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_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
9 select ACPI_IORT if ACPI
10 select ACPI_REDUCED_HARDWARE_ONLY if ACPI
11 select ACPI_MCFG if (ACPI && PCI)
12 select ACPI_SPCR_TABLE if ACPI
13 select ACPI_PPTT if ACPI
14 select ARCH_HAS_DEBUG_WX
15 select ARCH_BINFMT_ELF_EXTRA_PHDRS
16 select ARCH_BINFMT_ELF_STATE
17 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
18 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
19 select ARCH_ENABLE_MEMORY_HOTPLUG
20 select ARCH_ENABLE_MEMORY_HOTREMOVE
21 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
22 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
23 select ARCH_HAS_CACHE_LINE_SIZE
24 select ARCH_HAS_CC_PLATFORM
25 select ARCH_HAS_CURRENT_STACK_POINTER
26 select ARCH_HAS_DEBUG_VIRTUAL
27 select ARCH_HAS_DEBUG_VM_PGTABLE
28 select ARCH_HAS_DMA_OPS if XEN
29 select ARCH_HAS_DMA_PREP_COHERENT
30 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
31 select ARCH_HAS_FAST_MULTIPLIER
32 select ARCH_HAS_FORTIFY_SOURCE
33 select ARCH_HAS_GCOV_PROFILE_ALL
34 select ARCH_HAS_GIGANTIC_PAGE
36 select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON
37 select ARCH_HAS_KEEPINITRD
38 select ARCH_HAS_MEMBARRIER_SYNC_CORE
39 select ARCH_HAS_MEM_ENCRYPT
40 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
41 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
42 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
43 select ARCH_HAS_PTE_DEVMAP
44 select ARCH_HAS_PTE_SPECIAL
45 select ARCH_HAS_HW_PTE_YOUNG
46 select ARCH_HAS_SETUP_DMA_OPS
47 select ARCH_HAS_SET_DIRECT_MAP
48 select ARCH_HAS_SET_MEMORY
49 select ARCH_HAS_MEM_ENCRYPT
50 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
52 select ARCH_HAS_STRICT_KERNEL_RWX
53 select ARCH_HAS_STRICT_MODULE_RWX
54 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
55 select ARCH_HAS_SYNC_DMA_FOR_CPU
56 select ARCH_HAS_SYSCALL_WRAPPER
57 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
58 select ARCH_HAS_ZONE_DMA_SET if EXPERT
59 select ARCH_HAVE_ELF_PROT
60 select ARCH_HAVE_NMI_SAFE_CMPXCHG
61 select ARCH_HAVE_TRACE_MMIO_ACCESS
62 select ARCH_INLINE_READ_LOCK if !PREEMPTION
63 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
64 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
65 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
66 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
67 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
68 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
69 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
70 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
71 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
72 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
73 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
74 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
75 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
76 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
77 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
78 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
79 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
80 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
81 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
82 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
83 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
84 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
85 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
86 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
87 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
88 select ARCH_KEEP_MEMBLOCK
89 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
90 select ARCH_USE_CMPXCHG_LOCKREF
91 select ARCH_USE_GNU_PROPERTY
92 select ARCH_USE_MEMTEST
93 select ARCH_USE_QUEUED_RWLOCKS
94 select ARCH_USE_QUEUED_SPINLOCKS
95 select ARCH_USE_SYM_ANNOTATIONS
96 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
97 select ARCH_SUPPORTS_HUGETLBFS
98 select ARCH_SUPPORTS_MEMORY_FAILURE
99 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
100 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
101 select ARCH_SUPPORTS_LTO_CLANG_THIN
102 select ARCH_SUPPORTS_CFI_CLANG
103 select ARCH_SUPPORTS_ATOMIC_RMW
104 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
105 select ARCH_SUPPORTS_NUMA_BALANCING
106 select ARCH_SUPPORTS_PAGE_TABLE_CHECK
107 select ARCH_SUPPORTS_PER_VMA_LOCK
108 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
109 select ARCH_SUPPORTS_RT
110 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
111 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
112 select ARCH_WANT_DEFAULT_BPF_JIT
113 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
114 select ARCH_WANT_FRAME_POINTERS
115 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
116 select ARCH_WANT_LD_ORPHAN_WARN
117 select ARCH_WANTS_EXECMEM_LATE if EXECMEM
118 select ARCH_WANTS_NO_INSTR
119 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
120 select ARCH_HAS_UBSAN
122 select ARM_ARCH_TIMER
124 select AUDIT_ARCH_COMPAT_GENERIC
125 select ARM_GIC_V2M if PCI
127 select ARM_GIC_V3_ITS if PCI
129 select BUILDTIME_TABLE_SORT
130 select CLONE_BACKWARDS
132 select CPU_PM if (SUSPEND || CPU_IDLE)
133 select CPUMASK_OFFSTACK if NR_CPUS > 256
135 select DCACHE_WORD_ACCESS
136 select DYNAMIC_FTRACE if FUNCTION_TRACER
137 select DMA_BOUNCE_UNALIGNED_KMALLOC
138 select DMA_DIRECT_REMAP
141 select FUNCTION_ALIGNMENT_4B
142 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
143 select GENERIC_ALLOCATOR
144 select GENERIC_ARCH_TOPOLOGY
145 select GENERIC_CLOCKEVENTS_BROADCAST
146 select GENERIC_CPU_AUTOPROBE
147 select GENERIC_CPU_DEVICES
148 select GENERIC_CPU_VULNERABILITIES
149 select GENERIC_EARLY_IOREMAP
150 select GENERIC_IDLE_POLL_SETUP
151 select GENERIC_IOREMAP
152 select GENERIC_IRQ_IPI
153 select GENERIC_IRQ_PROBE
154 select GENERIC_IRQ_SHOW
155 select GENERIC_IRQ_SHOW_LEVEL
156 select GENERIC_LIB_DEVMEM_IS_ALLOWED
157 select GENERIC_PCI_IOMAP
158 select GENERIC_PTDUMP
159 select GENERIC_SCHED_CLOCK
160 select GENERIC_SMP_IDLE_THREAD
161 select GENERIC_TIME_VSYSCALL
162 select GENERIC_GETTIMEOFDAY
163 select GENERIC_VDSO_TIME_NS
164 select HARDIRQS_SW_RESEND
169 select HAVE_ACPI_APEI if (ACPI && EFI)
170 select HAVE_ALIGNED_STRUCT_PAGE
171 select HAVE_ARCH_AUDITSYSCALL
172 select HAVE_ARCH_BITREVERSE
173 select HAVE_ARCH_COMPILER_H
174 select HAVE_ARCH_HUGE_VMALLOC
175 select HAVE_ARCH_HUGE_VMAP
176 select HAVE_ARCH_JUMP_LABEL
177 select HAVE_ARCH_JUMP_LABEL_RELATIVE
178 select HAVE_ARCH_KASAN
179 select HAVE_ARCH_KASAN_VMALLOC
180 select HAVE_ARCH_KASAN_SW_TAGS
181 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
182 # Some instrumentation may be unsound, hence EXPERT
183 select HAVE_ARCH_KCSAN if EXPERT
184 select HAVE_ARCH_KFENCE
185 select HAVE_ARCH_KGDB
186 select HAVE_ARCH_MMAP_RND_BITS
187 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
188 select HAVE_ARCH_PREL32_RELOCATIONS
189 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
190 select HAVE_ARCH_SECCOMP_FILTER
191 select HAVE_ARCH_STACKLEAK
192 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
193 select HAVE_ARCH_TRACEHOOK
194 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
195 select HAVE_ARCH_VMAP_STACK
196 select HAVE_ARM_SMCCC
197 select HAVE_ASM_MODVERSIONS
199 select HAVE_C_RECORDMCOUNT
200 select HAVE_CMPXCHG_DOUBLE
201 select HAVE_CMPXCHG_LOCAL
202 select HAVE_CONTEXT_TRACKING_USER
203 select HAVE_DEBUG_KMEMLEAK
204 select HAVE_DMA_CONTIGUOUS
205 select HAVE_DYNAMIC_FTRACE
206 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
207 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
208 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
209 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
210 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
211 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
212 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
213 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
214 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
215 if DYNAMIC_FTRACE_WITH_ARGS
216 select HAVE_SAMPLE_FTRACE_DIRECT
217 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
218 select HAVE_EFFICIENT_UNALIGNED_ACCESS
220 select HAVE_FTRACE_MCOUNT_RECORD
221 select HAVE_FUNCTION_TRACER
222 select HAVE_FUNCTION_ERROR_INJECTION
223 select HAVE_FUNCTION_GRAPH_TRACER
224 select HAVE_FUNCTION_GRAPH_RETVAL
225 select HAVE_GCC_PLUGINS
226 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
227 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
228 select HAVE_HW_BREAKPOINT if PERF_EVENTS
229 select HAVE_IOREMAP_PROT
230 select HAVE_IRQ_TIME_ACCOUNTING
231 select HAVE_MOD_ARCH_SPECIFIC
233 select HAVE_PERF_EVENTS
234 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
235 select HAVE_PERF_REGS
236 select HAVE_PERF_USER_STACK_DUMP
237 select HAVE_PREEMPT_DYNAMIC_KEY
238 select HAVE_REGS_AND_STACK_ACCESS_API
239 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
240 select HAVE_FUNCTION_ARG_ACCESS_API
241 select MMU_GATHER_RCU_TABLE_FREE
243 select HAVE_RUST if RUSTC_SUPPORTS_ARM64
244 select HAVE_STACKPROTECTOR
245 select HAVE_SYSCALL_TRACEPOINTS
247 select HAVE_KRETPROBES
248 select HAVE_GENERIC_VDSO
249 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
251 select IRQ_FORCED_THREADING
252 select KASAN_VMALLOC if KASAN
253 select LOCK_MM_AND_FIND_VMA
254 select MODULES_USE_ELF_RELA
255 select NEED_DMA_MAP_STATE
256 select NEED_SG_DMA_LENGTH
258 select OF_EARLY_FLATTREE
259 select PCI_DOMAINS_GENERIC if PCI
260 select PCI_ECAM if (ACPI && PCI)
