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1 # SPDX-License-Identifier: GPL-2.0-only
2 config ARM64
3 def_bool y
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
32 select ARCH_HAS_KCOV
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
43 select ARCH_STACKWALK
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
111 select ARM_AMBA
112 select ARM_ARCH_TIMER
113 select ARM_GIC
114 select AUDIT_ARCH_COMPAT_GENERIC
115 select ARM_GIC_V2M if PCI
116 select ARM_GIC_V3
117 select ARM_GIC_V3_ITS if PCI
118 select ARM_PSCI_FW
119 select BUILDTIME_TABLE_SORT
120 select CLONE_BACKWARDS
121 select COMMON_CLK
122 select CPU_PM if (SUSPEND || CPU_IDLE)
123 select CRC32
124 select DCACHE_WORD_ACCESS
125 select DYNAMIC_FTRACE if FUNCTION_TRACER
126 select DMA_BOUNCE_UNALIGNED_KMALLOC
127 select DMA_DIRECT_REMAP
128 select EDAC_SUPPORT
129 select FRAME_POINTER
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_VULNERABILITIES
137 select GENERIC_EARLY_IOREMAP
138 select GENERIC_IDLE_POLL_SETUP
139 select GENERIC_IOREMAP
140 select GENERIC_IRQ_IPI
141 select GENERIC_IRQ_PROBE
142 select GENERIC_IRQ_SHOW
143 select GENERIC_IRQ_SHOW_LEVEL
144 select GENERIC_LIB_DEVMEM_IS_ALLOWED
145 select GENERIC_PCI_IOMAP
146 select GENERIC_PTDUMP
147 select GENERIC_SCHED_CLOCK
148 select GENERIC_SMP_IDLE_THREAD
149 select GENERIC_TIME_VSYSCALL
150 select GENERIC_GETTIMEOFDAY
151 select GENERIC_VDSO_TIME_NS
152 select HARDIRQS_SW_RESEND
153 select HAS_IOPORT
154 select HAVE_MOVE_PMD
155 select HAVE_MOVE_PUD
156 select HAVE_PCI
157 select HAVE_ACPI_APEI if (ACPI && EFI)
158 select HAVE_ALIGNED_STRUCT_PAGE
159 select HAVE_ARCH_AUDITSYSCALL
160 select HAVE_ARCH_BITREVERSE
161 select HAVE_ARCH_COMPILER_H
162 select HAVE_ARCH_HUGE_VMALLOC
163 select HAVE_ARCH_HUGE_VMAP
164 select HAVE_ARCH_JUMP_LABEL
165 select HAVE_ARCH_JUMP_LABEL_RELATIVE
166 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
167 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
168 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
169 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
170 # Some instrumentation may be unsound, hence EXPERT
171 select HAVE_ARCH_KCSAN if EXPERT
172 select HAVE_ARCH_KFENCE
173 select HAVE_ARCH_KGDB
174 select HAVE_ARCH_MMAP_RND_BITS
175 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
176 select HAVE_ARCH_PREL32_RELOCATIONS
177 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
178 select HAVE_ARCH_SECCOMP_FILTER
179 select HAVE_ARCH_STACKLEAK
180 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
181 select HAVE_ARCH_TRACEHOOK
182 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
183 select HAVE_ARCH_VMAP_STACK
184 select HAVE_ARM_SMCCC
185 select HAVE_ASM_MODVERSIONS
186 select HAVE_EBPF_JIT
187 select HAVE_C_RECORDMCOUNT
188 select HAVE_CMPXCHG_DOUBLE
189 select HAVE_CMPXCHG_LOCAL
190 select HAVE_CONTEXT_TRACKING_USER
191 select HAVE_DEBUG_KMEMLEAK
192 select HAVE_DMA_CONTIGUOUS
193 select HAVE_DYNAMIC_FTRACE
194 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
195 if $(cc-option,-fpatchable-function-entry=2)
196 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
197 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
198 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
199 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
200 !CC_OPTIMIZE_FOR_SIZE)
201 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
202 if DYNAMIC_FTRACE_WITH_ARGS
203 select HAVE_SAMPLE_FTRACE_DIRECT
204 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
205 select HAVE_EFFICIENT_UNALIGNED_ACCESS
206 select HAVE_FAST_GUP
207 select HAVE_FTRACE_MCOUNT_RECORD
208 select HAVE_FUNCTION_TRACER
209 select HAVE_FUNCTION_ERROR_INJECTION
210 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
211 select HAVE_FUNCTION_GRAPH_TRACER
212 select HAVE_GCC_PLUGINS
213 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
214 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
215 select HAVE_HW_BREAKPOINT if PERF_EVENTS
216 select HAVE_IOREMAP_PROT
217 select HAVE_IRQ_TIME_ACCOUNTING
218 select HAVE_KVM
219 select HAVE_MOD_ARCH_SPECIFIC
220 select HAVE_NMI
221 select HAVE_PERF_EVENTS
222 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
223 select HAVE_PERF_REGS
224 select HAVE_PERF_USER_STACK_DUMP
225 select HAVE_PREEMPT_DYNAMIC_KEY
226 select HAVE_REGS_AND_STACK_ACCESS_API
227 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
228 select HAVE_FUNCTION_ARG_ACCESS_API
229 select MMU_GATHER_RCU_TABLE_FREE
230 select HAVE_RSEQ
231 select HAVE_STACKPROTECTOR
232 select HAVE_SYSCALL_TRACEPOINTS
233 select HAVE_KPROBES
234 select HAVE_KRETPROBES
235 select HAVE_GENERIC_VDSO
236 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
237 select IRQ_DOMAIN
238 select IRQ_FORCED_THREADING
239 select KASAN_VMALLOC if KASAN
240 select LOCK_MM_AND_FIND_VMA
241 select MODULES_USE_ELF_RELA
242 select NEED_DMA_MAP_STATE
243 select NEED_SG_DMA_LENGTH
244 select OF
245 select OF_EARLY_FLATTREE
246 select PCI_DOMAINS_GENERIC if PCI
247 select PCI_ECAM if (ACPI && PCI)
248 select PCI_SYSCALL if PCI
249 select POWER_RESET
250 select POWER_SUPPLY
251 select SPARSE_IRQ
252 select SWIOTLB
253 select SYSCTL_EXCEPTION_TRACE
254 select THREAD_INFO_IN_TASK
255 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
256 select TRACE_IRQFLAGS_SUPPORT
257 select TRACE_IRQFLAGS_NMI_SUPPORT
258 select HAVE_SOFTIRQ_ON_OWN_STACK
259 help
260 ARM 64-bit (AArch64) Linux support.
261
262 config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
263 def_bool CC_IS_CLANG
264 # https://github.com/ClangBuiltLinux/linux/issues/1507
265 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
266 select HAVE_DYNAMIC_FTRACE_WITH_ARGS
267
268 config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
269 def_bool CC_IS_GCC
270 depends on $(cc-option,-fpatchable-function-entry=2)
271 select HAVE_DYNAMIC_FTRACE_WITH_ARGS
272
273 config 64BIT
274 def_bool y
275
276 config MMU
277 def_bool y
278
279 config ARM64_PAGE_SHIFT
280 int
281 default 16 if ARM64_64K_PAGES
282 default 14 if ARM64_16K_PAGES
283 default 12
284
285 config ARM64_CONT_PTE_SHIFT
286 int
287 default 5 if ARM64_64K_PAGES
288 default 7 if ARM64_16K_PAGES
289 default 4
290
291 config ARM64_CONT_PMD_SHIFT
292 int
293 default 5 if ARM64_64K_PAGES
294 default 5 if ARM64_16K_PAGES
295 default 4
296
297 config ARCH_MMAP_RND_BITS_MIN
298 default 14 if ARM64_64K_PAGES
299 default 16 if ARM64_16K_PAGES
300 default 18
301
302 # max bits determined by the following formula:
303 # VA_BITS - PAGE_SHIFT - 3
304 config ARCH_MMAP_RND_BITS_MAX
305 default 19 if ARM64_VA_BITS=36
306 default 24 if ARM64_VA_BITS=39
307 default 27 if ARM64_VA_BITS=42
308 default 30 if ARM64_VA_BITS=47
309 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
310 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
311 default 33 if ARM64_VA_BITS=48
312 default 14 if ARM64_64K_PAGES
313 default 16 if ARM64_16K_PAGES
314 default 18
315
316 config ARCH_MMAP_RND_COMPAT_BITS_MIN
317 default 7 if ARM64_64K_PAGES
318 default 9 if ARM64_16K_PAGES
319 default 11
320
321 config ARCH_MMAP_RND_COMPAT_BITS_MAX
322 default 16
323
324 config NO_IOPORT_MAP
325 def_bool y if !PCI
326
327 config STACKTRACE_SUPPORT
328 def_bool y
329
330 config ILLEGAL_POINTER_VALUE
331 hex
332 default 0xdead000000000000
333
334 config LOCKDEP_SUPPORT
335 def_bool y
336
337 config GENERIC_BUG
338 def_bool y
339 depends on BUG
340
341 config GENERIC_BUG_RELATIVE_POINTERS
342 def_bool y
343 depends on GENERIC_BUG
344
345 config GENERIC_HWEIGHT
346 def_bool y
347
348 config GENERIC_CSUM
349 def_bool y
350
351 config GENERIC_CALIBRATE_DELAY
352 def_bool y
353
354 config SMP
355 def_bool y
356
357 config KERNEL_MODE_NEON
358 def_bool y
359
360 config FIX_EARLYCON_MEM
361 def_bool y
362
363 config PGTABLE_LEVELS
364 int
365 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
366 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
367 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
368 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
369 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
370 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
371
372 config ARCH_SUPPORTS_UPROBES
373 def_bool y
374
375 config ARCH_PROC_KCORE_TEXT
376 def_bool y
377
378 config BROKEN_GAS_INST
379 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
380
381 config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
382 bool
383 # Clang's __builtin_return_adddress() strips the PAC since 12.0.0
384 # https://reviews.llvm.org/D75044
385 default y if CC_IS_CLANG && (CLANG_VERSION >= 120000)
386 # GCC's __builtin_return_address() strips the PAC since 11.1.0,
387 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
388 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
389 default y if CC_IS_GCC && (GCC_VERSION >= 110100)
390 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
391 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000)
392 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000)
393 default n
394
395 config KASAN_SHADOW_OFFSET
396 hex
397 depends on KASAN_GENERIC || KASAN_SW_TAGS
398 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
399 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
400 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
401 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
402 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
403 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
404 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
405 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
406 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
407 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
408 default 0xffffffffffffffff
409
410 config UNWIND_TABLES
411 bool
412
413 source "arch/arm64/Kconfig.platforms"
414
415 menu "Kernel Features"
416
417 menu "ARM errata workarounds via the alternatives framework"
418
419 config AMPERE_ERRATUM_AC03_CPU_38
420 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
421 default y
422 help
423 This option adds an alternative code sequence to work around Ampere
424 erratum AC03_CPU_38 on AmpereOne.
