1 # SPDX-License-Identifier: GPL-2.0-only
4 select ACPI_APMT if ACPI
5 select ACPI_CCA_REQUIRED if ACPI
6 select ACPI_GENERIC_GSI if ACPI
7 select ACPI_GTDT if ACPI
8 select ACPI_IORT if ACPI
9 select ACPI_REDUCED_HARDWARE_ONLY if ACPI
10 select ACPI_MCFG if (ACPI && PCI)
11 select ACPI_SPCR_TABLE if ACPI
12 select ACPI_PPTT if ACPI
13 select ARCH_HAS_DEBUG_WX
14 select ARCH_BINFMT_ELF_EXTRA_PHDRS
15 select ARCH_BINFMT_ELF_STATE
16 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
17 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
18 select ARCH_ENABLE_MEMORY_HOTPLUG
19 select ARCH_ENABLE_MEMORY_HOTREMOVE
20 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
21 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
22 select ARCH_HAS_CACHE_LINE_SIZE
23 select ARCH_HAS_CURRENT_STACK_POINTER
24 select ARCH_HAS_DEBUG_VIRTUAL
25 select ARCH_HAS_DEBUG_VM_PGTABLE
26 select ARCH_HAS_DMA_PREP_COHERENT
27 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
28 select ARCH_HAS_FAST_MULTIPLIER
29 select ARCH_HAS_FORTIFY_SOURCE
30 select ARCH_HAS_GCOV_PROFILE_ALL
31 select ARCH_HAS_GIGANTIC_PAGE
33 select ARCH_HAS_KEEPINITRD
34 select ARCH_HAS_MEMBARRIER_SYNC_CORE
35 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
36 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
37 select ARCH_HAS_PTE_DEVMAP
38 select ARCH_HAS_PTE_SPECIAL
39 select ARCH_HAS_HW_PTE_YOUNG
40 select ARCH_HAS_SETUP_DMA_OPS
41 select ARCH_HAS_SET_DIRECT_MAP
42 select ARCH_HAS_SET_MEMORY
44 select ARCH_HAS_STRICT_KERNEL_RWX
45 select ARCH_HAS_STRICT_MODULE_RWX
46 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
47 select ARCH_HAS_SYNC_DMA_FOR_CPU
48 select ARCH_HAS_SYSCALL_WRAPPER
49 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
50 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
51 select ARCH_HAS_ZONE_DMA_SET if EXPERT
52 select ARCH_HAVE_ELF_PROT
53 select ARCH_HAVE_NMI_SAFE_CMPXCHG
54 select ARCH_HAVE_TRACE_MMIO_ACCESS
55 select ARCH_INLINE_READ_LOCK if !PREEMPTION
56 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
57 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
58 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
59 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
60 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
61 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
62 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
63 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
64 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
65 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
66 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
67 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
68 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
69 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
70 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
71 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
72 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
73 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
74 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
75 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
76 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
77 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
78 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
79 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
80 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
81 select ARCH_KEEP_MEMBLOCK
82 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
83 select ARCH_USE_CMPXCHG_LOCKREF
84 select ARCH_USE_GNU_PROPERTY
85 select ARCH_USE_MEMTEST
86 select ARCH_USE_QUEUED_RWLOCKS
87 select ARCH_USE_QUEUED_SPINLOCKS
88 select ARCH_USE_SYM_ANNOTATIONS
89 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
90 select ARCH_SUPPORTS_HUGETLBFS
91 select ARCH_SUPPORTS_MEMORY_FAILURE
92 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
93 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
94 select ARCH_SUPPORTS_LTO_CLANG_THIN
95 select ARCH_SUPPORTS_CFI_CLANG
96 select ARCH_SUPPORTS_ATOMIC_RMW
97 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
98 select ARCH_SUPPORTS_NUMA_BALANCING
99 select ARCH_SUPPORTS_PAGE_TABLE_CHECK
100 select ARCH_SUPPORTS_PER_VMA_LOCK
101 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
102 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
103 select ARCH_WANT_DEFAULT_BPF_JIT
104 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
105 select ARCH_WANT_FRAME_POINTERS
106 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
107 select ARCH_WANT_LD_ORPHAN_WARN
108 select ARCH_WANTS_NO_INSTR
109 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
110 select ARCH_HAS_UBSAN_SANITIZE_ALL
112 select ARM_ARCH_TIMER
114 select AUDIT_ARCH_COMPAT_GENERIC
115 select ARM_GIC_V2M if PCI
117 select ARM_GIC_V3_ITS if PCI
119 select BUILDTIME_TABLE_SORT
120 select CLONE_BACKWARDS
122 select CPU_PM if (SUSPEND || CPU_IDLE)
124 select DCACHE_WORD_ACCESS
125 select DYNAMIC_FTRACE if FUNCTION_TRACER
126 select DMA_BOUNCE_UNALIGNED_KMALLOC
127 select DMA_DIRECT_REMAP
130 select FUNCTION_ALIGNMENT_4B
131 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
132 select GENERIC_ALLOCATOR
133 select GENERIC_ARCH_TOPOLOGY
134 select GENERIC_CLOCKEVENTS_BROADCAST
135 select GENERIC_CPU_AUTOPROBE
136 select GENERIC_CPU_DEVICES
137 select GENERIC_CPU_VULNERABILITIES
138 select GENERIC_EARLY_IOREMAP
139 select GENERIC_IDLE_POLL_SETUP
140 select GENERIC_IOREMAP
141 select GENERIC_IRQ_IPI
142 select GENERIC_IRQ_PROBE
143 select GENERIC_IRQ_SHOW
144 select GENERIC_IRQ_SHOW_LEVEL
145 select GENERIC_LIB_DEVMEM_IS_ALLOWED
146 select GENERIC_PCI_IOMAP
147 select GENERIC_PTDUMP
148 select GENERIC_SCHED_CLOCK
149 select GENERIC_SMP_IDLE_THREAD
150 select GENERIC_TIME_VSYSCALL
151 select GENERIC_GETTIMEOFDAY
152 select GENERIC_VDSO_TIME_NS
153 select HARDIRQS_SW_RESEND
158 select HAVE_ACPI_APEI if (ACPI && EFI)
159 select HAVE_ALIGNED_STRUCT_PAGE
160 select HAVE_ARCH_AUDITSYSCALL
161 select HAVE_ARCH_BITREVERSE
162 select HAVE_ARCH_COMPILER_H
163 select HAVE_ARCH_HUGE_VMALLOC
164 select HAVE_ARCH_HUGE_VMAP
165 select HAVE_ARCH_JUMP_LABEL
166 select HAVE_ARCH_JUMP_LABEL_RELATIVE
167 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
168 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
169 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
170 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
171 # Some instrumentation may be unsound, hence EXPERT
172 select HAVE_ARCH_KCSAN if EXPERT
173 select HAVE_ARCH_KFENCE
174 select HAVE_ARCH_KGDB
175 select HAVE_ARCH_MMAP_RND_BITS
176 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
177 select HAVE_ARCH_PREL32_RELOCATIONS
178 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
179 select HAVE_ARCH_SECCOMP_FILTER
180 select HAVE_ARCH_STACKLEAK
181 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
182 select HAVE_ARCH_TRACEHOOK
183 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
184 select HAVE_ARCH_VMAP_STACK
185 select HAVE_ARM_SMCCC
186 select HAVE_ASM_MODVERSIONS
188 select HAVE_C_RECORDMCOUNT
189 select HAVE_CMPXCHG_DOUBLE
190 select HAVE_CMPXCHG_LOCAL
191 select HAVE_CONTEXT_TRACKING_USER
192 select HAVE_DEBUG_KMEMLEAK
193 select HAVE_DMA_CONTIGUOUS
194 select HAVE_DYNAMIC_FTRACE
195 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
196 if $(cc-option,-fpatchable-function-entry=2)
197 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
198 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
199 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
200 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
201 !CC_OPTIMIZE_FOR_SIZE)
202 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
203 if DYNAMIC_FTRACE_WITH_ARGS
204 select HAVE_SAMPLE_FTRACE_DIRECT
205 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
206 select HAVE_EFFICIENT_UNALIGNED_ACCESS
208 select HAVE_FTRACE_MCOUNT_RECORD
209 select HAVE_FUNCTION_TRACER
210 select HAVE_FUNCTION_ERROR_INJECTION
211 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
212 select HAVE_FUNCTION_GRAPH_TRACER
213 select HAVE_GCC_PLUGINS
214 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
215 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
216 select HAVE_HW_BREAKPOINT if PERF_EVENTS
217 select HAVE_IOREMAP_PROT
218 select HAVE_IRQ_TIME_ACCOUNTING
220 select HAVE_MOD_ARCH_SPECIFIC
222 select HAVE_PERF_EVENTS
223 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
224 select HAVE_PERF_REGS
225 select HAVE_PERF_USER_STACK_DUMP
226 select HAVE_PREEMPT_DYNAMIC_KEY
227 select HAVE_REGS_AND_STACK_ACCESS_API
228 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
229 select HAVE_FUNCTION_ARG_ACCESS_API
230 select MMU_GATHER_RCU_TABLE_FREE
232 select HAVE_STACKPROTECTOR
233 select HAVE_SYSCALL_TRACEPOINTS
235 select HAVE_KRETPROBES
236 select HAVE_GENERIC_VDSO
237 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
239 select IRQ_FORCED_THREADING
240 select KASAN_VMALLOC if KASAN
241 select LOCK_MM_AND_FIND_VMA
242 select MODULES_USE_ELF_RELA
243 select NEED_DMA_MAP_STATE
244 select NEED_SG_DMA_LENGTH
246 select OF_EARLY_FLATTREE
247 select PCI_DOMAINS_GENERIC if PCI
248 select PCI_ECAM if (ACPI && PCI)
