]> git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - arch/arm64/Kconfig
Merge tag 'pinctrl-v5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...
[mirror_ubuntu-jammy-kernel.git] / arch / arm64 / Kconfig
1 # SPDX-License-Identifier: GPL-2.0-only
2 config ARM64
3 def_bool y
4 select ACPI_CCA_REQUIRED if ACPI
5 select ACPI_GENERIC_GSI if ACPI
6 select ACPI_GTDT if ACPI
7 select ACPI_IORT if ACPI
8 select ACPI_REDUCED_HARDWARE_ONLY if ACPI
9 select ACPI_MCFG if (ACPI && PCI)
10 select ACPI_SPCR_TABLE if ACPI
11 select ACPI_PPTT if ACPI
12 select ARCH_HAS_DEBUG_WX
13 select ARCH_BINFMT_ELF_STATE
14 select ARCH_HAS_DEBUG_VIRTUAL
15 select ARCH_HAS_DEBUG_VM_PGTABLE
16 select ARCH_HAS_DMA_PREP_COHERENT
17 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
18 select ARCH_HAS_FAST_MULTIPLIER
19 select ARCH_HAS_FORTIFY_SOURCE
20 select ARCH_HAS_GCOV_PROFILE_ALL
21 select ARCH_HAS_GIGANTIC_PAGE
22 select ARCH_HAS_KCOV
23 select ARCH_HAS_KEEPINITRD
24 select ARCH_HAS_MEMBARRIER_SYNC_CORE
25 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
26 select ARCH_HAS_PTE_DEVMAP
27 select ARCH_HAS_PTE_SPECIAL
28 select ARCH_HAS_SETUP_DMA_OPS
29 select ARCH_HAS_SET_DIRECT_MAP
30 select ARCH_HAS_SET_MEMORY
31 select ARCH_STACKWALK
32 select ARCH_HAS_STRICT_KERNEL_RWX
33 select ARCH_HAS_STRICT_MODULE_RWX
34 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
35 select ARCH_HAS_SYNC_DMA_FOR_CPU
36 select ARCH_HAS_SYSCALL_WRAPPER
37 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
38 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
39 select ARCH_HAVE_ELF_PROT
40 select ARCH_HAVE_NMI_SAFE_CMPXCHG
41 select ARCH_INLINE_READ_LOCK if !PREEMPTION
42 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
43 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
44 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
45 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
46 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
47 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
48 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
49 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
50 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
51 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
52 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
53 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
54 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
55 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
56 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
57 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
58 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
59 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
60 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
61 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
62 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
63 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
64 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
65 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
66 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
67 select ARCH_KEEP_MEMBLOCK
68 select ARCH_USE_CMPXCHG_LOCKREF
69 select ARCH_USE_GNU_PROPERTY
70 select ARCH_USE_QUEUED_RWLOCKS
71 select ARCH_USE_QUEUED_SPINLOCKS
72 select ARCH_USE_SYM_ANNOTATIONS
73 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
74 select ARCH_SUPPORTS_MEMORY_FAILURE
75 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
76 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
77 select ARCH_SUPPORTS_LTO_CLANG_THIN
78 select ARCH_SUPPORTS_CFI_CLANG
79 select ARCH_SUPPORTS_ATOMIC_RMW
80 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG)
81 select ARCH_SUPPORTS_NUMA_BALANCING
82 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
83 select ARCH_WANT_DEFAULT_BPF_JIT
84 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
85 select ARCH_WANT_FRAME_POINTERS
86 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
87 select ARCH_WANT_LD_ORPHAN_WARN
88 select ARCH_HAS_UBSAN_SANITIZE_ALL
89 select ARM_AMBA
90 select ARM_ARCH_TIMER
91 select ARM_GIC
92 select AUDIT_ARCH_COMPAT_GENERIC
93 select ARM_GIC_V2M if PCI
94 select ARM_GIC_V3
95 select ARM_GIC_V3_ITS if PCI
96 select ARM_PSCI_FW
97 select BUILDTIME_TABLE_SORT
98 select CLONE_BACKWARDS
99 select COMMON_CLK
100 select CPU_PM if (SUSPEND || CPU_IDLE)
101 select CRC32
102 select DCACHE_WORD_ACCESS
103 select DMA_DIRECT_REMAP
104 select EDAC_SUPPORT
105 select FRAME_POINTER
106 select GENERIC_ALLOCATOR
107 select GENERIC_ARCH_TOPOLOGY
108 select GENERIC_CLOCKEVENTS_BROADCAST
109 select GENERIC_CPU_AUTOPROBE
110 select GENERIC_CPU_VULNERABILITIES
111 select GENERIC_EARLY_IOREMAP
112 select GENERIC_FIND_FIRST_BIT
113 select GENERIC_IDLE_POLL_SETUP
114 select GENERIC_IRQ_IPI
115 select GENERIC_IRQ_PROBE
116 select GENERIC_IRQ_SHOW
117 select GENERIC_IRQ_SHOW_LEVEL
118 select GENERIC_LIB_DEVMEM_IS_ALLOWED
119 select GENERIC_PCI_IOMAP
120 select GENERIC_PTDUMP
121 select GENERIC_SCHED_CLOCK
122 select GENERIC_SMP_IDLE_THREAD
123 select GENERIC_STRNCPY_FROM_USER
124 select GENERIC_STRNLEN_USER
125 select GENERIC_TIME_VSYSCALL
126 select GENERIC_GETTIMEOFDAY
127 select GENERIC_VDSO_TIME_NS
128 select HANDLE_DOMAIN_IRQ
129 select HARDIRQS_SW_RESEND
130 select HAVE_MOVE_PMD
131 select HAVE_MOVE_PUD
132 select HAVE_PCI
133 select HAVE_ACPI_APEI if (ACPI && EFI)
134 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
135 select HAVE_ARCH_AUDITSYSCALL
136 select HAVE_ARCH_BITREVERSE
137 select HAVE_ARCH_COMPILER_H
138 select HAVE_ARCH_HUGE_VMAP
139 select HAVE_ARCH_JUMP_LABEL
140 select HAVE_ARCH_JUMP_LABEL_RELATIVE
141 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
142 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
143 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN
144 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE)
145 select HAVE_ARCH_KFENCE
146 select HAVE_ARCH_KGDB
147 select HAVE_ARCH_MMAP_RND_BITS
148 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
149 select HAVE_ARCH_PFN_VALID
150 select HAVE_ARCH_PREL32_RELOCATIONS
151 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
152 select HAVE_ARCH_SECCOMP_FILTER
153 select HAVE_ARCH_STACKLEAK
154 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
155 select HAVE_ARCH_TRACEHOOK
156 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
157 select HAVE_ARCH_VMAP_STACK
158 select HAVE_ARM_SMCCC
159 select HAVE_ASM_MODVERSIONS
160 select HAVE_EBPF_JIT
161 select HAVE_C_RECORDMCOUNT
162 select HAVE_CMPXCHG_DOUBLE
163 select HAVE_CMPXCHG_LOCAL
164 select HAVE_CONTEXT_TRACKING
165 select HAVE_DEBUG_BUGVERBOSE
166 select HAVE_DEBUG_KMEMLEAK
167 select HAVE_DMA_CONTIGUOUS
168 select HAVE_DYNAMIC_FTRACE
169 select HAVE_DYNAMIC_FTRACE_WITH_REGS \
170 if $(cc-option,-fpatchable-function-entry=2)
171 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
172 if DYNAMIC_FTRACE_WITH_REGS
173 select HAVE_EFFICIENT_UNALIGNED_ACCESS
174 select HAVE_FAST_GUP
175 select HAVE_FTRACE_MCOUNT_RECORD
176 select HAVE_FUNCTION_TRACER
177 select HAVE_FUNCTION_ERROR_INJECTION
178 select HAVE_FUNCTION_GRAPH_TRACER
179 select HAVE_GCC_PLUGINS
180 select HAVE_HW_BREAKPOINT if PERF_EVENTS
181 select HAVE_IRQ_TIME_ACCOUNTING
182 select HAVE_NMI
183 select HAVE_PATA_PLATFORM
184 select HAVE_PERF_EVENTS
185 select HAVE_PERF_REGS
186 select HAVE_PERF_USER_STACK_DUMP
187 select HAVE_REGS_AND_STACK_ACCESS_API
188 select HAVE_FUNCTION_ARG_ACCESS_API
189 select HAVE_FUTEX_CMPXCHG if FUTEX
190 select MMU_GATHER_RCU_TABLE_FREE
191 select HAVE_RSEQ
192 select HAVE_STACKPROTECTOR
193 select HAVE_SYSCALL_TRACEPOINTS
194 select HAVE_KPROBES
195 select HAVE_KRETPROBES
196 select HAVE_GENERIC_VDSO
197 select IOMMU_DMA if IOMMU_SUPPORT
198 select IRQ_DOMAIN
199 select IRQ_FORCED_THREADING
200 select KASAN_VMALLOC if KASAN_GENERIC
201 select MODULES_USE_ELF_RELA
202 select NEED_DMA_MAP_STATE
203 select NEED_SG_DMA_LENGTH
204 select OF
205 select OF_EARLY_FLATTREE
206 select PCI_DOMAINS_GENERIC if PCI
207 select PCI_ECAM if (ACPI && PCI)