261 select PCI_SYSCALL if PCI
266 select SYSCTL_EXCEPTION_TRACE
267 select THREAD_INFO_IN_TASK
268 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
269 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
270 select TRACE_IRQFLAGS_SUPPORT
271 select TRACE_IRQFLAGS_NMI_SUPPORT
272 select HAVE_SOFTIRQ_ON_OWN_STACK
273 select USER_STACKTRACE_SUPPORT
274 select VDSO_GETRANDOM
276 ARM 64-bit (AArch64) Linux support.
278 config RUSTC_SUPPORTS_ARM64
280 depends on CPU_LITTLE_ENDIAN
281 # Shadow call stack is only supported on certain rustc versions.
283 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is
284 # required due to use of the -Zfixed-x18 flag.
286 # Otherwise, rustc version 1.82+ is required due to use of the
287 # -Zsanitizer=shadow-call-stack flag.
288 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS
290 config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
292 # https://github.com/ClangBuiltLinux/linux/issues/1507
293 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
295 config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
297 depends on $(cc-option,-fpatchable-function-entry=2)
305 config ARM64_CONT_PTE_SHIFT
307 default 5 if PAGE_SIZE_64KB
308 default 7 if PAGE_SIZE_16KB
311 config ARM64_CONT_PMD_SHIFT
313 default 5 if PAGE_SIZE_64KB
314 default 5 if PAGE_SIZE_16KB
317 config ARCH_MMAP_RND_BITS_MIN
318 default 14 if PAGE_SIZE_64KB
319 default 16 if PAGE_SIZE_16KB
322 # max bits determined by the following formula:
323 # VA_BITS - PAGE_SHIFT - 3
324 config ARCH_MMAP_RND_BITS_MAX
325 default 19 if ARM64_VA_BITS=36
326 default 24 if ARM64_VA_BITS=39
327 default 27 if ARM64_VA_BITS=42
328 default 30 if ARM64_VA_BITS=47
329 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
330 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
331 default 33 if ARM64_VA_BITS=48
332 default 14 if ARM64_64K_PAGES
333 default 16 if ARM64_16K_PAGES
336 config ARCH_MMAP_RND_COMPAT_BITS_MIN
337 default 7 if ARM64_64K_PAGES
338 default 9 if ARM64_16K_PAGES
341 config ARCH_MMAP_RND_COMPAT_BITS_MAX
347 config STACKTRACE_SUPPORT
350 config ILLEGAL_POINTER_VALUE
352 default 0xdead000000000000
354 config LOCKDEP_SUPPORT
361 config GENERIC_BUG_RELATIVE_POINTERS
363 depends on GENERIC_BUG
365 config GENERIC_HWEIGHT
371 config GENERIC_CALIBRATE_DELAY
377 config KERNEL_MODE_NEON
380 config FIX_EARLYCON_MEM
383 config PGTABLE_LEVELS
385 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
386 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
387 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
388 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
389 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
390 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
391 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
392 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
394 config ARCH_SUPPORTS_UPROBES
397 config ARCH_PROC_KCORE_TEXT
400 config BROKEN_GAS_INST
401 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
403 config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
405 # Clang's __builtin_return_address() strips the PAC since 12.0.0
406 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
407 default y if CC_IS_CLANG
408 # GCC's __builtin_return_address() strips the PAC since 11.1.0,
409 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
410 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
411 default y if CC_IS_GCC && (GCC_VERSION >= 110100)
412 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
413 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000)
414 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000)
417 config KASAN_SHADOW_OFFSET
419 depends on KASAN_GENERIC || KASAN_SW_TAGS
420 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
421 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
422 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
423 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
424 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
425 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
426 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
427 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
428 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
429 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
430 default 0xffffffffffffffff
435 source "arch/arm64/Kconfig.platforms"
437 menu "Kernel Features"
439 menu "ARM errata workarounds via the alternatives framework"
441 config AMPERE_ERRATUM_AC03_CPU_38
442 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
445 This option adds an alternative code sequence to work around Ampere
446 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
448 The affected design reports FEAT_HAFDBS as not implemented in
449 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
450 as required by the architecture. The unadvertised HAFDBS
451 implementation suffers from an additional erratum where hardware
452 A/D updates can occur after a PTE has been marked invalid.
454 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
455 which avoids enabling unadvertised hardware Access Flag management
460 config ARM64_WORKAROUND_CLEAN_CACHE
463 config ARM64_ERRATUM_826319
464 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
466 select ARM64_WORKAROUND_CLEAN_CACHE
468 This option adds an alternative code sequence to work around ARM
469 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
470 AXI master interface and an L2 cache.
472 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
473 and is unable to accept a certain write via this interface, it will
474 not progress on read data presented on the read data channel and the
477 The workaround promotes data cache clean instructions to
478 data cache clean-and-invalidate.
479 Please note that this does not necessarily enable the workaround,
480 as it depends on the alternative framework, which will only patch
481 the kernel if an affected CPU is detected.
485 config ARM64_ERRATUM_827319
486 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
488 select ARM64_WORKAROUND_CLEAN_CACHE
490 This option adds an alternative code sequence to work around ARM
491 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
492 master interface and an L2 cache.
494 Under certain conditions this erratum can cause a clean line eviction
495 to occur at the same time as another transaction to the same address
496 on the AMBA 5 CHI interface, which can cause data corruption if the
497 interconnect reorders the two transactions.
499 The workaround promotes data cache clean instructions to
500 data cache clean-and-invalidate.
501 Please note that this does not necessarily enable the workaround,
502 as it depends on the alternative framework, which will only patch
503 the kernel if an affected CPU is detected.
507 config ARM64_ERRATUM_824069
508 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
510 select ARM64_WORKAROUND_CLEAN_CACHE
512 This option adds an alternative code sequence to work around ARM
513 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
514 to a coherent interconnect.
516 If a Cortex-A53 processor is executing a store or prefetch for
517 write instruction at the same time as a processor in another
518 cluster is executing a cache maintenance operation to the same
519 address, then this erratum might cause a clean cache line to be
520 incorrectly marked as dirty.
522 The workaround promotes data cache clean instructions to
523 data cache clean-and-invalidate.
524 Please note that this option does not necessarily enable the
525 workaround, as it depends on the alternative framework, which will
526 only patch the kernel if an affected CPU is detected.
530 config ARM64_ERRATUM_819472
531 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
533 select ARM64_WORKAROUND_CLEAN_CACHE
535 This option adds an alternative code sequence to work around ARM
536 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
537 present when it is connected to a coherent interconnect.
539 If the processor is executing a load and store exclusive sequence at
540 the same time as a processor in another cluster is executing a cache
541 maintenance operation to the same address, then this erratum might
542 cause data corruption.
544 The workaround promotes data cache clean instructions to
545 data cache clean-and-invalidate.
546 Please note that this does not necessarily enable the workaround,
547 as it depends on the alternative framework, which will only patch
548 the kernel if an affected CPU is detected.
552 config ARM64_ERRATUM_832075
553 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
556 This option adds an alternative code sequence to work around ARM
557 erratum 832075 on Cortex-A57 parts up to r1p2.
559 Affected Cortex-A57 parts might deadlock when exclusive load/store
560 instructions to Write-Back memory are mixed with Device loads.
562 The workaround is to promote device loads to use Load-Acquire
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_834220
571 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
574 This option adds an alternative code sequence to work around ARM
575 erratum 834220 on Cortex-A57 parts up to r1p2.
577 Affected Cortex-A57 parts might report a Stage 2 translation
578 fault as the result of a Stage 1 fault for load crossing a
579 page boundary when there is a permission or device memory
580 alignment fault at Stage 1 and a translation fault at Stage 2.
582 The workaround is to verify that the Stage 1 translation
583 doesn't generate a fault before handling the Stage 2 fault.
584 Please note that this does not necessarily enable the workaround,
585 as it depends on the alternative framework, which will only patch
586 the kernel if an affected CPU is detected.
590 config ARM64_ERRATUM_1742098
591 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
595 This option removes the AES hwcap for aarch32 user-space to
596 workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
598 Affected parts may corrupt the AES state if an interrupt is
599 taken between a pair of AES instructions. These instructions
600 are only present if the cryptography extensions are present.
