMv8.7 architectural features"
1869 bool "Enable support for Enhanced Privileged Access Never (EPAN)"
1871 depends on ARM64_PAN
1873 Enhanced Privileged Access Never (EPAN) allows Privileged
1874 Access Never to be used with Execute-only mappings.
1876 The feature is detected at runtime, and will remain disabled
1877 if the cpu does not implement the feature.
1881 bool "ARM Scalable Vector Extension support"
1884 The Scalable Vector Extension (SVE) is an extension to the AArch64
1885 execution state which complements and extends the SIMD functionality
1886 of the base architecture to support much larger vectors and to enable
1887 additional vectorisation opportunities.
1889 To enable use of this extension on CPUs that implement it, say Y.
1891 On CPUs that support the SVE2 extensions, this option will enable
1894 Note that for architectural reasons, firmware _must_ implement SVE
1895 support when running on SVE capable hardware. The required support
1898 * version 1.5 and later of the ARM Trusted Firmware
1899 * the AArch64 boot wrapper since commit 5e1261e08abf
1900 ("bootwrapper: SVE: Enable SVE for EL2 and below").
1902 For other firmware implementations, consult the firmware documentation
1905 If you need the kernel to boot on SVE-capable hardware with broken
1906 firmware, you may need to say N here until you get your firmware
1907 fixed. Otherwise, you may experience firmware panics or lockups when
1908 booting the kernel. If unsure and you are not observing these
1909 symptoms, you should assume that it is safe to say Y.
1911 config ARM64_MODULE_PLTS
1912 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1914 select HAVE_MOD_ARCH_SPECIFIC
1916 Allocate PLTs when loading modules so that jumps and calls whose
1917 targets are too far away for their relative offsets to be encoded
1918 in the instructions themselves can be bounced via veneers in the
1919 module's PLT. This allows modules to be allocated in the generic
1920 vmalloc area after the dedicated module memory area has been
1923 When running with address space randomization (KASLR), the module
1924 region itself may be too far away for ordinary relative jumps and
1925 calls, and so in that case, module PLTs are required and cannot be
1928 Specific errata workaround(s) might also force module PLTs to be
1929 enabled (ARM64_ERRATUM_843419).
1931 config ARM64_PSEUDO_NMI
1932 bool "Support for NMI-like interrupts"
1935 Adds support for mimicking Non-Maskable Interrupts through the use of
1936 GIC interrupt priority. This support requires version 3 or later of
1939 This high priority configuration for interrupts needs to be
1940 explicitly enabled by setting the kernel parameter
1941 "irqchip.gicv3_pseudo_nmi" to 1.
1946 config ARM64_DEBUG_PRIORITY_MASKING
1947 bool "Debug interrupt priority masking"
1949 This adds runtime checks to functions enabling/disabling
1950 interrupts when using priority masking. The additional checks verify
1951 the validity of ICC_PMR_EL1 when calling concerned functions.
1957 bool "Build a relocatable kernel image" if EXPERT
1958 select ARCH_HAS_RELR
1961 This builds the kernel as a Position Independent Executable (PIE),
1962 which retains all relocation metadata required to relocate the
1963 kernel binary at runtime to a different virtual address than the
1964 address it was linked at.
1965 Since AArch64 uses the RELA relocation format, this requires a
1966 relocation pass at runtime even if the kernel is loaded at the
1967 same address it was linked at.
1969 config RANDOMIZE_BASE
1970 bool "Randomize the address of the kernel image"
1971 select ARM64_MODULE_PLTS if MODULES
1974 Randomizes the virtual address at which the kernel image is
1975 loaded, as a security feature that deters exploit attempts
1976 relying on knowledge of the location of kernel internals.
1978 It is the bootloader's job to provide entropy, by passing a
1979 random u64 value in /chosen/kaslr-seed at kernel entry.
1981 When booting via the UEFI stub, it will invoke the firmware's
1982 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1983 to the kernel proper. In addition, it will randomise the physical
1984 location of the kernel Image as well.