249 select PCI_SYSCALL if PCI
254 select SYSCTL_EXCEPTION_TRACE
255 select THREAD_INFO_IN_TASK
256 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
257 select TRACE_IRQFLAGS_SUPPORT
258 select TRACE_IRQFLAGS_NMI_SUPPORT
259 select HAVE_SOFTIRQ_ON_OWN_STACK
261 ARM 64-bit (AArch64) Linux support.
263 config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
265 # https://github.com/ClangBuiltLinux/linux/issues/1507
266 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
267 select HAVE_DYNAMIC_FTRACE_WITH_ARGS
269 config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
271 depends on $(cc-option,-fpatchable-function-entry=2)
272 select HAVE_DYNAMIC_FTRACE_WITH_ARGS
280 config ARM64_PAGE_SHIFT
282 default 16 if ARM64_64K_PAGES
283 default 14 if ARM64_16K_PAGES
286 config ARM64_CONT_PTE_SHIFT
288 default 5 if ARM64_64K_PAGES
289 default 7 if ARM64_16K_PAGES
292 config ARM64_CONT_PMD_SHIFT
294 default 5 if ARM64_64K_PAGES
295 default 5 if ARM64_16K_PAGES
298 config ARCH_MMAP_RND_BITS_MIN
299 default 14 if ARM64_64K_PAGES
300 default 16 if ARM64_16K_PAGES
303 # max bits determined by the following formula:
304 # VA_BITS - PAGE_SHIFT - 3
305 config ARCH_MMAP_RND_BITS_MAX
306 default 19 if ARM64_VA_BITS=36
307 default 24 if ARM64_VA_BITS=39
308 default 27 if ARM64_VA_BITS=42
309 default 30 if ARM64_VA_BITS=47
310 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
311 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
312 default 33 if ARM64_VA_BITS=48
313 default 14 if ARM64_64K_PAGES
314 default 16 if ARM64_16K_PAGES
317 config ARCH_MMAP_RND_COMPAT_BITS_MIN
318 default 7 if ARM64_64K_PAGES
319 default 9 if ARM64_16K_PAGES
322 config ARCH_MMAP_RND_COMPAT_BITS_MAX
328 config STACKTRACE_SUPPORT
331 config ILLEGAL_POINTER_VALUE
333 default 0xdead000000000000
335 config LOCKDEP_SUPPORT
342 config GENERIC_BUG_RELATIVE_POINTERS
344 depends on GENERIC_BUG
346 config GENERIC_HWEIGHT
352 config GENERIC_CALIBRATE_DELAY
358 config KERNEL_MODE_NEON
361 config FIX_EARLYCON_MEM
364 config PGTABLE_LEVELS
366 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
367 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
368 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
369 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
370 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
371 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
373 config ARCH_SUPPORTS_UPROBES
376 config ARCH_PROC_KCORE_TEXT
379 config BROKEN_GAS_INST
380 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
382 config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
384 # Clang's __builtin_return_adddress() strips the PAC since 12.0.0
385 # https://reviews.llvm.org/D75044
386 default y if CC_IS_CLANG && (CLANG_VERSION >= 120000)
387 # GCC's __builtin_return_address() strips the PAC since 11.1.0,
388 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
389 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
390 default y if CC_IS_GCC && (GCC_VERSION >= 110100)
391 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
392 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000)
393 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000)
396 config KASAN_SHADOW_OFFSET
398 depends on KASAN_GENERIC || KASAN_SW_TAGS
399 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
400 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
401 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
402 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
403 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
404 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
405 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
406 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
407 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
408 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
409 default 0xffffffffffffffff
414 source "arch/arm64/Kconfig.platforms"
416 menu "Kernel Features"
418 menu "ARM errata workarounds via the alternatives framework"
420 config AMPERE_ERRATUM_AC03_CPU_38
421 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
424 This option adds an alternative code sequence to work around Ampere
425 erratum AC03_CPU_38 on AmpereOne.
427 The affected design reports FEAT_HAFDBS as not implemented in
428 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
429 as required by the architecture. The unadvertised HAFDBS
430 implementation suffers from an additional erratum where hardware
431 A/D updates can occur after a PTE has been marked invalid.
433 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
434 which avoids enabling unadvertised hardware Access Flag management
439 config ARM64_WORKAROUND_CLEAN_CACHE
442 config ARM64_ERRATUM_826319
443 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
445 select ARM64_WORKAROUND_CLEAN_CACHE
447 This option adds an alternative code sequence to work around ARM
448 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
449 AXI master interface and an L2 cache.
451 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
452 and is unable to accept a certain write via this interface, it will
453 not progress on read data presented on the read data channel and the
456 The workaround promotes data cache clean instructions to
457 data cache clean-and-invalidate.
458 Please note that this does not necessarily enable the workaround,
459 as it depends on the alternative framework, which will only patch
460 the kernel if an affected CPU is detected.
464 config ARM64_ERRATUM_827319
465 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
467 select ARM64_WORKAROUND_CLEAN_CACHE
469 This option adds an alternative code sequence to work around ARM
470 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
471 master interface and an L2 cache.
473 Under certain conditions this erratum can cause a clean line eviction
474 to occur at the same time as another transaction to the same address
475 on the AMBA 5 CHI interface, which can cause data corruption if the
476 interconnect reorders the two transactions.
478 The workaround promotes data cache clean instructions to
479 data cache clean-and-invalidate.
480 Please note that this does not necessarily enable the workaround,
481 as it depends on the alternative framework, which will only patch
482 the kernel if an affected CPU is detected.
486 config ARM64_ERRATUM_824069
487 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
489 select ARM64_WORKAROUND_CLEAN_CACHE
491 This option adds an alternative code sequence to work around ARM
492 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
493 to a coherent interconnect.
495 If a Cortex-A53 processor is executing a store or prefetch for
496 write instruction at the same time as a processor in another
497 cluster is executing a cache maintenance operation to the same
498 address, then this erratum might cause a clean cache line to be
499 incorrectly marked as dirty.
501 The workaround promotes data cache clean instructions to
502 data cache clean-and-invalidate.
503 Please note that this option does not necessarily enable the
504 workaround, as it depends on the alternative framework, which will
505 only patch the kernel if an affected CPU is detected.
509 config ARM64_ERRATUM_819472
510 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
512 select ARM64_WORKAROUND_CLEAN_CACHE
514 This option adds an alternative code sequence to work around ARM
515 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
516 present when it is connected to a coherent interconnect.
518 If the processor is executing a load and store exclusive sequence at
519 the same time as a processor in another cluster is executing a cache
520 maintenance operation to the same address, then this erratum might
521 cause data corruption.
523 The workaround promotes data cache clean instructions to
524 data cache clean-and-invalidate.
525 Please note that this does not necessarily enable the workaround,
526 as it depends on the alternative framework, which will only patch
527 the kernel if an affected CPU is detected.
531 config ARM64_ERRATUM_832075
532 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
535 This option adds an alternative code sequence to work around ARM
536 erratum 832075 on Cortex-A57 parts up to r1p2.
538 Affected Cortex-A57 parts might deadlock when exclusive load/store
539 instructions to Write-Back memory are mixed with Device loads.
541 The workaround is to promote device loads to use Load-Acquire
543 Please note that this does not necessarily enable the workaround,
544 as it depends on the alternative framework, which will only patch
545 the kernel if an affected CPU is detected.