425
426 The affected design reports FEAT_HAFDBS as not implemented in
427 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
428 as required by the architecture. The unadvertised HAFDBS
429 implementation suffers from an additional erratum where hardware
430 A/D updates can occur after a PTE has been marked invalid.
431
432 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
433 which avoids enabling unadvertised hardware Access Flag management
434 at stage-2.
435
436 If unsure, say Y.
437
438 config ARM64_WORKAROUND_CLEAN_CACHE
439 bool
440
441 config ARM64_ERRATUM_826319
442 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
443 default y
444 select ARM64_WORKAROUND_CLEAN_CACHE
445 help
446 This option adds an alternative code sequence to work around ARM
447 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
448 AXI master interface and an L2 cache.
449
450 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
451 and is unable to accept a certain write via this interface, it will
452 not progress on read data presented on the read data channel and the
453 system can deadlock.
454
455 The workaround promotes data cache clean instructions to
456 data cache clean-and-invalidate.
457 Please note that this does not necessarily enable the workaround,
458 as it depends on the alternative framework, which will only patch
459 the kernel if an affected CPU is detected.
460
461 If unsure, say Y.
462
463 config ARM64_ERRATUM_827319
464 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
465 default y
466 select ARM64_WORKAROUND_CLEAN_CACHE
467 help
468 This option adds an alternative code sequence to work around ARM
469 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
470 master interface and an L2 cache.
471
472 Under certain conditions this erratum can cause a clean line eviction
473 to occur at the same time as another transaction to the same address
474 on the AMBA 5 CHI interface, which can cause data corruption if the
475 interconnect reorders the two transactions.
476
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.
482
483 If unsure, say Y.
484
485 config ARM64_ERRATUM_824069
486 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
487 default y
488 select ARM64_WORKAROUND_CLEAN_CACHE
489 help
490 This option adds an alternative code sequence to work around ARM
491 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
492 to a coherent interconnect.
493
494 If a Cortex-A53 processor is executing a store or prefetch for
495 write instruction at the same time as a processor in another
496 cluster is executing a cache maintenance operation to the same
497 address, then this erratum might cause a clean cache line to be
498 incorrectly marked as dirty.
499
500 The workaround promotes data cache clean instructions to
501 data cache clean-and-invalidate.
502 Please note that this option does not necessarily enable the
503 workaround, as it depends on the alternative framework, which will
504 only patch the kernel if an affected CPU is detected.
505
506 If unsure, say Y.
507
508 config ARM64_ERRATUM_819472
509 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
510 default y
511 select ARM64_WORKAROUND_CLEAN_CACHE
512 help
513 This option adds an alternative code sequence to work around ARM
514 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
515 present when it is connected to a coherent interconnect.
516
517 If the processor is executing a load and store exclusive sequence at
518 the same time as a processor in another cluster is executing a cache
519 maintenance operation to the same address, then this erratum might
520 cause data corruption.
521
522 The workaround promotes data cache clean instructions to
523 data cache clean-and-invalidate.
524 Please note that this does not necessarily enable the workaround,
525 as it depends on the alternative framework, which will only patch
526 the kernel if an affected CPU is detected.
527
528 If unsure, say Y.
529
530 config ARM64_ERRATUM_832075
531 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
532 default y
533 help
534 This option adds an alternative code sequence to work around ARM
535 erratum 832075 on Cortex-A57 parts up to r1p2.
536
537 Affected Cortex-A57 parts might deadlock when exclusive load/store
538 instructions to Write-Back memory are mixed with Device loads.
539
540 The workaround is to promote device loads to use Load-Acquire
541 semantics.
542 Please note that this does not necessarily enable the workaround,
543 as it depends on the alternative framework, which will only patch
544 the kernel if an affected CPU is detected.
545
546 If unsure, say Y.
547
548 config ARM64_ERRATUM_834220
549 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
550 depends on KVM
551 default y
552 help
553 This option adds an alternative code sequence to work around ARM
554 erratum 834220 on Cortex-A57 parts up to r1p2.
555
556 Affected Cortex-A57 parts might report a Stage 2 translation
557 fault as the result of a Stage 1 fault for load crossing a
558 page boundary when there is a permission or device memory
559 alignment fault at Stage 1 and a translation fault at Stage 2.
560
561 The workaround is to verify that the Stage 1 translation
562 doesn't generate a fault before handling the Stage 2 fault.
563 Please note that this does not necessarily enable the workaround,
564 as it depends on the alternative framework, which will only patch
565 the kernel if an affected CPU is detected.
566
567 If unsure, say Y.
568
569 config ARM64_ERRATUM_1742098
570 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
571 depends on COMPAT
572 default y
573 help
574 This option removes the AES hwcap for aarch32 user-space to
575 workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
576
577 Affected parts may corrupt the AES state if an interrupt is
578 taken between a pair of AES instructions. These instructions
579 are only present if the cryptography extensions are present.
580 All software should have a fallback implementation for CPUs
581 that don't implement the cryptography extensions.
582
583 If unsure, say Y.
584
585 config ARM64_ERRATUM_845719
586 bool "Cortex-A53: 845719: a load might read incorrect data"
587 depends on COMPAT
588 default y
589 help
590 This option adds an alternative code sequence to work around ARM
591 erratum 845719 on Cortex-A53 parts up to r0p4.
592
593 When running a compat (AArch32) userspace on an affected Cortex-A53
594 part, a load at EL0 from a virtual address that matches the bottom 32
595 bits of the virtual address used by a recent load at (AArch64) EL1
596 might return incorrect data.
597
598 The workaround is to write the contextidr_el1 register on exception
599 return to a 32-bit task.
600 Please note that this does not necessarily enable the workaround,
601 as it depends on the alternative framework, which will only patch
602 the kernel if an affected CPU is detected.
603
604 If unsure, say Y.
605
606 config ARM64_ERRATUM_843419
607 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
608 default y
609 help
610 This option links the kernel with '--fix-cortex-a53-843419' and
611 enables PLT support to replace certain ADRP instructions, which can
612 cause subsequent memory accesses to use an incorrect address on
613 Cortex-A53 parts up to r0p4.
614
615 If unsure, say Y.
616
617 config ARM64_LD_HAS_FIX_ERRATUM_843419
618 def_bool $(ld-option,--fix-cortex-a53-843419)
619
620 config ARM64_ERRATUM_1024718
621 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
622 default y
623 help
624 This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
625
626 Affected Cortex-A55 cores (all revisions) could cause incorrect
627 update of the hardware dirty bit when the DBM/AP bits are updated
628 without a break-before-make. The workaround is to disable the usage
629 of hardware DBM locally on the affected cores. CPUs not affected by
630 this erratum will continue to use the feature.
631
632 If unsure, say Y.
633
634 config ARM64_ERRATUM_1418040
635 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
636 default y
637 depends on COMPAT
638 help
639 This option adds a workaround for ARM Cortex-A76/Neoverse-N1
640 errata 1188873 and 1418040.
641
642 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
643 cause register corruption when accessing the timer registers
644 from AArch32 userspace.
645
646 If unsure, say Y.
647
648 config ARM64_WORKAROUND_SPECULATIVE_AT
649 bool
650
651 config ARM64_ERRATUM_1165522
652 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
653 default y
654 select ARM64_WORKAROUND_SPECULATIVE_AT
655 help
656 This option adds a workaround for ARM Cortex-A76 erratum 1165522.
657
658 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
659 corrupted TLBs by speculating an AT instruction during a guest
660 context switch.
661
662 If unsure, say Y.
663
664 config ARM64_ERRATUM_1319367
665 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
666 default y
667 select ARM64_WORKAROUND_SPECULATIVE_AT
668 help
669 This option adds work arounds for ARM Cortex-A57 erratum 1319537
670 and A72 erratum 1319367
671
672 Cortex-A57 and A72 cores could end-up with corrupted TLBs by
673 speculating an AT instruction during a guest context switch.