601 All software should have a fallback implementation for CPUs
602 that don't implement the cryptography extensions.
606 config ARM64_ERRATUM_845719
607 bool "Cortex-A53: 845719: a load might read incorrect data"
611 This option adds an alternative code sequence to work around ARM
612 erratum 845719 on Cortex-A53 parts up to r0p4.
614 When running a compat (AArch32) userspace on an affected Cortex-A53
615 part, a load at EL0 from a virtual address that matches the bottom 32
616 bits of the virtual address used by a recent load at (AArch64) EL1
617 might return incorrect data.
619 The workaround is to write the contextidr_el1 register on exception
620 return to a 32-bit task.
621 Please note that this does not necessarily enable the workaround,
622 as it depends on the alternative framework, which will only patch
623 the kernel if an affected CPU is detected.
627 config ARM64_ERRATUM_843419
628 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
631 This option links the kernel with '--fix-cortex-a53-843419' and
632 enables PLT support to replace certain ADRP instructions, which can
633 cause subsequent memory accesses to use an incorrect address on
634 Cortex-A53 parts up to r0p4.
638 config ARM64_LD_HAS_FIX_ERRATUM_843419
639 def_bool $(ld-option,--fix-cortex-a53-843419)
641 config ARM64_ERRATUM_1024718
642 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
645 This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
647 Affected Cortex-A55 cores (all revisions) could cause incorrect
648 update of the hardware dirty bit when the DBM/AP bits are updated
649 without a break-before-make. The workaround is to disable the usage
650 of hardware DBM locally on the affected cores. CPUs not affected by
651 this erratum will continue to use the feature.
655 config ARM64_ERRATUM_1418040
656 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
660 This option adds a workaround for ARM Cortex-A76/Neoverse-N1
661 errata 1188873 and 1418040.
663 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
664 cause register corruption when accessing the timer registers
665 from AArch32 userspace.
669 config ARM64_WORKAROUND_SPECULATIVE_AT
672 config ARM64_ERRATUM_1165522
673 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
675 select ARM64_WORKAROUND_SPECULATIVE_AT
677 This option adds a workaround for ARM Cortex-A76 erratum 1165522.
679 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
680 corrupted TLBs by speculating an AT instruction during a guest
685 config ARM64_ERRATUM_1319367
686 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
688 select ARM64_WORKAROUND_SPECULATIVE_AT
690 This option adds work arounds for ARM Cortex-A57 erratum 1319537
691 and A72 erratum 1319367
693 Cortex-A57 and A72 cores could end-up with corrupted TLBs by
694 speculating an AT instruction during a guest context switch.
698 config ARM64_ERRATUM_1530923
699 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
701 select ARM64_WORKAROUND_SPECULATIVE_AT
703 This option adds a workaround for ARM Cortex-A55 erratum 1530923.
705 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
706 corrupted TLBs by speculating an AT instruction during a guest
711 config ARM64_WORKAROUND_REPEAT_TLBI
714 config ARM64_ERRATUM_2441007
715 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
716 select ARM64_WORKAROUND_REPEAT_TLBI
718 This option adds a workaround for ARM Cortex-A55 erratum #2441007.
720 Under very rare circumstances, affected Cortex-A55 CPUs
721 may not handle a race between a break-before-make sequence on one
722 CPU, and another CPU accessing the same page. This could allow a
723 store to a page that has been unmapped.
725 Work around this by adding the affected CPUs to the list that needs
726 TLB sequences to be done twice.
730 config ARM64_ERRATUM_1286807
731 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
732 select ARM64_WORKAROUND_REPEAT_TLBI
734 This option adds a workaround for ARM Cortex-A76 erratum 1286807.
736 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
737 address for a cacheable mapping of a location is being
738 accessed by a core while another core is remapping the virtual
739 address to a new physical page using the recommended
740 break-before-make sequence, then under very rare circumstances
741 TLBI+DSB completes before a read using the translation being
742 invalidated has been observed by other observers. The
743 workaround repeats the TLBI+DSB operation.
747 config ARM64_ERRATUM_1463225
748 bool "Cortex-A76: Software Step might prevent interrupt recognition"
751 This option adds a workaround for Arm Cortex-A76 erratum 1463225.
753 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
754 of a system call instruction (SVC) can prevent recognition of
755 subsequent interrupts when software stepping is disabled in the
756 exception handler of the system call and either kernel debugging
757 is enabled or VHE is in use.
759 Work around the erratum by triggering a dummy step exception
760 when handling a system call from a task that is being stepped
761 in a VHE configuration of the kernel.
765 config ARM64_ERRATUM_1542419
766 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
768 This option adds a workaround for ARM Neoverse-N1 erratum
771 Affected Neoverse-N1 cores could execute a stale instruction when
772 modified by another CPU. The workaround depends on a firmware
775 Workaround the issue by hiding the DIC feature from EL0. This
776 forces user-space to perform cache maintenance.
780 config ARM64_ERRATUM_1508412
781 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
784 This option adds a workaround for Arm Cortex-A77 erratum 1508412.
786 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
787 of a store-exclusive or read of PAR_EL1 and a load with device or
788 non-cacheable memory attributes. The workaround depends on a firmware
791 KVM guests must also have the workaround implemented or they can
794 Work around the issue by inserting DMB SY barriers around PAR_EL1
795 register reads and warning KVM users. The DMB barrier is sufficient
796 to prevent a speculative PAR_EL1 read.
800 config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
803 config ARM64_ERRATUM_2051678
804 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
807 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
808 Affected Cortex-A510 might not respect the ordering rules for
809 hardware update of the page table's dirty bit. The workaround
810 is to not enable the feature on affected CPUs.
814 config ARM64_ERRATUM_2077057
815 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
818 This option adds the workaround for ARM Cortex-A510 erratum 2077057.
819 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
820 expected, but a Pointer Authentication trap is taken instead. The
821 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
822 EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
824 This can only happen when EL2 is stepping EL1.
826 When these conditions occur, the SPSR_EL2 value is unchanged from the
827 previous guest entry, and can be restored from the in-memory copy.
831 config ARM64_ERRATUM_2658417
832 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
835 This option adds the workaround for ARM Cortex-A510 erratum 2658417.
836 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
837 BFMMLA or VMMLA instructions in rare circumstances when a pair of
838 A510 CPUs are using shared neon hardware. As the sharing is not
839 discoverable by the kernel, hide the BF16 HWCAP to indicate that
840 user-space should not be using these instructions.
844 config ARM64_ERRATUM_2119858
845 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
847 depends on CORESIGHT_TRBE
848 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
850 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
852 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
853 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
854 the event of a WRAP event.
856 Work around the issue by always making sure we move the TRBPTR_EL1 by
857 256 bytes before enabling the buffer and filling the first 256 bytes of
858 the buffer with ETM ignore packets upon disabling.
862 config ARM64_ERRATUM_2139208
863 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
865 depends on CORESIGHT_TRBE
866 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
868 This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
870 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
871 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
872 the event of a WRAP event.
874 Work around the issue by always making sure we move the TRBPTR_EL1 by
875 256 bytes before enabling the buffer and filling the first 256 bytes of
876 the buffer with ETM ignore packets upon disabling.
880 config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
883 config ARM64_ERRATUM_2054223
884 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
886 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
888 Enable workaround for ARM Cortex-A710 erratum 2054223
890 Affected cores may fail to flush the trace data on a TSB instruction, when
891 the PE is in trace prohibited state. This will cause losing a few bytes
894 Workaround is to issue two TSB consecutively on affected cores.
898 config ARM64_ERRATUM_2067961
899 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
901 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
903 Enable workaround for ARM Neoverse-N2 erratum 2067961
905 Affected cores may fail to flush the trace data on a TSB instruction, when
906 the PE is in trace prohibited state. This will cause losing a few bytes
909 Workaround is to issue two TSB consecutively on affected cores.
913 config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
916 config ARM64_ERRATUM_2253138
917 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
918 depends on CORESIGHT_TRBE
920 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
922 This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
924 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
925 for TRBE. Under some conditions, the TRBE might generate a write to the next
926 virtually addressed page following the last page of the TRBE address space
927 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
929 Work around this in the driver by always making sure that there is a
930 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
934 config ARM64_ERRATUM_2224489
935 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
936 depends on CORESIGHT_TRBE
938 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
940 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
942 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
943 for TRBE. Under some conditions, the TRBE might generate a write to the next
944 virtually addressed page following the last page of the TRBE address space
945 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
947 Work around this in the driver by always making sure that there is a
948 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
952 config ARM64_ERRATUM_2441009
953 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
954 select ARM64_WORKAROUND_REPEAT_TLBI
956 This option adds a workaround for ARM Cortex-A510 erratum #2441009.
958 Under very rare circumstances, affected Cortex-A510 CPUs
959 may not handle a race between a break-before-make sequence on one
960 CPU, and another CPU accessing the same page. This could allow a
961 store to a page that has been unmapped.