549 config ARM64_ERRATUM_834220
550 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
554 This option adds an alternative code sequence to work around ARM
555 erratum 834220 on Cortex-A57 parts up to r1p2.
557 Affected Cortex-A57 parts might report a Stage 2 translation
558 fault as the result of a Stage 1 fault for load crossing a
559 page boundary when there is a permission or device memory
560 alignment fault at Stage 1 and a translation fault at Stage 2.
562 The workaround is to verify that the Stage 1 translation
563 doesn't generate a fault before handling the Stage 2 fault.
564 Please note that this does not necessarily enable the workaround,
565 as it depends on the alternative framework, which will only patch
566 the kernel if an affected CPU is detected.
570 config ARM64_ERRATUM_1742098
571 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
575 This option removes the AES hwcap for aarch32 user-space to
576 workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
578 Affected parts may corrupt the AES state if an interrupt is
579 taken between a pair of AES instructions. These instructions
580 are only present if the cryptography extensions are present.
581 All software should have a fallback implementation for CPUs
582 that don't implement the cryptography extensions.
586 config ARM64_ERRATUM_845719
587 bool "Cortex-A53: 845719: a load might read incorrect data"
591 This option adds an alternative code sequence to work around ARM
592 erratum 845719 on Cortex-A53 parts up to r0p4.
594 When running a compat (AArch32) userspace on an affected Cortex-A53
595 part, a load at EL0 from a virtual address that matches the bottom 32
596 bits of the virtual address used by a recent load at (AArch64) EL1
597 might return incorrect data.
599 The workaround is to write the contextidr_el1 register on exception
600 return to a 32-bit task.
601 Please note that this does not necessarily enable the workaround,
602 as it depends on the alternative framework, which will only patch
603 the kernel if an affected CPU is detected.
607 config ARM64_ERRATUM_843419
608 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
611 This option links the kernel with '--fix-cortex-a53-843419' and
612 enables PLT support to replace certain ADRP instructions, which can
613 cause subsequent memory accesses to use an incorrect address on
614 Cortex-A53 parts up to r0p4.
618 config ARM64_LD_HAS_FIX_ERRATUM_843419
619 def_bool $(ld-option,--fix-cortex-a53-843419)
621 config ARM64_ERRATUM_1024718
622 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
625 This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
627 Affected Cortex-A55 cores (all revisions) could cause incorrect
628 update of the hardware dirty bit when the DBM/AP bits are updated
629 without a break-before-make. The workaround is to disable the usage
630 of hardware DBM locally on the affected cores. CPUs not affected by
631 this erratum will continue to use the feature.
635 config ARM64_ERRATUM_1418040
636 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
640 This option adds a workaround for ARM Cortex-A76/Neoverse-N1
641 errata 1188873 and 1418040.
643 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
644 cause register corruption when accessing the timer registers
645 from AArch32 userspace.
649 config ARM64_WORKAROUND_SPECULATIVE_AT
652 config ARM64_ERRATUM_1165522
653 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
655 select ARM64_WORKAROUND_SPECULATIVE_AT
657 This option adds a workaround for ARM Cortex-A76 erratum 1165522.
659 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
660 corrupted TLBs by speculating an AT instruction during a guest
665 config ARM64_ERRATUM_1319367
666 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
668 select ARM64_WORKAROUND_SPECULATIVE_AT
670 This option adds work arounds for ARM Cortex-A57 erratum 1319537
671 and A72 erratum 1319367
673 Cortex-A57 and A72 cores could end-up with corrupted TLBs by
674 speculating an AT instruction during a guest context switch.
678 config ARM64_ERRATUM_1530923
679 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
681 select ARM64_WORKAROUND_SPECULATIVE_AT
683 This option adds a workaround for ARM Cortex-A55 erratum 1530923.
685 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
686 corrupted TLBs by speculating an AT instruction during a guest
691 config ARM64_WORKAROUND_REPEAT_TLBI
694 config ARM64_ERRATUM_2441007
695 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
697 select ARM64_WORKAROUND_REPEAT_TLBI
699 This option adds a workaround for ARM Cortex-A55 erratum #2441007.
701 Under very rare circumstances, affected Cortex-A55 CPUs
702 may not handle a race between a break-before-make sequence on one
703 CPU, and another CPU accessing the same page. This could allow a
704 store to a page that has been unmapped.
706 Work around this by adding the affected CPUs to the list that needs
707 TLB sequences to be done twice.
711 config ARM64_ERRATUM_1286807
712 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
714 select ARM64_WORKAROUND_REPEAT_TLBI
716 This option adds a workaround for ARM Cortex-A76 erratum 1286807.
718 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
719 address for a cacheable mapping of a location is being
720 accessed by a core while another core is remapping the virtual
721 address to a new physical page using the recommended
722 break-before-make sequence, then under very rare circumstances
723 TLBI+DSB completes before a read using the translation being
724 invalidated has been observed by other observers. The
725 workaround repeats the TLBI+DSB operation.
727 config ARM64_ERRATUM_1463225
728 bool "Cortex-A76: Software Step might prevent interrupt recognition"
731 This option adds a workaround for Arm Cortex-A76 erratum 1463225.
733 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
734 of a system call instruction (SVC) can prevent recognition of
735 subsequent interrupts when software stepping is disabled in the
736 exception handler of the system call and either kernel debugging
737 is enabled or VHE is in use.
739 Work around the erratum by triggering a dummy step exception
740 when handling a system call from a task that is being stepped
741 in a VHE configuration of the kernel.
745 config ARM64_ERRATUM_1542419
746 bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
749 This option adds a workaround for ARM Neoverse-N1 erratum
752 Affected Neoverse-N1 cores could execute a stale instruction when
753 modified by another CPU. The workaround depends on a firmware
756 Workaround the issue by hiding the DIC feature from EL0. This
757 forces user-space to perform cache maintenance.
761 config ARM64_ERRATUM_1508412
762 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
765 This option adds a workaround for Arm Cortex-A77 erratum 1508412.
767 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
768 of a store-exclusive or read of PAR_EL1 and a load with device or
769 non-cacheable memory attributes. The workaround depends on a firmware
772 KVM guests must also have the workaround implemented or they can
775 Work around the issue by inserting DMB SY barriers around PAR_EL1
776 register reads and warning KVM users. The DMB barrier is sufficient
777 to prevent a speculative PAR_EL1 read.
781 config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
784 config ARM64_ERRATUM_2051678
785 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
788 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
789 Affected Cortex-A510 might not respect the ordering rules for
790 hardware update of the page table's dirty bit. The workaround
791 is to not enable the feature on affected CPUs.
795 config ARM64_ERRATUM_2077057
796 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
799 This option adds the workaround for ARM Cortex-A510 erratum 2077057.
800 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
801 expected, but a Pointer Authentication trap is taken instead. The
802 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
803 EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
805 This can only happen when EL2 is stepping EL1.
807 When these conditions occur, the SPSR_EL2 value is unchanged from the
808 previous guest entry, and can be restored from the in-memory copy.
812 config ARM64_ERRATUM_2658417
813 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
816 This option adds the workaround for ARM Cortex-A510 erratum 2658417.
817 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
818 BFMMLA or VMMLA instructions in rare circumstances when a pair of
819 A510 CPUs are using shared neon hardware. As the sharing is not
820 discoverable by the kernel, hide the BF16 HWCAP to indicate that
821 user-space should not be using these instructions.
825 config ARM64_ERRATUM_2119858
826 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
828 depends on CORESIGHT_TRBE
829 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
831 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
833 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
834 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
835 the event of a WRAP event.
837 Work around the issue by always making sure we move the TRBPTR_EL1 by
838 256 bytes before enabling the buffer and filling the first 256 bytes of
839 the buffer with ETM ignore packets upon disabling.
843 config ARM64_ERRATUM_2139208
844 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
846 depends on CORESIGHT_TRBE
847 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
849 This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
851 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
852 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
853 the event of a WRAP event.
855 Work around the issue by always making sure we move the TRBPTR_EL1 by
856 256 bytes before enabling the buffer and filling the first 256 bytes of
857 the buffer with ETM ignore packets upon disabling.