674
675 If unsure, say Y.
676
677 config ARM64_ERRATUM_1530923
678 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
679 default y
680 select ARM64_WORKAROUND_SPECULATIVE_AT
681 help
682 This option adds a workaround for ARM Cortex-A55 erratum 1530923.
683
684 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
685 corrupted TLBs by speculating an AT instruction during a guest
686 context switch.
687
688 If unsure, say Y.
689
690 config ARM64_WORKAROUND_REPEAT_TLBI
691 bool
692
693 config ARM64_ERRATUM_2441007
694 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
695 default y
696 select ARM64_WORKAROUND_REPEAT_TLBI
697 help
698 This option adds a workaround for ARM Cortex-A55 erratum #2441007.
699
700 Under very rare circumstances, affected Cortex-A55 CPUs
701 may not handle a race between a break-before-make sequence on one
702 CPU, and another CPU accessing the same page. This could allow a
703 store to a page that has been unmapped.
704
705 Work around this by adding the affected CPUs to the list that needs
706 TLB sequences to be done twice.
707
708 If unsure, say Y.
709
710 config ARM64_ERRATUM_1286807
711 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
712 default y
713 select ARM64_WORKAROUND_REPEAT_TLBI
714 help
715 This option adds a workaround for ARM Cortex-A76 erratum 1286807.
716
717 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
718 address for a cacheable mapping of a location is being
719 accessed by a core while another core is remapping the virtual
720 address to a new physical page using the recommended
721 break-before-make sequence, then under very rare circumstances
722 TLBI+DSB completes before a read using the translation being
723 invalidated has been observed by other observers. The
724 workaround repeats the TLBI+DSB operation.
725
726 config ARM64_ERRATUM_1463225
727 bool "Cortex-A76: Software Step might prevent interrupt recognition"
728 default y
729 help
730 This option adds a workaround for Arm Cortex-A76 erratum 1463225.
731
732 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
733 of a system call instruction (SVC) can prevent recognition of
734 subsequent interrupts when software stepping is disabled in the
735 exception handler of the system call and either kernel debugging
736 is enabled or VHE is in use.
737
738 Work around the erratum by triggering a dummy step exception
739 when handling a system call from a task that is being stepped
740 in a VHE configuration of the kernel.
741
742 If unsure, say Y.
743
744 config ARM64_ERRATUM_1542419
745 bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
746 default y
747 help
748 This option adds a workaround for ARM Neoverse-N1 erratum
749 1542419.
750
751 Affected Neoverse-N1 cores could execute a stale instruction when
752 modified by another CPU. The workaround depends on a firmware
753 counterpart.
754
755 Workaround the issue by hiding the DIC feature from EL0. This
756 forces user-space to perform cache maintenance.
757
758 If unsure, say Y.
759
760 config ARM64_ERRATUM_1508412
761 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
762 default y
763 help
764 This option adds a workaround for Arm Cortex-A77 erratum 1508412.
765
766 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
767 of a store-exclusive or read of PAR_EL1 and a load with device or
768 non-cacheable memory attributes. The workaround depends on a firmware
769 counterpart.
770
771 KVM guests must also have the workaround implemented or they can
772 deadlock the system.
773
774 Work around the issue by inserting DMB SY barriers around PAR_EL1
775 register reads and warning KVM users. The DMB barrier is sufficient
776 to prevent a speculative PAR_EL1 read.
777
778 If unsure, say Y.
779
780 config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
781 bool
782
783 config ARM64_ERRATUM_2051678
784 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
785 default y
786 help
787 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
788 Affected Cortex-A510 might not respect the ordering rules for
789 hardware update of the page table's dirty bit. The workaround
790 is to not enable the feature on affected CPUs.
791
792 If unsure, say Y.
793
794 config ARM64_ERRATUM_2077057
795 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
796 default y
797 help
798 This option adds the workaround for ARM Cortex-A510 erratum 2077057.
799 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
800 expected, but a Pointer Authentication trap is taken instead. The
801 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
802 EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
803
804 This can only happen when EL2 is stepping EL1.
805
806 When these conditions occur, the SPSR_EL2 value is unchanged from the
807 previous guest entry, and can be restored from the in-memory copy.
808
809 If unsure, say Y.
810
811 config ARM64_ERRATUM_2658417
812 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
813 default y
814 help
815 This option adds the workaround for ARM Cortex-A510 erratum 2658417.
816 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
817 BFMMLA or VMMLA instructions in rare circumstances when a pair of
818 A510 CPUs are using shared neon hardware. As the sharing is not
819 discoverable by the kernel, hide the BF16 HWCAP to indicate that
820 user-space should not be using these instructions.
821
822 If unsure, say Y.
823
824 config ARM64_ERRATUM_2119858
825 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
826 default y
827 depends on CORESIGHT_TRBE
828 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
829 help
830 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
831
832 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
833 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
834 the event of a WRAP event.
835
836 Work around the issue by always making sure we move the TRBPTR_EL1 by
837 256 bytes before enabling the buffer and filling the first 256 bytes of
838 the buffer with ETM ignore packets upon disabling.
839
840 If unsure, say Y.
841
842 config ARM64_ERRATUM_2139208
843 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
844 default y
845 depends on CORESIGHT_TRBE
846 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
847 help
848 This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
849
850 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
851 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
852 the event of a WRAP event.
853
854 Work around the issue by always making sure we move the TRBPTR_EL1 by
855 256 bytes before enabling the buffer and filling the first 256 bytes of
856 the buffer with ETM ignore packets upon disabling.
857
858 If unsure, say Y.
859
860 config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
861 bool
862
863 config ARM64_ERRATUM_2054223
864 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
865 default y
866 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
867 help
868 Enable workaround for ARM Cortex-A710 erratum 2054223
869
870 Affected cores may fail to flush the trace data on a TSB instruction, when
871 the PE is in trace prohibited state. This will cause losing a few bytes
872 of the trace cached.
873
874 Workaround is to issue two TSB consecutively on affected cores.
875
876 If unsure, say Y.
877
878 config ARM64_ERRATUM_2067961
879 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
880 default y
881 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
882 help
883 Enable workaround for ARM Neoverse-N2 erratum 2067961
884
885 Affected cores may fail to flush the trace data on a TSB instruction, when
886 the PE is in trace prohibited state. This will cause losing a few bytes
887 of the trace cached.
888
889 Workaround is to issue two TSB consecutively on affected cores.
890
891 If unsure, say Y.
892
893 config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
894 bool
895
896 config ARM64_ERRATUM_2253138
897 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
898 depends on CORESIGHT_TRBE
899 default y
900 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
901 help
902 This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
903
904 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
905 for TRBE. Under some conditions, the TRBE might generate a write to the next
906 virtually addressed page following the last page of the TRBE address space
907 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
908
909 Work around this in the driver by always making sure that there is a
910 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
911
912 If unsure, say Y.
913
914 config ARM64_ERRATUM_2224489
915 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
916 depends on CORESIGHT_TRBE
917 default y
918 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
919 help
920 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
921
922 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
923 for TRBE. Under some conditions, the TRBE might generate a write to the next
924 virtually addressed page following the last page of the TRBE address space
925 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
926
927 Work around this in the driver by always making sure that there is a
928 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
929
930 If unsure, say Y.
931
932 config ARM64_ERRATUM_2441009
933 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
934 default y
935 select ARM64_WORKAROUND_REPEAT_TLBI
936 help
937 This option adds a workaround for ARM Cortex-A510 erratum #2441009.
938
939 Under very rare circumstances, affected Cortex-A510 CPUs
940 may not handle a race between a break-before-make sequence on one
941 CPU, and another CPU accessing the same page. This could allow a
942 store to a page that has been unmapped.
943
944 Work around this by adding the affected CPUs to the list that needs
945 TLB sequences to be done twice.
946
947 If unsure, say Y.
948
949 config ARM64_ERRATUM_2064142
950 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
951 depends on CORESIGHT_TRBE
952 default y
953 help
954 This option adds the workaround for ARM Cortex-A510 erratum 2064142.
955
956 Affected Cortex-A510 core might fail to write into system registers after the
957 TRBE has been disabled. Under some conditions after the TRBE has been disabled
958 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
959 and TRBTRG_EL1 will be ignored and will not be effected.
960
961 Work around this in the driver by executing TSB CSYNC and DSB after collection
962 is stopped and before performing a system register write to one of the affected
963 registers.
964
965 If unsure, say Y.
966
967 config ARM64_ERRATUM_2038923
968 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
969 depends on CORESIGHT_TRBE
970 default y
971 help
972 This option adds the workaround for ARM Cortex-A510 erratum 2038923.
973
974 Affected Cortex-A510 core might cause an inconsistent view on whether trace is
975 prohibited within the CPU. As a result, the trace buffer or trace buffer state
976 might be corrupted. This happens after TRBE buffer has been enabled by setting
977 TRBLIMITR_EL1.E, followed by just a single context synchronization event before
978 execution changes from a context, in which trace is prohibited to one where it
979 isn't, or vice versa. In these mentioned conditions, the view of whether trace
980 is prohibited is inconsistent between parts of the CPU, and the trace buffer or
981 the trace buffer state might be corrupted.
982
983 Work around this in the driver by preventing an inconsistent view of whether the
984 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
985 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
986 two ISB instructions if no ERET is to take place.