963 Work around this by adding the affected CPUs to the list that needs
964 TLB sequences to be done twice.
968 config ARM64_ERRATUM_2064142
969 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
970 depends on CORESIGHT_TRBE
973 This option adds the workaround for ARM Cortex-A510 erratum 2064142.
975 Affected Cortex-A510 core might fail to write into system registers after the
976 TRBE has been disabled. Under some conditions after the TRBE has been disabled
977 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
978 and TRBTRG_EL1 will be ignored and will not be effected.
980 Work around this in the driver by executing TSB CSYNC and DSB after collection
981 is stopped and before performing a system register write to one of the affected
986 config ARM64_ERRATUM_2038923
987 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
988 depends on CORESIGHT_TRBE
991 This option adds the workaround for ARM Cortex-A510 erratum 2038923.
993 Affected Cortex-A510 core might cause an inconsistent view on whether trace is
994 prohibited within the CPU. As a result, the trace buffer or trace buffer state
995 might be corrupted. This happens after TRBE buffer has been enabled by setting
996 TRBLIMITR_EL1.E, followed by just a single context synchronization event before
997 execution changes from a context, in which trace is prohibited to one where it
998 isn't, or vice versa. In these mentioned conditions, the view of whether trace
999 is prohibited is inconsistent between parts of the CPU, and the trace buffer or
1000 the trace buffer state might be corrupted.
1002 Work around this in the driver by preventing an inconsistent view of whether the
1003 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
1004 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
1005 two ISB instructions if no ERET is to take place.
1009 config ARM64_ERRATUM_1902691
1010 bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1011 depends on CORESIGHT_TRBE
1014 This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1016 Affected Cortex-A510 core might cause trace data corruption, when being written
1017 into the memory. Effectively TRBE is broken and hence cannot be used to capture
1020 Work around this problem in the driver by just preventing TRBE initialization on
1021 affected cpus. The firmware must have disabled the access to TRBE for the kernel
1022 on such implementations. This will cover the kernel for any firmware that doesn't
1027 config ARM64_ERRATUM_2457168
1028 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1029 depends on ARM64_AMU_EXTN
1032 This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1034 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1035 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1036 incorrectly giving a significantly higher output value.
1038 Work around this problem by returning 0 when reading the affected counter in
1039 key locations that results in disabling all users of this counter. This effect
1040 is the same to firmware disabling affected counters.
1044 config ARM64_ERRATUM_2645198
1045 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1048 This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1050 If a Cortex-A715 cpu sees a page mapping permissions change from executable
1051 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1052 next instruction abort caused by permission fault.
1054 Only user-space does executable to non-executable permission transition via
1055 mprotect() system call. Workaround the problem by doing a break-before-make
1056 TLB invalidation, for all changes to executable user space mappings.
1060 config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1063 config ARM64_ERRATUM_2966298
1064 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1065 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1068 This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1070 On an affected Cortex-A520 core, a speculatively executed unprivileged
1071 load might leak data from a privileged level via a cache side channel.
1073 Work around this problem by executing a TLBI before returning to EL0.
1077 config ARM64_ERRATUM_3117295
1078 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1079 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1082 This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1084 On an affected Cortex-A510 core, a speculatively executed unprivileged
1085 load might leak data from a privileged level via a cache side channel.
1087 Work around this problem by executing a TLBI before returning to EL0.
1091 config ARM64_ERRATUM_3194386
1092 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1095 This option adds the workaround for the following errata:
1097 * ARM Cortex-A76 erratum 3324349
1098 * ARM Cortex-A77 erratum 3324348
1099 * ARM Cortex-A78 erratum 3324344
1100 * ARM Cortex-A78C erratum 3324346
1101 * ARM Cortex-A78C erratum 3324347
1102 * ARM Cortex-A710 erratam 3324338
1103 * ARM Cortex-A715 errartum 3456084
1104 * ARM Cortex-A720 erratum 3456091
1105 * ARM Cortex-A725 erratum 3456106
1106 * ARM Cortex-X1 erratum 3324344
1107 * ARM Cortex-X1C erratum 3324346
1108 * ARM Cortex-X2 erratum 3324338
1109 * ARM Cortex-X3 erratum 3324335
1110 * ARM Cortex-X4 erratum 3194386
1111 * ARM Cortex-X925 erratum 3324334
1112 * ARM Neoverse-N1 erratum 3324349
1113 * ARM Neoverse N2 erratum 3324339
1114 * ARM Neoverse-N3 erratum 3456111
1115 * ARM Neoverse-V1 erratum 3324341
1116 * ARM Neoverse V2 erratum 3324336
1117 * ARM Neoverse-V3 erratum 3312417
1119 On affected cores "MSR SSBS, #0" instructions may not affect
1120 subsequent speculative instructions, which may permit unexepected
1121 speculative store bypassing.
1123 Work around this problem by placing a Speculation Barrier (SB) or
1124 Instruction Synchronization Barrier (ISB) after kernel changes to
1125 SSBS. The presence of the SSBS special-purpose register is hidden
1126 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1127 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1131 config CAVIUM_ERRATUM_22375
1132 bool "Cavium erratum 22375, 24313"
1135 Enable workaround for errata 22375 and 24313.
1137 This implements two gicv3-its errata workarounds for ThunderX. Both
1138 with a small impact affecting only ITS table allocation.
1140 erratum 22375: only alloc 8MB table size
1141 erratum 24313: ignore memory access type
1143 The fixes are in ITS initialization and basically ignore memory access
1144 type and table size provided by the TYPER and BASER registers.
1148 config CAVIUM_ERRATUM_23144
1149 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1153 ITS SYNC command hang for cross node io and collections/cpu mapping.
1157 config CAVIUM_ERRATUM_23154
1158 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1161 The ThunderX GICv3 implementation requires a modified version for
1162 reading the IAR status to ensure data synchronization
1163 (access to icc_iar1_el1 is not sync'ed before and after).
1165 It also suffers from erratum 38545 (also present on Marvell's
1166 OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1167 spuriously presented to the CPU interface.
1171 config CAVIUM_ERRATUM_27456
1172 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1175 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1176 instructions may cause the icache to become corrupted if it
1177 contains data for a non-current ASID. The fix is to
1178 invalidate the icache when changing the mm context.
1182 config CAVIUM_ERRATUM_30115
1183 bool "Cavium erratum 30115: Guest may disable interrupts in host"
1186 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1187 1.2, and T83 Pass 1.0, KVM guest execution may disable
1188 interrupts in host. Trapping both GICv3 group-0 and group-1
1189 accesses sidesteps the issue.
1193 config CAVIUM_TX2_ERRATUM_219
1194 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1197 On Cavium ThunderX2, a load, store or prefetch instruction between a
1198 TTBR update and the corresponding context synchronizing operation can
1199 cause a spurious Data Abort to be delivered to any hardware thread in
1202 Work around the issue by avoiding the problematic code sequence and
1203 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1204 trap handler performs the corresponding register access, skips the
1205 instruction and ensures context synchronization by virtue of the
1210 config FUJITSU_ERRATUM_010001
1211 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1214 This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1215 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1216 accesses may cause undefined fault (Data abort, DFSC=0b111111).
1217 This fault occurs under a specific hardware condition when a
1218 load/store instruction performs an address translation using:
1219 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1220 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1221 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1222 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1224 The workaround is to ensure these bits are clear in TCR_ELx.
1225 The workaround only affects the Fujitsu-A64FX.
1229 config HISILICON_ERRATUM_161600802
1230 bool "Hip07 161600802: Erroneous redistributor VLPI base"
1233 The HiSilicon Hip07 SoC uses the wrong redistributor base
1234 when issued ITS commands such as VMOVP and VMAPP, and requires
1235 a 128kB offset to be applied to the target address in this commands.
1239 config QCOM_FALKOR_ERRATUM_1003
1240 bool "Falkor E1003: Incorrect translation due to ASID change"
1243 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1244 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1245 in TTBR1_EL1, this situation only occurs in the entry trampoline and
1246 then only for entries in the walk cache, since the leaf translation
1247 is unchanged. Work around the erratum by invalidating the walk cache
1248 entries for the trampoline before entering the kernel proper.
1250 config QCOM_FALKOR_ERRATUM_1009
1251 bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1253 select ARM64_WORKAROUND_REPEAT_TLBI
1255 On Falkor v1, the CPU may prematurely complete a DSB following a
1256 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1257 one more time to fix the issue.
1261 config QCOM_QDF2400_ERRATUM_0065
1262 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1265 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1266 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1267 been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1271 config QCOM_FALKOR_ERRATUM_E1041
1272 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1275 Falkor CPU may speculatively fetch instructions from an improper
1276 memory location when MMU translation is changed from SCTLR_ELn[M]=1
1277 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1281 config NVIDIA_CARMEL_CNP_ERRATUM
1282 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1285 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1286 invalidate shared TLB entries installed by a different core, as it would
1287 on standard ARM cores.
1291 config ROCKCHIP_ERRATUM_3588001
1292 bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1295 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1296 This means, that its sharability feature may not be used, even though it
1297 is supported by the IP itself.
