Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1# SPDX-License-Identifier: GPL-2.0-only
2config 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_SETUP_DMA_OPS
40 select ARCH_HAS_SET_DIRECT_MAP
41 select ARCH_HAS_SET_MEMORY
42 select ARCH_STACKWALK
43 select ARCH_HAS_STRICT_KERNEL_RWX
44 select ARCH_HAS_STRICT_MODULE_RWX
45 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
46 select ARCH_HAS_SYNC_DMA_FOR_CPU
47 select ARCH_HAS_SYSCALL_WRAPPER
48 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
49 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
50 select ARCH_HAS_ZONE_DMA_SET if EXPERT
51 select ARCH_HAVE_ELF_PROT
52 select ARCH_HAVE_NMI_SAFE_CMPXCHG
53 select ARCH_HAVE_TRACE_MMIO_ACCESS
54 select ARCH_INLINE_READ_LOCK if !PREEMPTION
55 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
56 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
57 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
58 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
59 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
60 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
61 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
62 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
63 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
64 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
65 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
66 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
67 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
68 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
69 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
70 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
71 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
72 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
73 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
74 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
75 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
76 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
77 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
78 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
79 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
80 select ARCH_KEEP_MEMBLOCK
81 select ARCH_USE_CMPXCHG_LOCKREF
82 select ARCH_USE_GNU_PROPERTY
83 select ARCH_USE_MEMTEST
84 select ARCH_USE_QUEUED_RWLOCKS
85 select ARCH_USE_QUEUED_SPINLOCKS
86 select ARCH_USE_SYM_ANNOTATIONS
87 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
88 select ARCH_SUPPORTS_HUGETLBFS
89 select ARCH_SUPPORTS_MEMORY_FAILURE
90 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
91 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
92 select ARCH_SUPPORTS_LTO_CLANG_THIN
93 select ARCH_SUPPORTS_CFI_CLANG
94 select ARCH_SUPPORTS_ATOMIC_RMW
95 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
96 select ARCH_SUPPORTS_NUMA_BALANCING
97 select ARCH_SUPPORTS_PAGE_TABLE_CHECK
98 select ARCH_SUPPORTS_PER_VMA_LOCK
99 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
100 select ARCH_WANT_DEFAULT_BPF_JIT
101 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
102 select ARCH_WANT_FRAME_POINTERS
103 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
104 select ARCH_WANT_LD_ORPHAN_WARN
105 select ARCH_WANTS_NO_INSTR
106 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
107 select ARCH_HAS_UBSAN_SANITIZE_ALL
108 select ARM_AMBA
109 select ARM_ARCH_TIMER
110 select ARM_GIC
111 select AUDIT_ARCH_COMPAT_GENERIC
112 select ARM_GIC_V2M if PCI
113 select ARM_GIC_V3
114 select ARM_GIC_V3_ITS if PCI
115 select ARM_PSCI_FW
116 select BUILDTIME_TABLE_SORT
117 select CLONE_BACKWARDS
118 select COMMON_CLK
119 select CPU_PM if (SUSPEND || CPU_IDLE)
120 select CRC32
121 select DCACHE_WORD_ACCESS
122 select DYNAMIC_FTRACE if FUNCTION_TRACER
123 select DMA_DIRECT_REMAP
124 select EDAC_SUPPORT
125 select FRAME_POINTER
126 select FUNCTION_ALIGNMENT_4B
127 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
128 select GENERIC_ALLOCATOR
129 select GENERIC_ARCH_TOPOLOGY
130 select GENERIC_CLOCKEVENTS_BROADCAST
131 select GENERIC_CPU_AUTOPROBE
132 select GENERIC_CPU_VULNERABILITIES
133 select GENERIC_EARLY_IOREMAP
134 select GENERIC_IDLE_POLL_SETUP
135 select GENERIC_IOREMAP
136 select GENERIC_IRQ_IPI
137 select GENERIC_IRQ_PROBE
138 select GENERIC_IRQ_SHOW
139 select GENERIC_IRQ_SHOW_LEVEL
140 select GENERIC_LIB_DEVMEM_IS_ALLOWED
141 select GENERIC_PCI_IOMAP
142 select GENERIC_PTDUMP
143 select GENERIC_SCHED_CLOCK
144 select GENERIC_SMP_IDLE_THREAD
145 select GENERIC_TIME_VSYSCALL
146 select GENERIC_GETTIMEOFDAY
147 select GENERIC_VDSO_TIME_NS
148 select HARDIRQS_SW_RESEND
149 select HAS_IOPORT
150 select HAVE_MOVE_PMD
151 select HAVE_MOVE_PUD
152 select HAVE_PCI
153 select HAVE_ACPI_APEI if (ACPI && EFI)
154 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
155 select HAVE_ARCH_AUDITSYSCALL
156 select HAVE_ARCH_BITREVERSE
157 select HAVE_ARCH_COMPILER_H
158 select HAVE_ARCH_HUGE_VMALLOC
159 select HAVE_ARCH_HUGE_VMAP
160 select HAVE_ARCH_JUMP_LABEL
161 select HAVE_ARCH_JUMP_LABEL_RELATIVE
162 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
163 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
164 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
165 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
166 # Some instrumentation may be unsound, hence EXPERT
167 select HAVE_ARCH_KCSAN if EXPERT
168 select HAVE_ARCH_KFENCE
169 select HAVE_ARCH_KGDB
170 select HAVE_ARCH_MMAP_RND_BITS
171 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
172 select HAVE_ARCH_PREL32_RELOCATIONS
173 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
174 select HAVE_ARCH_SECCOMP_FILTER
175 select HAVE_ARCH_STACKLEAK
176 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
177 select HAVE_ARCH_TRACEHOOK
178 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
179 select HAVE_ARCH_VMAP_STACK
180 select HAVE_ARM_SMCCC
181 select HAVE_ASM_MODVERSIONS
182 select HAVE_EBPF_JIT
183 select HAVE_C_RECORDMCOUNT
184 select HAVE_CMPXCHG_DOUBLE
185 select HAVE_CMPXCHG_LOCAL
186 select HAVE_CONTEXT_TRACKING_USER
187 select HAVE_DEBUG_KMEMLEAK
188 select HAVE_DMA_CONTIGUOUS
189 select HAVE_DYNAMIC_FTRACE
190 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
191 if $(cc-option,-fpatchable-function-entry=2)
192 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
193 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
194 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
195 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
196 !CC_OPTIMIZE_FOR_SIZE)
197 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
198 if DYNAMIC_FTRACE_WITH_ARGS
199 select HAVE_EFFICIENT_UNALIGNED_ACCESS
200 select HAVE_FAST_GUP
201 select HAVE_FTRACE_MCOUNT_RECORD
202 select HAVE_FUNCTION_TRACER
203 select HAVE_FUNCTION_ERROR_INJECTION
204 select HAVE_FUNCTION_GRAPH_TRACER
205 select HAVE_GCC_PLUGINS
206 select HAVE_HW_BREAKPOINT if PERF_EVENTS
207 select HAVE_IOREMAP_PROT
208 select HAVE_IRQ_TIME_ACCOUNTING
209 select HAVE_KVM
210 select HAVE_NMI
211 select HAVE_PERF_EVENTS
212 select HAVE_PERF_REGS
213 select HAVE_PERF_USER_STACK_DUMP
214 select HAVE_PREEMPT_DYNAMIC_KEY
215 select HAVE_REGS_AND_STACK_ACCESS_API
216 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
217 select HAVE_FUNCTION_ARG_ACCESS_API
218 select MMU_GATHER_RCU_TABLE_FREE
219 select HAVE_RSEQ
220 select HAVE_STACKPROTECTOR
221 select HAVE_SYSCALL_TRACEPOINTS
222 select HAVE_KPROBES
223 select HAVE_KRETPROBES
224 select HAVE_GENERIC_VDSO
225 select IRQ_DOMAIN
226 select IRQ_FORCED_THREADING
227 select KASAN_VMALLOC if KASAN
228 select MODULES_USE_ELF_RELA
229 select NEED_DMA_MAP_STATE
230 select NEED_SG_DMA_LENGTH
231 select OF
232 select OF_EARLY_FLATTREE
233 select PCI_DOMAINS_GENERIC if PCI
234 select PCI_ECAM if (ACPI && PCI)