208 select PCI_SYSCALL if PCI
209 select POWER_RESET
210 select POWER_SUPPLY
211 select SPARSE_IRQ
212 select SWIOTLB
213 select SYSCTL_EXCEPTION_TRACE
214 select THREAD_INFO_IN_TASK
215 help
216 ARM 64-bit (AArch64) Linux support.
217
218 config 64BIT
219 def_bool y
220
221 config MMU
222 def_bool y
223
224 config ARM64_PAGE_SHIFT
225 int
226 default 16 if ARM64_64K_PAGES
227 default 14 if ARM64_16K_PAGES
228 default 12
229
230 config ARM64_CONT_PTE_SHIFT
231 int
232 default 5 if ARM64_64K_PAGES
233 default 7 if ARM64_16K_PAGES
234 default 4
235
236 config ARM64_CONT_PMD_SHIFT
237 int
238 default 5 if ARM64_64K_PAGES
239 default 5 if ARM64_16K_PAGES
240 default 4
241
242 config ARCH_MMAP_RND_BITS_MIN
243 default 14 if ARM64_64K_PAGES
244 default 16 if ARM64_16K_PAGES
245 default 18
246
247 # max bits determined by the following formula:
248 # VA_BITS - PAGE_SHIFT - 3
249 config ARCH_MMAP_RND_BITS_MAX
250 default 19 if ARM64_VA_BITS=36
251 default 24 if ARM64_VA_BITS=39
252 default 27 if ARM64_VA_BITS=42
253 default 30 if ARM64_VA_BITS=47
254 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
255 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
256 default 33 if ARM64_VA_BITS=48
257 default 14 if ARM64_64K_PAGES
258 default 16 if ARM64_16K_PAGES
259 default 18
260
261 config ARCH_MMAP_RND_COMPAT_BITS_MIN
262 default 7 if ARM64_64K_PAGES
263 default 9 if ARM64_16K_PAGES
264 default 11
265
266 config ARCH_MMAP_RND_COMPAT_BITS_MAX
267 default 16
268
269 config NO_IOPORT_MAP
270 def_bool y if !PCI
271
272 config STACKTRACE_SUPPORT
273 def_bool y
274
275 config ILLEGAL_POINTER_VALUE
276 hex
277 default 0xdead000000000000
278
279 config LOCKDEP_SUPPORT
280 def_bool y
281
282 config TRACE_IRQFLAGS_SUPPORT
283 def_bool y
284
285 config GENERIC_BUG
286 def_bool y
287 depends on BUG
288
289 config GENERIC_BUG_RELATIVE_POINTERS
290 def_bool y
291 depends on GENERIC_BUG
292
293 config GENERIC_HWEIGHT
294 def_bool y
295
296 config GENERIC_CSUM
297 def_bool y
298
299 config GENERIC_CALIBRATE_DELAY
300 def_bool y
301
302 config ZONE_DMA
303 bool "Support DMA zone" if EXPERT
304 default y
305
306 config ZONE_DMA32
307 bool "Support DMA32 zone" if EXPERT
308 default y
309
310 config ARCH_ENABLE_MEMORY_HOTPLUG
311 def_bool y
312
313 config ARCH_ENABLE_MEMORY_HOTREMOVE
314 def_bool y
315
316 config SMP
317 def_bool y
318
319 config KERNEL_MODE_NEON
320 def_bool y
321
322 config FIX_EARLYCON_MEM
323 def_bool y
324
325 config PGTABLE_LEVELS
326 int
327 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
328 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
329 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
330 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
331 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
332 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
333
334 config ARCH_SUPPORTS_UPROBES
335 def_bool y
336
337 config ARCH_PROC_KCORE_TEXT
338 def_bool y
339
340 config BROKEN_GAS_INST
341 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
342
343 config KASAN_SHADOW_OFFSET
344 hex
345 depends on KASAN_GENERIC || KASAN_SW_TAGS
346 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
347 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
348 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
349 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
350 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
351 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS
352 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS
353 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
354 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
355 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
356 default 0xffffffffffffffff
357
358 source "arch/arm64/Kconfig.platforms"
359
360 menu "Kernel Features"
361
362 menu "ARM errata workarounds via the alternatives framework"
363
364 config ARM64_WORKAROUND_CLEAN_CACHE
365 bool
366
367 config ARM64_ERRATUM_826319
368 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
369 default y
370 select ARM64_WORKAROUND_CLEAN_CACHE
371 help
372 This option adds an alternative code sequence to work around ARM
373 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
374 AXI master interface and an L2 cache.
375
376 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
377 and is unable to accept a certain write via this interface, it will
378 not progress on read data presented on the read data channel and the
379 system can deadlock.
380
381 The workaround promotes data cache clean instructions to
382 data cache clean-and-invalidate.
383 Please note that this does not necessarily enable the workaround,
384 as it depends on the alternative framework, which will only patch
385 the kernel if an affected CPU is detected.
386
387 If unsure, say Y.
388
389 config ARM64_ERRATUM_827319
390 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
391 default y
392 select ARM64_WORKAROUND_CLEAN_CACHE
393 help
394 This option adds an alternative code sequence to work around ARM
395 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
396 master interface and an L2 cache.
397
398 Under certain conditions this erratum can cause a clean line eviction
399 to occur at the same time as another transaction to the same address
400 on the AMBA 5 CHI interface, which can cause data corruption if the
401 interconnect reorders the two transactions.
402
403 The workaround promotes data cache clean instructions to
404 data cache clean-and-invalidate.
405 Please note that this does not necessarily enable the workaround,
406 as it depends on the alternative framework, which will only patch
407 the kernel if an affected CPU is detected.
408
409 If unsure, say Y.
410
411 config ARM64_ERRATUM_824069
412 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
413 default y
414 select ARM64_WORKAROUND_CLEAN_CACHE
415 help
416 This option adds an alternative code sequence to work around ARM
417 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
418 to a coherent interconnect.
419
420 If a Cortex-A53 processor is executing a store or prefetch for
421 write instruction at the same time as a processor in another
422 cluster is executing a cache maintenance operation to the same
423 address, then this erratum might cause a clean cache line to be
424 incorrectly marked as dirty.
425
426 The workaround promotes data cache clean instructions to
427 data cache clean-and-invalidate.
428 Please note that this option does not necessarily enable the
429 workaround, as it depends on the alternative framework, which will
430 only patch the kernel if an affected CPU is detected.
431
432 If unsure, say Y.
433
434 config ARM64_ERRATUM_819472
435 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
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 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
441 present when it is connected to a coherent interconnect.
442
443 If the processor is executing a load and store exclusive sequence at
444 the same time as a processor in another cluster is executing a cache
445 maintenance operation to the same address, then this erratum might
446 cause data corruption.
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
456 config ARM64_ERRATUM_832075
457 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
458 default y
459 help
460 This option adds an alternative code sequence to work around ARM
461 erratum 832075 on Cortex-A57 parts up to r1p2.
462
463 Affected Cortex-A57 parts might deadlock when exclusive load/store
464 instructions to Write-Back memory are mixed with Device loads.
465
466 The workaround is to promote device loads to use Load-Acquire
467 semantics.
468 Please note that this does not necessarily enable the workaround,
469 as it depends on the alternative framework, which will only patch
470 the kernel if an affected CPU is detected.
471
472 If unsure, say Y.
473
474 config ARM64_ERRATUM_834220
475 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
476 depends on KVM
477 default y
478 help
479 This option adds an alternative code sequence to work around ARM
480 erratum 834220 on Cortex-A57 parts up to r1p2.
481
482 Affected Cortex-A57 parts might report a Stage 2 translation
483 fault as the result of a Stage 1 fault for load crossing a
484 page boundary when there is a permission or device memory
485 alignment fault at Stage 1 and a translation fault at Stage 2.
486
487 The workaround is to verify that the Stage 1 translation
488 doesn't generate a fault before handling the Stage 2 fault.