987
988 If unsure, say Y.
989
990 config ARM64_ERRATUM_1902691
991 bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
992 depends on CORESIGHT_TRBE
993 default y
994 help
995 This option adds the workaround for ARM Cortex-A510 erratum 1902691.
996
997 Affected Cortex-A510 core might cause trace data corruption, when being written
998 into the memory. Effectively TRBE is broken and hence cannot be used to capture
999 trace data.
1000
1001 Work around this problem in the driver by just preventing TRBE initialization on
1002 affected cpus. The firmware must have disabled the access to TRBE for the kernel
1003 on such implementations. This will cover the kernel for any firmware that doesn't
1004 do this already.
1005
1006 If unsure, say Y.
1007
1008 config ARM64_ERRATUM_2457168
1009 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1010 depends on ARM64_AMU_EXTN
1011 default y
1012 help
1013 This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1014
1015 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1016 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1017 incorrectly giving a significantly higher output value.
1018
1019 Work around this problem by returning 0 when reading the affected counter in
1020 key locations that results in disabling all users of this counter. This effect
1021 is the same to firmware disabling affected counters.
1022
1023 If unsure, say Y.
1024
1025 config ARM64_ERRATUM_2645198
1026 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1027 default y
1028 help
1029 This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1030
1031 If a Cortex-A715 cpu sees a page mapping permissions change from executable
1032 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1033 next instruction abort caused by permission fault.
1034
1035 Only user-space does executable to non-executable permission transition via
1036 mprotect() system call. Workaround the problem by doing a break-before-make
1037 TLB invalidation, for all changes to executable user space mappings.
1038
1039 If unsure, say Y.
1040
1041 config ARM64_ERRATUM_2966298
1042 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1043 default y
1044 help
1045 This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1046
1047 On an affected Cortex-A520 core, a speculatively executed unprivileged
1048 load might leak data from a privileged level via a cache side channel.
1049
1050 Work around this problem by executing a TLBI before returning to EL0.
1051
1052 If unsure, say Y.
1053
1054 config CAVIUM_ERRATUM_22375
1055 bool "Cavium erratum 22375, 24313"
1056 default y
1057 help
1058 Enable workaround for errata 22375 and 24313.
1059
1060 This implements two gicv3-its errata workarounds for ThunderX. Both
1061 with a small impact affecting only ITS table allocation.
1062
1063 erratum 22375: only alloc 8MB table size
1064 erratum 24313: ignore memory access type
1065
1066 The fixes are in ITS initialization and basically ignore memory access
1067 type and table size provided by the TYPER and BASER registers.
1068
1069 If unsure, say Y.
1070
1071 config CAVIUM_ERRATUM_23144
1072 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1073 depends on NUMA
1074 default y
1075 help
1076 ITS SYNC command hang for cross node io and collections/cpu mapping.
1077
1078 If unsure, say Y.
1079
1080 config CAVIUM_ERRATUM_23154
1081 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1082 default y
1083 help
1084 The ThunderX GICv3 implementation requires a modified version for
1085 reading the IAR status to ensure data synchronization
1086 (access to icc_iar1_el1 is not sync'ed before and after).
1087
1088 It also suffers from erratum 38545 (also present on Marvell's
1089 OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1090 spuriously presented to the CPU interface.
1091
1092 If unsure, say Y.
1093
1094 config CAVIUM_ERRATUM_27456
1095 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1096 default y
1097 help
1098 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1099 instructions may cause the icache to become corrupted if it
1100 contains data for a non-current ASID. The fix is to
1101 invalidate the icache when changing the mm context.
1102
1103 If unsure, say Y.
1104
1105 config CAVIUM_ERRATUM_30115
1106 bool "Cavium erratum 30115: Guest may disable interrupts in host"
1107 default y
1108 help
1109 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1110 1.2, and T83 Pass 1.0, KVM guest execution may disable
1111 interrupts in host. Trapping both GICv3 group-0 and group-1
1112 accesses sidesteps the issue.
1113
1114 If unsure, say Y.
1115
1116 config CAVIUM_TX2_ERRATUM_219
1117 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1118 default y
1119 help
1120 On Cavium ThunderX2, a load, store or prefetch instruction between a
1121 TTBR update and the corresponding context synchronizing operation can
1122 cause a spurious Data Abort to be delivered to any hardware thread in
1123 the CPU core.
1124
1125 Work around the issue by avoiding the problematic code sequence and
1126 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1127 trap handler performs the corresponding register access, skips the
1128 instruction and ensures context synchronization by virtue of the
1129 exception return.
1130
1131 If unsure, say Y.
1132
1133 config FUJITSU_ERRATUM_010001
1134 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1135 default y
1136 help
1137 This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1138 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1139 accesses may cause undefined fault (Data abort, DFSC=0b111111).
1140 This fault occurs under a specific hardware condition when a
1141 load/store instruction performs an address translation using:
1142 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1143 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1144 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1145 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1146
1147 The workaround is to ensure these bits are clear in TCR_ELx.
1148 The workaround only affects the Fujitsu-A64FX.
1149
1150 If unsure, say Y.
1151
1152 config HISILICON_ERRATUM_161600802
1153 bool "Hip07 161600802: Erroneous redistributor VLPI base"
1154 default y
1155 help
1156 The HiSilicon Hip07 SoC uses the wrong redistributor base
1157 when issued ITS commands such as VMOVP and VMAPP, and requires
1158 a 128kB offset to be applied to the target address in this commands.
1159
1160 If unsure, say Y.
1161
1162 config QCOM_FALKOR_ERRATUM_1003
1163 bool "Falkor E1003: Incorrect translation due to ASID change"
1164 default y
1165 help
1166 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1167 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1168 in TTBR1_EL1, this situation only occurs in the entry trampoline and
1169 then only for entries in the walk cache, since the leaf translation
1170 is unchanged. Work around the erratum by invalidating the walk cache
1171 entries for the trampoline before entering the kernel proper.
1172
1173 config QCOM_FALKOR_ERRATUM_1009
1174 bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1175 default y
1176 select ARM64_WORKAROUND_REPEAT_TLBI
1177 help
1178 On Falkor v1, the CPU may prematurely complete a DSB following a
1179 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1180 one more time to fix the issue.
1181
1182 If unsure, say Y.
1183
1184 config QCOM_QDF2400_ERRATUM_0065
1185 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1186 default y
1187 help
1188 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1189 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1190 been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1191
1192 If unsure, say Y.
1193
1194 config QCOM_FALKOR_ERRATUM_E1041
1195 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1196 default y
1197 help
1198 Falkor CPU may speculatively fetch instructions from an improper
1199 memory location when MMU translation is changed from SCTLR_ELn[M]=1
1200 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1201
1202 If unsure, say Y.
1203
1204 config NVIDIA_CARMEL_CNP_ERRATUM
1205 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1206 default y
1207 help
1208 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1209 invalidate shared TLB entries installed by a different core, as it would
1210 on standard ARM cores.
1211
1212 If unsure, say Y.
1213
1214 config ROCKCHIP_ERRATUM_3588001
1215 bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1216 default y
1217 help
1218 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1219 This means, that its sharability feature may not be used, even though it
1220 is supported by the IP itself.
1221
1222 If unsure, say Y.
1223
1224 config SOCIONEXT_SYNQUACER_PREITS
1225 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1226 default y
1227 help
1228 Socionext Synquacer SoCs implement a separate h/w block to generate
1229 MSI doorbell writes with non-zero values for the device ID.
1230
1231 If unsure, say Y.
1232
1233 endmenu # "ARM errata workarounds via the alternatives framework"
1234
1235 choice
1236 prompt "Page size"
1237 default ARM64_4K_PAGES
1238 help
1239 Page size (translation granule) configuration.
1240
1241 config ARM64_4K_PAGES
1242 bool "4KB"
1243 help
1244 This feature enables 4KB pages support.
1245
1246 config ARM64_16K_PAGES
1247 bool "16KB"
1248 help
1249 The system will use 16KB pages support. AArch32 emulation
1250 requires applications compiled with 16K (or a multiple of 16K)
1251 aligned segments.
1252
1253 config ARM64_64K_PAGES
1254 bool "64KB"
1255 help
1256 This feature enables 64KB pages support (4KB by default)
1257 allowing only two levels of page tables and faster TLB
1258 look-up. AArch32 emulation requires applications compiled
1259 with 64K aligned segments.
1260
1261 endchoice
1262
1263 choice
1264 prompt "Virtual address space size"
1265 default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1266 default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1267 default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1268 help
1269 Allows choosing one of multiple possible virtual address
1270 space sizes. The level of translation table is determined by
1271 a combination of page size and virtual address space size.
1272
1273 config ARM64_VA_BITS_36
1274 bool "36-bit" if EXPERT
1275 depends on ARM64_16K_PAGES
1276
1277 config ARM64_VA_BITS_39
1278 bool "39-bit"
1279 depends on ARM64_4K_PAGES
1280
1281 config ARM64_VA_BITS_42
1282 bool "42-bit"
1283 depends on ARM64_64K_PAGES
1284
1285 config ARM64_VA_BITS_47
1286 bool "47-bit"
1287 depends on ARM64_16K_PAGES
1288
1289 config ARM64_VA_BITS_48
1290 bool "48-bit"
1291
1292 config ARM64_VA_BITS_52
1293 bool "52-bit"
1294 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1295 help
1296 Enable 52-bit virtual addressing for userspace when explicitly
1297 requested via a hint to mmap(). The kernel will also use 52-bit
1298 virtual addresses for its own mappings (provided HW support for
1299 this feature is available, otherwise it reverts to 48-bit).