1988 config RANDOMIZE_MODULE_REGION_FULL
1989 bool "Randomize the module region over a 2 GB range"
1990 depends on RANDOMIZE_BASE
1993 Randomizes the location of the module region inside a 2 GB window
1994 covering the core kernel. This way, it is less likely for modules
1995 to leak information about the location of core kernel data structures
1996 but it does imply that function calls between modules and the core
1997 kernel will need to be resolved via veneers in the module PLT.
1999 When this option is not set, the module region will be randomized over
2000 a limited range that contains the [_stext, _etext] interval of the
2001 core kernel, so branch relocations are almost always in range unless
2002 ARM64_MODULE_PLTS is enabled and the region is exhausted. In this
2003 particular case of region exhaustion, modules might be able to fall
2004 back to a larger 2GB area.
2006 config CC_HAVE_STACKPROTECTOR_SYSREG
2007 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2009 config STACKPROTECTOR_PER_TASK
2011 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2017 config ARM64_ACPI_PARKING_PROTOCOL
2018 bool "Enable support for the ARM64 ACPI parking protocol"
2021 Enable support for the ARM64 ACPI parking protocol. If disabled
2022 the kernel will not allow booting through the ARM64 ACPI parking
2023 protocol even if the corresponding data is present in the ACPI
2027 string "Default kernel command string"
2030 Provide a set of default command-line options at build time by
2031 entering them here. As a minimum, you should specify the the
2032 root device (e.g. root=/dev/nfs).
2035 prompt "Kernel command line type" if CMDLINE != ""
2036 default CMDLINE_FROM_BOOTLOADER
2038 Choose how the kernel will handle the provided default kernel
2039 command line string.
2041 config CMDLINE_FROM_BOOTLOADER
2042 bool "Use bootloader kernel arguments if available"
2044 Uses the command-line options passed by the boot loader. If
2045 the boot loader doesn't provide any, the default kernel command
2046 string provided in CMDLINE will be used.
2048 config CMDLINE_FORCE
2049 bool "Always use the default kernel command string"
2051 Always use the default kernel command string, even if the boot
2052 loader passes other arguments to the kernel.
2053 This is useful if you cannot or don't want to change the
2054 command-line options your boot loader passes to the kernel.
2062 bool "UEFI runtime support"
2063 depends on OF && !CPU_BIG_ENDIAN
2064 depends on KERNEL_MODE_NEON
2065 select ARCH_SUPPORTS_ACPI
2068 select EFI_PARAMS_FROM_FDT
2069 select EFI_RUNTIME_WRAPPERS
2071 select EFI_GENERIC_STUB
2072 imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2075 This option provides support for runtime services provided
2076 by UEFI firmware (such as non-volatile variables, realtime
2077 clock, and platform reset). A UEFI stub is also provided to
2078 allow the kernel to be booted as an EFI application. This
2079 is only useful on systems that have UEFI firmware.
2082 bool "Enable support for SMBIOS (DMI) tables"
2086 This enables SMBIOS/DMI feature for systems.
2088 This option is only useful on systems that have UEFI firmware.
2089 However, even with this option, the resultant kernel should
2090 continue to boot on existing non-UEFI platforms.
2094 config SYSVIPC_COMPAT
2096 depends on COMPAT && SYSVIPC
2098 menu "Power management options"
2100 source "kernel/power/Kconfig"
2102 config ARCH_HIBERNATION_POSSIBLE
2106 config ARCH_HIBERNATION_HEADER
2108 depends on HIBERNATION
2110 config ARCH_SUSPEND_POSSIBLE
2115 menu "CPU Power Management"
2117 source "drivers/cpuidle/Kconfig"
2119 source "drivers/cpufreq/Kconfig"
2123 source "drivers/acpi/Kconfig"
2125 source "arch/arm64/kvm/Kconfig"
2128 source "arch/arm64/crypto/Kconfig"