235 select PCI_SYSCALL if PCI
236 select POWER_RESET
237 select POWER_SUPPLY
238 select SPARSE_IRQ
239 select SWIOTLB
240 select SYSCTL_EXCEPTION_TRACE
241 select THREAD_INFO_IN_TASK
242 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
243 select TRACE_IRQFLAGS_SUPPORT
244 select TRACE_IRQFLAGS_NMI_SUPPORT
245 select HAVE_SOFTIRQ_ON_OWN_STACK
246 help
247 ARM 64-bit (AArch64) Linux support.
248
249config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
250 def_bool CC_IS_CLANG
251 # https://github.com/ClangBuiltLinux/linux/issues/1507
252 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
253 select HAVE_DYNAMIC_FTRACE_WITH_ARGS
254
255config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
256 def_bool CC_IS_GCC
257 depends on $(cc-option,-fpatchable-function-entry=2)
258 select HAVE_DYNAMIC_FTRACE_WITH_ARGS
259
260config 64BIT
261 def_bool y
262
263config MMU
264 def_bool y
265
266config ARM64_PAGE_SHIFT
267 int
268 default 16 if ARM64_64K_PAGES
269 default 14 if ARM64_16K_PAGES
270 default 12
271
272config ARM64_CONT_PTE_SHIFT
273 int
274 default 5 if ARM64_64K_PAGES
275 default 7 if ARM64_16K_PAGES
276 default 4
277
278config ARM64_CONT_PMD_SHIFT
279 int
280 default 5 if ARM64_64K_PAGES
281 default 5 if ARM64_16K_PAGES
282 default 4
283
284config ARCH_MMAP_RND_BITS_MIN
285 default 14 if ARM64_64K_PAGES
286 default 16 if ARM64_16K_PAGES
287 default 18
288
289# max bits determined by the following formula:
290# VA_BITS - PAGE_SHIFT - 3
291config ARCH_MMAP_RND_BITS_MAX
292 default 19 if ARM64_VA_BITS=36
293 default 24 if ARM64_VA_BITS=39
294 default 27 if ARM64_VA_BITS=42
295 default 30 if ARM64_VA_BITS=47
296 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
297 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
298 default 33 if ARM64_VA_BITS=48
299 default 14 if ARM64_64K_PAGES
300 default 16 if ARM64_16K_PAGES
301 default 18
302
303config ARCH_MMAP_RND_COMPAT_BITS_MIN
304 default 7 if ARM64_64K_PAGES
305 default 9 if ARM64_16K_PAGES
306 default 11
307
308config ARCH_MMAP_RND_COMPAT_BITS_MAX
309 default 16
310
311config NO_IOPORT_MAP
312 def_bool y if !PCI
313
314config STACKTRACE_SUPPORT
315 def_bool y
316
317config ILLEGAL_POINTER_VALUE
318 hex
319 default 0xdead000000000000
320
321config LOCKDEP_SUPPORT
322 def_bool y
323
324config GENERIC_BUG
325 def_bool y
326 depends on BUG
327
328config GENERIC_BUG_RELATIVE_POINTERS
329 def_bool y
330 depends on GENERIC_BUG
331
332config GENERIC_HWEIGHT
333 def_bool y
334
335config GENERIC_CSUM
336 def_bool y
337
338config GENERIC_CALIBRATE_DELAY
339 def_bool y
340
341config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
342 def_bool y
343
344config SMP
345 def_bool y
346
347config KERNEL_MODE_NEON
348 def_bool y
349
350config FIX_EARLYCON_MEM
351 def_bool y
352
353config PGTABLE_LEVELS
354 int
355 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
356 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
357 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
358 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
359 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
360 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
361
362config ARCH_SUPPORTS_UPROBES
363 def_bool y
364
365config ARCH_PROC_KCORE_TEXT
366 def_bool y
367
368config BROKEN_GAS_INST
369 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
370
371config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
372 bool
373 # Clang's __builtin_return_adddress() strips the PAC since 12.0.0
374 # https://reviews.llvm.org/D75044
375 default y if CC_IS_CLANG && (CLANG_VERSION >= 120000)
376 # GCC's __builtin_return_address() strips the PAC since 11.1.0,
377 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
378 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
379 default y if CC_IS_GCC && (GCC_VERSION >= 110100)
380 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
381 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000)
382 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000)
383 default n
384
385config KASAN_SHADOW_OFFSET
386 hex
387 depends on KASAN_GENERIC || KASAN_SW_TAGS
388 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
389 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
390 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
391 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
392 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
393 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
394 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
395 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
396 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
397 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
398 default 0xffffffffffffffff
399
400config UNWIND_TABLES
401 bool
402
403source "arch/arm64/Kconfig.platforms"
404
405menu "Kernel Features"
406
407menu "ARM errata workarounds via the alternatives framework"
408
409config ARM64_WORKAROUND_CLEAN_CACHE
410 bool
411
412config ARM64_ERRATUM_826319
413 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
414 default y
415 select ARM64_WORKAROUND_CLEAN_CACHE
416 help
417 This option adds an alternative code sequence to work around ARM
418 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
419 AXI master interface and an L2 cache.
420
421 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
422 and is unable to accept a certain write via this interface, it will
423 not progress on read data presented on the read data channel and the
424 system can deadlock.
425
426 The workaround promotes data cache clean instructions to
427 data cache clean-and-invalidate.
428 Please note that this does not necessarily enable the workaround,
429 as it depends on the alternative framework, which will only patch
430 the kernel if an affected CPU is detected.
431
432 If unsure, say Y.
433
434config ARM64_ERRATUM_827319
435 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
436 default y
437 select ARM64_WORKAROUND_CLEAN_CACHE
438 help
439 This option adds an alternative code sequence to work around ARM
440 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
441 master interface and an L2 cache.
442
443 Under certain conditions this erratum can cause a clean line eviction
444 to occur at the same time as another transaction to the same address
445 on the AMBA 5 CHI interface, which can cause data corruption if the
446 interconnect reorders the two transactions.
447
448 The workaround promotes data cache clean instructions to
449 data cache clean-and-invalidate.
450 Please note that this does not necessarily enable the workaround,
451 as it depends on the alternative framework, which will only patch
452 the kernel if an affected CPU is detected.
453
454 If unsure, say Y.
455
456config ARM64_ERRATUM_824069
457 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
458 default y
459 select ARM64_WORKAROUND_CLEAN_CACHE
460 help
461 This option adds an alternative code sequence to work around ARM
462 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
463 to a coherent interconnect.
464
465 If a Cortex-A53 processor is executing a store or prefetch for
466 write instruction at the same time as a processor in another
467 cluster is executing a cache maintenance operation to the same
468 address, then this erratum might cause a clean cache line to be
469 incorrectly marked as dirty.
470
471 The workaround promotes data cache clean instructions to
472 data cache clean-and-invalidate.
473 Please note that this option does not necessarily enable the
474 workaround, as it depends on the alternative framework, which will
475 only patch the kernel if an affected CPU is detected.
476
477 If unsure, say Y.
478
479config ARM64_ERRATUM_819472
480 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
481 default y
482 select ARM64_WORKAROUND_CLEAN_CACHE
483 help
484 This option adds an alternative code sequence to work around ARM
485 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
486 present when it is connected to a coherent interconnect.
487
488 If the processor is executing a load and store exclusive sequence at
489 the same time as a processor in another cluster is executing a cache
490 maintenance operation to the same address, then this erratum might
491 cause data corruption.
492
493 The workaround promotes data cache clean instructions to
494 data cache clean-and-invalidate.
495 Please note that this does not necessarily enable the workaround,
496 as it depends on the alternative framework, which will only patch
497 the kernel if an affected CPU is detected.
498
499 If unsure, say Y.
500
501config ARM64_ERRATUM_832075
502 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
503 default y
504 help
505 This option adds an alternative code sequence to work around ARM
506 erratum 832075 on Cortex-A57 parts up to r1p2.
507
508 Affected Cortex-A57 parts might deadlock when exclusive load/store
509 instructions to Write-Back memory are mixed with Device loads.
510
511 The workaround is to promote device loads to use Load-Acquire
512 semantics.
513 Please note that this does not necessarily enable the workaround,
514 as it depends on the alternative framework, which will only patch
515 the kernel if an affected CPU is detected.
516
517 If unsure, say Y.
518
519config ARM64_ERRATUM_834220
520 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
521 depends on KVM
522 default y
523 help
524 This option adds an alternative code sequence to work around ARM
525 erratum 834220 on Cortex-A57 parts up to r1p2.
526
527 Affected Cortex-A57 parts might report a Stage 2 translation
528 fault as the result of a Stage 1 fault for load crossing a
529 page boundary when there is a permission or device memory
530 alignment fault at Stage 1 and a translation fault at Stage 2.
531
532 The workaround is to verify that the Stage 1 translation
533 doesn't generate a fault before handling the Stage 2 fault.
534 Please note that this does not necessarily enable the workaround,
535 as it depends on the alternative framework, which will only patch
536 the kernel if an affected CPU is detected.
537
538 If unsure, say Y.
539
540config ARM64_ERRATUM_1742098
541 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
542 depends on COMPAT
543 default y
544 help
545 This option removes the AES hwcap for aarch32 user-space to
546 workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
547
548 Affected parts may corrupt the AES state if an interrupt is
549 taken between a pair of AES instructions. These instructions
550 are only present if the cryptography extensions are present.
551 All software should have a fallback implementation for CPUs
552 that don't implement the cryptography extensions.
553
554 If unsure, say Y.
555
556config ARM64_ERRATUM_845719
557 bool "Cortex-A53: 845719: a load might read incorrect data"
558 depends on COMPAT
559 default y
560 help
561 This option adds an alternative code sequence to work around ARM
562 erratum 845719 on Cortex-A53 parts up to r0p4.
563
564 When running a compat (AArch32) userspace on an affected Cortex-A53
565 part, a load at EL0 from a virtual address that matches the bottom 32
566 bits of the virtual address used by a recent load at (AArch64) EL1
567 might return incorrect data.
568
569 The workaround is to write the contextidr_el1 register on exception
570 return to a 32-bit task.
571 Please note that this does not necessarily enable the workaround,
572 as it depends on the alternative framework, which will only patch
573 the kernel if an affected CPU is detected.
574
575 If unsure, say Y.
576
577config ARM64_ERRATUM_843419
578 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
579 default y
580 select ARM64_MODULE_PLTS if MODULES
581 help
582 This option links the kernel with '--fix-cortex-a53-843419' and
583 enables PLT support to replace certain ADRP instructions, which can
584 cause subsequent memory accesses to use an incorrect address on
585 Cortex-A53 parts up to r0p4.
586
587 If unsure, say Y.
588
589config ARM64_LD_HAS_FIX_ERRATUM_843419
590 def_bool $(ld-option,--fix-cortex-a53-843419)
591
592config ARM64_ERRATUM_1024718
593 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
594 default y
595 help
596 This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
597
598 Affected Cortex-A55 cores (all revisions) could cause incorrect
599 update of the hardware dirty bit when the DBM/AP bits are updated
600 without a break-before-make. The workaround is to disable the usage
601 of hardware DBM locally on the affected cores. CPUs not affected by
602 this erratum will continue to use the feature.
603
604 If unsure, say Y.
605
606config ARM64_ERRATUM_1418040
607 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
608 default y
609 depends on COMPAT
610 help
611 This option adds a workaround for ARM Cortex-A76/Neoverse-N1
612 errata 1188873 and 1418040.