1300
1301 NOTE: Enabling 52-bit virtual addressing in conjunction with
1302 ARMv8.3 Pointer Authentication will result in the PAC being
1303 reduced from 7 bits to 3 bits, which may have a significant
1304 impact on its susceptibility to brute-force attacks.
1305
1306 If unsure, select 48-bit virtual addressing instead.
1307
1308 endchoice
1309
1310 config ARM64_FORCE_52BIT
1311 bool "Force 52-bit virtual addresses for userspace"
1312 depends on ARM64_VA_BITS_52 && EXPERT
1313 help
1314 For systems with 52-bit userspace VAs enabled, the kernel will attempt
1315 to maintain compatibility with older software by providing 48-bit VAs
1316 unless a hint is supplied to mmap.
1317
1318 This configuration option disables the 48-bit compatibility logic, and
1319 forces all userspace addresses to be 52-bit on HW that supports it. One
1320 should only enable this configuration option for stress testing userspace
1321 memory management code. If unsure say N here.
1322
1323 config ARM64_VA_BITS
1324 int
1325 default 36 if ARM64_VA_BITS_36
1326 default 39 if ARM64_VA_BITS_39
1327 default 42 if ARM64_VA_BITS_42
1328 default 47 if ARM64_VA_BITS_47
1329 default 48 if ARM64_VA_BITS_48
1330 default 52 if ARM64_VA_BITS_52
1331
1332 choice
1333 prompt "Physical address space size"
1334 default ARM64_PA_BITS_48
1335 help
1336 Choose the maximum physical address range that the kernel will
1337 support.
1338
1339 config ARM64_PA_BITS_48
1340 bool "48-bit"
1341
1342 config ARM64_PA_BITS_52
1343 bool "52-bit (ARMv8.2)"
1344 depends on ARM64_64K_PAGES
1345 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1346 help
1347 Enable support for a 52-bit physical address space, introduced as
1348 part of the ARMv8.2-LPA extension.
1349
1350 With this enabled, the kernel will also continue to work on CPUs that
1351 do not support ARMv8.2-LPA, but with some added memory overhead (and
1352 minor performance overhead).
1353
1354 endchoice
1355
1356 config ARM64_PA_BITS
1357 int
1358 default 48 if ARM64_PA_BITS_48
1359 default 52 if ARM64_PA_BITS_52
1360
1361 choice
1362 prompt "Endianness"
1363 default CPU_LITTLE_ENDIAN
1364 help
1365 Select the endianness of data accesses performed by the CPU. Userspace
1366 applications will need to be compiled and linked for the endianness
1367 that is selected here.
1368
1369 config CPU_BIG_ENDIAN
1370 bool "Build big-endian kernel"
1371 depends on !LD_IS_LLD || LLD_VERSION >= 130000
1372 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1373 depends on AS_IS_GNU || AS_VERSION >= 150000
1374 help
1375 Say Y if you plan on running a kernel with a big-endian userspace.
1376
1377 config CPU_LITTLE_ENDIAN
1378 bool "Build little-endian kernel"
1379 help
1380 Say Y if you plan on running a kernel with a little-endian userspace.
1381 This is usually the case for distributions targeting arm64.
1382
1383 endchoice
1384
1385 config SCHED_MC
1386 bool "Multi-core scheduler support"
1387 help
1388 Multi-core scheduler support improves the CPU scheduler's decision
1389 making when dealing with multi-core CPU chips at a cost of slightly
1390 increased overhead in some places. If unsure say N here.
1391
1392 config SCHED_CLUSTER
1393 bool "Cluster scheduler support"
1394 help
1395 Cluster scheduler support improves the CPU scheduler's decision
1396 making when dealing with machines that have clusters of CPUs.
1397 Cluster usually means a couple of CPUs which are placed closely
1398 by sharing mid-level caches, last-level cache tags or internal
1399 busses.
1400
1401 config SCHED_SMT
1402 bool "SMT scheduler support"
1403 help
1404 Improves the CPU scheduler's decision making when dealing with
1405 MultiThreading at a cost of slightly increased overhead in some
1406 places. If unsure say N here.
1407
1408 config NR_CPUS
1409 int "Maximum number of CPUs (2-4096)"
1410 range 2 4096
1411 default "256"
1412
1413 config HOTPLUG_CPU
1414 bool "Support for hot-pluggable CPUs"
1415 select GENERIC_IRQ_MIGRATION
1416 help
1417 Say Y here to experiment with turning CPUs off and on. CPUs
1418 can be controlled through /sys/devices/system/cpu.
1419
1420 # Common NUMA Features
1421 config NUMA
1422 bool "NUMA Memory Allocation and Scheduler Support"
1423 select GENERIC_ARCH_NUMA
1424 select ACPI_NUMA if ACPI
1425 select OF_NUMA
1426 select HAVE_SETUP_PER_CPU_AREA
1427 select NEED_PER_CPU_EMBED_FIRST_CHUNK
1428 select NEED_PER_CPU_PAGE_FIRST_CHUNK
1429 select USE_PERCPU_NUMA_NODE_ID
1430 help
1431 Enable NUMA (Non-Uniform Memory Access) support.
1432
1433 The kernel will try to allocate memory used by a CPU on the
1434 local memory of the CPU and add some more
1435 NUMA awareness to the kernel.
1436
1437 config NODES_SHIFT
1438 int "Maximum NUMA Nodes (as a power of 2)"
1439 range 1 10
1440 default "4"
1441 depends on NUMA
1442 help
1443 Specify the maximum number of NUMA Nodes available on the target
1444 system. Increases memory reserved to accommodate various tables.
1445
1446 source "kernel/Kconfig.hz"
1447
1448 config ARCH_SPARSEMEM_ENABLE
1449 def_bool y
1450 select SPARSEMEM_VMEMMAP_ENABLE
1451 select SPARSEMEM_VMEMMAP
1452
1453 config HW_PERF_EVENTS
1454 def_bool y
1455 depends on ARM_PMU
1456
1457 # Supported by clang >= 7.0 or GCC >= 12.0.0
1458 config CC_HAVE_SHADOW_CALL_STACK
1459 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1460
1461 config PARAVIRT
1462 bool "Enable paravirtualization code"
1463 help
1464 This changes the kernel so it can modify itself when it is run
1465 under a hypervisor, potentially improving performance significantly
1466 over full virtualization.
1467
1468 config PARAVIRT_TIME_ACCOUNTING
1469 bool "Paravirtual steal time accounting"
1470 select PARAVIRT
1471 help
1472 Select this option to enable fine granularity task steal time
1473 accounting. Time spent executing other tasks in parallel with
1474 the current vCPU is discounted from the vCPU power. To account for
1475 that, there can be a small performance impact.
1476
1477 If in doubt, say N here.
1478
1479 config ARCH_SUPPORTS_KEXEC
1480 def_bool PM_SLEEP_SMP
1481
1482 config ARCH_SUPPORTS_KEXEC_FILE
1483 def_bool y
1484
1485 config ARCH_SELECTS_KEXEC_FILE
1486 def_bool y
1487 depends on KEXEC_FILE
1488 select HAVE_IMA_KEXEC if IMA
1489
1490 config ARCH_SUPPORTS_KEXEC_SIG
1491 def_bool y
1492
1493 config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1494 def_bool y
1495
1496 config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1497 def_bool y
1498
1499 config ARCH_SUPPORTS_CRASH_DUMP
1500 def_bool y
1501
1502 config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1503 def_bool CRASH_CORE
1504
1505 config TRANS_TABLE
1506 def_bool y
1507 depends on HIBERNATION || KEXEC_CORE
1508
1509 config XEN_DOM0
1510 def_bool y
1511 depends on XEN
1512
1513 config XEN
1514 bool "Xen guest support on ARM64"
1515 depends on ARM64 && OF
1516 select SWIOTLB_XEN
1517 select PARAVIRT
1518 help
1519 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1520
1521 # include/linux/mmzone.h requires the following to be true:
1522 #
1523 # MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1524 #
1525 # so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1526 #
1527 # | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER |
1528 # ----+-------------------+--------------+----------------------+-------------------------+
1529 # 4K | 27 | 12 | 15 | 10 |
1530 # 16K | 27 | 14 | 13 | 11 |
1531 # 64K | 29 | 16 | 13 | 13 |
1532 config ARCH_FORCE_MAX_ORDER
1533 int
1534 default "13" if ARM64_64K_PAGES
1535 default "11" if ARM64_16K_PAGES
1536 default "10"
1537 help
1538 The kernel page allocator limits the size of maximal physically
1539 contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1540 defines the maximal power of two of number of pages that can be
1541 allocated as a single contiguous block. This option allows
1542 overriding the default setting when ability to allocate very
1543 large blocks of physically contiguous memory is required.
1544
1545 The maximal size of allocation cannot exceed the size of the
1546 section, so the value of MAX_PAGE_ORDER should satisfy
1547
1548 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1549
1550 Don't change if unsure.
1551
1552 config UNMAP_KERNEL_AT_EL0
1553 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1554 default y
1555 help
1556 Speculation attacks against some high-performance processors can
1557 be used to bypass MMU permission checks and leak kernel data to
1558 userspace. This can be defended against by unmapping the kernel
1559 when running in userspace, mapping it back in on exception entry
1560 via a trampoline page in the vector table.
1561
1562 If unsure, say Y.
1563
1564 config MITIGATE_SPECTRE_BRANCH_HISTORY
1565 bool "Mitigate Spectre style attacks against branch history" if EXPERT
1566 default y
1567 help
1568 Speculation attacks against some high-performance processors can
1569 make use of branch history to influence future speculation.