489 Please note that this does not necessarily enable the workaround,
490 as it depends on the alternative framework, which will only patch
491 the kernel if an affected CPU is detected.
492
493 If unsure, say Y.
494
495 config ARM64_ERRATUM_845719
496 bool "Cortex-A53: 845719: a load might read incorrect data"
497 depends on COMPAT
498 default y
499 help
500 This option adds an alternative code sequence to work around ARM
501 erratum 845719 on Cortex-A53 parts up to r0p4.
502
503 When running a compat (AArch32) userspace on an affected Cortex-A53
504 part, a load at EL0 from a virtual address that matches the bottom 32
505 bits of the virtual address used by a recent load at (AArch64) EL1
506 might return incorrect data.
507
508 The workaround is to write the contextidr_el1 register on exception
509 return to a 32-bit task.
510 Please note that this does not necessarily enable the workaround,
511 as it depends on the alternative framework, which will only patch
512 the kernel if an affected CPU is detected.
513
514 If unsure, say Y.
515
516 config ARM64_ERRATUM_843419
517 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
518 default y
519 select ARM64_MODULE_PLTS if MODULES
520 help
521 This option links the kernel with '--fix-cortex-a53-843419' and
522 enables PLT support to replace certain ADRP instructions, which can
523 cause subsequent memory accesses to use an incorrect address on
524 Cortex-A53 parts up to r0p4.
525
526 If unsure, say Y.
527
528 config ARM64_LD_HAS_FIX_ERRATUM_843419
529 def_bool $(ld-option,--fix-cortex-a53-843419)
530
531 config ARM64_ERRATUM_1024718
532 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
533 default y
534 help
535 This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
536
537 Affected Cortex-A55 cores (all revisions) could cause incorrect
538 update of the hardware dirty bit when the DBM/AP bits are updated
539 without a break-before-make. The workaround is to disable the usage
540 of hardware DBM locally on the affected cores. CPUs not affected by
541 this erratum will continue to use the feature.
542
543 If unsure, say Y.
544
545 config ARM64_ERRATUM_1418040
546 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
547 default y
548 depends on COMPAT
549 help
550 This option adds a workaround for ARM Cortex-A76/Neoverse-N1
551 errata 1188873 and 1418040.
552
553 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
554 cause register corruption when accessing the timer registers
555 from AArch32 userspace.
556
557 If unsure, say Y.
558
559 config ARM64_WORKAROUND_SPECULATIVE_AT
560 bool
561
562 config ARM64_ERRATUM_1165522
563 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
564 default y
565 select ARM64_WORKAROUND_SPECULATIVE_AT
566 help
567 This option adds a workaround for ARM Cortex-A76 erratum 1165522.
568
569 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
570 corrupted TLBs by speculating an AT instruction during a guest
571 context switch.
572
573 If unsure, say Y.
574
575 config ARM64_ERRATUM_1319367
576 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
577 default y
578 select ARM64_WORKAROUND_SPECULATIVE_AT
579 help
580 This option adds work arounds for ARM Cortex-A57 erratum 1319537
581 and A72 erratum 1319367
582
583 Cortex-A57 and A72 cores could end-up with corrupted TLBs by
584 speculating an AT instruction during a guest context switch.
585
586 If unsure, say Y.
587
588 config ARM64_ERRATUM_1530923
589 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
590 default y
591 select ARM64_WORKAROUND_SPECULATIVE_AT
592 help
593 This option adds a workaround for ARM Cortex-A55 erratum 1530923.
594
595 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
596 corrupted TLBs by speculating an AT instruction during a guest
597 context switch.
598
599 If unsure, say Y.
600
601 config ARM64_WORKAROUND_REPEAT_TLBI
602 bool
603
604 config ARM64_ERRATUM_1286807
605 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
606 default y
607 select ARM64_WORKAROUND_REPEAT_TLBI
608 help
609 This option adds a workaround for ARM Cortex-A76 erratum 1286807.
610
611 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
612 address for a cacheable mapping of a location is being
613 accessed by a core while another core is remapping the virtual
614 address to a new physical page using the recommended
615 break-before-make sequence, then under very rare circumstances
616 TLBI+DSB completes before a read using the translation being
617 invalidated has been observed by other observers. The
618 workaround repeats the TLBI+DSB operation.
619
620 config ARM64_ERRATUM_1463225
621 bool "Cortex-A76: Software Step might prevent interrupt recognition"
622 default y
623 help
624 This option adds a workaround for Arm Cortex-A76 erratum 1463225.
625
626 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
627 of a system call instruction (SVC) can prevent recognition of
628 subsequent interrupts when software stepping is disabled in the
629 exception handler of the system call and either kernel debugging
630 is enabled or VHE is in use.
631
632 Work around the erratum by triggering a dummy step exception
633 when handling a system call from a task that is being stepped
634 in a VHE configuration of the kernel.
635
636 If unsure, say Y.
637
638 config ARM64_ERRATUM_1542419
639 bool "Neoverse-N1: workaround mis-ordering of instruction fetches"
640 default y
641 help
642 This option adds a workaround for ARM Neoverse-N1 erratum
643 1542419.
644
645 Affected Neoverse-N1 cores could execute a stale instruction when
646 modified by another CPU. The workaround depends on a firmware
647 counterpart.
648
649 Workaround the issue by hiding the DIC feature from EL0. This
650 forces user-space to perform cache maintenance.
651
652 If unsure, say Y.
653
654 config ARM64_ERRATUM_1508412
655 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
656 default y
657 help
658 This option adds a workaround for Arm Cortex-A77 erratum 1508412.
659
660 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
661 of a store-exclusive or read of PAR_EL1 and a load with device or
662 non-cacheable memory attributes. The workaround depends on a firmware
663 counterpart.
664
665 KVM guests must also have the workaround implemented or they can
666 deadlock the system.
667
668 Work around the issue by inserting DMB SY barriers around PAR_EL1
669 register reads and warning KVM users. The DMB barrier is sufficient
670 to prevent a speculative PAR_EL1 read.
671
672 If unsure, say Y.
673
674 config CAVIUM_ERRATUM_22375
675 bool "Cavium erratum 22375, 24313"
676 default y
677 help
678 Enable workaround for errata 22375 and 24313.
679
680 This implements two gicv3-its errata workarounds for ThunderX. Both
681 with a small impact affecting only ITS table allocation.
682
683 erratum 22375: only alloc 8MB table size
684 erratum 24313: ignore memory access type
685
686 The fixes are in ITS initialization and basically ignore memory access
687 type and table size provided by the TYPER and BASER registers.
688
689 If unsure, say Y.
690
691 config CAVIUM_ERRATUM_23144
692 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
693 depends on NUMA
694 default y
695 help
696 ITS SYNC command hang for cross node io and collections/cpu mapping.
697
698 If unsure, say Y.
699
700 config CAVIUM_ERRATUM_23154
701 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
702 default y
703 help
704 The gicv3 of ThunderX requires a modified version for
705 reading the IAR status to ensure data synchronization
706 (access to icc_iar1_el1 is not sync'ed before and after).
707
708 If unsure, say Y.
709
710 config CAVIUM_ERRATUM_27456
711 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
712 default y
713 help
714 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
715 instructions may cause the icache to become corrupted if it
716 contains data for a non-current ASID. The fix is to
717 invalidate the icache when changing the mm context.
718
719 If unsure, say Y.
720
721 config CAVIUM_ERRATUM_30115
722 bool "Cavium erratum 30115: Guest may disable interrupts in host"
723 default y
724 help
725 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
726 1.2, and T83 Pass 1.0, KVM guest execution may disable
727 interrupts in host. Trapping both GICv3 group-0 and group-1
728 accesses sidesteps the issue.
729
730 If unsure, say Y.
731
732 config CAVIUM_TX2_ERRATUM_219
733 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
734 default y
735 help
736 On Cavium ThunderX2, a load, store or prefetch instruction between a
737 TTBR update and the corresponding context synchronizing operation can
738 cause a spurious Data Abort to be delivered to any hardware thread in
739 the CPU core.
740
741 Work around the issue by avoiding the problematic code sequence and
742 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
743 trap handler performs the corresponding register access, skips the
744 instruction and ensures context synchronization by virtue of the
745 exception return.
746
747 If unsure, say Y.
748
749 config FUJITSU_ERRATUM_010001
750 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
751 default y
752 help
753 This option adds a workaround for Fujitsu-A64FX erratum E#010001.
754 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
755 accesses may cause undefined fault (Data abort, DFSC=0b111111).
756 This fault occurs under a specific hardware condition when a
757 load/store instruction performs an address translation using:
758 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1.
759 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1.
760 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1.
761 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1.