613
614 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
615 cause register corruption when accessing the timer registers
616 from AArch32 userspace.
617
618 If unsure, say Y.
619
620config ARM64_WORKAROUND_SPECULATIVE_AT
621 bool
622
623config ARM64_ERRATUM_1165522
624 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
625 default y
626 select ARM64_WORKAROUND_SPECULATIVE_AT
627 help
628 This option adds a workaround for ARM Cortex-A76 erratum 1165522.
629
630 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
631 corrupted TLBs by speculating an AT instruction during a guest
632 context switch.
633
634 If unsure, say Y.
635
636config ARM64_ERRATUM_1319367
637 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
638 default y
639 select ARM64_WORKAROUND_SPECULATIVE_AT
640 help
641 This option adds work arounds for ARM Cortex-A57 erratum 1319537
642 and A72 erratum 1319367
643
644 Cortex-A57 and A72 cores could end-up with corrupted TLBs by
645 speculating an AT instruction during a guest context switch.
646
647 If unsure, say Y.
648
649config ARM64_ERRATUM_1530923
650 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
651 default y
652 select ARM64_WORKAROUND_SPECULATIVE_AT
653 help
654 This option adds a workaround for ARM Cortex-A55 erratum 1530923.
655
656 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
657 corrupted TLBs by speculating an AT instruction during a guest
658 context switch.
659
660 If unsure, say Y.
661
662config ARM64_WORKAROUND_REPEAT_TLBI
663 bool
664
665config ARM64_ERRATUM_2441007
666 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
667 default y
668 select ARM64_WORKAROUND_REPEAT_TLBI
669 help
670 This option adds a workaround for ARM Cortex-A55 erratum #2441007.
671
672 Under very rare circumstances, affected Cortex-A55 CPUs
673 may not handle a race between a break-before-make sequence on one
674 CPU, and another CPU accessing the same page. This could allow a
675 store to a page that has been unmapped.
676
677 Work around this by adding the affected CPUs to the list that needs
678 TLB sequences to be done twice.
679
680 If unsure, say Y.
681
682config ARM64_ERRATUM_1286807
683 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
684 default y
685 select ARM64_WORKAROUND_REPEAT_TLBI
686 help
687 This option adds a workaround for ARM Cortex-A76 erratum 1286807.
688
689 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
690 address for a cacheable mapping of a location is being
691 accessed by a core while another core is remapping the virtual
692 address to a new physical page using the recommended
693 break-before-make sequence, then under very rare circumstances
694 TLBI+DSB completes before a read using the translation being
695 invalidated has been observed by other observers. The
696 workaround repeats the TLBI+DSB operation.
697
698config ARM64_ERRATUM_1463225
699 bool "Cortex-A76: Software Step might prevent interrupt recognition"
700 default y
701 help
702 This option adds a workaround for Arm Cortex-A76 erratum 1463225.
703
704 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
705 of a system call instruction (SVC) can prevent recognition of
706 subsequent interrupts when software stepping is disabled in the
707 exception handler of the system call and either kernel debugging
708 is enabled or VHE is in use.
709
710 Work around the erratum by triggering a dummy step exception
711 when handling a system call from a task that is being stepped
712 in a VHE configuration of the kernel.
713
714 If unsure, say Y.
715
716config ARM64_ERRATUM_1542419
717 bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
718 default y
719 help
720 This option adds a workaround for ARM Neoverse-N1 erratum
721 1542419.
722
723 Affected Neoverse-N1 cores could execute a stale instruction when
724 modified by another CPU. The workaround depends on a firmware
725 counterpart.
726
727 Workaround the issue by hiding the DIC feature from EL0. This
728 forces user-space to perform cache maintenance.
729
730 If unsure, say Y.
731
732config ARM64_ERRATUM_1508412
733 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
734 default y
735 help
736 This option adds a workaround for Arm Cortex-A77 erratum 1508412.
737
738 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
739 of a store-exclusive or read of PAR_EL1 and a load with device or
740 non-cacheable memory attributes. The workaround depends on a firmware
741 counterpart.
742
743 KVM guests must also have the workaround implemented or they can
744 deadlock the system.
745
746 Work around the issue by inserting DMB SY barriers around PAR_EL1
747 register reads and warning KVM users. The DMB barrier is sufficient
748 to prevent a speculative PAR_EL1 read.
749
750 If unsure, say Y.
751
752config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
753 bool
754
755config ARM64_ERRATUM_2051678
756 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
757 default y
758 help
759 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
760 Affected Cortex-A510 might not respect the ordering rules for
761 hardware update of the page table's dirty bit. The workaround
762 is to not enable the feature on affected CPUs.
763
764 If unsure, say Y.
765
766config ARM64_ERRATUM_2077057
767 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
768 default y
769 help
770 This option adds the workaround for ARM Cortex-A510 erratum 2077057.
771 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
772 expected, but a Pointer Authentication trap is taken instead. The
773 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
774 EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
775
776 This can only happen when EL2 is stepping EL1.
777
778 When these conditions occur, the SPSR_EL2 value is unchanged from the
779 previous guest entry, and can be restored from the in-memory copy.
780
781 If unsure, say Y.
782
783config ARM64_ERRATUM_2658417
784 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
785 default y
786 help
787 This option adds the workaround for ARM Cortex-A510 erratum 2658417.
788 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
789 BFMMLA or VMMLA instructions in rare circumstances when a pair of
790 A510 CPUs are using shared neon hardware. As the sharing is not
791 discoverable by the kernel, hide the BF16 HWCAP to indicate that
792 user-space should not be using these instructions.
793
794 If unsure, say Y.
795
796config ARM64_ERRATUM_2119858
797 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
798 default y
799 depends on CORESIGHT_TRBE
800 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
801 help
802 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
803
804 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
805 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
806 the event of a WRAP event.
807
808 Work around the issue by always making sure we move the TRBPTR_EL1 by
809 256 bytes before enabling the buffer and filling the first 256 bytes of
810 the buffer with ETM ignore packets upon disabling.
811
812 If unsure, say Y.
813
814config ARM64_ERRATUM_2139208
815 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
816 default y
817 depends on CORESIGHT_TRBE
818 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
819 help
820 This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
821
822 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
823 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
824 the event of a WRAP event.
825
826 Work around the issue by always making sure we move the TRBPTR_EL1 by
827 256 bytes before enabling the buffer and filling the first 256 bytes of
828 the buffer with ETM ignore packets upon disabling.
829
830 If unsure, say Y.
831
832config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
833 bool
834
835config ARM64_ERRATUM_2054223
836 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
837 default y
838 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
839 help
840 Enable workaround for ARM Cortex-A710 erratum 2054223
841
842 Affected cores may fail to flush the trace data on a TSB instruction, when
843 the PE is in trace prohibited state. This will cause losing a few bytes
844 of the trace cached.
845
846 Workaround is to issue two TSB consecutively on affected cores.
847
848 If unsure, say Y.
849
850config ARM64_ERRATUM_2067961
851 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
852 default y
853 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
854 help
855 Enable workaround for ARM Neoverse-N2 erratum 2067961
856
857 Affected cores may fail to flush the trace data on a TSB instruction, when
858 the PE is in trace prohibited state. This will cause losing a few bytes
859 of the trace cached.
860
861 Workaround is to issue two TSB consecutively on affected cores.
862
863 If unsure, say Y.
864
865config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
866 bool
867
868config ARM64_ERRATUM_2253138
869 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
870 depends on CORESIGHT_TRBE
871 default y
872 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
873 help
874 This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
875
876 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
877 for TRBE. Under some conditions, the TRBE might generate a write to the next
878 virtually addressed page following the last page of the TRBE address space
879 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
880
881 Work around this in the driver by always making sure that there is a
882 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
883
884 If unsure, say Y.
885
886config ARM64_ERRATUM_2224489
887 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
888 depends on CORESIGHT_TRBE
889 default y
890 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
891 help
892 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
893
894 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
895 for TRBE. Under some conditions, the TRBE might generate a write to the next
896 virtually addressed page following the last page of the TRBE address space
897 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
898
899 Work around this in the driver by always making sure that there is a
900 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
901
902 If unsure, say Y.
903
904config ARM64_ERRATUM_2441009
905 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI"
906 default y
907 select ARM64_WORKAROUND_REPEAT_TLBI
908 help
909 This option adds a workaround for ARM Cortex-A510 erratum #2441009.
910
911 Under very rare circumstances, affected Cortex-A510 CPUs
912 may not handle a race between a break-before-make sequence on one
913 CPU, and another CPU accessing the same page. This could allow a
914 store to a page that has been unmapped.
915
916 Work around this by adding the affected CPUs to the list that needs
917 TLB sequences to be done twice.
918
919 If unsure, say Y.
920
921config ARM64_ERRATUM_2064142
922 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
923 depends on CORESIGHT_TRBE
924 default y
925 help
926 This option adds the workaround for ARM Cortex-A510 erratum 2064142.
927
928 Affected Cortex-A510 core might fail to write into system registers after the
929 TRBE has been disabled. Under some conditions after the TRBE has been disabled
930 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
931 and TRBTRG_EL1 will be ignored and will not be effected.
932
933 Work around this in the driver by executing TSB CSYNC and DSB after collection
934 is stopped and before performing a system register write to one of the affected
935 registers.
936
937 If unsure, say Y.
938
939config ARM64_ERRATUM_2038923
940 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
941 depends on CORESIGHT_TRBE
942 default y
943 help
944 This option adds the workaround for ARM Cortex-A510 erratum 2038923.
945
946 Affected Cortex-A510 core might cause an inconsistent view on whether trace is
947 prohibited within the CPU. As a result, the trace buffer or trace buffer state
948 might be corrupted. This happens after TRBE buffer has been enabled by setting
949 TRBLIMITR_EL1.E, followed by just a single context synchronization event before
950 execution changes from a context, in which trace is prohibited to one where it
951 isn't, or vice versa. In these mentioned conditions, the view of whether trace
952 is prohibited is inconsistent between parts of the CPU, and the trace buffer or
953 the trace buffer state might be corrupted.