1301 config SOCIONEXT_SYNQUACER_PREITS
1302 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1305 Socionext Synquacer SoCs implement a separate h/w block to generate
1306 MSI doorbell writes with non-zero values for the device ID.
1310 endmenu # "ARM errata workarounds via the alternatives framework"
1314 default ARM64_4K_PAGES
1316 Page size (translation granule) configuration.
1318 config ARM64_4K_PAGES
1320 select HAVE_PAGE_SIZE_4KB
1322 This feature enables 4KB pages support.
1324 config ARM64_16K_PAGES
1326 select HAVE_PAGE_SIZE_16KB
1328 The system will use 16KB pages support. AArch32 emulation
1329 requires applications compiled with 16K (or a multiple of 16K)
1332 config ARM64_64K_PAGES
1334 select HAVE_PAGE_SIZE_64KB
1336 This feature enables 64KB pages support (4KB by default)
1337 allowing only two levels of page tables and faster TLB
1338 look-up. AArch32 emulation requires applications compiled
1339 with 64K aligned segments.
1344 prompt "Virtual address space size"
1345 default ARM64_VA_BITS_52
1347 Allows choosing one of multiple possible virtual address
1348 space sizes. The level of translation table is determined by
1349 a combination of page size and virtual address space size.
1351 config ARM64_VA_BITS_36
1352 bool "36-bit" if EXPERT
1353 depends on PAGE_SIZE_16KB
1355 config ARM64_VA_BITS_39
1357 depends on PAGE_SIZE_4KB
1359 config ARM64_VA_BITS_42
1361 depends on PAGE_SIZE_64KB
1363 config ARM64_VA_BITS_47
1365 depends on PAGE_SIZE_16KB
1367 config ARM64_VA_BITS_48
1370 config ARM64_VA_BITS_52
1372 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1374 Enable 52-bit virtual addressing for userspace when explicitly
1375 requested via a hint to mmap(). The kernel will also use 52-bit
1376 virtual addresses for its own mappings (provided HW support for
1377 this feature is available, otherwise it reverts to 48-bit).
1379 NOTE: Enabling 52-bit virtual addressing in conjunction with
1380 ARMv8.3 Pointer Authentication will result in the PAC being
1381 reduced from 7 bits to 3 bits, which may have a significant
1382 impact on its susceptibility to brute-force attacks.
1384 If unsure, select 48-bit virtual addressing instead.
1388 config ARM64_FORCE_52BIT
1389 bool "Force 52-bit virtual addresses for userspace"
1390 depends on ARM64_VA_BITS_52 && EXPERT
1392 For systems with 52-bit userspace VAs enabled, the kernel will attempt
1393 to maintain compatibility with older software by providing 48-bit VAs
1394 unless a hint is supplied to mmap.
1396 This configuration option disables the 48-bit compatibility logic, and
1397 forces all userspace addresses to be 52-bit on HW that supports it. One
1398 should only enable this configuration option for stress testing userspace
1399 memory management code. If unsure say N here.
1401 config ARM64_VA_BITS
1403 default 36 if ARM64_VA_BITS_36
1404 default 39 if ARM64_VA_BITS_39
1405 default 42 if ARM64_VA_BITS_42
1406 default 47 if ARM64_VA_BITS_47
1407 default 48 if ARM64_VA_BITS_48
1408 default 52 if ARM64_VA_BITS_52
1411 prompt "Physical address space size"
1412 default ARM64_PA_BITS_48
1414 Choose the maximum physical address range that the kernel will
1417 config ARM64_PA_BITS_48
1419 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1421 config ARM64_PA_BITS_52
1423 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1424 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1426 Enable support for a 52-bit physical address space, introduced as
1427 part of the ARMv8.2-LPA extension.
1429 With this enabled, the kernel will also continue to work on CPUs that
1430 do not support ARMv8.2-LPA, but with some added memory overhead (and
1431 minor performance overhead).
1435 config ARM64_PA_BITS
1437 default 48 if ARM64_PA_BITS_48
1438 default 52 if ARM64_PA_BITS_52
1442 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1446 default CPU_LITTLE_ENDIAN
1448 Select the endianness of data accesses performed by the CPU. Userspace
1449 applications will need to be compiled and linked for the endianness
1450 that is selected here.
1452 config CPU_BIG_ENDIAN
1453 bool "Build big-endian kernel"
1454 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1455 depends on AS_IS_GNU || AS_VERSION >= 150000
1457 Say Y if you plan on running a kernel with a big-endian userspace.
1459 config CPU_LITTLE_ENDIAN
1460 bool "Build little-endian kernel"
1462 Say Y if you plan on running a kernel with a little-endian userspace.
1463 This is usually the case for distributions targeting arm64.
1468 bool "Multi-core scheduler support"
1470 Multi-core scheduler support improves the CPU scheduler's decision
1471 making when dealing with multi-core CPU chips at a cost of slightly
1472 increased overhead in some places. If unsure say N here.
1474 config SCHED_CLUSTER
1475 bool "Cluster scheduler support"
1477 Cluster scheduler support improves the CPU scheduler's decision
1478 making when dealing with machines that have clusters of CPUs.
1479 Cluster usually means a couple of CPUs which are placed closely
1480 by sharing mid-level caches, last-level cache tags or internal
1484 bool "SMT scheduler support"
1486 Improves the CPU scheduler's decision making when dealing with
1487 MultiThreading at a cost of slightly increased overhead in some
1488 places. If unsure say N here.
1491 int "Maximum number of CPUs (2-4096)"
1496 bool "Support for hot-pluggable CPUs"
1497 select GENERIC_IRQ_MIGRATION
1499 Say Y here to experiment with turning CPUs off and on. CPUs
1500 can be controlled through /sys/devices/system/cpu.
1502 # Common NUMA Features
1504 bool "NUMA Memory Allocation and Scheduler Support"
1505 select GENERIC_ARCH_NUMA
1507 select HAVE_SETUP_PER_CPU_AREA
1508 select NEED_PER_CPU_EMBED_FIRST_CHUNK
1509 select NEED_PER_CPU_PAGE_FIRST_CHUNK
1510 select USE_PERCPU_NUMA_NODE_ID
1512 Enable NUMA (Non-Uniform Memory Access) support.
1514 The kernel will try to allocate memory used by a CPU on the
1515 local memory of the CPU and add some more
1516 NUMA awareness to the kernel.
1519 int "Maximum NUMA Nodes (as a power of 2)"
1524 Specify the maximum number of NUMA Nodes available on the target
1525 system. Increases memory reserved to accommodate various tables.
1527 source "kernel/Kconfig.hz"
1529 config ARCH_SPARSEMEM_ENABLE
1531 select SPARSEMEM_VMEMMAP_ENABLE
1532 select SPARSEMEM_VMEMMAP
1534 config HW_PERF_EVENTS
1538 # Supported by clang >= 7.0 or GCC >= 12.0.0
1539 config CC_HAVE_SHADOW_CALL_STACK
1540 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1543 bool "Enable paravirtualization code"
1545 This changes the kernel so it can modify itself when it is run
1546 under a hypervisor, potentially improving performance significantly
1547 over full virtualization.
1549 config PARAVIRT_TIME_ACCOUNTING
1550 bool "Paravirtual steal time accounting"
1553 Select this option to enable fine granularity task steal time
1554 accounting. Time spent executing other tasks in parallel with
1555 the current vCPU is discounted from the vCPU power. To account for
1556 that, there can be a small performance impact.
1558 If in doubt, say N here.
1560 config ARCH_SUPPORTS_KEXEC
1561 def_bool PM_SLEEP_SMP
1563 config ARCH_SUPPORTS_KEXEC_FILE
1566 config ARCH_SELECTS_KEXEC_FILE
1568 depends on KEXEC_FILE
1569 select HAVE_IMA_KEXEC if IMA
1571 config ARCH_SUPPORTS_KEXEC_SIG
1574 config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1577 config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1580 config ARCH_SUPPORTS_CRASH_DUMP
1583 config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1584 def_bool CRASH_RESERVE
1588 depends on HIBERNATION || KEXEC_CORE
1595 bool "Xen guest support on ARM64"
1596 depends on ARM64 && OF
1600 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1602 # include/linux/mmzone.h requires the following to be true:
1604 # MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1606 # so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1608 # | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER |
1609 # ----+-------------------+--------------+----------------------+-------------------------+
1610 # 4K | 27 | 12 | 15 | 10 |
1611 # 16K | 27 | 14 | 13 | 11 |
1612 # 64K | 29 | 16 | 13 | 13 |
1613 config ARCH_FORCE_MAX_ORDER
1615 default "13" if ARM64_64K_PAGES
1616 default "11" if ARM64_16K_PAGES
1619 The kernel page allocator limits the size of maximal physically
1620 contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1621 defines the maximal power of two of number of pages that can be
1622 allocated as a single contiguous block. This option allows
1623 overriding the default setting when ability to allocate very
1624 large blocks of physically contiguous memory is required.
1626 The maximal size of allocation cannot exceed the size of the
1627 section, so the value of MAX_PAGE_ORDER should satisfy
1629 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1631 Don't change if unsure.