861 config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
864 config ARM64_ERRATUM_2054223
865 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
867 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
869 Enable workaround for ARM Cortex-A710 erratum 2054223
871 Affected cores may fail to flush the trace data on a TSB instruction, when
872 the PE is in trace prohibited state. This will cause losing a few bytes
875 Workaround is to issue two TSB consecutively on affected cores.
879 config ARM64_ERRATUM_2067961
880 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
882 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
884 Enable workaround for ARM Neoverse-N2 erratum 2067961
886 Affected cores may fail to flush the trace data on a TSB instruction, when
887 the PE is in trace prohibited state. This will cause losing a few bytes
890 Workaround is to issue two TSB consecutively on affected cores.
894 config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
897 config ARM64_ERRATUM_2253138
898 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
899 depends on CORESIGHT_TRBE
901 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
903 This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
905 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
906 for TRBE. Under some conditions, the TRBE might generate a write to the next
907 virtually addressed page following the last page of the TRBE address space
908 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
910 Work around this in the driver by always making sure that there is a
911 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
915 config ARM64_ERRATUM_2224489
916 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
917 depends on CORESIGHT_TRBE
919 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
921 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
923 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
924 for TRBE. Under some conditions, the TRBE might generate a write to the next
925 virtually addressed page following the last page of the TRBE address space
926 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
928 Work around this in the driver by always making sure that there is a
929 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
933 config ARM64_ERRATUM_2441009
934 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
936 select ARM64_WORKAROUND_REPEAT_TLBI
938 This option adds a workaround for ARM Cortex-A510 erratum #2441009.
940 Under very rare circumstances, affected Cortex-A510 CPUs
941 may not handle a race between a break-before-make sequence on one
942 CPU, and another CPU accessing the same page. This could allow a
943 store to a page that has been unmapped.
945 Work around this by adding the affected CPUs to the list that needs
946 TLB sequences to be done twice.
950 config ARM64_ERRATUM_2064142
951 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
952 depends on CORESIGHT_TRBE
955 This option adds the workaround for ARM Cortex-A510 erratum 2064142.
957 Affected Cortex-A510 core might fail to write into system registers after the
958 TRBE has been disabled. Under some conditions after the TRBE has been disabled
959 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
960 and TRBTRG_EL1 will be ignored and will not be effected.
962 Work around this in the driver by executing TSB CSYNC and DSB after collection
963 is stopped and before performing a system register write to one of the affected
968 config ARM64_ERRATUM_2038923
969 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
970 depends on CORESIGHT_TRBE
973 This option adds the workaround for ARM Cortex-A510 erratum 2038923.
975 Affected Cortex-A510 core might cause an inconsistent view on whether trace is
976 prohibited within the CPU. As a result, the trace buffer or trace buffer state
977 might be corrupted. This happens after TRBE buffer has been enabled by setting
978 TRBLIMITR_EL1.E, followed by just a single context synchronization event before
979 execution changes from a context, in which trace is prohibited to one where it
980 isn't, or vice versa. In these mentioned conditions, the view of whether trace
981 is prohibited is inconsistent between parts of the CPU, and the trace buffer or
982 the trace buffer state might be corrupted.
984 Work around this in the driver by preventing an inconsistent view of whether the
985 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
986 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
987 two ISB instructions if no ERET is to take place.
991 config ARM64_ERRATUM_1902691
992 bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
993 depends on CORESIGHT_TRBE
996 This option adds the workaround for ARM Cortex-A510 erratum 1902691.
998 Affected Cortex-A510 core might cause trace data corruption, when being written
999 into the memory. Effectively TRBE is broken and hence cannot be used to capture
1002 Work around this problem in the driver by just preventing TRBE initialization on
1003 affected cpus. The firmware must have disabled the access to TRBE for the kernel
1004 on such implementations. This will cover the kernel for any firmware that doesn't
1009 config ARM64_ERRATUM_2457168
1010 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1011 depends on ARM64_AMU_EXTN
1014 This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1016 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1017 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1018 incorrectly giving a significantly higher output value.
1020 Work around this problem by returning 0 when reading the affected counter in
1021 key locations that results in disabling all users of this counter. This effect
1022 is the same to firmware disabling affected counters.
1026 config ARM64_ERRATUM_2645198
1027 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1030 This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1032 If a Cortex-A715 cpu sees a page mapping permissions change from executable
1033 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1034 next instruction abort caused by permission fault.
1036 Only user-space does executable to non-executable permission transition via
1037 mprotect() system call. Workaround the problem by doing a break-before-make
1038 TLB invalidation, for all changes to executable user space mappings.
1042 config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1045 config ARM64_ERRATUM_2966298
1046 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1047 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1050 This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1052 On an affected Cortex-A520 core, a speculatively executed unprivileged
1053 load might leak data from a privileged level via a cache side channel.
1055 Work around this problem by executing a TLBI before returning to EL0.
1059 config ARM64_ERRATUM_3117295
1060 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1061 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1064 This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1066 On an affected Cortex-A510 core, a speculatively executed unprivileged
1067 load might leak data from a privileged level via a cache side channel.
1069 Work around this problem by executing a TLBI before returning to EL0.
1073 config CAVIUM_ERRATUM_22375
1074 bool "Cavium erratum 22375, 24313"
1077 Enable workaround for errata 22375 and 24313.
1079 This implements two gicv3-its errata workarounds for ThunderX. Both
1080 with a small impact affecting only ITS table allocation.
1082 erratum 22375: only alloc 8MB table size
1083 erratum 24313: ignore memory access type
1085 The fixes are in ITS initialization and basically ignore memory access
1086 type and table size provided by the TYPER and BASER registers.
1090 config CAVIUM_ERRATUM_23144
1091 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1095 ITS SYNC command hang for cross node io and collections/cpu mapping.
1099 config CAVIUM_ERRATUM_23154
1100 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1103 The ThunderX GICv3 implementation requires a modified version for
1104 reading the IAR status to ensure data synchronization
1105 (access to icc_iar1_el1 is not sync'ed before and after).
1107 It also suffers from erratum 38545 (also present on Marvell's
1108 OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1109 spuriously presented to the CPU interface.
1113 config CAVIUM_ERRATUM_27456
1114 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1117 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1118 instructions may cause the icache to become corrupted if it
1119 contains data for a non-current ASID. The fix is to
1120 invalidate the icache when changing the mm context.
1124 config CAVIUM_ERRATUM_30115
1125 bool "Cavium erratum 30115: Guest may disable interrupts in host"
1128 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1129 1.2, and T83 Pass 1.0, KVM guest execution may disable
1130 interrupts in host. Trapping both GICv3 group-0 and group-1
1131 accesses sidesteps the issue.
1135 config CAVIUM_TX2_ERRATUM_219
1136 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1139 On Cavium ThunderX2, a load, store or prefetch instruction between a
1140 TTBR update and the corresponding context synchronizing operation can
1141 cause a spurious Data Abort to be delivered to any hardware thread in
1144 Work around the issue by avoiding the problematic code sequence and
1145 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1146 trap handler performs the corresponding register access, skips the
1147 instruction and ensures context synchronization by virtue of the
1152 config FUJITSU_ERRATUM_010001
1153 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1156 This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1157 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1158 accesses may cause undefined fault (Data abort, DFSC=0b111111).
1159 This fault occurs under a specific hardware condition when a
1160 load/store instruction performs an address translation using:
1161 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1162 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1163 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1164 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1166 The workaround is to ensure these bits are clear in TCR_ELx.
1167 The workaround only affects the Fujitsu-A64FX.
1171 config HISILICON_ERRATUM_161600802
1172 bool "Hip07 161600802: Erroneous redistributor VLPI base"
1175 The HiSilicon Hip07 SoC uses the wrong redistributor base
1176 when issued ITS commands such as VMOVP and VMAPP, and requires
1177 a 128kB offset to be applied to the target address in this commands.
1181 config QCOM_FALKOR_ERRATUM_1003
1182 bool "Falkor E1003: Incorrect translation due to ASID change"
1185 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1186 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1187 in TTBR1_EL1, this situation only occurs in the entry trampoline and
1188 then only for entries in the walk cache, since the leaf translation
1189 is unchanged. Work around the erratum by invalidating the walk cache
1190 entries for the trampoline before entering the kernel proper.
1192 config QCOM_FALKOR_ERRATUM_1009
1193 bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1195 select ARM64_WORKAROUND_REPEAT_TLBI
1197 On Falkor v1, the CPU may prematurely complete a DSB following a
1198 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1199 one more time to fix the issue.
1203 config QCOM_QDF2400_ERRATUM_0065
1204 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1207 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1208 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1209 been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1213 config QCOM_FALKOR_ERRATUM_E1041
1214 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1217 Falkor CPU may speculatively fetch instructions from an improper
1218 memory location when MMU translation is changed from SCTLR_ELn[M]=1
1219 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1223 config NVIDIA_CARMEL_CNP_ERRATUM
1224 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1227 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1228 invalidate shared TLB entries installed by a different core, as it would
1229 on standard ARM cores.