954
955 Work around this in the driver by preventing an inconsistent view of whether the
956 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
957 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
958 two ISB instructions if no ERET is to take place.
959
960 If unsure, say Y.
961
962config ARM64_ERRATUM_1902691
963 bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
964 depends on CORESIGHT_TRBE
965 default y
966 help
967 This option adds the workaround for ARM Cortex-A510 erratum 1902691.
968
969 Affected Cortex-A510 core might cause trace data corruption, when being written
970 into the memory. Effectively TRBE is broken and hence cannot be used to capture
971 trace data.
972
973 Work around this problem in the driver by just preventing TRBE initialization on
974 affected cpus. The firmware must have disabled the access to TRBE for the kernel
975 on such implementations. This will cover the kernel for any firmware that doesn't
976 do this already.
977
978 If unsure, say Y.
979
980config ARM64_ERRATUM_2457168
981 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
982 depends on ARM64_AMU_EXTN
983 default y
984 help
985 This option adds the workaround for ARM Cortex-A510 erratum 2457168.
986
987 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
988 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
989 incorrectly giving a significantly higher output value.
990
991 Work around this problem by returning 0 when reading the affected counter in
992 key locations that results in disabling all users of this counter. This effect
993 is the same to firmware disabling affected counters.
994
995 If unsure, say Y.
996
997config ARM64_ERRATUM_2645198
998 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
999 default y
1000 help
1001 This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1002
1003 If a Cortex-A715 cpu sees a page mapping permissions change from executable
1004 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1005 next instruction abort caused by permission fault.
1006
1007 Only user-space does executable to non-executable permission transition via
1008 mprotect() system call. Workaround the problem by doing a break-before-make
1009 TLB invalidation, for all changes to executable user space mappings.
1010
1011 If unsure, say Y.
1012
1013config CAVIUM_ERRATUM_22375
1014 bool "Cavium erratum 22375, 24313"
1015 default y
1016 help
1017 Enable workaround for errata 22375 and 24313.
1018
1019 This implements two gicv3-its errata workarounds for ThunderX. Both
1020 with a small impact affecting only ITS table allocation.
1021
1022 erratum 22375: only alloc 8MB table size
1023 erratum 24313: ignore memory access type
1024
1025 The fixes are in ITS initialization and basically ignore memory access
1026 type and table size provided by the TYPER and BASER registers.
1027
1028 If unsure, say Y.
1029
1030config CAVIUM_ERRATUM_23144
1031 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1032 depends on NUMA
1033 default y
1034 help
1035 ITS SYNC command hang for cross node io and collections/cpu mapping.
1036
1037 If unsure, say Y.
1038
1039config CAVIUM_ERRATUM_23154
1040 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1041 default y
1042 help
1043 The ThunderX GICv3 implementation requires a modified version for
1044 reading the IAR status to ensure data synchronization
1045 (access to icc_iar1_el1 is not sync'ed before and after).
1046
1047 It also suffers from erratum 38545 (also present on Marvell's
1048 OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1049 spuriously presented to the CPU interface.
1050
1051 If unsure, say Y.
1052
1053config CAVIUM_ERRATUM_27456
1054 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1055 default y
1056 help
1057 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1058 instructions may cause the icache to become corrupted if it
1059 contains data for a non-current ASID. The fix is to
1060 invalidate the icache when changing the mm context.
1061
1062 If unsure, say Y.
1063
1064config CAVIUM_ERRATUM_30115
1065 bool "Cavium erratum 30115: Guest may disable interrupts in host"
1066 default y
1067 help
1068 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1069 1.2, and T83 Pass 1.0, KVM guest execution may disable
1070 interrupts in host. Trapping both GICv3 group-0 and group-1
1071 accesses sidesteps the issue.
1072
1073 If unsure, say Y.
1074
1075config CAVIUM_TX2_ERRATUM_219
1076 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1077 default y
1078 help
1079 On Cavium ThunderX2, a load, store or prefetch instruction between a
1080 TTBR update and the corresponding context synchronizing operation can
1081 cause a spurious Data Abort to be delivered to any hardware thread in
1082 the CPU core.
1083
1084 Work around the issue by avoiding the problematic code sequence and
1085 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1086 trap handler performs the corresponding register access, skips the
1087 instruction and ensures context synchronization by virtue of the
1088 exception return.
1089
1090 If unsure, say Y.
1091
1092config FUJITSU_ERRATUM_010001
1093 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1094 default y
1095 help
1096 This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1097 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1098 accesses may cause undefined fault (Data abort, DFSC=0b111111).
1099 This fault occurs under a specific hardware condition when a
1100 load/store instruction performs an address translation using:
1101 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1102 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1103 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1104 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1105
1106 The workaround is to ensure these bits are clear in TCR_ELx.
1107 The workaround only affects the Fujitsu-A64FX.
1108
1109 If unsure, say Y.
1110
1111config HISILICON_ERRATUM_161600802
1112 bool "Hip07 161600802: Erroneous redistributor VLPI base"
1113 default y
1114 help
1115 The HiSilicon Hip07 SoC uses the wrong redistributor base
1116 when issued ITS commands such as VMOVP and VMAPP, and requires
1117 a 128kB offset to be applied to the target address in this commands.
1118
1119 If unsure, say Y.
1120
1121config QCOM_FALKOR_ERRATUM_1003
1122 bool "Falkor E1003: Incorrect translation due to ASID change"
1123 default y
1124 help
1125 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1126 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1127 in TTBR1_EL1, this situation only occurs in the entry trampoline and
1128 then only for entries in the walk cache, since the leaf translation
1129 is unchanged. Work around the erratum by invalidating the walk cache
1130 entries for the trampoline before entering the kernel proper.
1131
1132config QCOM_FALKOR_ERRATUM_1009
1133 bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1134 default y
1135 select ARM64_WORKAROUND_REPEAT_TLBI
1136 help
1137 On Falkor v1, the CPU may prematurely complete a DSB following a
1138 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1139 one more time to fix the issue.
1140
1141 If unsure, say Y.
1142
1143config QCOM_QDF2400_ERRATUM_0065
1144 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1145 default y
1146 help
1147 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1148 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1149 been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1150
1151 If unsure, say Y.
1152
1153config QCOM_FALKOR_ERRATUM_E1041
1154 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1155 default y
1156 help
1157 Falkor CPU may speculatively fetch instructions from an improper
1158 memory location when MMU translation is changed from SCTLR_ELn[M]=1
1159 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1160
1161 If unsure, say Y.
1162
1163config NVIDIA_CARMEL_CNP_ERRATUM
1164 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1165 default y
1166 help
1167 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1168 invalidate shared TLB entries installed by a different core, as it would
1169 on standard ARM cores.
1170
1171 If unsure, say Y.
1172
1173config ROCKCHIP_ERRATUM_3588001
1174 bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1175 default y
1176 help
1177 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1178 This means, that its sharability feature may not be used, even though it
1179 is supported by the IP itself.
1180
1181 If unsure, say Y.
1182
1183config SOCIONEXT_SYNQUACER_PREITS
1184 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1185 default y
1186 help
1187 Socionext Synquacer SoCs implement a separate h/w block to generate
1188 MSI doorbell writes with non-zero values for the device ID.
1189
1190 If unsure, say Y.
1191
1192endmenu # "ARM errata workarounds via the alternatives framework"
1193
1194choice
1195 prompt "Page size"
1196 default ARM64_4K_PAGES
1197 help
1198 Page size (translation granule) configuration.
1199
1200config ARM64_4K_PAGES
1201 bool "4KB"
1202 help
1203 This feature enables 4KB pages support.
1204
1205config ARM64_16K_PAGES
1206 bool "16KB"
1207 help
1208 The system will use 16KB pages support. AArch32 emulation
1209 requires applications compiled with 16K (or a multiple of 16K)
1210 aligned segments.
1211
1212config ARM64_64K_PAGES
1213 bool "64KB"
1214 help
1215 This feature enables 64KB pages support (4KB by default)
1216 allowing only two levels of page tables and faster TLB
1217 look-up. AArch32 emulation requires applications compiled
1218 with 64K aligned segments.
1219
1220endchoice
1221
1222choice
1223 prompt "Virtual address space size"
1224 default ARM64_VA_BITS_39 if ARM64_4K_PAGES
1225 default ARM64_VA_BITS_47 if ARM64_16K_PAGES
1226 default ARM64_VA_BITS_42 if ARM64_64K_PAGES
1227 help
1228 Allows choosing one of multiple possible virtual address
1229 space sizes. The level of translation table is determined by
1230 a combination of page size and virtual address space size.
1231
1232config ARM64_VA_BITS_36
1233 bool "36-bit" if EXPERT
1234 depends on ARM64_16K_PAGES
1235
1236config ARM64_VA_BITS_39
1237 bool "39-bit"
1238 depends on ARM64_4K_PAGES
1239
1240config ARM64_VA_BITS_42
1241 bool "42-bit"
1242 depends on ARM64_64K_PAGES
1243
1244config ARM64_VA_BITS_47
1245 bool "47-bit"
1246 depends on ARM64_16K_PAGES
1247
1248config ARM64_VA_BITS_48
1249 bool "48-bit"
1250
1251config ARM64_VA_BITS_52
1252 bool "52-bit"
1253 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
1254 help
1255 Enable 52-bit virtual addressing for userspace when explicitly
1256 requested via a hint to mmap(). The kernel will also use 52-bit
1257 virtual addresses for its own mappings (provided HW support for
1258 this feature is available, otherwise it reverts to 48-bit).
1259
1260 NOTE: Enabling 52-bit virtual addressing in conjunction with
1261 ARMv8.3 Pointer Authentication will result in the PAC being
1262 reduced from 7 bits to 3 bits, which may have a significant
1263 impact on its susceptibility to brute-force attacks.