1633 config UNMAP_KERNEL_AT_EL0
1634 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1637 Speculation attacks against some high-performance processors can
1638 be used to bypass MMU permission checks and leak kernel data to
1639 userspace. This can be defended against by unmapping the kernel
1640 when running in userspace, mapping it back in on exception entry
1641 via a trampoline page in the vector table.
1645 config MITIGATE_SPECTRE_BRANCH_HISTORY
1646 bool "Mitigate Spectre style attacks against branch history" if EXPERT
1649 Speculation attacks against some high-performance processors can
1650 make use of branch history to influence future speculation.
1651 When taking an exception from user-space, a sequence of branches
1652 or a firmware call overwrites the branch history.
1654 config RODATA_FULL_DEFAULT_ENABLED
1655 bool "Apply r/o permissions of VM areas also to their linear aliases"
1658 Apply read-only attributes of VM areas to the linear alias of
1659 the backing pages as well. This prevents code or read-only data
1660 from being modified (inadvertently or intentionally) via another
1661 mapping of the same memory page. This additional enhancement can
1662 be turned off at runtime by passing rodata=[off|on] (and turned on
1663 with rodata=full if this option is set to 'n')
1665 This requires the linear region to be mapped down to pages,
1666 which may adversely affect performance in some cases.
1668 config ARM64_SW_TTBR0_PAN
1669 bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1672 Enabling this option prevents the kernel from accessing
1673 user-space memory directly by pointing TTBR0_EL1 to a reserved
1674 zeroed area and reserved ASID. The user access routines
1675 restore the valid TTBR0_EL1 temporarily.
1677 config ARM64_TAGGED_ADDR_ABI
1678 bool "Enable the tagged user addresses syscall ABI"
1681 When this option is enabled, user applications can opt in to a
1682 relaxed ABI via prctl() allowing tagged addresses to be passed
1683 to system calls as pointer arguments. For details, see
1684 Documentation/arch/arm64/tagged-address-abi.rst.
1687 bool "Kernel support for 32-bit EL0"
1688 depends on ARM64_4K_PAGES || EXPERT
1690 select OLD_SIGSUSPEND3
1691 select COMPAT_OLD_SIGACTION
1693 This option enables support for a 32-bit EL0 running under a 64-bit
1694 kernel at EL1. AArch32-specific components such as system calls,
1695 the user helper functions, VFP support and the ptrace interface are
1696 handled appropriately by the kernel.
1698 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1699 that you will only be able to execute AArch32 binaries that were compiled
1700 with page size aligned segments.
1702 If you want to execute 32-bit userspace applications, say Y.
1706 config KUSER_HELPERS
1707 bool "Enable kuser helpers page for 32-bit applications"
1710 Warning: disabling this option may break 32-bit user programs.
1712 Provide kuser helpers to compat tasks. The kernel provides
1713 helper code to userspace in read only form at a fixed location
1714 to allow userspace to be independent of the CPU type fitted to
1715 the system. This permits binaries to be run on ARMv4 through
1716 to ARMv8 without modification.
1718 See Documentation/arch/arm/kernel_user_helpers.rst for details.
1720 However, the fixed address nature of these helpers can be used
1721 by ROP (return orientated programming) authors when creating
1724 If all of the binaries and libraries which run on your platform
1725 are built specifically for your platform, and make no use of
1726 these helpers, then you can turn this option off to hinder
1727 such exploits. However, in that case, if a binary or library
1728 relying on those helpers is run, it will not function correctly.
1730 Say N here only if you are absolutely certain that you do not
1731 need these helpers; otherwise, the safe option is to say Y.
1734 bool "Enable vDSO for 32-bit applications"
1735 depends on !CPU_BIG_ENDIAN
1736 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1737 select GENERIC_COMPAT_VDSO
1740 Place in the process address space of 32-bit applications an
1741 ELF shared object providing fast implementations of gettimeofday
1744 You must have a 32-bit build of glibc 2.22 or later for programs
1745 to seamlessly take advantage of this.
1747 config THUMB2_COMPAT_VDSO
1748 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1749 depends on COMPAT_VDSO
1752 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1753 otherwise with '-marm'.
1755 config COMPAT_ALIGNMENT_FIXUPS
1756 bool "Fix up misaligned multi-word loads and stores in user space"
1758 menuconfig ARMV8_DEPRECATED
1759 bool "Emulate deprecated/obsolete ARMv8 instructions"
1762 Legacy software support may require certain instructions
1763 that have been deprecated or obsoleted in the architecture.
1765 Enable this config to enable selective emulation of these
1772 config SWP_EMULATION
1773 bool "Emulate SWP/SWPB instructions"
1775 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1776 they are always undefined. Say Y here to enable software
1777 emulation of these instructions for userspace using LDXR/STXR.
1778 This feature can be controlled at runtime with the abi.swp
1779 sysctl which is disabled by default.
1781 In some older versions of glibc [<=2.8] SWP is used during futex
1782 trylock() operations with the assumption that the code will not
1783 be preempted. This invalid assumption may be more likely to fail
1784 with SWP emulation enabled, leading to deadlock of the user
1787 NOTE: when accessing uncached shared regions, LDXR/STXR rely
1788 on an external transaction monitoring block called a global
1789 monitor to maintain update atomicity. If your system does not
1790 implement a global monitor, this option can cause programs that
1791 perform SWP operations to uncached memory to deadlock.
1795 config CP15_BARRIER_EMULATION
1796 bool "Emulate CP15 Barrier instructions"
1798 The CP15 barrier instructions - CP15ISB, CP15DSB, and
1799 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1800 strongly recommended to use the ISB, DSB, and DMB
1801 instructions instead.
1803 Say Y here to enable software emulation of these
1804 instructions for AArch32 userspace code. When this option is
1805 enabled, CP15 barrier usage is traced which can help
1806 identify software that needs updating. This feature can be
1807 controlled at runtime with the abi.cp15_barrier sysctl.
1811 config SETEND_EMULATION
1812 bool "Emulate SETEND instruction"
1814 The SETEND instruction alters the data-endianness of the
1815 AArch32 EL0, and is deprecated in ARMv8.
1817 Say Y here to enable software emulation of the instruction
1818 for AArch32 userspace code. This feature can be controlled
1819 at runtime with the abi.setend sysctl.
1821 Note: All the cpus on the system must have mixed endian support at EL0
1822 for this feature to be enabled. If a new CPU - which doesn't support mixed
1823 endian - is hotplugged in after this feature has been enabled, there could
1824 be unexpected results in the applications.
1827 endif # ARMV8_DEPRECATED
1831 menu "ARMv8.1 architectural features"
1833 config ARM64_HW_AFDBM
1834 bool "Support for hardware updates of the Access and Dirty page flags"
1837 The ARMv8.1 architecture extensions introduce support for
1838 hardware updates of the access and dirty information in page
1839 table entries. When enabled in TCR_EL1 (HA and HD bits) on
1840 capable processors, accesses to pages with PTE_AF cleared will
1841 set this bit instead of raising an access flag fault.
1842 Similarly, writes to read-only pages with the DBM bit set will
1843 clear the read-only bit (AP[2]) instead of raising a
1846 Kernels built with this configuration option enabled continue
1847 to work on pre-ARMv8.1 hardware and the performance impact is
1848 minimal. If unsure, say Y.
1851 bool "Enable support for Privileged Access Never (PAN)"
1854 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1855 prevents the kernel or hypervisor from accessing user-space (EL0)
1858 Choosing this option will cause any unprotected (not using
1859 copy_to_user et al) memory access to fail with a permission fault.
1861 The feature is detected at runtime, and will remain as a 'nop'
1862 instruction if the cpu does not implement the feature.
1864 config AS_HAS_LSE_ATOMICS
1865 def_bool $(as-instr,.arch_extension lse)
1867 config ARM64_LSE_ATOMICS
1869 default ARM64_USE_LSE_ATOMICS
1870 depends on AS_HAS_LSE_ATOMICS
1872 config ARM64_USE_LSE_ATOMICS
1873 bool "Atomic instructions"
1876 As part of the Large System Extensions, ARMv8.1 introduces new
1877 atomic instructions that are designed specifically to scale in
1880 Say Y here to make use of these instructions for the in-kernel
1881 atomic routines. This incurs a small overhead on CPUs that do
1882 not support these instructions and requires the kernel to be
1883 built with binutils >= 2.25 in order for the new instructions
1886 endmenu # "ARMv8.1 architectural features"
1888 menu "ARMv8.2 architectural features"
1890 config AS_HAS_ARMV8_2
1891 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1894 def_bool $(as-instr,.arch armv8.2-a+sha3)
1897 bool "Enable support for persistent memory"
1898 select ARCH_HAS_PMEM_API
1899 select ARCH_HAS_UACCESS_FLUSHCACHE
1901 Say Y to enable support for the persistent memory API based on the
1902 ARMv8.2 DCPoP feature.
1904 The feature is detected at runtime, and the kernel will use DC CVAC
1905 operations if DC CVAP is not supported (following the behaviour of
1906 DC CVAP itself if the system does not define a point of persistence).
1908 config ARM64_RAS_EXTN
1909 bool "Enable support for RAS CPU Extensions"
1912 CPUs that support the Reliability, Availability and Serviceability
1913 (RAS) Extensions, part of ARMv8.2 are able to track faults and
1914 errors, classify them and report them to software.