762
763 The workaround is to ensure these bits are clear in TCR_ELx.
764 The workaround only affects the Fujitsu-A64FX.
765
766 If unsure, say Y.
767
768 config HISILICON_ERRATUM_161600802
769 bool "Hip07 161600802: Erroneous redistributor VLPI base"
770 default y
771 help
772 The HiSilicon Hip07 SoC uses the wrong redistributor base
773 when issued ITS commands such as VMOVP and VMAPP, and requires
774 a 128kB offset to be applied to the target address in this commands.
775
776 If unsure, say Y.
777
778 config QCOM_FALKOR_ERRATUM_1003
779 bool "Falkor E1003: Incorrect translation due to ASID change"
780 default y
781 help
782 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
783 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
784 in TTBR1_EL1, this situation only occurs in the entry trampoline and
785 then only for entries in the walk cache, since the leaf translation
786 is unchanged. Work around the erratum by invalidating the walk cache
787 entries for the trampoline before entering the kernel proper.
788
789 config QCOM_FALKOR_ERRATUM_1009
790 bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
791 default y
792 select ARM64_WORKAROUND_REPEAT_TLBI
793 help
794 On Falkor v1, the CPU may prematurely complete a DSB following a
795 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
796 one more time to fix the issue.
797
798 If unsure, say Y.
799
800 config QCOM_QDF2400_ERRATUM_0065
801 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
802 default y
803 help
804 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
805 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
806 been indicated as 16Bytes (0xf), not 8Bytes (0x7).
807
808 If unsure, say Y.
809
810 config QCOM_FALKOR_ERRATUM_E1041
811 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
812 default y
813 help
814 Falkor CPU may speculatively fetch instructions from an improper
815 memory location when MMU translation is changed from SCTLR_ELn[M]=1
816 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
817
818 If unsure, say Y.
819
820 config NVIDIA_CARMEL_CNP_ERRATUM
821 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
822 default y
823 help
824 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
825 invalidate shared TLB entries installed by a different core, as it would
826 on standard ARM cores.
827
828 If unsure, say Y.
829
830 config SOCIONEXT_SYNQUACER_PREITS
831 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
832 default y
833 help
834 Socionext Synquacer SoCs implement a separate h/w block to generate
835 MSI doorbell writes with non-zero values for the device ID.
836
837 If unsure, say Y.
838
839 endmenu
840
841
842 choice
843 prompt "Page size"
844 default ARM64_4K_PAGES
845 help
846 Page size (translation granule) configuration.
847
848 config ARM64_4K_PAGES
849 bool "4KB"
850 help
851 This feature enables 4KB pages support.
852
853 config ARM64_16K_PAGES
854 bool "16KB"
855 help
856 The system will use 16KB pages support. AArch32 emulation
857 requires applications compiled with 16K (or a multiple of 16K)
858 aligned segments.
859
860 config ARM64_64K_PAGES
861 bool "64KB"
862 help
863 This feature enables 64KB pages support (4KB by default)
864 allowing only two levels of page tables and faster TLB
865 look-up. AArch32 emulation requires applications compiled
866 with 64K aligned segments.
867
868 endchoice
869
870 choice
871 prompt "Virtual address space size"
872 default ARM64_VA_BITS_39 if ARM64_4K_PAGES
873 default ARM64_VA_BITS_47 if ARM64_16K_PAGES
874 default ARM64_VA_BITS_42 if ARM64_64K_PAGES
875 help
876 Allows choosing one of multiple possible virtual address
877 space sizes. The level of translation table is determined by
878 a combination of page size and virtual address space size.
879
880 config ARM64_VA_BITS_36
881 bool "36-bit" if EXPERT
882 depends on ARM64_16K_PAGES
883
884 config ARM64_VA_BITS_39
885 bool "39-bit"
886 depends on ARM64_4K_PAGES
887
888 config ARM64_VA_BITS_42
889 bool "42-bit"
890 depends on ARM64_64K_PAGES
891
892 config ARM64_VA_BITS_47
893 bool "47-bit"
894 depends on ARM64_16K_PAGES
895
896 config ARM64_VA_BITS_48
897 bool "48-bit"
898
899 config ARM64_VA_BITS_52
900 bool "52-bit"
901 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN)
902 help
903 Enable 52-bit virtual addressing for userspace when explicitly
904 requested via a hint to mmap(). The kernel will also use 52-bit
905 virtual addresses for its own mappings (provided HW support for
906 this feature is available, otherwise it reverts to 48-bit).
907
908 NOTE: Enabling 52-bit virtual addressing in conjunction with
909 ARMv8.3 Pointer Authentication will result in the PAC being
910 reduced from 7 bits to 3 bits, which may have a significant
911 impact on its susceptibility to brute-force attacks.
912
913 If unsure, select 48-bit virtual addressing instead.
914
915 endchoice
916
917 config ARM64_FORCE_52BIT
918 bool "Force 52-bit virtual addresses for userspace"
919 depends on ARM64_VA_BITS_52 && EXPERT
920 help
921 For systems with 52-bit userspace VAs enabled, the kernel will attempt
922 to maintain compatibility with older software by providing 48-bit VAs
923 unless a hint is supplied to mmap.
924
925 This configuration option disables the 48-bit compatibility logic, and
926 forces all userspace addresses to be 52-bit on HW that supports it. One
927 should only enable this configuration option for stress testing userspace
928 memory management code. If unsure say N here.
929
930 config ARM64_VA_BITS
931 int
932 default 36 if ARM64_VA_BITS_36
933 default 39 if ARM64_VA_BITS_39
934 default 42 if ARM64_VA_BITS_42
935 default 47 if ARM64_VA_BITS_47
936 default 48 if ARM64_VA_BITS_48
937 default 52 if ARM64_VA_BITS_52
938
939 choice
940 prompt "Physical address space size"
941 default ARM64_PA_BITS_48
942 help
943 Choose the maximum physical address range that the kernel will
944 support.
945
946 config ARM64_PA_BITS_48
947 bool "48-bit"
948
949 config ARM64_PA_BITS_52
950 bool "52-bit (ARMv8.2)"
951 depends on ARM64_64K_PAGES
952 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
953 help
954 Enable support for a 52-bit physical address space, introduced as
955 part of the ARMv8.2-LPA extension.
956
957 With this enabled, the kernel will also continue to work on CPUs that
958 do not support ARMv8.2-LPA, but with some added memory overhead (and
959 minor performance overhead).
960
961 endchoice
962
963 config ARM64_PA_BITS
964 int
965 default 48 if ARM64_PA_BITS_48
966 default 52 if ARM64_PA_BITS_52
967
968 choice
969 prompt "Endianness"
970 default CPU_LITTLE_ENDIAN
971 help
972 Select the endianness of data accesses performed by the CPU. Userspace
973 applications will need to be compiled and linked for the endianness
974 that is selected here.
975
976 config CPU_BIG_ENDIAN
977 bool "Build big-endian kernel"
978 depends on !LD_IS_LLD || LLD_VERSION >= 130000
979 help
980 Say Y if you plan on running a kernel with a big-endian userspace.
981
982 config CPU_LITTLE_ENDIAN
983 bool "Build little-endian kernel"
984 help
985 Say Y if you plan on running a kernel with a little-endian userspace.
986 This is usually the case for distributions targeting arm64.
987
988 endchoice
989
990 config SCHED_MC
991 bool "Multi-core scheduler support"
992 help
993 Multi-core scheduler support improves the CPU scheduler's decision
994 making when dealing with multi-core CPU chips at a cost of slightly
995 increased overhead in some places. If unsure say N here.
996
997 config SCHED_SMT
998 bool "SMT scheduler support"
999 help
1000 Improves the CPU scheduler's decision making when dealing with
1001 MultiThreading at a cost of slightly increased overhead in some
1002 places. If unsure say N here.
1003
1004 config NR_CPUS
1005 int "Maximum number of CPUs (2-4096)"
1006 range 2 4096
1007 default "256"
1008
1009 config HOTPLUG_CPU
1010 bool "Support for hot-pluggable CPUs"
1011 select GENERIC_IRQ_MIGRATION
1012 help
1013 Say Y here to experiment with turning CPUs off and on. CPUs
1014 can be controlled through /sys/devices/system/cpu.
1015
1016 # Common NUMA Features
1017 config NUMA
1018 bool "NUMA Memory Allocation and Scheduler Support"
1019 select GENERIC_ARCH_NUMA
1020 select ACPI_NUMA if ACPI
1021 select OF_NUMA
1022 help
1023 Enable NUMA (Non-Uniform Memory Access) support.
1024
1025 The kernel will try to allocate memory used by a CPU on the
1026 local memory of the CPU and add some more
1027 NUMA awareness to the kernel.
1028
1029 config NODES_SHIFT
1030 int "Maximum NUMA Nodes (as a power of 2)"
1031 range 1 10
1032 default "4"
1033 depends on NEED_MULTIPLE_NODES
1034 help
1035 Specify the maximum number of NUMA Nodes available on the target
1036 system. Increases memory reserved to accommodate various tables.