1264
1265 If unsure, select 48-bit virtual addressing instead.
1266
1267endchoice
1268
1269config ARM64_FORCE_52BIT
1270 bool "Force 52-bit virtual addresses for userspace"
1271 depends on ARM64_VA_BITS_52 && EXPERT
1272 help
1273 For systems with 52-bit userspace VAs enabled, the kernel will attempt
1274 to maintain compatibility with older software by providing 48-bit VAs
1275 unless a hint is supplied to mmap.
1276
1277 This configuration option disables the 48-bit compatibility logic, and
1278 forces all userspace addresses to be 52-bit on HW that supports it. One
1279 should only enable this configuration option for stress testing userspace
1280 memory management code. If unsure say N here.
1281
1282config ARM64_VA_BITS
1283 int
1284 default 36 if ARM64_VA_BITS_36
1285 default 39 if ARM64_VA_BITS_39
1286 default 42 if ARM64_VA_BITS_42
1287 default 47 if ARM64_VA_BITS_47
1288 default 48 if ARM64_VA_BITS_48
1289 default 52 if ARM64_VA_BITS_52
1290
1291choice
1292 prompt "Physical address space size"
1293 default ARM64_PA_BITS_48
1294 help
1295 Choose the maximum physical address range that the kernel will
1296 support.
1297
1298config ARM64_PA_BITS_48
1299 bool "48-bit"
1300
1301config ARM64_PA_BITS_52
1302 bool "52-bit (ARMv8.2)"
1303 depends on ARM64_64K_PAGES
1304 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1305 help
1306 Enable support for a 52-bit physical address space, introduced as
1307 part of the ARMv8.2-LPA extension.
1308
1309 With this enabled, the kernel will also continue to work on CPUs that
1310 do not support ARMv8.2-LPA, but with some added memory overhead (and
1311 minor performance overhead).
1312
1313endchoice
1314
1315config ARM64_PA_BITS
1316 int
1317 default 48 if ARM64_PA_BITS_48
1318 default 52 if ARM64_PA_BITS_52
1319
1320choice
1321 prompt "Endianness"
1322 default CPU_LITTLE_ENDIAN
1323 help
1324 Select the endianness of data accesses performed by the CPU. Userspace
1325 applications will need to be compiled and linked for the endianness
1326 that is selected here.
1327
1328config CPU_BIG_ENDIAN
1329 bool "Build big-endian kernel"
1330 depends on !LD_IS_LLD || LLD_VERSION >= 130000
1331 help
1332 Say Y if you plan on running a kernel with a big-endian userspace.
1333
1334config CPU_LITTLE_ENDIAN
1335 bool "Build little-endian kernel"
1336 help
1337 Say Y if you plan on running a kernel with a little-endian userspace.
1338 This is usually the case for distributions targeting arm64.
1339
1340endchoice
1341
1342config SCHED_MC
1343 bool "Multi-core scheduler support"
1344 help
1345 Multi-core scheduler support improves the CPU scheduler's decision
1346 making when dealing with multi-core CPU chips at a cost of slightly
1347 increased overhead in some places. If unsure say N here.
1348
1349config SCHED_CLUSTER
1350 bool "Cluster scheduler support"
1351 help
1352 Cluster scheduler support improves the CPU scheduler's decision
1353 making when dealing with machines that have clusters of CPUs.
1354 Cluster usually means a couple of CPUs which are placed closely
1355 by sharing mid-level caches, last-level cache tags or internal
1356 busses.
1357
1358config SCHED_SMT
1359 bool "SMT scheduler support"
1360 help
1361 Improves the CPU scheduler's decision making when dealing with
1362 MultiThreading at a cost of slightly increased overhead in some
1363 places. If unsure say N here.
1364
1365config NR_CPUS
1366 int "Maximum number of CPUs (2-4096)"
1367 range 2 4096
1368 default "256"
1369
1370config HOTPLUG_CPU
1371 bool "Support for hot-pluggable CPUs"
1372 select GENERIC_IRQ_MIGRATION
1373 help
1374 Say Y here to experiment with turning CPUs off and on. CPUs
1375 can be controlled through /sys/devices/system/cpu.
1376
1377# Common NUMA Features
1378config NUMA
1379 bool "NUMA Memory Allocation and Scheduler Support"
1380 select GENERIC_ARCH_NUMA
1381 select ACPI_NUMA if ACPI
1382 select OF_NUMA
1383 select HAVE_SETUP_PER_CPU_AREA
1384 select NEED_PER_CPU_EMBED_FIRST_CHUNK
1385 select NEED_PER_CPU_PAGE_FIRST_CHUNK
1386 select USE_PERCPU_NUMA_NODE_ID
1387 help
1388 Enable NUMA (Non-Uniform Memory Access) support.
1389
1390 The kernel will try to allocate memory used by a CPU on the
1391 local memory of the CPU and add some more
1392 NUMA awareness to the kernel.
1393
1394config NODES_SHIFT
1395 int "Maximum NUMA Nodes (as a power of 2)"
1396 range 1 10
1397 default "4"
1398 depends on NUMA
1399 help
1400 Specify the maximum number of NUMA Nodes available on the target
1401 system. Increases memory reserved to accommodate various tables.
1402
1403source "kernel/Kconfig.hz"
1404
1405config ARCH_SPARSEMEM_ENABLE
1406 def_bool y
1407 select SPARSEMEM_VMEMMAP_ENABLE
1408 select SPARSEMEM_VMEMMAP
1409
1410config HW_PERF_EVENTS
1411 def_bool y
1412 depends on ARM_PMU
1413
1414# Supported by clang >= 7.0 or GCC >= 12.0.0
1415config CC_HAVE_SHADOW_CALL_STACK
1416 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1417
1418config PARAVIRT
1419 bool "Enable paravirtualization code"
1420 help
1421 This changes the kernel so it can modify itself when it is run
1422 under a hypervisor, potentially improving performance significantly
1423 over full virtualization.
1424
1425config PARAVIRT_TIME_ACCOUNTING
1426 bool "Paravirtual steal time accounting"
1427 select PARAVIRT
1428 help
1429 Select this option to enable fine granularity task steal time
1430 accounting. Time spent executing other tasks in parallel with
1431 the current vCPU is discounted from the vCPU power. To account for
1432 that, there can be a small performance impact.
1433
1434 If in doubt, say N here.
1435
1436config KEXEC
1437 depends on PM_SLEEP_SMP
1438 select KEXEC_CORE
1439 bool "kexec system call"
1440 help
1441 kexec is a system call that implements the ability to shutdown your
1442 current kernel, and to start another kernel. It is like a reboot
1443 but it is independent of the system firmware. And like a reboot
1444 you can start any kernel with it, not just Linux.
1445
1446config KEXEC_FILE
1447 bool "kexec file based system call"
1448 select KEXEC_CORE
1449 select HAVE_IMA_KEXEC if IMA
1450 help
1451 This is new version of kexec system call. This system call is
1452 file based and takes file descriptors as system call argument
1453 for kernel and initramfs as opposed to list of segments as
1454 accepted by previous system call.
1455
1456config KEXEC_SIG
1457 bool "Verify kernel signature during kexec_file_load() syscall"
1458 depends on KEXEC_FILE
1459 help
1460 Select this option to verify a signature with loaded kernel
1461 image. If configured, any attempt of loading a image without
1462 valid signature will fail.
1463
1464 In addition to that option, you need to enable signature
1465 verification for the corresponding kernel image type being
1466 loaded in order for this to work.
1467
1468config KEXEC_IMAGE_VERIFY_SIG
1469 bool "Enable Image signature verification support"
1470 default y
1471 depends on KEXEC_SIG
1472 depends on EFI && SIGNED_PE_FILE_VERIFICATION
1473 help
1474 Enable Image signature verification support.
1475
1476comment "Support for PE file signature verification disabled"
1477 depends on KEXEC_SIG
1478 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
1479
1480config CRASH_DUMP
1481 bool "Build kdump crash kernel"
1482 help
1483 Generate crash dump after being started by kexec. This should
1484 be normally only set in special crash dump kernels which are
1485 loaded in the main kernel with kexec-tools into a specially
1486 reserved region and then later executed after a crash by
1487 kdump/kexec.
1488
1489 For more details see Documentation/admin-guide/kdump/kdump.rst
1490
1491config TRANS_TABLE
1492 def_bool y
1493 depends on HIBERNATION || KEXEC_CORE
1494
1495config XEN_DOM0
1496 def_bool y
1497 depends on XEN
1498
1499config XEN
1500 bool "Xen guest support on ARM64"
1501 depends on ARM64 && OF
1502 select SWIOTLB_XEN
1503 select PARAVIRT
1504 help
1505 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1506
1507# include/linux/mmzone.h requires the following to be true:
1508#
1509# MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1510#
1511# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1512#
1513# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_ORDER | default MAX_ORDER |
1514# ----+-------------------+--------------+-----------------+--------------------+
1515# 4K | 27 | 12 | 15 | 10 |
1516# 16K | 27 | 14 | 13 | 11 |
1517# 64K | 29 | 16 | 13 | 13 |
1518config ARCH_FORCE_MAX_ORDER
1519 int
1520 default "13" if ARM64_64K_PAGES
1521 default "11" if ARM64_16K_PAGES
1522 default "10"
1523 help
1524 The kernel page allocator limits the size of maximal physically
1525 contiguous allocations. The limit is called MAX_ORDER and it
1526 defines the maximal power of two of number of pages that can be
1527 allocated as a single contiguous block. This option allows
1528 overriding the default setting when ability to allocate very
1529 large blocks of physically contiguous memory is required.