1233 config ROCKCHIP_ERRATUM_3588001
1234 bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1237 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1238 This means, that its sharability feature may not be used, even though it
1239 is supported by the IP itself.
1243 config SOCIONEXT_SYNQUACER_PREITS
1244 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1247 Socionext Synquacer SoCs implement a separate h/w block to generate
1248 MSI doorbell writes with non-zero values for the device ID.
1252 endmenu # "ARM errata workarounds via the alternatives framework"
1256 default ARM64_4K_PAGES
1258 Page size (translation granule) configuration.
1260 config ARM64_4K_PAGES
1263 This feature enables 4KB pages support.
1265 config ARM64_16K_PAGES
1268 The system will use 16KB pages support. AArch32 emulation
1269 requires applications compiled with 16K (or a multiple of 16K)
1272 config ARM64_64K_PAGES
1275 This feature enables 64KB pages support (4KB by default)
1276 allowing only two levels of page tables and faster TLB
1277 look-up. AArch32 emulation requires applications compiled
1278 with 64K aligned segments.
1283 prompt "Virtual address space size"
1284 default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1285 default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1286 default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1288 Allows choosing one of multiple possible virtual address
1289 space sizes. The level of translation table is determined by
1290 a combination of page size and virtual address space size.
1292 config ARM64_VA_BITS_36
1293 bool "36-bit" if EXPERT
1294 depends on ARM64_16K_PAGES
1296 config ARM64_VA_BITS_39
1298 depends on ARM64_4K_PAGES
1300 config ARM64_VA_BITS_42
1302 depends on ARM64_64K_PAGES
1304 config ARM64_VA_BITS_47
1306 depends on ARM64_16K_PAGES
1308 config ARM64_VA_BITS_48
1311 config ARM64_VA_BITS_52
1313 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1315 Enable 52-bit virtual addressing for userspace when explicitly
1316 requested via a hint to mmap(). The kernel will also use 52-bit
1317 virtual addresses for its own mappings (provided HW support for
1318 this feature is available, otherwise it reverts to 48-bit).
1320 NOTE: Enabling 52-bit virtual addressing in conjunction with
1321 ARMv8.3 Pointer Authentication will result in the PAC being
1322 reduced from 7 bits to 3 bits, which may have a significant
1323 impact on its susceptibility to brute-force attacks.
1325 If unsure, select 48-bit virtual addressing instead.
1329 config ARM64_FORCE_52BIT
1330 bool "Force 52-bit virtual addresses for userspace"
1331 depends on ARM64_VA_BITS_52 && EXPERT
1333 For systems with 52-bit userspace VAs enabled, the kernel will attempt
1334 to maintain compatibility with older software by providing 48-bit VAs
1335 unless a hint is supplied to mmap.
1337 This configuration option disables the 48-bit compatibility logic, and
1338 forces all userspace addresses to be 52-bit on HW that supports it. One
1339 should only enable this configuration option for stress testing userspace
1340 memory management code. If unsure say N here.
1342 config ARM64_VA_BITS
1344 default 36 if ARM64_VA_BITS_36
1345 default 39 if ARM64_VA_BITS_39
1346 default 42 if ARM64_VA_BITS_42
1347 default 47 if ARM64_VA_BITS_47
1348 default 48 if ARM64_VA_BITS_48
1349 default 52 if ARM64_VA_BITS_52
1352 prompt "Physical address space size"
1353 default ARM64_PA_BITS_48
1355 Choose the maximum physical address range that the kernel will
1358 config ARM64_PA_BITS_48
1361 config ARM64_PA_BITS_52
1362 bool "52-bit (ARMv8.2)"
1363 depends on ARM64_64K_PAGES
1364 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1366 Enable support for a 52-bit physical address space, introduced as
1367 part of the ARMv8.2-LPA extension.
1369 With this enabled, the kernel will also continue to work on CPUs that
1370 do not support ARMv8.2-LPA, but with some added memory overhead (and
1371 minor performance overhead).
1375 config ARM64_PA_BITS
1377 default 48 if ARM64_PA_BITS_48
1378 default 52 if ARM64_PA_BITS_52
1382 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1386 default CPU_LITTLE_ENDIAN
1388 Select the endianness of data accesses performed by the CPU. Userspace
1389 applications will need to be compiled and linked for the endianness
1390 that is selected here.
1392 config CPU_BIG_ENDIAN
1393 bool "Build big-endian kernel"
1394 depends on !LD_IS_LLD || LLD_VERSION >= 130000
1395 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1396 depends on AS_IS_GNU || AS_VERSION >= 150000
1398 Say Y if you plan on running a kernel with a big-endian userspace.
1400 config CPU_LITTLE_ENDIAN
1401 bool "Build little-endian kernel"
1403 Say Y if you plan on running a kernel with a little-endian userspace.
1404 This is usually the case for distributions targeting arm64.
1409 bool "Multi-core scheduler support"
1411 Multi-core scheduler support improves the CPU scheduler's decision
1412 making when dealing with multi-core CPU chips at a cost of slightly
1413 increased overhead in some places. If unsure say N here.
1415 config SCHED_CLUSTER
1416 bool "Cluster scheduler support"
1418 Cluster scheduler support improves the CPU scheduler's decision
1419 making when dealing with machines that have clusters of CPUs.
1420 Cluster usually means a couple of CPUs which are placed closely
1421 by sharing mid-level caches, last-level cache tags or internal
1425 bool "SMT scheduler support"
1427 Improves the CPU scheduler's decision making when dealing with
1428 MultiThreading at a cost of slightly increased overhead in some
1429 places. If unsure say N here.
1432 int "Maximum number of CPUs (2-4096)"
1437 bool "Support for hot-pluggable CPUs"
1438 select GENERIC_IRQ_MIGRATION
1440 Say Y here to experiment with turning CPUs off and on. CPUs
1441 can be controlled through /sys/devices/system/cpu.
1443 # Common NUMA Features
1445 bool "NUMA Memory Allocation and Scheduler Support"
1446 select GENERIC_ARCH_NUMA
1447 select ACPI_NUMA if ACPI
1449 select HAVE_SETUP_PER_CPU_AREA
1450 select NEED_PER_CPU_EMBED_FIRST_CHUNK
1451 select NEED_PER_CPU_PAGE_FIRST_CHUNK
1452 select USE_PERCPU_NUMA_NODE_ID
1454 Enable NUMA (Non-Uniform Memory Access) support.
1456 The kernel will try to allocate memory used by a CPU on the
1457 local memory of the CPU and add some more
1458 NUMA awareness to the kernel.
1461 int "Maximum NUMA Nodes (as a power of 2)"
1466 Specify the maximum number of NUMA Nodes available on the target
1467 system. Increases memory reserved to accommodate various tables.
1469 source "kernel/Kconfig.hz"
1471 config ARCH_SPARSEMEM_ENABLE
1473 select SPARSEMEM_VMEMMAP_ENABLE
1474 select SPARSEMEM_VMEMMAP
1476 config HW_PERF_EVENTS
1480 # Supported by clang >= 7.0 or GCC >= 12.0.0
1481 config CC_HAVE_SHADOW_CALL_STACK
1482 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1485 bool "Enable paravirtualization code"
1487 This changes the kernel so it can modify itself when it is run
1488 under a hypervisor, potentially improving performance significantly
1489 over full virtualization.
1491 config PARAVIRT_TIME_ACCOUNTING
1492 bool "Paravirtual steal time accounting"
1495 Select this option to enable fine granularity task steal time
1496 accounting. Time spent executing other tasks in parallel with
1497 the current vCPU is discounted from the vCPU power. To account for
1498 that, there can be a small performance impact.
1500 If in doubt, say N here.
1502 config ARCH_SUPPORTS_KEXEC
1503 def_bool PM_SLEEP_SMP
1505 config ARCH_SUPPORTS_KEXEC_FILE
1508 config ARCH_SELECTS_KEXEC_FILE
1510 depends on KEXEC_FILE
1511 select HAVE_IMA_KEXEC if IMA
1513 config ARCH_SUPPORTS_KEXEC_SIG
1516 config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1519 config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1522 config ARCH_SUPPORTS_CRASH_DUMP
1525 config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1530 depends on HIBERNATION || KEXEC_CORE
1537 bool "Xen guest support on ARM64"
1538 depends on ARM64 && OF
1542 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1544 # include/linux/mmzone.h requires the following to be true:
1546 # MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1548 # so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1550 # | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER |
1551 # ----+-------------------+--------------+----------------------+-------------------------+
1552 # 4K | 27 | 12 | 15 | 10 |
1553 # 16K | 27 | 14 | 13 | 11 |
1554 # 64K | 29 | 16 | 13 | 13 |
1555 config ARCH_FORCE_MAX_ORDER
1557 default "13" if ARM64_64K_PAGES
1558 default "11" if ARM64_16K_PAGES
1561 The kernel page allocator limits the size of maximal physically
1562 contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1563 defines the maximal power of two of number of pages that can be
1564 allocated as a single contiguous block. This option allows
1565 overriding the default setting when ability to allocate very
1566 large blocks of physically contiguous memory is required.