1037
1038 config USE_PERCPU_NUMA_NODE_ID
1039 def_bool y
1040 depends on NUMA
1041
1042 config HAVE_SETUP_PER_CPU_AREA
1043 def_bool y
1044 depends on NUMA
1045
1046 config NEED_PER_CPU_EMBED_FIRST_CHUNK
1047 def_bool y
1048 depends on NUMA
1049
1050 config HOLES_IN_ZONE
1051 def_bool y
1052
1053 source "kernel/Kconfig.hz"
1054
1055 config ARCH_SPARSEMEM_ENABLE
1056 def_bool y
1057 select SPARSEMEM_VMEMMAP_ENABLE
1058
1059 config ARCH_SPARSEMEM_DEFAULT
1060 def_bool ARCH_SPARSEMEM_ENABLE
1061
1062 config ARCH_SELECT_MEMORY_MODEL
1063 def_bool ARCH_SPARSEMEM_ENABLE
1064
1065 config ARCH_FLATMEM_ENABLE
1066 def_bool !NUMA
1067
1068 config HW_PERF_EVENTS
1069 def_bool y
1070 depends on ARM_PMU
1071
1072 config SYS_SUPPORTS_HUGETLBFS
1073 def_bool y
1074
1075 config ARCH_HAS_CACHE_LINE_SIZE
1076 def_bool y
1077
1078 config ARCH_HAS_FILTER_PGPROT
1079 def_bool y
1080
1081 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1082 def_bool y if PGTABLE_LEVELS > 2
1083
1084 # Supported by clang >= 7.0
1085 config CC_HAVE_SHADOW_CALL_STACK
1086 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1087
1088 config PARAVIRT
1089 bool "Enable paravirtualization code"
1090 help
1091 This changes the kernel so it can modify itself when it is run
1092 under a hypervisor, potentially improving performance significantly
1093 over full virtualization.
1094
1095 config PARAVIRT_TIME_ACCOUNTING
1096 bool "Paravirtual steal time accounting"
1097 select PARAVIRT
1098 help
1099 Select this option to enable fine granularity task steal time
1100 accounting. Time spent executing other tasks in parallel with
1101 the current vCPU is discounted from the vCPU power. To account for
1102 that, there can be a small performance impact.
1103
1104 If in doubt, say N here.
1105
1106 config KEXEC
1107 depends on PM_SLEEP_SMP
1108 select KEXEC_CORE
1109 bool "kexec system call"
1110 help
1111 kexec is a system call that implements the ability to shutdown your
1112 current kernel, and to start another kernel. It is like a reboot
1113 but it is independent of the system firmware. And like a reboot
1114 you can start any kernel with it, not just Linux.
1115
1116 config KEXEC_FILE
1117 bool "kexec file based system call"
1118 select KEXEC_CORE
1119 select HAVE_IMA_KEXEC if IMA
1120 help
1121 This is new version of kexec system call. This system call is
1122 file based and takes file descriptors as system call argument
1123 for kernel and initramfs as opposed to list of segments as
1124 accepted by previous system call.
1125
1126 config KEXEC_SIG
1127 bool "Verify kernel signature during kexec_file_load() syscall"
1128 depends on KEXEC_FILE
1129 help
1130 Select this option to verify a signature with loaded kernel
1131 image. If configured, any attempt of loading a image without
1132 valid signature will fail.
1133
1134 In addition to that option, you need to enable signature
1135 verification for the corresponding kernel image type being
1136 loaded in order for this to work.
1137
1138 config KEXEC_IMAGE_VERIFY_SIG
1139 bool "Enable Image signature verification support"
1140 default y
1141 depends on KEXEC_SIG
1142 depends on EFI && SIGNED_PE_FILE_VERIFICATION
1143 help
1144 Enable Image signature verification support.
1145
1146 comment "Support for PE file signature verification disabled"
1147 depends on KEXEC_SIG
1148 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
1149
1150 config CRASH_DUMP
1151 bool "Build kdump crash kernel"
1152 help
1153 Generate crash dump after being started by kexec. This should
1154 be normally only set in special crash dump kernels which are
1155 loaded in the main kernel with kexec-tools into a specially
1156 reserved region and then later executed after a crash by
1157 kdump/kexec.
1158
1159 For more details see Documentation/admin-guide/kdump/kdump.rst
1160
1161 config TRANS_TABLE
1162 def_bool y
1163 depends on HIBERNATION
1164
1165 config XEN_DOM0
1166 def_bool y
1167 depends on XEN
1168
1169 config XEN
1170 bool "Xen guest support on ARM64"
1171 depends on ARM64 && OF
1172 select SWIOTLB_XEN
1173 select PARAVIRT
1174 help
1175 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1176
1177 config FORCE_MAX_ZONEORDER
1178 int
1179 default "14" if ARM64_64K_PAGES
1180 default "12" if ARM64_16K_PAGES
1181 default "11"
1182 help
1183 The kernel memory allocator divides physically contiguous memory
1184 blocks into "zones", where each zone is a power of two number of
1185 pages. This option selects the largest power of two that the kernel
1186 keeps in the memory allocator. If you need to allocate very large
1187 blocks of physically contiguous memory, then you may need to
1188 increase this value.
1189
1190 This config option is actually maximum order plus one. For example,
1191 a value of 11 means that the largest free memory block is 2^10 pages.
1192
1193 We make sure that we can allocate upto a HugePage size for each configuration.
1194 Hence we have :
1195 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
1196
1197 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
1198 4M allocations matching the default size used by generic code.
1199
1200 config UNMAP_KERNEL_AT_EL0
1201 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
1202 default y
1203 help
1204 Speculation attacks against some high-performance processors can
1205 be used to bypass MMU permission checks and leak kernel data to
1206 userspace. This can be defended against by unmapping the kernel
1207 when running in userspace, mapping it back in on exception entry
1208 via a trampoline page in the vector table.
1209
1210 If unsure, say Y.
1211
1212 config RODATA_FULL_DEFAULT_ENABLED
1213 bool "Apply r/o permissions of VM areas also to their linear aliases"
1214 default y
1215 help
1216 Apply read-only attributes of VM areas to the linear alias of
1217 the backing pages as well. This prevents code or read-only data
1218 from being modified (inadvertently or intentionally) via another
1219 mapping of the same memory page. This additional enhancement can
1220 be turned off at runtime by passing rodata=[off|on] (and turned on
1221 with rodata=full if this option is set to 'n')
1222
1223 This requires the linear region to be mapped down to pages,
1224 which may adversely affect performance in some cases.
1225
1226 config ARM64_SW_TTBR0_PAN
1227 bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1228 help
1229 Enabling this option prevents the kernel from accessing
1230 user-space memory directly by pointing TTBR0_EL1 to a reserved
1231 zeroed area and reserved ASID. The user access routines
1232 restore the valid TTBR0_EL1 temporarily.
1233
1234 config ARM64_TAGGED_ADDR_ABI
1235 bool "Enable the tagged user addresses syscall ABI"
1236 default y
1237 help
1238 When this option is enabled, user applications can opt in to a
1239 relaxed ABI via prctl() allowing tagged addresses to be passed
1240 to system calls as pointer arguments. For details, see
1241 Documentation/arm64/tagged-address-abi.rst.
1242
1243 menuconfig COMPAT
1244 bool "Kernel support for 32-bit EL0"
1245 depends on ARM64_4K_PAGES || EXPERT
1246 select HAVE_UID16
1247 select OLD_SIGSUSPEND3
1248 select COMPAT_OLD_SIGACTION
1249 help
1250 This option enables support for a 32-bit EL0 running under a 64-bit
1251 kernel at EL1. AArch32-specific components such as system calls,
1252 the user helper functions, VFP support and the ptrace interface are
1253 handled appropriately by the kernel.
1254
1255 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1256 that you will only be able to execute AArch32 binaries that were compiled
1257 with page size aligned segments.
1258
1259 If you want to execute 32-bit userspace applications, say Y.
1260
1261 if COMPAT
1262
1263 config KUSER_HELPERS
1264 bool "Enable kuser helpers page for 32-bit applications"
1265 default y
1266 help
1267 Warning: disabling this option may break 32-bit user programs.
1268
1269 Provide kuser helpers to compat tasks. The kernel provides
1270 helper code to userspace in read only form at a fixed location
1271 to allow userspace to be independent of the CPU type fitted to
1272 the system. This permits binaries to be run on ARMv4 through
1273 to ARMv8 without modification.