1530
1531 The maximal size of allocation cannot exceed the size of the
1532 section, so the value of MAX_ORDER should satisfy
1533
1534 MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1535
1536 Don't change if unsure.
1537
1538config UNMAP_KERNEL_AT_EL0
1539 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1540 default y
1541 help
1542 Speculation attacks against some high-performance processors can
1543 be used to bypass MMU permission checks and leak kernel data to
1544 userspace. This can be defended against by unmapping the kernel
1545 when running in userspace, mapping it back in on exception entry
1546 via a trampoline page in the vector table.
1547
1548 If unsure, say Y.
1549
1550config MITIGATE_SPECTRE_BRANCH_HISTORY
1551 bool "Mitigate Spectre style attacks against branch history" if EXPERT
1552 default y
1553 help
1554 Speculation attacks against some high-performance processors can
1555 make use of branch history to influence future speculation.
1556 When taking an exception from user-space, a sequence of branches
1557 or a firmware call overwrites the branch history.
1558
1559config RODATA_FULL_DEFAULT_ENABLED
1560 bool "Apply r/o permissions of VM areas also to their linear aliases"
1561 default y
1562 help
1563 Apply read-only attributes of VM areas to the linear alias of
1564 the backing pages as well. This prevents code or read-only data
1565 from being modified (inadvertently or intentionally) via another
1566 mapping of the same memory page. This additional enhancement can
1567 be turned off at runtime by passing rodata=[off|on] (and turned on
1568 with rodata=full if this option is set to 'n')
1569
1570 This requires the linear region to be mapped down to pages,
1571 which may adversely affect performance in some cases.
1572
1573config ARM64_SW_TTBR0_PAN
1574 bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1575 help
1576 Enabling this option prevents the kernel from accessing
1577 user-space memory directly by pointing TTBR0_EL1 to a reserved
1578 zeroed area and reserved ASID. The user access routines
1579 restore the valid TTBR0_EL1 temporarily.
1580
1581config ARM64_TAGGED_ADDR_ABI
1582 bool "Enable the tagged user addresses syscall ABI"
1583 default y
1584 help
1585 When this option is enabled, user applications can opt in to a
1586 relaxed ABI via prctl() allowing tagged addresses to be passed
1587 to system calls as pointer arguments. For details, see
1588 Documentation/arm64/tagged-address-abi.rst.
1589
1590menuconfig COMPAT
1591 bool "Kernel support for 32-bit EL0"
1592 depends on ARM64_4K_PAGES || EXPERT
1593 select HAVE_UID16
1594 select OLD_SIGSUSPEND3
1595 select COMPAT_OLD_SIGACTION
1596 help
1597 This option enables support for a 32-bit EL0 running under a 64-bit
1598 kernel at EL1. AArch32-specific components such as system calls,
1599 the user helper functions, VFP support and the ptrace interface are
1600 handled appropriately by the kernel.
1601
1602 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1603 that you will only be able to execute AArch32 binaries that were compiled
1604 with page size aligned segments.
1605
1606 If you want to execute 32-bit userspace applications, say Y.
1607
1608if COMPAT
1609
1610config KUSER_HELPERS
1611 bool "Enable kuser helpers page for 32-bit applications"
1612 default y
1613 help
1614 Warning: disabling this option may break 32-bit user programs.
1615
1616 Provide kuser helpers to compat tasks. The kernel provides
1617 helper code to userspace in read only form at a fixed location
1618 to allow userspace to be independent of the CPU type fitted to
1619 the system. This permits binaries to be run on ARMv4 through
1620 to ARMv8 without modification.
1621
1622 See Documentation/arm/kernel_user_helpers.rst for details.
1623
1624 However, the fixed address nature of these helpers can be used
1625 by ROP (return orientated programming) authors when creating
1626 exploits.
1627
1628 If all of the binaries and libraries which run on your platform
1629 are built specifically for your platform, and make no use of
1630 these helpers, then you can turn this option off to hinder
1631 such exploits. However, in that case, if a binary or library
1632 relying on those helpers is run, it will not function correctly.
1633
1634 Say N here only if you are absolutely certain that you do not
1635 need these helpers; otherwise, the safe option is to say Y.
1636
1637config COMPAT_VDSO
1638 bool "Enable vDSO for 32-bit applications"
1639 depends on !CPU_BIG_ENDIAN
1640 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1641 select GENERIC_COMPAT_VDSO
1642 default y
1643 help
1644 Place in the process address space of 32-bit applications an
1645 ELF shared object providing fast implementations of gettimeofday
1646 and clock_gettime.
1647
1648 You must have a 32-bit build of glibc 2.22 or later for programs
1649 to seamlessly take advantage of this.
1650
1651config THUMB2_COMPAT_VDSO
1652 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1653 depends on COMPAT_VDSO
1654 default y
1655 help
1656 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1657 otherwise with '-marm'.
1658
1659config COMPAT_ALIGNMENT_FIXUPS
1660 bool "Fix up misaligned multi-word loads and stores in user space"
1661
1662menuconfig ARMV8_DEPRECATED
1663 bool "Emulate deprecated/obsolete ARMv8 instructions"
1664 depends on SYSCTL
1665 help
1666 Legacy software support may require certain instructions
1667 that have been deprecated or obsoleted in the architecture.
1668
1669 Enable this config to enable selective emulation of these
1670 features.
1671
1672 If unsure, say Y
1673
1674if ARMV8_DEPRECATED
1675
1676config SWP_EMULATION
1677 bool "Emulate SWP/SWPB instructions"
1678 help
1679 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1680 they are always undefined. Say Y here to enable software
1681 emulation of these instructions for userspace using LDXR/STXR.
1682 This feature can be controlled at runtime with the abi.swp
1683 sysctl which is disabled by default.
1684
1685 In some older versions of glibc [<=2.8] SWP is used during futex
1686 trylock() operations with the assumption that the code will not
1687 be preempted. This invalid assumption may be more likely to fail
1688 with SWP emulation enabled, leading to deadlock of the user
1689 application.
1690
1691 NOTE: when accessing uncached shared regions, LDXR/STXR rely
1692 on an external transaction monitoring block called a global
1693 monitor to maintain update atomicity. If your system does not
1694 implement a global monitor, this option can cause programs that
1695 perform SWP operations to uncached memory to deadlock.
1696
1697 If unsure, say Y
1698
1699config CP15_BARRIER_EMULATION
1700 bool "Emulate CP15 Barrier instructions"
1701 help
1702 The CP15 barrier instructions - CP15ISB, CP15DSB, and
1703 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1704 strongly recommended to use the ISB, DSB, and DMB
1705 instructions instead.
1706
1707 Say Y here to enable software emulation of these
1708 instructions for AArch32 userspace code. When this option is
1709 enabled, CP15 barrier usage is traced which can help
1710 identify software that needs updating. This feature can be
1711 controlled at runtime with the abi.cp15_barrier sysctl.
1712
1713 If unsure, say Y
1714
1715config SETEND_EMULATION
1716 bool "Emulate SETEND instruction"
1717 help
1718 The SETEND instruction alters the data-endianness of the
1719 AArch32 EL0, and is deprecated in ARMv8.
1720
1721 Say Y here to enable software emulation of the instruction
1722 for AArch32 userspace code. This feature can be controlled
1723 at runtime with the abi.setend sysctl.
1724
1725 Note: All the cpus on the system must have mixed endian support at EL0
1726 for this feature to be enabled. If a new CPU - which doesn't support mixed
1727 endian - is hotplugged in after this feature has been enabled, there could
1728 be unexpected results in the applications.
1729
1730 If unsure, say Y
1731endif # ARMV8_DEPRECATED
1732
1733endif # COMPAT
1734
1735menu "ARMv8.1 architectural features"
1736
1737config ARM64_HW_AFDBM
1738 bool "Support for hardware updates of the Access and Dirty page flags"
1739 default y
1740 help
1741 The ARMv8.1 architecture extensions introduce support for
1742 hardware updates of the access and dirty information in page
1743 table entries. When enabled in TCR_EL1 (HA and HD bits) on
1744 capable processors, accesses to pages with PTE_AF cleared will
1745 set this bit instead of raising an access flag fault.
1746 Similarly, writes to read-only pages with the DBM bit set will
1747 clear the read-only bit (AP[2]) instead of raising a
1748 permission fault.
1749
1750 Kernels built with this configuration option enabled continue
1751 to work on pre-ARMv8.1 hardware and the performance impact is
1752 minimal. If unsure, say Y.
1753
1754config ARM64_PAN
1755 bool "Enable support for Privileged Access Never (PAN)"
1756 default y
1757 help
1758 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1759 prevents the kernel or hypervisor from accessing user-space (EL0)
1760 memory directly.
1761
1762 Choosing this option will cause any unprotected (not using
1763 copy_to_user et al) memory access to fail with a permission fault.
1764
1765 The feature is detected at runtime, and will remain as a 'nop'
1766 instruction if the cpu does not implement the feature.
1767
1768config AS_HAS_LDAPR
1769 def_bool $(as-instr,.arch_extension rcpc)
1770
1771config AS_HAS_LSE_ATOMICS
1772 def_bool $(as-instr,.arch_extension lse)
1773
1774config ARM64_LSE_ATOMICS
1775 bool
1776 default ARM64_USE_LSE_ATOMICS
1777 depends on AS_HAS_LSE_ATOMICS
1778
1779config ARM64_USE_LSE_ATOMICS
1780 bool "Atomic instructions"
1781 default y
1782 help
1783 As part of the Large System Extensions, ARMv8.1 introduces new
1784 atomic instructions that are designed specifically to scale in
1785 very large systems.
1786
1787 Say Y here to make use of these instructions for the in-kernel
1788 atomic routines. This incurs a small overhead on CPUs that do
1789 not support these instructions and requires the kernel to be
1790 built with binutils >= 2.25 in order for the new instructions
1791 to be used.