1916 On CPUs with these extensions system software can use additional
1917 barriers to determine if faults are pending and read the
1918 classification from a new set of registers.
1920 Selecting this feature will allow the kernel to use these barriers
1921 and access the new registers if the system supports the extension.
1922 Platform RAS features may additionally depend on firmware support.
1925 bool "Enable support for Common Not Private (CNP) translations"
1927 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1929 Common Not Private (CNP) allows translation table entries to
1930 be shared between different PEs in the same inner shareable
1931 domain, so the hardware can use this fact to optimise the
1932 caching of such entries in the TLB.
1934 Selecting this option allows the CNP feature to be detected
1935 at runtime, and does not affect PEs that do not implement
1938 endmenu # "ARMv8.2 architectural features"
1940 menu "ARMv8.3 architectural features"
1942 config ARM64_PTR_AUTH
1943 bool "Enable support for pointer authentication"
1946 Pointer authentication (part of the ARMv8.3 Extensions) provides
1947 instructions for signing and authenticating pointers against secret
1948 keys, which can be used to mitigate Return Oriented Programming (ROP)
1951 This option enables these instructions at EL0 (i.e. for userspace).
1952 Choosing this option will cause the kernel to initialise secret keys
1953 for each process at exec() time, with these keys being
1954 context-switched along with the process.
1956 The feature is detected at runtime. If the feature is not present in
1957 hardware it will not be advertised to userspace/KVM guest nor will it
1960 If the feature is present on the boot CPU but not on a late CPU, then
1961 the late CPU will be parked. Also, if the boot CPU does not have
1962 address auth and the late CPU has then the late CPU will still boot
1963 but with the feature disabled. On such a system, this option should
1966 config ARM64_PTR_AUTH_KERNEL
1967 bool "Use pointer authentication for kernel"
1969 depends on ARM64_PTR_AUTH
1970 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1971 # Modern compilers insert a .note.gnu.property section note for PAC
1972 # which is only understood by binutils starting with version 2.33.1.
1973 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1974 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1975 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1977 If the compiler supports the -mbranch-protection or
1978 -msign-return-address flag (e.g. GCC 7 or later), then this option
1979 will cause the kernel itself to be compiled with return address
1980 protection. In this case, and if the target hardware is known to
1981 support pointer authentication, then CONFIG_STACKPROTECTOR can be
1982 disabled with minimal loss of protection.
1984 This feature works with FUNCTION_GRAPH_TRACER option only if
1985 DYNAMIC_FTRACE_WITH_ARGS is enabled.
1987 config CC_HAS_BRANCH_PROT_PAC_RET
1988 # GCC 9 or later, clang 8 or later
1989 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1991 config CC_HAS_SIGN_RETURN_ADDRESS
1993 def_bool $(cc-option,-msign-return-address=all)
1995 config AS_HAS_ARMV8_3
1996 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1998 config AS_HAS_CFI_NEGATE_RA_STATE
1999 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
2002 def_bool $(as-instr,.arch_extension rcpc)
2004 endmenu # "ARMv8.3 architectural features"
2006 menu "ARMv8.4 architectural features"
2008 config ARM64_AMU_EXTN
2009 bool "Enable support for the Activity Monitors Unit CPU extension"
2012 The activity monitors extension is an optional extension introduced
2013 by the ARMv8.4 CPU architecture. This enables support for version 1
2014 of the activity monitors architecture, AMUv1.
2016 To enable the use of this extension on CPUs that implement it, say Y.
2018 Note that for architectural reasons, firmware _must_ implement AMU
2019 support when running on CPUs that present the activity monitors
2020 extension. The required support is present in:
2021 * Version 1.5 and later of the ARM Trusted Firmware
2023 For kernels that have this configuration enabled but boot with broken
2024 firmware, you may need to say N here until the firmware is fixed.
2025 Otherwise you may experience firmware panics or lockups when
2026 accessing the counter registers. Even if you are not observing these
2027 symptoms, the values returned by the register reads might not
2028 correctly reflect reality. Most commonly, the value read will be 0,
2029 indicating that the counter is not enabled.
2031 config AS_HAS_ARMV8_4
2032 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
2034 config ARM64_TLB_RANGE
2035 bool "Enable support for tlbi range feature"
2037 depends on AS_HAS_ARMV8_4
2039 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2040 range of input addresses.
2042 The feature introduces new assembly instructions, and they were
2043 support when binutils >= 2.30.
2045 endmenu # "ARMv8.4 architectural features"
2047 menu "ARMv8.5 architectural features"
2049 config AS_HAS_ARMV8_5
2050 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2053 bool "Branch Target Identification support"
2056 Branch Target Identification (part of the ARMv8.5 Extensions)
2057 provides a mechanism to limit the set of locations to which computed
2058 branch instructions such as BR or BLR can jump.
2060 To make use of BTI on CPUs that support it, say Y.
2062 BTI is intended to provide complementary protection to other control
2063 flow integrity protection mechanisms, such as the Pointer
2064 authentication mechanism provided as part of the ARMv8.3 Extensions.
2065 For this reason, it does not make sense to enable this option without
2066 also enabling support for pointer authentication. Thus, when
2067 enabling this option you should also select ARM64_PTR_AUTH=y.
2069 Userspace binaries must also be specifically compiled to make use of
2070 this mechanism. If you say N here or the hardware does not support
2071 BTI, such binaries can still run, but you get no additional
2072 enforcement of branch destinations.
2074 config ARM64_BTI_KERNEL
2075 bool "Use Branch Target Identification for kernel"
2077 depends on ARM64_BTI
2078 depends on ARM64_PTR_AUTH_KERNEL
2079 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2080 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2081 depends on !CC_IS_GCC || GCC_VERSION >= 100100
2082 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2083 depends on !CC_IS_GCC
2084 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2086 Build the kernel with Branch Target Identification annotations
2087 and enable enforcement of this for kernel code. When this option
2088 is enabled and the system supports BTI all kernel code including
2089 modular code must have BTI enabled.
2091 config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2092 # GCC 9 or later, clang 8 or later
2093 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2096 bool "Enable support for E0PD"
2099 E0PD (part of the ARMv8.5 extensions) allows us to ensure
2100 that EL0 accesses made via TTBR1 always fault in constant time,
2101 providing similar benefits to KASLR as those provided by KPTI, but
2102 with lower overhead and without disrupting legitimate access to
2103 kernel memory such as SPE.
2105 This option enables E0PD for TTBR1 where available.
2107 config ARM64_AS_HAS_MTE
2108 # Initial support for MTE went in binutils 2.32.0, checked with
2109 # ".arch armv8.5-a+memtag" below. However, this was incomplete
2110 # as a late addition to the final architecture spec (LDGM/STGM)
2111 # is only supported in the newer 2.32.x and 2.33 binutils
2112 # versions, hence the extra "stgm" instruction check below.
2113 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2116 bool "Memory Tagging Extension support"
2118 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2119 depends on AS_HAS_ARMV8_5
2120 depends on AS_HAS_LSE_ATOMICS
2121 # Required for tag checking in the uaccess routines
2122 depends on ARM64_PAN
2123 select ARCH_HAS_SUBPAGE_FAULTS
2124 select ARCH_USES_HIGH_VMA_FLAGS
2125 select ARCH_USES_PG_ARCH_2
2126 select ARCH_USES_PG_ARCH_3
2128 Memory Tagging (part of the ARMv8.5 Extensions) provides
2129 architectural support for run-time, always-on detection of
2130 various classes of memory error to aid with software debugging
2131 to eliminate vulnerabilities arising from memory-unsafe
2134 This option enables the support for the Memory Tagging
2135 Extension at EL0 (i.e. for userspace).
2137 Selecting this option allows the feature to be detected at
2138 runtime. Any secondary CPU not implementing this feature will
2139 not be allowed a late bring-up.
2141 Userspace binaries that want to use this feature must
2142 explicitly opt in. The mechanism for the userspace is
2145 Documentation/arch/arm64/memory-tagging-extension.rst.
2147 endmenu # "ARMv8.5 architectural features"
2149 menu "ARMv8.7 architectural features"
2152 bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2154 depends on ARM64_PAN
2156 Enhanced Privileged Access Never (EPAN) allows Privileged
2157 Access Never to be used with Execute-only mappings.
2159 The feature is detected at runtime, and will remain disabled
2160 if the cpu does not implement the feature.
2161 endmenu # "ARMv8.7 architectural features"
2163 menu "ARMv8.9 architectural features"
2166 prompt "Permission Overlay Extension"
2168 select ARCH_USES_HIGH_VMA_FLAGS
2169 select ARCH_HAS_PKEYS
2171 The Permission Overlay Extension is used to implement Memory
2172 Protection Keys. Memory Protection Keys provides a mechanism for
2173 enforcing page-based protections, but without requiring modification
2174 of the page tables when an application changes protection domains.