1274
1275 See Documentation/arm/kernel_user_helpers.rst for details.
1276
1277 However, the fixed address nature of these helpers can be used
1278 by ROP (return orientated programming) authors when creating
1279 exploits.
1280
1281 If all of the binaries and libraries which run on your platform
1282 are built specifically for your platform, and make no use of
1283 these helpers, then you can turn this option off to hinder
1284 such exploits. However, in that case, if a binary or library
1285 relying on those helpers is run, it will not function correctly.
1286
1287 Say N here only if you are absolutely certain that you do not
1288 need these helpers; otherwise, the safe option is to say Y.
1289
1290 config COMPAT_VDSO
1291 bool "Enable vDSO for 32-bit applications"
1292 depends on !CPU_BIG_ENDIAN && "$(CROSS_COMPILE_COMPAT)" != ""
1293 select GENERIC_COMPAT_VDSO
1294 default y
1295 help
1296 Place in the process address space of 32-bit applications an
1297 ELF shared object providing fast implementations of gettimeofday
1298 and clock_gettime.
1299
1300 You must have a 32-bit build of glibc 2.22 or later for programs
1301 to seamlessly take advantage of this.
1302
1303 config THUMB2_COMPAT_VDSO
1304 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1305 depends on COMPAT_VDSO
1306 default y
1307 help
1308 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1309 otherwise with '-marm'.
1310
1311 menuconfig ARMV8_DEPRECATED
1312 bool "Emulate deprecated/obsolete ARMv8 instructions"
1313 depends on SYSCTL
1314 help
1315 Legacy software support may require certain instructions
1316 that have been deprecated or obsoleted in the architecture.
1317
1318 Enable this config to enable selective emulation of these
1319 features.
1320
1321 If unsure, say Y
1322
1323 if ARMV8_DEPRECATED
1324
1325 config SWP_EMULATION
1326 bool "Emulate SWP/SWPB instructions"
1327 help
1328 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1329 they are always undefined. Say Y here to enable software
1330 emulation of these instructions for userspace using LDXR/STXR.
1331 This feature can be controlled at runtime with the abi.swp
1332 sysctl which is disabled by default.
1333
1334 In some older versions of glibc [<=2.8] SWP is used during futex
1335 trylock() operations with the assumption that the code will not
1336 be preempted. This invalid assumption may be more likely to fail
1337 with SWP emulation enabled, leading to deadlock of the user
1338 application.
1339
1340 NOTE: when accessing uncached shared regions, LDXR/STXR rely
1341 on an external transaction monitoring block called a global
1342 monitor to maintain update atomicity. If your system does not
1343 implement a global monitor, this option can cause programs that
1344 perform SWP operations to uncached memory to deadlock.
1345
1346 If unsure, say Y
1347
1348 config CP15_BARRIER_EMULATION
1349 bool "Emulate CP15 Barrier instructions"
1350 help
1351 The CP15 barrier instructions - CP15ISB, CP15DSB, and
1352 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1353 strongly recommended to use the ISB, DSB, and DMB
1354 instructions instead.
1355
1356 Say Y here to enable software emulation of these
1357 instructions for AArch32 userspace code. When this option is
1358 enabled, CP15 barrier usage is traced which can help
1359 identify software that needs updating. This feature can be
1360 controlled at runtime with the abi.cp15_barrier sysctl.
1361
1362 If unsure, say Y
1363
1364 config SETEND_EMULATION
1365 bool "Emulate SETEND instruction"
1366 help
1367 The SETEND instruction alters the data-endianness of the
1368 AArch32 EL0, and is deprecated in ARMv8.
1369
1370 Say Y here to enable software emulation of the instruction
1371 for AArch32 userspace code. This feature can be controlled
1372 at runtime with the abi.setend sysctl.
1373
1374 Note: All the cpus on the system must have mixed endian support at EL0
1375 for this feature to be enabled. If a new CPU - which doesn't support mixed
1376 endian - is hotplugged in after this feature has been enabled, there could
1377 be unexpected results in the applications.
1378
1379 If unsure, say Y
1380 endif
1381
1382 endif
1383
1384 menu "ARMv8.1 architectural features"
1385
1386 config ARM64_HW_AFDBM
1387 bool "Support for hardware updates of the Access and Dirty page flags"
1388 default y
1389 help
1390 The ARMv8.1 architecture extensions introduce support for
1391 hardware updates of the access and dirty information in page
1392 table entries. When enabled in TCR_EL1 (HA and HD bits) on
1393 capable processors, accesses to pages with PTE_AF cleared will
1394 set this bit instead of raising an access flag fault.
1395 Similarly, writes to read-only pages with the DBM bit set will
1396 clear the read-only bit (AP[2]) instead of raising a
1397 permission fault.
1398
1399 Kernels built with this configuration option enabled continue
1400 to work on pre-ARMv8.1 hardware and the performance impact is
1401 minimal. If unsure, say Y.
1402
1403 config ARM64_PAN
1404 bool "Enable support for Privileged Access Never (PAN)"
1405 default y
1406 help
1407 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1408 prevents the kernel or hypervisor from accessing user-space (EL0)
1409 memory directly.
1410
1411 Choosing this option will cause any unprotected (not using
1412 copy_to_user et al) memory access to fail with a permission fault.
1413
1414 The feature is detected at runtime, and will remain as a 'nop'
1415 instruction if the cpu does not implement the feature.
1416
1417 config AS_HAS_LDAPR
1418 def_bool $(as-instr,.arch_extension rcpc)
1419
1420 config AS_HAS_LSE_ATOMICS
1421 def_bool $(as-instr,.arch_extension lse)
1422
1423 config ARM64_LSE_ATOMICS
1424 bool
1425 default ARM64_USE_LSE_ATOMICS
1426 depends on AS_HAS_LSE_ATOMICS
1427
1428 config ARM64_USE_LSE_ATOMICS
1429 bool "Atomic instructions"
1430 depends on JUMP_LABEL
1431 default y
1432 help
1433 As part of the Large System Extensions, ARMv8.1 introduces new
1434 atomic instructions that are designed specifically to scale in
1435 very large systems.
1436
1437 Say Y here to make use of these instructions for the in-kernel
1438 atomic routines. This incurs a small overhead on CPUs that do
1439 not support these instructions and requires the kernel to be
1440 built with binutils >= 2.25 in order for the new instructions
1441 to be used.
1442
1443 endmenu
1444
1445 menu "ARMv8.2 architectural features"
1446
1447 config ARM64_PMEM
1448 bool "Enable support for persistent memory"
1449 select ARCH_HAS_PMEM_API
1450 select ARCH_HAS_UACCESS_FLUSHCACHE
1451 help
1452 Say Y to enable support for the persistent memory API based on the
1453 ARMv8.2 DCPoP feature.
1454
1455 The feature is detected at runtime, and the kernel will use DC CVAC
1456 operations if DC CVAP is not supported (following the behaviour of
1457 DC CVAP itself if the system does not define a point of persistence).
1458
1459 config ARM64_RAS_EXTN
1460 bool "Enable support for RAS CPU Extensions"
1461 default y
1462 help
1463 CPUs that support the Reliability, Availability and Serviceability
1464 (RAS) Extensions, part of ARMv8.2 are able to track faults and
1465 errors, classify them and report them to software.
1466
1467 On CPUs with these extensions system software can use additional
1468 barriers to determine if faults are pending and read the
1469 classification from a new set of registers.
1470
1471 Selecting this feature will allow the kernel to use these barriers
1472 and access the new registers if the system supports the extension.
1473 Platform RAS features may additionally depend on firmware support.
1474
1475 config ARM64_CNP
1476 bool "Enable support for Common Not Private (CNP) translations"
1477 default y
1478 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1479 help
1480 Common Not Private (CNP) allows translation table entries to
1481 be shared between different PEs in the same inner shareable
1482 domain, so the hardware can use this fact to optimise the
1483 caching of such entries in the TLB.
1484
1485 Selecting this option allows the CNP feature to be detected
1486 at runtime, and does not affect PEs that do not implement
1487 this feature.
1488
1489 endmenu
1490
1491 menu "ARMv8.3 architectural features"
1492
1493 config ARM64_PTR_AUTH
1494 bool "Enable support for pointer authentication"
1495 default y
1496 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC
1497 # Modern compilers insert a .note.gnu.property section note for PAC
1498 # which is only understood by binutils starting with version 2.33.1.