1792
1793endmenu # "ARMv8.1 architectural features"
1794
1795menu "ARMv8.2 architectural features"
1796
1797config AS_HAS_ARMV8_2
1798 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1799
1800config AS_HAS_SHA3
1801 def_bool $(as-instr,.arch armv8.2-a+sha3)
1802
1803config ARM64_PMEM
1804 bool "Enable support for persistent memory"
1805 select ARCH_HAS_PMEM_API
1806 select ARCH_HAS_UACCESS_FLUSHCACHE
1807 help
1808 Say Y to enable support for the persistent memory API based on the
1809 ARMv8.2 DCPoP feature.
1810
1811 The feature is detected at runtime, and the kernel will use DC CVAC
1812 operations if DC CVAP is not supported (following the behaviour of
1813 DC CVAP itself if the system does not define a point of persistence).
1814
1815config ARM64_RAS_EXTN
1816 bool "Enable support for RAS CPU Extensions"
1817 default y
1818 help
1819 CPUs that support the Reliability, Availability and Serviceability
1820 (RAS) Extensions, part of ARMv8.2 are able to track faults and
1821 errors, classify them and report them to software.
1822
1823 On CPUs with these extensions system software can use additional
1824 barriers to determine if faults are pending and read the
1825 classification from a new set of registers.
1826
1827 Selecting this feature will allow the kernel to use these barriers
1828 and access the new registers if the system supports the extension.
1829 Platform RAS features may additionally depend on firmware support.
1830
1831config ARM64_CNP
1832 bool "Enable support for Common Not Private (CNP) translations"
1833 default y
1834 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1835 help
1836 Common Not Private (CNP) allows translation table entries to
1837 be shared between different PEs in the same inner shareable
1838 domain, so the hardware can use this fact to optimise the
1839 caching of such entries in the TLB.
1840
1841 Selecting this option allows the CNP feature to be detected
1842 at runtime, and does not affect PEs that do not implement
1843 this feature.
1844
1845endmenu # "ARMv8.2 architectural features"
1846
1847menu "ARMv8.3 architectural features"
1848
1849config ARM64_PTR_AUTH
1850 bool "Enable support for pointer authentication"
1851 default y
1852 help
1853 Pointer authentication (part of the ARMv8.3 Extensions) provides
1854 instructions for signing and authenticating pointers against secret
1855 keys, which can be used to mitigate Return Oriented Programming (ROP)
1856 and other attacks.
1857
1858 This option enables these instructions at EL0 (i.e. for userspace).
1859 Choosing this option will cause the kernel to initialise secret keys
1860 for each process at exec() time, with these keys being
1861 context-switched along with the process.
1862
1863 The feature is detected at runtime. If the feature is not present in
1864 hardware it will not be advertised to userspace/KVM guest nor will it
1865 be enabled.
1866
1867 If the feature is present on the boot CPU but not on a late CPU, then
1868 the late CPU will be parked. Also, if the boot CPU does not have
1869 address auth and the late CPU has then the late CPU will still boot
1870 but with the feature disabled. On such a system, this option should
1871 not be selected.
1872
1873config ARM64_PTR_AUTH_KERNEL
1874 bool "Use pointer authentication for kernel"
1875 default y
1876 depends on ARM64_PTR_AUTH
1877 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1878 # Modern compilers insert a .note.gnu.property section note for PAC
1879 # which is only understood by binutils starting with version 2.33.1.
1880 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1881 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1882 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1883 help
1884 If the compiler supports the -mbranch-protection or
1885 -msign-return-address flag (e.g. GCC 7 or later), then this option
1886 will cause the kernel itself to be compiled with return address
1887 protection. In this case, and if the target hardware is known to
1888 support pointer authentication, then CONFIG_STACKPROTECTOR can be
1889 disabled with minimal loss of protection.
1890
1891 This feature works with FUNCTION_GRAPH_TRACER option only if
1892 DYNAMIC_FTRACE_WITH_ARGS is enabled.
1893
1894config CC_HAS_BRANCH_PROT_PAC_RET
1895 # GCC 9 or later, clang 8 or later
1896 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1897
1898config CC_HAS_SIGN_RETURN_ADDRESS
1899 # GCC 7, 8
1900 def_bool $(cc-option,-msign-return-address=all)
1901
1902config AS_HAS_ARMV8_3
1903 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1904
1905config AS_HAS_CFI_NEGATE_RA_STATE
1906 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1907
1908endmenu # "ARMv8.3 architectural features"
1909
1910menu "ARMv8.4 architectural features"
1911
1912config ARM64_AMU_EXTN
1913 bool "Enable support for the Activity Monitors Unit CPU extension"
1914 default y
1915 help
1916 The activity monitors extension is an optional extension introduced
1917 by the ARMv8.4 CPU architecture. This enables support for version 1
1918 of the activity monitors architecture, AMUv1.
1919
1920 To enable the use of this extension on CPUs that implement it, say Y.
1921
1922 Note that for architectural reasons, firmware _must_ implement AMU
1923 support when running on CPUs that present the activity monitors
1924 extension. The required support is present in:
1925 * Version 1.5 and later of the ARM Trusted Firmware
1926
1927 For kernels that have this configuration enabled but boot with broken
1928 firmware, you may need to say N here until the firmware is fixed.
1929 Otherwise you may experience firmware panics or lockups when
1930 accessing the counter registers. Even if you are not observing these
1931 symptoms, the values returned by the register reads might not
1932 correctly reflect reality. Most commonly, the value read will be 0,
1933 indicating that the counter is not enabled.
1934
1935config AS_HAS_ARMV8_4
1936 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1937
1938config ARM64_TLB_RANGE
1939 bool "Enable support for tlbi range feature"
1940 default y
1941 depends on AS_HAS_ARMV8_4
1942 help
1943 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1944 range of input addresses.
1945
1946 The feature introduces new assembly instructions, and they were
1947 support when binutils >= 2.30.
1948
1949endmenu # "ARMv8.4 architectural features"
1950
1951menu "ARMv8.5 architectural features"
1952
1953config AS_HAS_ARMV8_5
1954 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1955
1956config ARM64_BTI
1957 bool "Branch Target Identification support"
1958 default y
1959 help
1960 Branch Target Identification (part of the ARMv8.5 Extensions)
1961 provides a mechanism to limit the set of locations to which computed
1962 branch instructions such as BR or BLR can jump.
1963
1964 To make use of BTI on CPUs that support it, say Y.
1965
1966 BTI is intended to provide complementary protection to other control
1967 flow integrity protection mechanisms, such as the Pointer
1968 authentication mechanism provided as part of the ARMv8.3 Extensions.
1969 For this reason, it does not make sense to enable this option without
1970 also enabling support for pointer authentication. Thus, when
1971 enabling this option you should also select ARM64_PTR_AUTH=y.
1972
1973 Userspace binaries must also be specifically compiled to make use of
1974 this mechanism. If you say N here or the hardware does not support
1975 BTI, such binaries can still run, but you get no additional
1976 enforcement of branch destinations.
1977
1978config ARM64_BTI_KERNEL
1979 bool "Use Branch Target Identification for kernel"
1980 default y
1981 depends on ARM64_BTI
1982 depends on ARM64_PTR_AUTH_KERNEL
1983 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1984 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1985 depends on !CC_IS_GCC || GCC_VERSION >= 100100
1986 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
1987 depends on !CC_IS_GCC
1988 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9
1989 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000
1990 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1991 help
1992 Build the kernel with Branch Target Identification annotations
1993 and enable enforcement of this for kernel code. When this option
1994 is enabled and the system supports BTI all kernel code including
1995 modular code must have BTI enabled.
1996
1997config CC_HAS_BRANCH_PROT_PAC_RET_BTI
1998 # GCC 9 or later, clang 8 or later
1999 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2000
2001config ARM64_E0PD
2002 bool "Enable support for E0PD"
2003 default y
2004 help
2005 E0PD (part of the ARMv8.5 extensions) allows us to ensure
2006 that EL0 accesses made via TTBR1 always fault in constant time,
2007 providing similar benefits to KASLR as those provided by KPTI, but
2008 with lower overhead and without disrupting legitimate access to
2009 kernel memory such as SPE.
2010
2011 This option enables E0PD for TTBR1 where available.
2012
2013config ARM64_AS_HAS_MTE
2014 # Initial support for MTE went in binutils 2.32.0, checked with
2015 # ".arch armv8.5-a+memtag" below. However, this was incomplete
2016 # as a late addition to the final architecture spec (LDGM/STGM)
2017 # is only supported in the newer 2.32.x and 2.33 binutils
2018 # versions, hence the extra "stgm" instruction check below.
2019 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2020
2021config ARM64_MTE
2022 bool "Memory Tagging Extension support"
2023 default y
2024 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2025 depends on AS_HAS_ARMV8_5
2026 depends on AS_HAS_LSE_ATOMICS
2027 # Required for tag checking in the uaccess routines
2028 depends on ARM64_PAN
2029 select ARCH_HAS_SUBPAGE_FAULTS
2030 select ARCH_USES_HIGH_VMA_FLAGS
2031 select ARCH_USES_PG_ARCH_X
2032 help
2033 Memory Tagging (part of the ARMv8.5 Extensions) provides
2034 architectural support for run-time, always-on detection of
2035 various classes of memory error to aid with software debugging
2036 to eliminate vulnerabilities arising from memory-unsafe
2037 languages.
2038
2039 This option enables the support for the Memory Tagging
2040 Extension at EL0 (i.e. for userspace).
2041
2042 Selecting this option allows the feature to be detected at
2043 runtime. Any secondary CPU not implementing this feature will
2044 not be allowed a late bring-up.
2045
2046 Userspace binaries that want to use this feature must
2047 explicitly opt in. The mechanism for the userspace is
2048 described in:
2049
2050 Documentation/arm64/memory-tagging-extension.rst.
2051
2052endmenu # "ARMv8.5 architectural features"
2053
2054menu "ARMv8.7 architectural features"
2055
2056config ARM64_EPAN
2057 bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2058 default y
2059 depends on ARM64_PAN
2060 help
2061 Enhanced Privileged Access Never (EPAN) allows Privileged
2062 Access Never to be used with Execute-only mappings.
2063
2064 The feature is detected at runtime, and will remain disabled
2065 if the cpu does not implement the feature.