1568 The maximal size of allocation cannot exceed the size of the
1569 section, so the value of MAX_PAGE_ORDER should satisfy
1571 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1573 Don't change if unsure.
1575 config UNMAP_KERNEL_AT_EL0
1576 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1579 Speculation attacks against some high-performance processors can
1580 be used to bypass MMU permission checks and leak kernel data to
1581 userspace. This can be defended against by unmapping the kernel
1582 when running in userspace, mapping it back in on exception entry
1583 via a trampoline page in the vector table.
1587 config MITIGATE_SPECTRE_BRANCH_HISTORY
1588 bool "Mitigate Spectre style attacks against branch history" if EXPERT
1591 Speculation attacks against some high-performance processors can
1592 make use of branch history to influence future speculation.
1593 When taking an exception from user-space, a sequence of branches
1594 or a firmware call overwrites the branch history.
1596 config RODATA_FULL_DEFAULT_ENABLED
1597 bool "Apply r/o permissions of VM areas also to their linear aliases"
1600 Apply read-only attributes of VM areas to the linear alias of
1601 the backing pages as well. This prevents code or read-only data
1602 from being modified (inadvertently or intentionally) via another
1603 mapping of the same memory page. This additional enhancement can
1604 be turned off at runtime by passing rodata=[off|on] (and turned on
1605 with rodata=full if this option is set to 'n')
1607 This requires the linear region to be mapped down to pages,
1608 which may adversely affect performance in some cases.
1610 config ARM64_SW_TTBR0_PAN
1611 bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1613 Enabling this option prevents the kernel from accessing
1614 user-space memory directly by pointing TTBR0_EL1 to a reserved
1615 zeroed area and reserved ASID. The user access routines
1616 restore the valid TTBR0_EL1 temporarily.
1618 config ARM64_TAGGED_ADDR_ABI
1619 bool "Enable the tagged user addresses syscall ABI"
1622 When this option is enabled, user applications can opt in to a
1623 relaxed ABI via prctl() allowing tagged addresses to be passed
1624 to system calls as pointer arguments. For details, see
1625 Documentation/arch/arm64/tagged-address-abi.rst.
1628 bool "Kernel support for 32-bit EL0"
1629 depends on ARM64_4K_PAGES || EXPERT
1631 select OLD_SIGSUSPEND3
1632 select COMPAT_OLD_SIGACTION
1634 This option enables support for a 32-bit EL0 running under a 64-bit
1635 kernel at EL1. AArch32-specific components such as system calls,
1636 the user helper functions, VFP support and the ptrace interface are
1637 handled appropriately by the kernel.
1639 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1640 that you will only be able to execute AArch32 binaries that were compiled
1641 with page size aligned segments.
1643 If you want to execute 32-bit userspace applications, say Y.
1647 config KUSER_HELPERS
1648 bool "Enable kuser helpers page for 32-bit applications"
1651 Warning: disabling this option may break 32-bit user programs.
1653 Provide kuser helpers to compat tasks. The kernel provides
1654 helper code to userspace in read only form at a fixed location
1655 to allow userspace to be independent of the CPU type fitted to
1656 the system. This permits binaries to be run on ARMv4 through
1657 to ARMv8 without modification.
1659 See Documentation/arch/arm/kernel_user_helpers.rst for details.
1661 However, the fixed address nature of these helpers can be used
1662 by ROP (return orientated programming) authors when creating
1665 If all of the binaries and libraries which run on your platform
1666 are built specifically for your platform, and make no use of
1667 these helpers, then you can turn this option off to hinder
1668 such exploits. However, in that case, if a binary or library
1669 relying on those helpers is run, it will not function correctly.
1671 Say N here only if you are absolutely certain that you do not
1672 need these helpers; otherwise, the safe option is to say Y.
1675 bool "Enable vDSO for 32-bit applications"
1676 depends on !CPU_BIG_ENDIAN
1677 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1678 select GENERIC_COMPAT_VDSO
1681 Place in the process address space of 32-bit applications an
1682 ELF shared object providing fast implementations of gettimeofday
1685 You must have a 32-bit build of glibc 2.22 or later for programs
1686 to seamlessly take advantage of this.
1688 config THUMB2_COMPAT_VDSO
1689 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1690 depends on COMPAT_VDSO
1693 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1694 otherwise with '-marm'.
1696 config COMPAT_ALIGNMENT_FIXUPS
1697 bool "Fix up misaligned multi-word loads and stores in user space"
1699 menuconfig ARMV8_DEPRECATED
1700 bool "Emulate deprecated/obsolete ARMv8 instructions"
1703 Legacy software support may require certain instructions
1704 that have been deprecated or obsoleted in the architecture.
1706 Enable this config to enable selective emulation of these
1713 config SWP_EMULATION
1714 bool "Emulate SWP/SWPB instructions"
1716 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1717 they are always undefined. Say Y here to enable software
1718 emulation of these instructions for userspace using LDXR/STXR.
1719 This feature can be controlled at runtime with the abi.swp
1720 sysctl which is disabled by default.
1722 In some older versions of glibc [<=2.8] SWP is used during futex
1723 trylock() operations with the assumption that the code will not
1724 be preempted. This invalid assumption may be more likely to fail
1725 with SWP emulation enabled, leading to deadlock of the user
1728 NOTE: when accessing uncached shared regions, LDXR/STXR rely
1729 on an external transaction monitoring block called a global
1730 monitor to maintain update atomicity. If your system does not
1731 implement a global monitor, this option can cause programs that
1732 perform SWP operations to uncached memory to deadlock.
1736 config CP15_BARRIER_EMULATION
1737 bool "Emulate CP15 Barrier instructions"
1739 The CP15 barrier instructions - CP15ISB, CP15DSB, and
1740 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1741 strongly recommended to use the ISB, DSB, and DMB
1742 instructions instead.
1744 Say Y here to enable software emulation of these
1745 instructions for AArch32 userspace code. When this option is
1746 enabled, CP15 barrier usage is traced which can help
1747 identify software that needs updating. This feature can be
1748 controlled at runtime with the abi.cp15_barrier sysctl.
1752 config SETEND_EMULATION
1753 bool "Emulate SETEND instruction"
1755 The SETEND instruction alters the data-endianness of the
1756 AArch32 EL0, and is deprecated in ARMv8.
1758 Say Y here to enable software emulation of the instruction
1759 for AArch32 userspace code. This feature can be controlled
1760 at runtime with the abi.setend sysctl.
1762 Note: All the cpus on the system must have mixed endian support at EL0
1763 for this feature to be enabled. If a new CPU - which doesn't support mixed
1764 endian - is hotplugged in after this feature has been enabled, there could
1765 be unexpected results in the applications.
1768 endif # ARMV8_DEPRECATED
1772 menu "ARMv8.1 architectural features"
1774 config ARM64_HW_AFDBM
1775 bool "Support for hardware updates of the Access and Dirty page flags"
1778 The ARMv8.1 architecture extensions introduce support for
1779 hardware updates of the access and dirty information in page
1780 table entries. When enabled in TCR_EL1 (HA and HD bits) on
1781 capable processors, accesses to pages with PTE_AF cleared will
1782 set this bit instead of raising an access flag fault.
1783 Similarly, writes to read-only pages with the DBM bit set will
1784 clear the read-only bit (AP[2]) instead of raising a
1787 Kernels built with this configuration option enabled continue
1788 to work on pre-ARMv8.1 hardware and the performance impact is
1789 minimal. If unsure, say Y.
1792 bool "Enable support for Privileged Access Never (PAN)"
1795 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1796 prevents the kernel or hypervisor from accessing user-space (EL0)
1799 Choosing this option will cause any unprotected (not using
1800 copy_to_user et al) memory access to fail with a permission fault.
1802 The feature is detected at runtime, and will remain as a 'nop'
1803 instruction if the cpu does not implement the feature.