1570 When taking an exception from user-space, a sequence of branches
1571 or a firmware call overwrites the branch history.
1572
1573 config RODATA_FULL_DEFAULT_ENABLED
1574 bool "Apply r/o permissions of VM areas also to their linear aliases"
1575 default y
1576 help
1577 Apply read-only attributes of VM areas to the linear alias of
1578 the backing pages as well. This prevents code or read-only data
1579 from being modified (inadvertently or intentionally) via another
1580 mapping of the same memory page. This additional enhancement can
1581 be turned off at runtime by passing rodata=[off|on] (and turned on
1582 with rodata=full if this option is set to 'n')
1583
1584 This requires the linear region to be mapped down to pages,
1585 which may adversely affect performance in some cases.
1586
1587 config ARM64_SW_TTBR0_PAN
1588 bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1589 help
1590 Enabling this option prevents the kernel from accessing
1591 user-space memory directly by pointing TTBR0_EL1 to a reserved
1592 zeroed area and reserved ASID. The user access routines
1593 restore the valid TTBR0_EL1 temporarily.
1594
1595 config ARM64_TAGGED_ADDR_ABI
1596 bool "Enable the tagged user addresses syscall ABI"
1597 default y
1598 help
1599 When this option is enabled, user applications can opt in to a
1600 relaxed ABI via prctl() allowing tagged addresses to be passed
1601 to system calls as pointer arguments. For details, see
1602 Documentation/arch/arm64/tagged-address-abi.rst.
1603
1604 menuconfig COMPAT
1605 bool "Kernel support for 32-bit EL0"
1606 depends on ARM64_4K_PAGES || EXPERT
1607 select HAVE_UID16
1608 select OLD_SIGSUSPEND3
1609 select COMPAT_OLD_SIGACTION
1610 help
1611 This option enables support for a 32-bit EL0 running under a 64-bit
1612 kernel at EL1. AArch32-specific components such as system calls,
1613 the user helper functions, VFP support and the ptrace interface are
1614 handled appropriately by the kernel.
1615
1616 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1617 that you will only be able to execute AArch32 binaries that were compiled
1618 with page size aligned segments.
1619
1620 If you want to execute 32-bit userspace applications, say Y.
1621
1622 if COMPAT
1623
1624 config KUSER_HELPERS
1625 bool "Enable kuser helpers page for 32-bit applications"
1626 default y
1627 help
1628 Warning: disabling this option may break 32-bit user programs.
1629
1630 Provide kuser helpers to compat tasks. The kernel provides
1631 helper code to userspace in read only form at a fixed location
1632 to allow userspace to be independent of the CPU type fitted to
1633 the system. This permits binaries to be run on ARMv4 through
1634 to ARMv8 without modification.
1635
1636 See Documentation/arch/arm/kernel_user_helpers.rst for details.
1637
1638 However, the fixed address nature of these helpers can be used
1639 by ROP (return orientated programming) authors when creating
1640 exploits.
1641
1642 If all of the binaries and libraries which run on your platform
1643 are built specifically for your platform, and make no use of
1644 these helpers, then you can turn this option off to hinder
1645 such exploits. However, in that case, if a binary or library
1646 relying on those helpers is run, it will not function correctly.
1647
1648 Say N here only if you are absolutely certain that you do not
1649 need these helpers; otherwise, the safe option is to say Y.
1650
1651 config COMPAT_VDSO
1652 bool "Enable vDSO for 32-bit applications"
1653 depends on !CPU_BIG_ENDIAN
1654 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1655 select GENERIC_COMPAT_VDSO
1656 default y
1657 help
1658 Place in the process address space of 32-bit applications an
1659 ELF shared object providing fast implementations of gettimeofday
1660 and clock_gettime.
1661
1662 You must have a 32-bit build of glibc 2.22 or later for programs
1663 to seamlessly take advantage of this.
1664
1665 config THUMB2_COMPAT_VDSO
1666 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1667 depends on COMPAT_VDSO
1668 default y
1669 help
1670 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1671 otherwise with '-marm'.
1672
1673 config COMPAT_ALIGNMENT_FIXUPS
1674 bool "Fix up misaligned multi-word loads and stores in user space"
1675
1676 menuconfig ARMV8_DEPRECATED
1677 bool "Emulate deprecated/obsolete ARMv8 instructions"
1678 depends on SYSCTL
1679 help
1680 Legacy software support may require certain instructions
1681 that have been deprecated or obsoleted in the architecture.
1682
1683 Enable this config to enable selective emulation of these
1684 features.
1685
1686 If unsure, say Y
1687
1688 if ARMV8_DEPRECATED
1689
1690 config SWP_EMULATION
1691 bool "Emulate SWP/SWPB instructions"
1692 help
1693 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1694 they are always undefined. Say Y here to enable software
1695 emulation of these instructions for userspace using LDXR/STXR.
1696 This feature can be controlled at runtime with the abi.swp
1697 sysctl which is disabled by default.
1698
1699 In some older versions of glibc [<=2.8] SWP is used during futex
1700 trylock() operations with the assumption that the code will not
1701 be preempted. This invalid assumption may be more likely to fail
1702 with SWP emulation enabled, leading to deadlock of the user
1703 application.
1704
1705 NOTE: when accessing uncached shared regions, LDXR/STXR rely
1706 on an external transaction monitoring block called a global
1707 monitor to maintain update atomicity. If your system does not
1708 implement a global monitor, this option can cause programs that
1709 perform SWP operations to uncached memory to deadlock.
1710
1711 If unsure, say Y
1712
1713 config CP15_BARRIER_EMULATION
1714 bool "Emulate CP15 Barrier instructions"
1715 help
1716 The CP15 barrier instructions - CP15ISB, CP15DSB, and
1717 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1718 strongly recommended to use the ISB, DSB, and DMB
1719 instructions instead.
1720
1721 Say Y here to enable software emulation of these
1722 instructions for AArch32 userspace code. When this option is
1723 enabled, CP15 barrier usage is traced which can help
1724 identify software that needs updating. This feature can be
1725 controlled at runtime with the abi.cp15_barrier sysctl.
1726
1727 If unsure, say Y
1728
1729 config SETEND_EMULATION
1730 bool "Emulate SETEND instruction"
1731 help
1732 The SETEND instruction alters the data-endianness of the
1733 AArch32 EL0, and is deprecated in ARMv8.
1734
1735 Say Y here to enable software emulation of the instruction
1736 for AArch32 userspace code. This feature can be controlled
1737 at runtime with the abi.setend sysctl.
1738
1739 Note: All the cpus on the system must have mixed endian support at EL0
1740 for this feature to be enabled. If a new CPU - which doesn't support mixed
1741 endian - is hotplugged in after this feature has been enabled, there could
1742 be unexpected results in the applications.
1743
1744 If unsure, say Y
1745 endif # ARMV8_DEPRECATED
1746
1747 endif # COMPAT
1748
1749 menu "ARMv8.1 architectural features"
1750
1751 config ARM64_HW_AFDBM
1752 bool "Support for hardware updates of the Access and Dirty page flags"
1753 default y
1754 help
1755 The ARMv8.1 architecture extensions introduce support for
1756 hardware updates of the access and dirty information in page
1757 table entries. When enabled in TCR_EL1 (HA and HD bits) on
1758 capable processors, accesses to pages with PTE_AF cleared will
1759 set this bit instead of raising an access flag fault.
1760 Similarly, writes to read-only pages with the DBM bit set will
1761 clear the read-only bit (AP[2]) instead of raising a
1762 permission fault.
1763
1764 Kernels built with this configuration option enabled continue
1765 to work on pre-ARMv8.1 hardware and the performance impact is
1766 minimal. If unsure, say Y.
1767
1768 config ARM64_PAN
1769 bool "Enable support for Privileged Access Never (PAN)"
1770 default y
1771 help
1772 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1773 prevents the kernel or hypervisor from accessing user-space (EL0)
1774 memory directly.
1775
1776 Choosing this option will cause any unprotected (not using
1777 copy_to_user et al) memory access to fail with a permission fault.
1778
1779 The feature is detected at runtime, and will remain as a 'nop'
1780 instruction if the cpu does not implement the feature.
1781
1782 config AS_HAS_LSE_ATOMICS
1783 def_bool $(as-instr,.arch_extension lse)
1784
1785 config ARM64_LSE_ATOMICS
1786 bool
1787 default ARM64_USE_LSE_ATOMICS
1788 depends on AS_HAS_LSE_ATOMICS
1789
1790 config ARM64_USE_LSE_ATOMICS
1791 bool "Atomic instructions"
1792 default y
1793 help
1794 As part of the Large System Extensions, ARMv8.1 introduces new
1795 atomic instructions that are designed specifically to scale in
1796 very large systems.
1797
1798 Say Y here to make use of these instructions for the in-kernel
1799 atomic routines. This incurs a small overhead on CPUs that do
1800 not support these instructions and requires the kernel to be
1801 built with binutils >= 2.25 in order for the new instructions
1802 to be used.