2066endmenu # "ARMv8.7 architectural features"
2067
2068config ARM64_SVE
2069 bool "ARM Scalable Vector Extension support"
2070 default y
2071 help
2072 The Scalable Vector Extension (SVE) is an extension to the AArch64
2073 execution state which complements and extends the SIMD functionality
2074 of the base architecture to support much larger vectors and to enable
2075 additional vectorisation opportunities.
2076
2077 To enable use of this extension on CPUs that implement it, say Y.
2078
2079 On CPUs that support the SVE2 extensions, this option will enable
2080 those too.
2081
2082 Note that for architectural reasons, firmware _must_ implement SVE
2083 support when running on SVE capable hardware. The required support
2084 is present in:
2085
2086 * version 1.5 and later of the ARM Trusted Firmware
2087 * the AArch64 boot wrapper since commit 5e1261e08abf
2088 ("bootwrapper: SVE: Enable SVE for EL2 and below").
2089
2090 For other firmware implementations, consult the firmware documentation
2091 or vendor.
2092
2093 If you need the kernel to boot on SVE-capable hardware with broken
2094 firmware, you may need to say N here until you get your firmware
2095 fixed. Otherwise, you may experience firmware panics or lockups when
2096 booting the kernel. If unsure and you are not observing these
2097 symptoms, you should assume that it is safe to say Y.
2098
2099config ARM64_SME
2100 bool "ARM Scalable Matrix Extension support"
2101 default y
2102 depends on ARM64_SVE
2103 help
2104 The Scalable Matrix Extension (SME) is an extension to the AArch64
2105 execution state which utilises a substantial subset of the SVE
2106 instruction set, together with the addition of new architectural
2107 register state capable of holding two dimensional matrix tiles to
2108 enable various matrix operations.
2109
2110config ARM64_MODULE_PLTS
2111 bool "Use PLTs to allow module memory to spill over into vmalloc area"
2112 depends on MODULES
2113 select HAVE_MOD_ARCH_SPECIFIC
2114 help
2115 Allocate PLTs when loading modules so that jumps and calls whose
2116 targets are too far away for their relative offsets to be encoded
2117 in the instructions themselves can be bounced via veneers in the
2118 module's PLT. This allows modules to be allocated in the generic
2119 vmalloc area after the dedicated module memory area has been
2120 exhausted.
2121
2122 When running with address space randomization (KASLR), the module
2123 region itself may be too far away for ordinary relative jumps and
2124 calls, and so in that case, module PLTs are required and cannot be
2125 disabled.
2126
2127 Specific errata workaround(s) might also force module PLTs to be
2128 enabled (ARM64_ERRATUM_843419).
2129
2130config ARM64_PSEUDO_NMI
2131 bool "Support for NMI-like interrupts"
2132 select ARM_GIC_V3
2133 help
2134 Adds support for mimicking Non-Maskable Interrupts through the use of
2135 GIC interrupt priority. This support requires version 3 or later of
2136 ARM GIC.
2137
2138 This high priority configuration for interrupts needs to be
2139 explicitly enabled by setting the kernel parameter
2140 "irqchip.gicv3_pseudo_nmi" to 1.
2141
2142 If unsure, say N
2143
2144if ARM64_PSEUDO_NMI
2145config ARM64_DEBUG_PRIORITY_MASKING
2146 bool "Debug interrupt priority masking"
2147 help
2148 This adds runtime checks to functions enabling/disabling
2149 interrupts when using priority masking. The additional checks verify
2150 the validity of ICC_PMR_EL1 when calling concerned functions.
2151
2152 If unsure, say N
2153endif # ARM64_PSEUDO_NMI
2154
2155config RELOCATABLE
2156 bool "Build a relocatable kernel image" if EXPERT
2157 select ARCH_HAS_RELR
2158 default y
2159 help
2160 This builds the kernel as a Position Independent Executable (PIE),
2161 which retains all relocation metadata required to relocate the
2162 kernel binary at runtime to a different virtual address than the
2163 address it was linked at.
2164 Since AArch64 uses the RELA relocation format, this requires a
2165 relocation pass at runtime even if the kernel is loaded at the
2166 same address it was linked at.
2167
2168config RANDOMIZE_BASE
2169 bool "Randomize the address of the kernel image"
2170 select ARM64_MODULE_PLTS if MODULES
2171 select RELOCATABLE
2172 help
2173 Randomizes the virtual address at which the kernel image is
2174 loaded, as a security feature that deters exploit attempts
2175 relying on knowledge of the location of kernel internals.
2176
2177 It is the bootloader's job to provide entropy, by passing a
2178 random u64 value in /chosen/kaslr-seed at kernel entry.
2179
2180 When booting via the UEFI stub, it will invoke the firmware's
2181 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2182 to the kernel proper. In addition, it will randomise the physical
2183 location of the kernel Image as well.
2184
2185 If unsure, say N.
2186
2187config RANDOMIZE_MODULE_REGION_FULL
2188 bool "Randomize the module region over a 2 GB range"
2189 depends on RANDOMIZE_BASE
2190 default y
2191 help
2192 Randomizes the location of the module region inside a 2 GB window
2193 covering the core kernel. This way, it is less likely for modules
2194 to leak information about the location of core kernel data structures
2195 but it does imply that function calls between modules and the core
2196 kernel will need to be resolved via veneers in the module PLT.
2197
2198 When this option is not set, the module region will be randomized over
2199 a limited range that contains the [_stext, _etext] interval of the
2200 core kernel, so branch relocations are almost always in range unless
2201 ARM64_MODULE_PLTS is enabled and the region is exhausted. In this
2202 particular case of region exhaustion, modules might be able to fall
2203 back to a larger 2GB area.
2204
2205config CC_HAVE_STACKPROTECTOR_SYSREG
2206 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2207
2208config STACKPROTECTOR_PER_TASK
2209 def_bool y
2210 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2211
2212config UNWIND_PATCH_PAC_INTO_SCS
2213 bool "Enable shadow call stack dynamically using code patching"
2214 # needs Clang with https://reviews.llvm.org/D111780 incorporated
2215 depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2216 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2217 depends on SHADOW_CALL_STACK
2218 select UNWIND_TABLES
2219 select DYNAMIC_SCS
2220
2221endmenu # "Kernel Features"
2222
2223menu "Boot options"
2224
2225config ARM64_ACPI_PARKING_PROTOCOL
2226 bool "Enable support for the ARM64 ACPI parking protocol"
2227 depends on ACPI
2228 help
2229 Enable support for the ARM64 ACPI parking protocol. If disabled
2230 the kernel will not allow booting through the ARM64 ACPI parking
2231 protocol even if the corresponding data is present in the ACPI
2232 MADT table.
2233
2234config CMDLINE
2235 string "Default kernel command string"
2236 default ""
2237 help
2238 Provide a set of default command-line options at build time by
2239 entering them here. As a minimum, you should specify the the
2240 root device (e.g. root=/dev/nfs).
2241
2242choice
2243 prompt "Kernel command line type" if CMDLINE != ""
2244 default CMDLINE_FROM_BOOTLOADER
2245 help
2246 Choose how the kernel will handle the provided default kernel
2247 command line string.
2248
2249config CMDLINE_FROM_BOOTLOADER
2250 bool "Use bootloader kernel arguments if available"
2251 help
2252 Uses the command-line options passed by the boot loader. If
2253 the boot loader doesn't provide any, the default kernel command
2254 string provided in CMDLINE will be used.
2255
2256config CMDLINE_FORCE
2257 bool "Always use the default kernel command string"
2258 help
2259 Always use the default kernel command string, even if the boot
2260 loader passes other arguments to the kernel.
2261 This is useful if you cannot or don't want to change the
2262 command-line options your boot loader passes to the kernel.
2263
2264endchoice
2265
2266config EFI_STUB
2267 bool
2268
2269config EFI
2270 bool "UEFI runtime support"
2271 depends on OF && !CPU_BIG_ENDIAN
2272 depends on KERNEL_MODE_NEON
2273 select ARCH_SUPPORTS_ACPI
2274 select LIBFDT
2275 select UCS2_STRING
2276 select EFI_PARAMS_FROM_FDT
2277 select EFI_RUNTIME_WRAPPERS
2278 select EFI_STUB
2279 select EFI_GENERIC_STUB
2280 imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2281 default y
2282 help
2283 This option provides support for runtime services provided
2284 by UEFI firmware (such as non-volatile variables, realtime
2285 clock, and platform reset). A UEFI stub is also provided to
2286 allow the kernel to be booted as an EFI application. This
2287 is only useful on systems that have UEFI firmware.
2288
2289config DMI
2290 bool "Enable support for SMBIOS (DMI) tables"
2291 depends on EFI
2292 default y
2293 help
2294 This enables SMBIOS/DMI feature for systems.
2295
2296 This option is only useful on systems that have UEFI firmware.
2297 However, even with this option, the resultant kernel should
2298 continue to boot on existing non-UEFI platforms.
2299
2300endmenu # "Boot options"
2301
2302menu "Power management options"
2303
2304source "kernel/power/Kconfig"
2305
2306config ARCH_HIBERNATION_POSSIBLE
2307 def_bool y
2308 depends on CPU_PM
2309
2310config ARCH_HIBERNATION_HEADER
2311 def_bool y
2312 depends on HIBERNATION
2313
2314config ARCH_SUSPEND_POSSIBLE
2315 def_bool y
2316
2317endmenu # "Power management options"
2318
2319menu "CPU Power Management"
2320
2321source "drivers/cpuidle/Kconfig"
2322
2323source "drivers/cpufreq/Kconfig"
2324
2325endmenu # "CPU Power Management"
2326
2327source "drivers/acpi/Kconfig"
2328
2329source "arch/arm64/kvm/Kconfig"
2330