1499 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1500 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1501 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
1502 help
1503 Pointer authentication (part of the ARMv8.3 Extensions) provides
1504 instructions for signing and authenticating pointers against secret
1505 keys, which can be used to mitigate Return Oriented Programming (ROP)
1506 and other attacks.
1507
1508 This option enables these instructions at EL0 (i.e. for userspace).
1509 Choosing this option will cause the kernel to initialise secret keys
1510 for each process at exec() time, with these keys being
1511 context-switched along with the process.
1512
1513 If the compiler supports the -mbranch-protection or
1514 -msign-return-address flag (e.g. GCC 7 or later), then this option
1515 will also cause the kernel itself to be compiled with return address
1516 protection. In this case, and if the target hardware is known to
1517 support pointer authentication, then CONFIG_STACKPROTECTOR can be
1518 disabled with minimal loss of protection.
1519
1520 The feature is detected at runtime. If the feature is not present in
1521 hardware it will not be advertised to userspace/KVM guest nor will it
1522 be enabled.
1523
1524 If the feature is present on the boot CPU but not on a late CPU, then
1525 the late CPU will be parked. Also, if the boot CPU does not have
1526 address auth and the late CPU has then the late CPU will still boot
1527 but with the feature disabled. On such a system, this option should
1528 not be selected.
1529
1530 This feature works with FUNCTION_GRAPH_TRACER option only if
1531 DYNAMIC_FTRACE_WITH_REGS is enabled.
1532
1533 config CC_HAS_BRANCH_PROT_PAC_RET
1534 # GCC 9 or later, clang 8 or later
1535 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1536
1537 config CC_HAS_SIGN_RETURN_ADDRESS
1538 # GCC 7, 8
1539 def_bool $(cc-option,-msign-return-address=all)
1540
1541 config AS_HAS_PAC
1542 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1543
1544 config AS_HAS_CFI_NEGATE_RA_STATE
1545 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1546
1547 endmenu
1548
1549 menu "ARMv8.4 architectural features"
1550
1551 config ARM64_AMU_EXTN
1552 bool "Enable support for the Activity Monitors Unit CPU extension"
1553 default y
1554 help
1555 The activity monitors extension is an optional extension introduced
1556 by the ARMv8.4 CPU architecture. This enables support for version 1
1557 of the activity monitors architecture, AMUv1.
1558
1559 To enable the use of this extension on CPUs that implement it, say Y.
1560
1561 Note that for architectural reasons, firmware _must_ implement AMU
1562 support when running on CPUs that present the activity monitors
1563 extension. The required support is present in:
1564 * Version 1.5 and later of the ARM Trusted Firmware
1565
1566 For kernels that have this configuration enabled but boot with broken
1567 firmware, you may need to say N here until the firmware is fixed.
1568 Otherwise you may experience firmware panics or lockups when
1569 accessing the counter registers. Even if you are not observing these
1570 symptoms, the values returned by the register reads might not
1571 correctly reflect reality. Most commonly, the value read will be 0,
1572 indicating that the counter is not enabled.
1573
1574 config AS_HAS_ARMV8_4
1575 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
1576
1577 config ARM64_TLB_RANGE
1578 bool "Enable support for tlbi range feature"
1579 default y
1580 depends on AS_HAS_ARMV8_4
1581 help
1582 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
1583 range of input addresses.
1584
1585 The feature introduces new assembly instructions, and they were
1586 support when binutils >= 2.30.
1587
1588 endmenu
1589
1590 menu "ARMv8.5 architectural features"
1591
1592 config AS_HAS_ARMV8_5
1593 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
1594
1595 config ARM64_BTI
1596 bool "Branch Target Identification support"
1597 default y
1598 help
1599 Branch Target Identification (part of the ARMv8.5 Extensions)
1600 provides a mechanism to limit the set of locations to which computed
1601 branch instructions such as BR or BLR can jump.
1602
1603 To make use of BTI on CPUs that support it, say Y.
1604
1605 BTI is intended to provide complementary protection to other control
1606 flow integrity protection mechanisms, such as the Pointer
1607 authentication mechanism provided as part of the ARMv8.3 Extensions.
1608 For this reason, it does not make sense to enable this option without
1609 also enabling support for pointer authentication. Thus, when
1610 enabling this option you should also select ARM64_PTR_AUTH=y.
1611
1612 Userspace binaries must also be specifically compiled to make use of
1613 this mechanism. If you say N here or the hardware does not support
1614 BTI, such binaries can still run, but you get no additional
1615 enforcement of branch destinations.
1616
1617 config ARM64_BTI_KERNEL
1618 bool "Use Branch Target Identification for kernel"
1619 default y
1620 depends on ARM64_BTI
1621 depends on ARM64_PTR_AUTH
1622 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
1623 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
1624 depends on !CC_IS_GCC || GCC_VERSION >= 100100
1625 depends on !(CC_IS_CLANG && GCOV_KERNEL)
1626 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
1627 help
1628 Build the kernel with Branch Target Identification annotations
1629 and enable enforcement of this for kernel code. When this option
1630 is enabled and the system supports BTI all kernel code including
1631 modular code must have BTI enabled.
1632
1633 config CC_HAS_BRANCH_PROT_PAC_RET_BTI
1634 # GCC 9 or later, clang 8 or later
1635 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
1636
1637 config ARM64_E0PD
1638 bool "Enable support for E0PD"
1639 default y
1640 help
1641 E0PD (part of the ARMv8.5 extensions) allows us to ensure
1642 that EL0 accesses made via TTBR1 always fault in constant time,
1643 providing similar benefits to KASLR as those provided by KPTI, but
1644 with lower overhead and without disrupting legitimate access to
1645 kernel memory such as SPE.
1646
1647 This option enables E0PD for TTBR1 where available.
1648
1649 config ARCH_RANDOM
1650 bool "Enable support for random number generation"
1651 default y
1652 help
1653 Random number generation (part of the ARMv8.5 Extensions)
1654 provides a high bandwidth, cryptographically secure
1655 hardware random number generator.
1656
1657 config ARM64_AS_HAS_MTE
1658 # Initial support for MTE went in binutils 2.32.0, checked with
1659 # ".arch armv8.5-a+memtag" below. However, this was incomplete
1660 # as a late addition to the final architecture spec (LDGM/STGM)
1661 # is only supported in the newer 2.32.x and 2.33 binutils
1662 # versions, hence the extra "stgm" instruction check below.
1663 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
1664
1665 config ARM64_MTE
1666 bool "Memory Tagging Extension support"
1667 default y
1668 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
1669 depends on AS_HAS_ARMV8_5
1670 depends on AS_HAS_LSE_ATOMICS
1671 # Required for tag checking in the uaccess routines
1672 depends on ARM64_PAN
1673 select ARCH_USES_HIGH_VMA_FLAGS
1674 help
1675 Memory Tagging (part of the ARMv8.5 Extensions) provides
1676 architectural support for run-time, always-on detection of
1677 various classes of memory error to aid with software debugging
1678 to eliminate vulnerabilities arising from memory-unsafe
1679 languages.
1680
1681 This option enables the support for the Memory Tagging
1682 Extension at EL0 (i.e. for userspace).
1683
1684 Selecting this option allows the feature to be detected at
1685 runtime. Any secondary CPU not implementing this feature will
1686 not be allowed a late bring-up.
1687
1688 Userspace binaries that want to use this feature must
1689 explicitly opt in. The mechanism for the userspace is
1690 described in:
1691
1692 Documentation/arm64/memory-tagging-extension.rst.
1693
1694 endmenu
1695
1696 menu "ARMv8.7 architectural features"
1697
1698 config ARM64_EPAN
1699 bool "Enable support for Enhanced Privileged Access Never (EPAN)"
1700 default y
1701 depends on ARM64_PAN
1702 help
1703 Enhanced Privileged Access Never (EPAN) allows Privileged
1704 Access Never to be used with Execute-only mappings.
1705
1706 The feature is detected at runtime, and will remain disabled
1707 if the cpu does not implement the feature.
1708 endmenu
1709
1710 config ARM64_SVE
1711 bool "ARM Scalable Vector Extension support"
1712 default y
1713 help
1714 The Scalable Vector Extension (SVE) is an extension to the AArch64
1715 execution state which complements and extends the SIMD functionality
1716 of the base architecture to support much larger vectors and to enable
1717 additional vectorisation opportunities.
1718
1719 To enable use of this extension on CPUs that implement it, say Y.
1720
1721 On CPUs that support the SVE2 extensions, this option will enable
1722 those too.