1803
1804 endmenu # "ARMv8.1 architectural features"
1805
1806 menu "ARMv8.2 architectural features"
1807
1808 config AS_HAS_ARMV8_2
1809 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1810
1811 config AS_HAS_SHA3
1812 def_bool $(as-instr,.arch armv8.2-a+sha3)
1813
1814 config ARM64_PMEM
1815 bool "Enable support for persistent memory"
1816 select ARCH_HAS_PMEM_API
1817 select ARCH_HAS_UACCESS_FLUSHCACHE
1818 help
1819 Say Y to enable support for the persistent memory API based on the
1820 ARMv8.2 DCPoP feature.
1821
1822 The feature is detected at runtime, and the kernel will use DC CVAC
1823 operations if DC CVAP is not supported (following the behaviour of
1824 DC CVAP itself if the system does not define a point of persistence).
1825
1826 config ARM64_RAS_EXTN
1827 bool "Enable support for RAS CPU Extensions"
1828 default y
1829 help
1830 CPUs that support the Reliability, Availability and Serviceability
1831 (RAS) Extensions, part of ARMv8.2 are able to track faults and
1832 errors, classify them and report them to software.
1833
1834 On CPUs with these extensions system software can use additional
1835 barriers to determine if faults are pending and read the
1836 classification from a new set of registers.
1837
1838 Selecting this feature will allow the kernel to use these barriers
1839 and access the new registers if the system supports the extension.
1840 Platform RAS features may additionally depend on firmware support.
1841
1842 config ARM64_CNP
1843 bool "Enable support for Common Not Private (CNP) translations"
1844 default y
1845 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1846 help
1847 Common Not Private (CNP) allows translation table entries to
1848 be shared between different PEs in the same inner shareable
1849 domain, so the hardware can use this fact to optimise the
1850 caching of such entries in the TLB.
1851
1852 Selecting this option allows the CNP feature to be detected
1853 at runtime, and does not affect PEs that do not implement
1854 this feature.
1855
1856 endmenu # "ARMv8.2 architectural features"
1857
1858 menu "ARMv8.3 architectural features"
1859
1860 config ARM64_PTR_AUTH
1861 bool "Enable support for pointer authentication"
1862 default y
1863 help
1864 Pointer authentication (part of the ARMv8.3 Extensions) provides
1865 instructions for signing and authenticating pointers against secret
1866 keys, which can be used to mitigate Return Oriented Programming (ROP)
1867 and other attacks.
1868
1869 This option enables these instructions at EL0 (i.e. for userspace).
1870 Choosing this option will cause the kernel to initialise secret keys
1871 for each process at exec() time, with these keys being
1872 context-switched along with the process.
1873
1874 The feature is detected at runtime. If the feature is not present in
1875 hardware it will not be advertised to userspace/KVM guest nor will it
1876 be enabled.
1877
1878 If the feature is present on the boot CPU but not on a late CPU, then
1879 the late CPU will be parked. Also, if the boot CPU does not have
1880 address auth and the late CPU has then the late CPU will still boot
1881 but with the feature disabled. On such a system, this option should
1882 not be selected.
1883
1884 config ARM64_PTR_AUTH_KERNEL
1885 bool "Use pointer authentication for kernel"
1886 default y
1887 depends on ARM64_PTR_AUTH
1888 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1889 # Modern compilers insert a .note.gnu.property section note for PAC
1890 # which is only understood by binutils starting with version 2.33.1.
1891 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1892 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1893 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1894 help
1895 If the compiler supports the -mbranch-protection or
1896 -msign-return-address flag (e.g. GCC 7 or later), then this option
1897 will cause the kernel itself to be compiled with return address
1898 protection. In this case, and if the target hardware is known to
1899 support pointer authentication, then CONFIG_STACKPROTECTOR can be
1900 disabled with minimal loss of protection.
1901
1902 This feature works with FUNCTION_GRAPH_TRACER option only if
1903 DYNAMIC_FTRACE_WITH_ARGS is enabled.
1904
1905 config CC_HAS_BRANCH_PROT_PAC_RET
1906 # GCC 9 or later, clang 8 or later
1907 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1908
1909 config CC_HAS_SIGN_RETURN_ADDRESS
1910 # GCC 7, 8
1911 def_bool $(cc-option,-msign-return-address=all)
1912
1913 config AS_HAS_ARMV8_3
1914 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1915
1916 config AS_HAS_CFI_NEGATE_RA_STATE
1917 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1918
1919 config AS_HAS_LDAPR
1920 def_bool $(as-instr,.arch_extension rcpc)
1921
1922 endmenu # "ARMv8.3 architectural features"
1923
1924 menu "ARMv8.4 architectural features"
1925
1926 config ARM64_AMU_EXTN
1927 bool "Enable support for the Activity Monitors Unit CPU extension"
1928 default y
1929 help
1930 The activity monitors extension is an optional extension introduced
1931 by the ARMv8.4 CPU architecture. This enables support for version 1
1932 of the activity monitors architecture, AMUv1.
1933
1934 To enable the use of this extension on CPUs that implement it, say Y.
1935
1936 Note that for architectural reasons, firmware _must_ implement AMU
1937 support when running on CPUs that present the activity monitors
1938 extension. The required support is present in:
1939 * Version 1.5 and later of the ARM Trusted Firmware
1940
1941 For kernels that have this configuration enabled but boot with broken
1942 firmware, you may need to say N here until the firmware is fixed.
1943 Otherwise you may experience firmware panics or lockups when
1944 accessing the counter registers. Even if you are not observing these
1945 symptoms, the values returned by the register reads might not
1946 correctly reflect reality. Most commonly, the value read will be 0,
1947 indicating that the counter is not enabled.
1948
1949 config AS_HAS_ARMV8_4
1950 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1951
1952 config ARM64_TLB_RANGE
1953 bool "Enable support for tlbi range feature"
1954 default y
1955 depends on AS_HAS_ARMV8_4
1956 help
1957 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1958 range of input addresses.
1959
1960 The feature introduces new assembly instructions, and they were
1961 support when binutils >= 2.30.
1962
1963 endmenu # "ARMv8.4 architectural features"
1964
1965 menu "ARMv8.5 architectural features"
1966
1967 config AS_HAS_ARMV8_5
1968 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1969
1970 config ARM64_BTI
1971 bool "Branch Target Identification support"
1972 default y
1973 help
1974 Branch Target Identification (part of the ARMv8.5 Extensions)
1975 provides a mechanism to limit the set of locations to which computed
1976 branch instructions such as BR or BLR can jump.
1977
1978 To make use of BTI on CPUs that support it, say Y.
1979
1980 BTI is intended to provide complementary protection to other control
1981 flow integrity protection mechanisms, such as the Pointer
1982 authentication mechanism provided as part of the ARMv8.3 Extensions.
1983 For this reason, it does not make sense to enable this option without
1984 also enabling support for pointer authentication. Thus, when
1985 enabling this option you should also select ARM64_PTR_AUTH=y.
1986
1987 Userspace binaries must also be specifically compiled to make use of
1988 this mechanism. If you say N here or the hardware does not support
1989 BTI, such binaries can still run, but you get no additional
1990 enforcement of branch destinations.
1991
1992 config ARM64_BTI_KERNEL
1993 bool "Use Branch Target Identification for kernel"
1994 default y
1995 depends on ARM64_BTI
1996 depends on ARM64_PTR_AUTH_KERNEL
1997 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1998 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1999 depends on !CC_IS_GCC || GCC_VERSION >= 100100
2000 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2001 depends on !CC_IS_GCC
2002 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
2003 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
2004 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2005 help
2006 Build the kernel with Branch Target Identification annotations
2007 and enable enforcement of this for kernel code. When this option
2008 is enabled and the system supports BTI all kernel code including
2009 modular code must have BTI enabled.
2010
2011 config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2012 # GCC 9 or later, clang 8 or later
2013 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2014
2015 config ARM64_E0PD
2016 bool "Enable support for E0PD"
2017 default y
2018 help
2019 E0PD (part of the ARMv8.5 extensions) allows us to ensure
2020 that EL0 accesses made via TTBR1 always fault in constant time,
2021 providing similar benefits to KASLR as those provided by KPTI, but
2022 with lower overhead and without disrupting legitimate access to
2023 kernel memory such as SPE.
2024
2025 This option enables E0PD for TTBR1 where available.
2026
2027 config ARM64_AS_HAS_MTE
2028 # Initial support for MTE went in binutils 2.32.0, checked with
2029 # ".arch armv8.5-a+memtag" below. However, this was incomplete
2030 # as a late addition to the final architecture spec (LDGM/STGM)
2031 # is only supported in the newer 2.32.x and 2.33 binutils
2032 # versions, hence the extra "stgm" instruction check below.
2033 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2034
2035 config ARM64_MTE
2036 bool "Memory Tagging Extension support"
2037 default y
2038 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2039 depends on AS_HAS_ARMV8_5
2040 depends on AS_HAS_LSE_ATOMICS
2041 # Required for tag checking in the uaccess routines
2042 depends on ARM64_PAN
2043 select ARCH_HAS_SUBPAGE_FAULTS
2044 select ARCH_USES_HIGH_VMA_FLAGS
2045 select ARCH_USES_PG_ARCH_X
2046 help
2047 Memory Tagging (part of the ARMv8.5 Extensions) provides
2048 architectural support for run-time, always-on detection of
2049 various classes of memory error to aid with software debugging
2050 to eliminate vulnerabilities arising from memory-unsafe
2051 languages.
2052
2053 This option enables the support for the Memory Tagging
2054 Extension at EL0 (i.e. for userspace).
2055
2056 Selecting this option allows the feature to be detected at
2057 runtime. Any secondary CPU not implementing this feature will
2058 not be allowed a late bring-up.