1805 config AS_HAS_LSE_ATOMICS
1806 def_bool $(as-instr,.arch_extension lse)
1808 config ARM64_LSE_ATOMICS
1810 default ARM64_USE_LSE_ATOMICS
1811 depends on AS_HAS_LSE_ATOMICS
1813 config ARM64_USE_LSE_ATOMICS
1814 bool "Atomic instructions"
1817 As part of the Large System Extensions, ARMv8.1 introduces new
1818 atomic instructions that are designed specifically to scale in
1821 Say Y here to make use of these instructions for the in-kernel
1822 atomic routines. This incurs a small overhead on CPUs that do
1823 not support these instructions and requires the kernel to be
1824 built with binutils >= 2.25 in order for the new instructions
1827 endmenu # "ARMv8.1 architectural features"
1829 menu "ARMv8.2 architectural features"
1831 config AS_HAS_ARMV8_2
1832 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1835 def_bool $(as-instr,.arch armv8.2-a+sha3)
1838 bool "Enable support for persistent memory"
1839 select ARCH_HAS_PMEM_API
1840 select ARCH_HAS_UACCESS_FLUSHCACHE
1842 Say Y to enable support for the persistent memory API based on the
1843 ARMv8.2 DCPoP feature.
1845 The feature is detected at runtime, and the kernel will use DC CVAC
1846 operations if DC CVAP is not supported (following the behaviour of
1847 DC CVAP itself if the system does not define a point of persistence).
1849 config ARM64_RAS_EXTN
1850 bool "Enable support for RAS CPU Extensions"
1853 CPUs that support the Reliability, Availability and Serviceability
1854 (RAS) Extensions, part of ARMv8.2 are able to track faults and
1855 errors, classify them and report them to software.
1857 On CPUs with these extensions system software can use additional
1858 barriers to determine if faults are pending and read the
1859 classification from a new set of registers.
1861 Selecting this feature will allow the kernel to use these barriers
1862 and access the new registers if the system supports the extension.
1863 Platform RAS features may additionally depend on firmware support.
1866 bool "Enable support for Common Not Private (CNP) translations"
1868 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1870 Common Not Private (CNP) allows translation table entries to
1871 be shared between different PEs in the same inner shareable
1872 domain, so the hardware can use this fact to optimise the
1873 caching of such entries in the TLB.
1875 Selecting this option allows the CNP feature to be detected
1876 at runtime, and does not affect PEs that do not implement
1879 endmenu # "ARMv8.2 architectural features"
1881 menu "ARMv8.3 architectural features"
1883 config ARM64_PTR_AUTH
1884 bool "Enable support for pointer authentication"
1887 Pointer authentication (part of the ARMv8.3 Extensions) provides
1888 instructions for signing and authenticating pointers against secret
1889 keys, which can be used to mitigate Return Oriented Programming (ROP)
1892 This option enables these instructions at EL0 (i.e. for userspace).
1893 Choosing this option will cause the kernel to initialise secret keys
1894 for each process at exec() time, with these keys being
1895 context-switched along with the process.
1897 The feature is detected at runtime. If the feature is not present in
1898 hardware it will not be advertised to userspace/KVM guest nor will it
1901 If the feature is present on the boot CPU but not on a late CPU, then
1902 the late CPU will be parked. Also, if the boot CPU does not have
1903 address auth and the late CPU has then the late CPU will still boot
1904 but with the feature disabled. On such a system, this option should
1907 config ARM64_PTR_AUTH_KERNEL
1908 bool "Use pointer authentication for kernel"
1910 depends on ARM64_PTR_AUTH
1911 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1912 # Modern compilers insert a .note.gnu.property section note for PAC
1913 # which is only understood by binutils starting with version 2.33.1.
1914 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1915 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1916 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1918 If the compiler supports the -mbranch-protection or
1919 -msign-return-address flag (e.g. GCC 7 or later), then this option
1920 will cause the kernel itself to be compiled with return address
1921 protection. In this case, and if the target hardware is known to
1922 support pointer authentication, then CONFIG_STACKPROTECTOR can be
1923 disabled with minimal loss of protection.
1925 This feature works with FUNCTION_GRAPH_TRACER option only if
1926 DYNAMIC_FTRACE_WITH_ARGS is enabled.
1928 config CC_HAS_BRANCH_PROT_PAC_RET
1929 # GCC 9 or later, clang 8 or later
1930 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1932 config CC_HAS_SIGN_RETURN_ADDRESS
1934 def_bool $(cc-option,-msign-return-address=all)
1936 config AS_HAS_ARMV8_3
1937 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1939 config AS_HAS_CFI_NEGATE_RA_STATE
1940 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1943 def_bool $(as-instr,.arch_extension rcpc)
1945 endmenu # "ARMv8.3 architectural features"
1947 menu "ARMv8.4 architectural features"
1949 config ARM64_AMU_EXTN
1950 bool "Enable support for the Activity Monitors Unit CPU extension"
1953 The activity monitors extension is an optional extension introduced
1954 by the ARMv8.4 CPU architecture. This enables support for version 1
1955 of the activity monitors architecture, AMUv1.
1957 To enable the use of this extension on CPUs that implement it, say Y.
1959 Note that for architectural reasons, firmware _must_ implement AMU
1960 support when running on CPUs that present the activity monitors
1961 extension. The required support is present in:
1962 * Version 1.5 and later of the ARM Trusted Firmware
1964 For kernels that have this configuration enabled but boot with broken
1965 firmware, you may need to say N here until the firmware is fixed.
1966 Otherwise you may experience firmware panics or lockups when
1967 accessing the counter registers. Even if you are not observing these
1968 symptoms, the values returned by the register reads might not
1969 correctly reflect reality. Most commonly, the value read will be 0,
1970 indicating that the counter is not enabled.
1972 config AS_HAS_ARMV8_4
1973 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1975 config ARM64_TLB_RANGE
1976 bool "Enable support for tlbi range feature"
1978 depends on AS_HAS_ARMV8_4
1980 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1981 range of input addresses.
1983 The feature introduces new assembly instructions, and they were
1984 support when binutils >= 2.30.
1986 endmenu # "ARMv8.4 architectural features"
1988 menu "ARMv8.5 architectural features"
1990 config AS_HAS_ARMV8_5
1991 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1994 bool "Branch Target Identification support"
1997 Branch Target Identification (part of the ARMv8.5 Extensions)
1998 provides a mechanism to limit the set of locations to which computed
1999 branch instructions such as BR or BLR can jump.
2001 To make use of BTI on CPUs that support it, say Y.
2003 BTI is intended to provide complementary protection to other control
2004 flow integrity protection mechanisms, such as the Pointer
2005 authentication mechanism provided as part of the ARMv8.3 Extensions.
2006 For this reason, it does not make sense to enable this option without
2007 also enabling support for pointer authentication. Thus, when
2008 enabling this option you should also select ARM64_PTR_AUTH=y.
2010 Userspace binaries must also be specifically compiled to make use of
2011 this mechanism. If you say N here or the hardware does not support
2012 BTI, such binaries can still run, but you get no additional
2013 enforcement of branch destinations.
2015 config ARM64_BTI_KERNEL
2016 bool "Use Branch Target Identification for kernel"
2018 depends on ARM64_BTI
2019 depends on ARM64_PTR_AUTH_KERNEL
2020 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2021 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2022 depends on !CC_IS_GCC || GCC_VERSION >= 100100
2023 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2024 depends on !CC_IS_GCC
2025 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
2026 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
2027 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2029 Build the kernel with Branch Target Identification annotations
2030 and enable enforcement of this for kernel code. When this option
2031 is enabled and the system supports BTI all kernel code including
2032 modular code must have BTI enabled.
2034 config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2035 # GCC 9 or later, clang 8 or later
2036 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2039 bool "Enable support for E0PD"
2042 E0PD (part of the ARMv8.5 extensions) allows us to ensure
2043 that EL0 accesses made via TTBR1 always fault in constant time,
2044 providing similar benefits to KASLR as those provided by KPTI, but
2045 with lower overhead and without disrupting legitimate access to
2046 kernel memory such as SPE.
2048 This option enables E0PD for TTBR1 where available.
2050 config ARM64_AS_HAS_MTE
2051 # Initial support for MTE went in binutils 2.32.0, checked with
2052 # ".arch armv8.5-a+memtag" below. However, this was incomplete
2053 # as a late addition to the final architecture spec (LDGM/STGM)
2054 # is only supported in the newer 2.32.x and 2.33 binutils
2055 # versions, hence the extra "stgm" instruction check below.