1723
1724 Note that for architectural reasons, firmware _must_ implement SVE
1725 support when running on SVE capable hardware. The required support
1726 is present in:
1727
1728 * version 1.5 and later of the ARM Trusted Firmware
1729 * the AArch64 boot wrapper since commit 5e1261e08abf
1730 ("bootwrapper: SVE: Enable SVE for EL2 and below").
1731
1732 For other firmware implementations, consult the firmware documentation
1733 or vendor.
1734
1735 If you need the kernel to boot on SVE-capable hardware with broken
1736 firmware, you may need to say N here until you get your firmware
1737 fixed. Otherwise, you may experience firmware panics or lockups when
1738 booting the kernel. If unsure and you are not observing these
1739 symptoms, you should assume that it is safe to say Y.
1740
1741 config ARM64_MODULE_PLTS
1742 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1743 depends on MODULES
1744 select HAVE_MOD_ARCH_SPECIFIC
1745 help
1746 Allocate PLTs when loading modules so that jumps and calls whose
1747 targets are too far away for their relative offsets to be encoded
1748 in the instructions themselves can be bounced via veneers in the
1749 module's PLT. This allows modules to be allocated in the generic
1750 vmalloc area after the dedicated module memory area has been
1751 exhausted.
1752
1753 When running with address space randomization (KASLR), the module
1754 region itself may be too far away for ordinary relative jumps and
1755 calls, and so in that case, module PLTs are required and cannot be
1756 disabled.
1757
1758 Specific errata workaround(s) might also force module PLTs to be
1759 enabled (ARM64_ERRATUM_843419).
1760
1761 config ARM64_PSEUDO_NMI
1762 bool "Support for NMI-like interrupts"
1763 select ARM_GIC_V3
1764 help
1765 Adds support for mimicking Non-Maskable Interrupts through the use of
1766 GIC interrupt priority. This support requires version 3 or later of
1767 ARM GIC.
1768
1769 This high priority configuration for interrupts needs to be
1770 explicitly enabled by setting the kernel parameter
1771 "irqchip.gicv3_pseudo_nmi" to 1.
1772
1773 If unsure, say N
1774
1775 if ARM64_PSEUDO_NMI
1776 config ARM64_DEBUG_PRIORITY_MASKING
1777 bool "Debug interrupt priority masking"
1778 help
1779 This adds runtime checks to functions enabling/disabling
1780 interrupts when using priority masking. The additional checks verify
1781 the validity of ICC_PMR_EL1 when calling concerned functions.
1782
1783 If unsure, say N
1784 endif
1785
1786 config RELOCATABLE
1787 bool "Build a relocatable kernel image" if EXPERT
1788 select ARCH_HAS_RELR
1789 default y
1790 help
1791 This builds the kernel as a Position Independent Executable (PIE),
1792 which retains all relocation metadata required to relocate the
1793 kernel binary at runtime to a different virtual address than the
1794 address it was linked at.
1795 Since AArch64 uses the RELA relocation format, this requires a
1796 relocation pass at runtime even if the kernel is loaded at the
1797 same address it was linked at.
1798
1799 config RANDOMIZE_BASE
1800 bool "Randomize the address of the kernel image"
1801 select ARM64_MODULE_PLTS if MODULES
1802 select RELOCATABLE
1803 help
1804 Randomizes the virtual address at which the kernel image is
1805 loaded, as a security feature that deters exploit attempts
1806 relying on knowledge of the location of kernel internals.
1807
1808 It is the bootloader's job to provide entropy, by passing a
1809 random u64 value in /chosen/kaslr-seed at kernel entry.
1810
1811 When booting via the UEFI stub, it will invoke the firmware's
1812 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
1813 to the kernel proper. In addition, it will randomise the physical
1814 location of the kernel Image as well.
1815
1816 If unsure, say N.
1817
1818 config RANDOMIZE_MODULE_REGION_FULL
1819 bool "Randomize the module region over a 4 GB range"
1820 depends on RANDOMIZE_BASE
1821 default y
1822 help
1823 Randomizes the location of the module region inside a 4 GB window
1824 covering the core kernel. This way, it is less likely for modules
1825 to leak information about the location of core kernel data structures
1826 but it does imply that function calls between modules and the core
1827 kernel will need to be resolved via veneers in the module PLT.
1828
1829 When this option is not set, the module region will be randomized over
1830 a limited range that contains the [_stext, _etext] interval of the
1831 core kernel, so branch relocations are always in range.
1832
1833 config CC_HAVE_STACKPROTECTOR_SYSREG
1834 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
1835
1836 config STACKPROTECTOR_PER_TASK
1837 def_bool y
1838 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
1839
1840 endmenu
1841
1842 menu "Boot options"
1843
1844 config ARM64_ACPI_PARKING_PROTOCOL
1845 bool "Enable support for the ARM64 ACPI parking protocol"
1846 depends on ACPI
1847 help
1848 Enable support for the ARM64 ACPI parking protocol. If disabled
1849 the kernel will not allow booting through the ARM64 ACPI parking
1850 protocol even if the corresponding data is present in the ACPI
1851 MADT table.
1852
1853 config CMDLINE
1854 string "Default kernel command string"
1855 default ""
1856 help
1857 Provide a set of default command-line options at build time by
1858 entering them here. As a minimum, you should specify the the
1859 root device (e.g. root=/dev/nfs).
1860
1861 choice
1862 prompt "Kernel command line type" if CMDLINE != ""
1863 default CMDLINE_FROM_BOOTLOADER
1864 help
1865 Choose how the kernel will handle the provided default kernel
1866 command line string.
1867
1868 config CMDLINE_FROM_BOOTLOADER
1869 bool "Use bootloader kernel arguments if available"
1870 help
1871 Uses the command-line options passed by the boot loader. If
1872 the boot loader doesn't provide any, the default kernel command
1873 string provided in CMDLINE will be used.
1874
1875 config CMDLINE_FORCE
1876 bool "Always use the default kernel command string"
1877 help
1878 Always use the default kernel command string, even if the boot
1879 loader passes other arguments to the kernel.
1880 This is useful if you cannot or don't want to change the
1881 command-line options your boot loader passes to the kernel.
1882
1883 endchoice
1884
1885 config EFI_STUB
1886 bool
1887
1888 config EFI
1889 bool "UEFI runtime support"
1890 depends on OF && !CPU_BIG_ENDIAN
1891 depends on KERNEL_MODE_NEON
1892 select ARCH_SUPPORTS_ACPI
1893 select LIBFDT
1894 select UCS2_STRING
1895 select EFI_PARAMS_FROM_FDT
1896 select EFI_RUNTIME_WRAPPERS
1897 select EFI_STUB
1898 select EFI_GENERIC_STUB
1899 imply IMA_SECURE_AND_OR_TRUSTED_BOOT
1900 default y
1901 help
1902 This option provides support for runtime services provided
1903 by UEFI firmware (such as non-volatile variables, realtime
1904 clock, and platform reset). A UEFI stub is also provided to
1905 allow the kernel to be booted as an EFI application. This
1906 is only useful on systems that have UEFI firmware.
1907
1908 config DMI
1909 bool "Enable support for SMBIOS (DMI) tables"
1910 depends on EFI
1911 default y
1912 help
1913 This enables SMBIOS/DMI feature for systems.
1914
1915 This option is only useful on systems that have UEFI firmware.
1916 However, even with this option, the resultant kernel should
1917 continue to boot on existing non-UEFI platforms.
1918
1919 endmenu
1920
1921 config SYSVIPC_COMPAT
1922 def_bool y
1923 depends on COMPAT && SYSVIPC
1924
1925 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1926 def_bool y
1927 depends on HUGETLB_PAGE && MIGRATION
1928
1929 config ARCH_ENABLE_THP_MIGRATION
1930 def_bool y
1931 depends on TRANSPARENT_HUGEPAGE
1932
1933 menu "Power management options"
1934
1935 source "kernel/power/Kconfig"
1936
1937 config ARCH_HIBERNATION_POSSIBLE
1938 def_bool y
1939 depends on CPU_PM
1940
1941 config ARCH_HIBERNATION_HEADER
1942 def_bool y
1943 depends on HIBERNATION
1944
1945 config ARCH_SUSPEND_POSSIBLE
1946 def_bool y
1947
1948 endmenu
1949
1950 menu "CPU Power Management"
1951
1952 source "drivers/cpuidle/Kconfig"
1953
1954 source "drivers/cpufreq/Kconfig"
1955
1956 endmenu
1957
1958 source "drivers/firmware/Kconfig"
1959
1960 source "drivers/acpi/Kconfig"
1961
1962 source "arch/arm64/kvm/Kconfig"
1963
1964 if CRYPTO
1965 source "arch/arm64/crypto/Kconfig"
1966 endif