2176 For details, see Documentation/core-api/protection-keys.rst
2180 config ARCH_PKEY_BITS
2185 bool "Support for Hardware managed Access Flag for Table Descriptors"
2186 depends on ARM64_HW_AFDBM
2189 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access
2190 Flag for Table descriptors. When enabled an architectural executed
2191 memory access will update the Access Flag in each Table descriptor
2192 which is accessed during the translation table walk and for which
2193 the Access Flag is 0. The Access Flag of the Table descriptor use
2194 the same bit of PTE_AF.
2196 The feature will only be enabled if all the CPUs in the system
2197 support this feature. If unsure, say Y.
2199 endmenu # "ARMv8.9 architectural features"
2201 menu "v9.4 architectural features"
2204 bool "Enable support for Guarded Control Stack (GCS)"
2206 select ARCH_HAS_USER_SHADOW_STACK
2207 select ARCH_USES_HIGH_VMA_FLAGS
2210 Guarded Control Stack (GCS) provides support for a separate
2211 stack with restricted access which contains only return
2212 addresses. This can be used to harden against some attacks
2213 by comparing return address used by the program with what is
2214 stored in the GCS, and may also be used to efficiently obtain
2215 the call stack for applications such as profiling.
2217 The feature is detected at runtime, and will remain disabled
2218 if the system does not implement the feature.
2220 endmenu # "v9.4 architectural features"
2223 bool "ARM Scalable Vector Extension support"
2226 The Scalable Vector Extension (SVE) is an extension to the AArch64
2227 execution state which complements and extends the SIMD functionality
2228 of the base architecture to support much larger vectors and to enable
2229 additional vectorisation opportunities.
2231 To enable use of this extension on CPUs that implement it, say Y.
2233 On CPUs that support the SVE2 extensions, this option will enable
2236 Note that for architectural reasons, firmware _must_ implement SVE
2237 support when running on SVE capable hardware. The required support
2240 * version 1.5 and later of the ARM Trusted Firmware
2241 * the AArch64 boot wrapper since commit 5e1261e08abf
2242 ("bootwrapper: SVE: Enable SVE for EL2 and below").
2244 For other firmware implementations, consult the firmware documentation
2247 If you need the kernel to boot on SVE-capable hardware with broken
2248 firmware, you may need to say N here until you get your firmware
2249 fixed. Otherwise, you may experience firmware panics or lockups when
2250 booting the kernel. If unsure and you are not observing these
2251 symptoms, you should assume that it is safe to say Y.
2254 bool "ARM Scalable Matrix Extension support"
2256 depends on ARM64_SVE
2258 The Scalable Matrix Extension (SME) is an extension to the AArch64
2259 execution state which utilises a substantial subset of the SVE
2260 instruction set, together with the addition of new architectural
2261 register state capable of holding two dimensional matrix tiles to
2262 enable various matrix operations.
2264 config ARM64_PSEUDO_NMI
2265 bool "Support for NMI-like interrupts"
2268 Adds support for mimicking Non-Maskable Interrupts through the use of
2269 GIC interrupt priority. This support requires version 3 or later of
2272 This high priority configuration for interrupts needs to be
2273 explicitly enabled by setting the kernel parameter
2274 "irqchip.gicv3_pseudo_nmi" to 1.
2279 config ARM64_DEBUG_PRIORITY_MASKING
2280 bool "Debug interrupt priority masking"
2282 This adds runtime checks to functions enabling/disabling
2283 interrupts when using priority masking. The additional checks verify
2284 the validity of ICC_PMR_EL1 when calling concerned functions.
2287 endif # ARM64_PSEUDO_NMI
2290 bool "Build a relocatable kernel image" if EXPERT
2291 select ARCH_HAS_RELR
2294 This builds the kernel as a Position Independent Executable (PIE),
2295 which retains all relocation metadata required to relocate the
2296 kernel binary at runtime to a different virtual address than the
2297 address it was linked at.
2298 Since AArch64 uses the RELA relocation format, this requires a
2299 relocation pass at runtime even if the kernel is loaded at the
2300 same address it was linked at.
2302 config RANDOMIZE_BASE
2303 bool "Randomize the address of the kernel image"
2306 Randomizes the virtual address at which the kernel image is
2307 loaded, as a security feature that deters exploit attempts
2308 relying on knowledge of the location of kernel internals.
2310 It is the bootloader's job to provide entropy, by passing a
2311 random u64 value in /chosen/kaslr-seed at kernel entry.
2313 When booting via the UEFI stub, it will invoke the firmware's
2314 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2315 to the kernel proper. In addition, it will randomise the physical
2316 location of the kernel Image as well.
2320 config RANDOMIZE_MODULE_REGION_FULL
2321 bool "Randomize the module region over a 2 GB range"
2322 depends on RANDOMIZE_BASE
2325 Randomizes the location of the module region inside a 2 GB window
2326 covering the core kernel. This way, it is less likely for modules
2327 to leak information about the location of core kernel data structures
2328 but it does imply that function calls between modules and the core
2329 kernel will need to be resolved via veneers in the module PLT.
2331 When this option is not set, the module region will be randomized over
2332 a limited range that contains the [_stext, _etext] interval of the
2333 core kernel, so branch relocations are almost always in range unless
2334 the region is exhausted. In this particular case of region
2335 exhaustion, modules might be able to fall back to a larger 2GB area.
2337 config CC_HAVE_STACKPROTECTOR_SYSREG
2338 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2340 config STACKPROTECTOR_PER_TASK
2342 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2344 config UNWIND_PATCH_PAC_INTO_SCS
2345 bool "Enable shadow call stack dynamically using code patching"
2346 # needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated
2347 depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2348 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2349 depends on SHADOW_CALL_STACK
2350 select UNWIND_TABLES
2353 config ARM64_CONTPTE
2354 bool "Contiguous PTE mappings for user memory" if EXPERT
2355 depends on TRANSPARENT_HUGEPAGE
2358 When enabled, user mappings are configured using the PTE contiguous
2359 bit, for any mappings that meet the size and alignment requirements.
2360 This reduces TLB pressure and improves performance.
2362 endmenu # "Kernel Features"
2366 config ARM64_ACPI_PARKING_PROTOCOL
2367 bool "Enable support for the ARM64 ACPI parking protocol"
2370 Enable support for the ARM64 ACPI parking protocol. If disabled
2371 the kernel will not allow booting through the ARM64 ACPI parking
2372 protocol even if the corresponding data is present in the ACPI
2376 string "Default kernel command string"
2379 Provide a set of default command-line options at build time by
2380 entering them here. As a minimum, you should specify the the
2381 root device (e.g. root=/dev/nfs).
2384 prompt "Kernel command line type"
2385 depends on CMDLINE != ""
2386 default CMDLINE_FROM_BOOTLOADER
2388 Choose how the kernel will handle the provided default kernel
2389 command line string.
2391 config CMDLINE_FROM_BOOTLOADER
2392 bool "Use bootloader kernel arguments if available"
2394 Uses the command-line options passed by the boot loader. If
2395 the boot loader doesn't provide any, the default kernel command
2396 string provided in CMDLINE will be used.
2398 config CMDLINE_FORCE
2399 bool "Always use the default kernel command string"
2401 Always use the default kernel command string, even if the boot
2402 loader passes other arguments to the kernel.
2403 This is useful if you cannot or don't want to change the
2404 command-line options your boot loader passes to the kernel.
2412 bool "UEFI runtime support"
2413 depends on OF && !CPU_BIG_ENDIAN
2414 depends on KERNEL_MODE_NEON
2415 select ARCH_SUPPORTS_ACPI
2418 select EFI_PARAMS_FROM_FDT
2419 select EFI_RUNTIME_WRAPPERS
2421 select EFI_GENERIC_STUB
2422 imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2425 This option provides support for runtime services provided
2426 by UEFI firmware (such as non-volatile variables, realtime
2427 clock, and platform reset). A UEFI stub is also provided to
2428 allow the kernel to be booted as an EFI application. This
2429 is only useful on systems that have UEFI firmware.
2431 config COMPRESSED_INSTALL
2432 bool "Install compressed image by default"
2434 This makes the regular "make install" install the compressed
2435 image we built, not the legacy uncompressed one.
2437 You can check that a compressed image works for you by doing
2438 "make zinstall" first, and verifying that everything is fine
2439 in your environment before making "make install" do this for
2443 bool "Enable support for SMBIOS (DMI) tables"
2447 This enables SMBIOS/DMI feature for systems.
2449 This option is only useful on systems that have UEFI firmware.
2450 However, even with this option, the resultant kernel should
2451 continue to boot on existing non-UEFI platforms.
2453 endmenu # "Boot options"
2455 menu "Power management options"
2457 source "kernel/power/Kconfig"
2459 config ARCH_HIBERNATION_POSSIBLE
2463 config ARCH_HIBERNATION_HEADER
2465 depends on HIBERNATION
2467 config ARCH_SUSPEND_POSSIBLE
2470 endmenu # "Power management options"
2472 menu "CPU Power Management"
2474 source "drivers/cpuidle/Kconfig"
2476 source "drivers/cpufreq/Kconfig"
2478 endmenu # "CPU Power Management"
2480 source "drivers/acpi/Kconfig"
2482 source "arch/arm64/kvm/Kconfig"