2059
2060 Userspace binaries that want to use this feature must
2061 explicitly opt in. The mechanism for the userspace is
2062 described in:
2063
2064 Documentation/arch/arm64/memory-tagging-extension.rst.
2065
2066 endmenu # "ARMv8.5 architectural features"
2067
2068 menu "ARMv8.7 architectural features"
2069
2070 config ARM64_EPAN
2071 bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2072 default y
2073 depends on ARM64_PAN
2074 help
2075 Enhanced Privileged Access Never (EPAN) allows Privileged
2076 Access Never to be used with Execute-only mappings.
2077
2078 The feature is detected at runtime, and will remain disabled
2079 if the cpu does not implement the feature.
2080 endmenu # "ARMv8.7 architectural features"
2081
2082 config ARM64_SVE
2083 bool "ARM Scalable Vector Extension support"
2084 default y
2085 help
2086 The Scalable Vector Extension (SVE) is an extension to the AArch64
2087 execution state which complements and extends the SIMD functionality
2088 of the base architecture to support much larger vectors and to enable
2089 additional vectorisation opportunities.
2090
2091 To enable use of this extension on CPUs that implement it, say Y.
2092
2093 On CPUs that support the SVE2 extensions, this option will enable
2094 those too.
2095
2096 Note that for architectural reasons, firmware _must_ implement SVE
2097 support when running on SVE capable hardware. The required support
2098 is present in:
2099
2100 * version 1.5 and later of the ARM Trusted Firmware
2101 * the AArch64 boot wrapper since commit 5e1261e08abf
2102 ("bootwrapper: SVE: Enable SVE for EL2 and below").
2103
2104 For other firmware implementations, consult the firmware documentation
2105 or vendor.
2106
2107 If you need the kernel to boot on SVE-capable hardware with broken
2108 firmware, you may need to say N here until you get your firmware
2109 fixed. Otherwise, you may experience firmware panics or lockups when
2110 booting the kernel. If unsure and you are not observing these
2111 symptoms, you should assume that it is safe to say Y.
2112
2113 config ARM64_SME
2114 bool "ARM Scalable Matrix Extension support"
2115 default y
2116 depends on ARM64_SVE
2117 help
2118 The Scalable Matrix Extension (SME) is an extension to the AArch64
2119 execution state which utilises a substantial subset of the SVE
2120 instruction set, together with the addition of new architectural
2121 register state capable of holding two dimensional matrix tiles to
2122 enable various matrix operations.
2123
2124 config ARM64_PSEUDO_NMI
2125 bool "Support for NMI-like interrupts"
2126 select ARM_GIC_V3
2127 help
2128 Adds support for mimicking Non-Maskable Interrupts through the use of
2129 GIC interrupt priority. This support requires version 3 or later of
2130 ARM GIC.
2131
2132 This high priority configuration for interrupts needs to be
2133 explicitly enabled by setting the kernel parameter
2134 "irqchip.gicv3_pseudo_nmi" to 1.
2135
2136 If unsure, say N
2137
2138 if ARM64_PSEUDO_NMI
2139 config ARM64_DEBUG_PRIORITY_MASKING
2140 bool "Debug interrupt priority masking"
2141 help
2142 This adds runtime checks to functions enabling/disabling
2143 interrupts when using priority masking. The additional checks verify
2144 the validity of ICC_PMR_EL1 when calling concerned functions.
2145
2146 If unsure, say N
2147 endif # ARM64_PSEUDO_NMI
2148
2149 config RELOCATABLE
2150 bool "Build a relocatable kernel image" if EXPERT
2151 select ARCH_HAS_RELR
2152 default y
2153 help
2154 This builds the kernel as a Position Independent Executable (PIE),
2155 which retains all relocation metadata required to relocate the
2156 kernel binary at runtime to a different virtual address than the
2157 address it was linked at.
2158 Since AArch64 uses the RELA relocation format, this requires a
2159 relocation pass at runtime even if the kernel is loaded at the
2160 same address it was linked at.
2161
2162 config RANDOMIZE_BASE
2163 bool "Randomize the address of the kernel image"
2164 select RELOCATABLE
2165 help
2166 Randomizes the virtual address at which the kernel image is
2167 loaded, as a security feature that deters exploit attempts
2168 relying on knowledge of the location of kernel internals.
2169
2170 It is the bootloader's job to provide entropy, by passing a
2171 random u64 value in /chosen/kaslr-seed at kernel entry.
2172
2173 When booting via the UEFI stub, it will invoke the firmware's
2174 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2175 to the kernel proper. In addition, it will randomise the physical
2176 location of the kernel Image as well.
2177
2178 If unsure, say N.
2179
2180 config RANDOMIZE_MODULE_REGION_FULL
2181 bool "Randomize the module region over a 2 GB range"
2182 depends on RANDOMIZE_BASE
2183 default y
2184 help
2185 Randomizes the location of the module region inside a 2 GB window
2186 covering the core kernel. This way, it is less likely for modules
2187 to leak information about the location of core kernel data structures
2188 but it does imply that function calls between modules and the core
2189 kernel will need to be resolved via veneers in the module PLT.
2190
2191 When this option is not set, the module region will be randomized over
2192 a limited range that contains the [_stext, _etext] interval of the
2193 core kernel, so branch relocations are almost always in range unless
2194 the region is exhausted. In this particular case of region
2195 exhaustion, modules might be able to fall back to a larger 2GB area.
2196
2197 config CC_HAVE_STACKPROTECTOR_SYSREG
2198 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2199
2200 config STACKPROTECTOR_PER_TASK
2201 def_bool y
2202 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2203
2204 config UNWIND_PATCH_PAC_INTO_SCS
2205 bool "Enable shadow call stack dynamically using code patching"
2206 # needs Clang with https://reviews.llvm.org/D111780 incorporated
2207 depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2208 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2209 depends on SHADOW_CALL_STACK
2210 select UNWIND_TABLES
2211 select DYNAMIC_SCS
2212
2213 endmenu # "Kernel Features"
2214
2215 menu "Boot options"
2216
2217 config ARM64_ACPI_PARKING_PROTOCOL
2218 bool "Enable support for the ARM64 ACPI parking protocol"
2219 depends on ACPI
2220 help
2221 Enable support for the ARM64 ACPI parking protocol. If disabled
2222 the kernel will not allow booting through the ARM64 ACPI parking
2223 protocol even if the corresponding data is present in the ACPI
2224 MADT table.
2225
2226 config CMDLINE
2227 string "Default kernel command string"
2228 default ""
2229 help
2230 Provide a set of default command-line options at build time by
2231 entering them here. As a minimum, you should specify the the
2232 root device (e.g. root=/dev/nfs).
2233
2234 choice
2235 prompt "Kernel command line type" if CMDLINE != ""
2236 default CMDLINE_FROM_BOOTLOADER
2237 help
2238 Choose how the kernel will handle the provided default kernel
2239 command line string.
2240
2241 config CMDLINE_FROM_BOOTLOADER
2242 bool "Use bootloader kernel arguments if available"
2243 help
2244 Uses the command-line options passed by the boot loader. If
2245 the boot loader doesn't provide any, the default kernel command
2246 string provided in CMDLINE will be used.
2247
2248 config CMDLINE_FORCE
2249 bool "Always use the default kernel command string"
2250 help
2251 Always use the default kernel command string, even if the boot
2252 loader passes other arguments to the kernel.
2253 This is useful if you cannot or don't want to change the
2254 command-line options your boot loader passes to the kernel.
2255
2256 endchoice
2257
2258 config EFI_STUB
2259 bool
2260
2261 config EFI
2262 bool "UEFI runtime support"
2263 depends on OF && !CPU_BIG_ENDIAN
2264 depends on KERNEL_MODE_NEON
2265 select ARCH_SUPPORTS_ACPI
2266 select LIBFDT
2267 select UCS2_STRING
2268 select EFI_PARAMS_FROM_FDT
2269 select EFI_RUNTIME_WRAPPERS
2270 select EFI_STUB
2271 select EFI_GENERIC_STUB
2272 imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2273 default y
2274 help
2275 This option provides support for runtime services provided
2276 by UEFI firmware (such as non-volatile variables, realtime
2277 clock, and platform reset). A UEFI stub is also provided to
2278 allow the kernel to be booted as an EFI application. This
2279 is only useful on systems that have UEFI firmware.
2280
2281 config DMI
2282 bool "Enable support for SMBIOS (DMI) tables"
2283 depends on EFI
2284 default y
2285 help
2286 This enables SMBIOS/DMI feature for systems.
2287
2288 This option is only useful on systems that have UEFI firmware.
2289 However, even with this option, the resultant kernel should
2290 continue to boot on existing non-UEFI platforms.
2291
2292 endmenu # "Boot options"
2293
2294 menu "Power management options"
2295
2296 source "kernel/power/Kconfig"
2297
2298 config ARCH_HIBERNATION_POSSIBLE
2299 def_bool y
2300 depends on CPU_PM
2301
2302 config ARCH_HIBERNATION_HEADER
2303 def_bool y
2304 depends on HIBERNATION
2305
2306 config ARCH_SUSPEND_POSSIBLE
2307 def_bool y
2308
2309 endmenu # "Power management options"
2310
2311 menu "CPU Power Management"
2312
2313 source "drivers/cpuidle/Kconfig"
2314
2315 source "drivers/cpufreq/Kconfig"
2316
2317 endmenu # "CPU Power Management"
2318
2319 source "drivers/acpi/Kconfig"
2320
2321 source "arch/arm64/kvm/Kconfig"
2322