2056 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2059 bool "Memory Tagging Extension support"
2061 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2062 depends on AS_HAS_ARMV8_5
2063 depends on AS_HAS_LSE_ATOMICS
2064 # Required for tag checking in the uaccess routines
2065 depends on ARM64_PAN
2066 select ARCH_HAS_SUBPAGE_FAULTS
2067 select ARCH_USES_HIGH_VMA_FLAGS
2068 select ARCH_USES_PG_ARCH_X
2070 Memory Tagging (part of the ARMv8.5 Extensions) provides
2071 architectural support for run-time, always-on detection of
2072 various classes of memory error to aid with software debugging
2073 to eliminate vulnerabilities arising from memory-unsafe
2076 This option enables the support for the Memory Tagging
2077 Extension at EL0 (i.e. for userspace).
2079 Selecting this option allows the feature to be detected at
2080 runtime. Any secondary CPU not implementing this feature will
2081 not be allowed a late bring-up.
2083 Userspace binaries that want to use this feature must
2084 explicitly opt in. The mechanism for the userspace is
2087 Documentation/arch/arm64/memory-tagging-extension.rst.
2089 endmenu # "ARMv8.5 architectural features"
2091 menu "ARMv8.7 architectural features"
2094 bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2096 depends on ARM64_PAN
2098 Enhanced Privileged Access Never (EPAN) allows Privileged
2099 Access Never to be used with Execute-only mappings.
2101 The feature is detected at runtime, and will remain disabled
2102 if the cpu does not implement the feature.
2103 endmenu # "ARMv8.7 architectural features"
2106 bool "ARM Scalable Vector Extension support"
2109 The Scalable Vector Extension (SVE) is an extension to the AArch64
2110 execution state which complements and extends the SIMD functionality
2111 of the base architecture to support much larger vectors and to enable
2112 additional vectorisation opportunities.
2114 To enable use of this extension on CPUs that implement it, say Y.
2116 On CPUs that support the SVE2 extensions, this option will enable
2119 Note that for architectural reasons, firmware _must_ implement SVE
2120 support when running on SVE capable hardware. The required support
2123 * version 1.5 and later of the ARM Trusted Firmware
2124 * the AArch64 boot wrapper since commit 5e1261e08abf
2125 ("bootwrapper: SVE: Enable SVE for EL2 and below").
2127 For other firmware implementations, consult the firmware documentation
2130 If you need the kernel to boot on SVE-capable hardware with broken
2131 firmware, you may need to say N here until you get your firmware
2132 fixed. Otherwise, you may experience firmware panics or lockups when
2133 booting the kernel. If unsure and you are not observing these
2134 symptoms, you should assume that it is safe to say Y.
2137 bool "ARM Scalable Matrix Extension support"
2139 depends on ARM64_SVE
2141 The Scalable Matrix Extension (SME) is an extension to the AArch64
2142 execution state which utilises a substantial subset of the SVE
2143 instruction set, together with the addition of new architectural
2144 register state capable of holding two dimensional matrix tiles to
2145 enable various matrix operations.
2147 config ARM64_PSEUDO_NMI
2148 bool "Support for NMI-like interrupts"
2151 Adds support for mimicking Non-Maskable Interrupts through the use of
2152 GIC interrupt priority. This support requires version 3 or later of
2155 This high priority configuration for interrupts needs to be
2156 explicitly enabled by setting the kernel parameter
2157 "irqchip.gicv3_pseudo_nmi" to 1.
2162 config ARM64_DEBUG_PRIORITY_MASKING
2163 bool "Debug interrupt priority masking"
2165 This adds runtime checks to functions enabling/disabling
2166 interrupts when using priority masking. The additional checks verify
2167 the validity of ICC_PMR_EL1 when calling concerned functions.
2170 endif # ARM64_PSEUDO_NMI
2173 bool "Build a relocatable kernel image" if EXPERT
2174 select ARCH_HAS_RELR
2177 This builds the kernel as a Position Independent Executable (PIE),
2178 which retains all relocation metadata required to relocate the
2179 kernel binary at runtime to a different virtual address than the
2180 address it was linked at.
2181 Since AArch64 uses the RELA relocation format, this requires a
2182 relocation pass at runtime even if the kernel is loaded at the
2183 same address it was linked at.
2185 config RANDOMIZE_BASE
2186 bool "Randomize the address of the kernel image"
2189 Randomizes the virtual address at which the kernel image is
2190 loaded, as a security feature that deters exploit attempts
2191 relying on knowledge of the location of kernel internals.
2193 It is the bootloader's job to provide entropy, by passing a
2194 random u64 value in /chosen/kaslr-seed at kernel entry.
2196 When booting via the UEFI stub, it will invoke the firmware's
2197 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2198 to the kernel proper. In addition, it will randomise the physical
2199 location of the kernel Image as well.
2203 config RANDOMIZE_MODULE_REGION_FULL
2204 bool "Randomize the module region over a 2 GB range"
2205 depends on RANDOMIZE_BASE
2208 Randomizes the location of the module region inside a 2 GB window
2209 covering the core kernel. This way, it is less likely for modules
2210 to leak information about the location of core kernel data structures
2211 but it does imply that function calls between modules and the core
2212 kernel will need to be resolved via veneers in the module PLT.
2214 When this option is not set, the module region will be randomized over
2215 a limited range that contains the [_stext, _etext] interval of the
2216 core kernel, so branch relocations are almost always in range unless
2217 the region is exhausted. In this particular case of region
2218 exhaustion, modules might be able to fall back to a larger 2GB area.
2220 config CC_HAVE_STACKPROTECTOR_SYSREG
2221 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2223 config STACKPROTECTOR_PER_TASK
2225 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2227 config UNWIND_PATCH_PAC_INTO_SCS
2228 bool "Enable shadow call stack dynamically using code patching"
2229 # needs Clang with https://reviews.llvm.org/D111780 incorporated
2230 depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2231 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2232 depends on SHADOW_CALL_STACK
2233 select UNWIND_TABLES
2236 endmenu # "Kernel Features"
2240 config ARM64_ACPI_PARKING_PROTOCOL
2241 bool "Enable support for the ARM64 ACPI parking protocol"
2244 Enable support for the ARM64 ACPI parking protocol. If disabled
2245 the kernel will not allow booting through the ARM64 ACPI parking
2246 protocol even if the corresponding data is present in the ACPI
2250 string "Default kernel command string"
2253 Provide a set of default command-line options at build time by
2254 entering them here. As a minimum, you should specify the the
2255 root device (e.g. root=/dev/nfs).
2258 prompt "Kernel command line type" if CMDLINE != ""
2259 default CMDLINE_FROM_BOOTLOADER
2261 Choose how the kernel will handle the provided default kernel
2262 command line string.
2264 config CMDLINE_FROM_BOOTLOADER
2265 bool "Use bootloader kernel arguments if available"
2267 Uses the command-line options passed by the boot loader. If
2268 the boot loader doesn't provide any, the default kernel command
2269 string provided in CMDLINE will be used.
2271 config CMDLINE_FORCE
2272 bool "Always use the default kernel command string"
2274 Always use the default kernel command string, even if the boot
2275 loader passes other arguments to the kernel.
2276 This is useful if you cannot or don't want to change the
2277 command-line options your boot loader passes to the kernel.
2285 bool "UEFI runtime support"
2286 depends on OF && !CPU_BIG_ENDIAN
2287 depends on KERNEL_MODE_NEON
2288 select ARCH_SUPPORTS_ACPI
2291 select EFI_PARAMS_FROM_FDT
2292 select EFI_RUNTIME_WRAPPERS
2294 select EFI_GENERIC_STUB
2295 imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2298 This option provides support for runtime services provided
2299 by UEFI firmware (such as non-volatile variables, realtime
2300 clock, and platform reset). A UEFI stub is also provided to
2301 allow the kernel to be booted as an EFI application. This
2302 is only useful on systems that have UEFI firmware.
2305 bool "Enable support for SMBIOS (DMI) tables"
2309 This enables SMBIOS/DMI feature for systems.
2311 This option is only useful on systems that have UEFI firmware.
2312 However, even with this option, the resultant kernel should
2313 continue to boot on existing non-UEFI platforms.
2315 endmenu # "Boot options"
2317 menu "Power management options"
2319 source "kernel/power/Kconfig"
2321 config ARCH_HIBERNATION_POSSIBLE
2325 config ARCH_HIBERNATION_HEADER
2327 depends on HIBERNATION
2329 config ARCH_SUSPEND_POSSIBLE
2332 endmenu # "Power management options"
2334 menu "CPU Power Management"
2336 source "drivers/cpuidle/Kconfig"
2338 source "drivers/cpufreq/Kconfig"
2340 endmenu # "CPU Power Management"
2342 source "drivers/acpi/Kconfig"
2344 source "arch/arm64/kvm/Kconfig"