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_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
9 select ACPI_IORT if ACPI
10 select ACPI_REDUCED_HARDWARE_ONLY if ACPI
11 select ACPI_MCFG if (ACPI && PCI)
12 select ACPI_SPCR_TABLE if ACPI
13 select ACPI_PPTT if ACPI
14 select ARCH_HAS_DEBUG_WX
15 select ARCH_BINFMT_ELF_EXTRA_PHDRS
16 select ARCH_BINFMT_ELF_STATE
17 select ARCH_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_CC_PLATFORM
24 select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
25 select ARCH_HAS_CURRENT_STACK_POINTER
26 select ARCH_HAS_DEBUG_VIRTUAL
27 select ARCH_HAS_DEBUG_VM_PGTABLE
28 select ARCH_HAS_DMA_OPS if XEN
29 select ARCH_HAS_DMA_PREP_COHERENT
30 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
31 select ARCH_HAS_FAST_MULTIPLIER
32 select ARCH_HAS_FORTIFY_SOURCE
33 select ARCH_HAS_GCOV_PROFILE_ALL
34 select ARCH_HAS_GIGANTIC_PAGE
35 select ARCH_HAS_KCOV
36 select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON
37 select ARCH_HAS_KEEPINITRD
38 select ARCH_HAS_LAZY_MMU_MODE
39 select ARCH_HAS_MEMBARRIER_SYNC_CORE
40 select ARCH_HAS_MEM_ENCRYPT
41 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
42 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
43 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
44 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
45 select ARCH_HAS_PREEMPT_LAZY
46 select ARCH_HAS_PTDUMP
47 select ARCH_HAS_PTE_SPECIAL
48 select ARCH_HAS_HW_PTE_YOUNG
49 select ARCH_HAS_SETUP_DMA_OPS
50 select ARCH_HAS_SET_DIRECT_MAP
51 select ARCH_HAS_SET_MEMORY
52 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
53 select ARCH_STACKWALK
54 select ARCH_HAS_STRICT_KERNEL_RWX
55 select ARCH_HAS_STRICT_MODULE_RWX
56 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
57 select ARCH_HAS_SYNC_DMA_FOR_CPU
58 select ARCH_HAS_SYSCALL_WRAPPER
59 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
60 select ARCH_HAS_ZONE_DMA_SET if EXPERT
61 select ARCH_HAVE_ELF_PROT
62 select ARCH_HAVE_NMI_SAFE_CMPXCHG
63 select ARCH_HAVE_TRACE_MMIO_ACCESS
64 select ARCH_INLINE_READ_LOCK if !PREEMPTION
65 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
66 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
67 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
68 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
69 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
70 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
71 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
72 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
73 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
74 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
75 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
76 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
77 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
78 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
79 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
80 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
81 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
82 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
83 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
84 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
85 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
86 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
87 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
88 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
89 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
90 select ARCH_KEEP_MEMBLOCK
91 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
92 select ARCH_USE_CMPXCHG_LOCKREF
93 select ARCH_USE_GNU_PROPERTY
94 select ARCH_USE_MEMTEST
95 select ARCH_USE_QUEUED_RWLOCKS
96 select ARCH_USE_QUEUED_SPINLOCKS
97 select ARCH_USE_SYM_ANNOTATIONS
98 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
99 select ARCH_SUPPORTS_HUGETLBFS
100 select ARCH_SUPPORTS_MEMORY_FAILURE
101 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
102 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
103 select ARCH_SUPPORTS_LTO_CLANG_THIN
104 select ARCH_SUPPORTS_CFI
105 select ARCH_SUPPORTS_ATOMIC_RMW
106 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
107 select ARCH_SUPPORTS_NUMA_BALANCING
108 select ARCH_SUPPORTS_PAGE_TABLE_CHECK
109 select ARCH_SUPPORTS_PER_VMA_LOCK
110 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
111 select ARCH_SUPPORTS_RT
112 select ARCH_SUPPORTS_SCHED_SMT
113 select ARCH_SUPPORTS_SCHED_CLUSTER
114 select ARCH_SUPPORTS_SCHED_MC
115 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
116 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
117 select ARCH_WANT_DEFAULT_BPF_JIT
118 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
119 select ARCH_WANT_FRAME_POINTERS
120 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
121 select ARCH_WANT_LD_ORPHAN_WARN
122 select ARCH_WANTS_EXECMEM_LATE
123 select ARCH_WANTS_NO_INSTR
124 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
125 select ARCH_HAS_UBSAN
126 select ARM_AMBA
127 select ARM_ARCH_TIMER
128 select ARM_GIC
129 select AUDIT_ARCH_COMPAT_GENERIC
130 select ARM_GIC_V2M if PCI
131 select ARM_GIC_V3
132 select ARM_GIC_V3_ITS if PCI
133 select ARM_GIC_V5
134 select ARM_PSCI_FW
135 select BUILDTIME_TABLE_SORT
136 select CLONE_BACKWARDS
137 select COMMON_CLK
138 select CPU_PM if (SUSPEND || CPU_IDLE)
139 select CPUMASK_OFFSTACK if NR_CPUS > 256
140 select DCACHE_WORD_ACCESS
141 select HAVE_EXTRA_IPI_TRACEPOINTS
142 select DYNAMIC_FTRACE if FUNCTION_TRACER
143 select DMA_BOUNCE_UNALIGNED_KMALLOC
144 select DMA_DIRECT_REMAP
145 select EDAC_SUPPORT
146 select FRAME_POINTER
147 select FUNCTION_ALIGNMENT_4B
148 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
149 select GENERIC_ALLOCATOR
150 select GENERIC_ARCH_TOPOLOGY
151 select GENERIC_CLOCKEVENTS_BROADCAST
152 select GENERIC_CPU_AUTOPROBE
153 select GENERIC_CPU_CACHE_MAINTENANCE
154 select GENERIC_CPU_DEVICES
155 select GENERIC_CPU_VULNERABILITIES
156 select GENERIC_EARLY_IOREMAP
157 select GENERIC_IDLE_POLL_SETUP
158 select GENERIC_IOREMAP
159 select GENERIC_IRQ_ENTRY
160 select GENERIC_IRQ_IPI
161 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
162 select GENERIC_IRQ_PROBE
163 select GENERIC_IRQ_SHOW
164 select GENERIC_IRQ_SHOW_LEVEL
165 select GENERIC_LIB_DEVMEM_IS_ALLOWED
166 select GENERIC_PCI_IOMAP
167 select GENERIC_SCHED_CLOCK
168 select GENERIC_SMP_IDLE_THREAD
169 select GENERIC_TIME_VSYSCALL
170 select GENERIC_GETTIMEOFDAY
171 select HARDIRQS_SW_RESEND
172 select HAS_IOPORT
173 select HAVE_MOVE_PMD
174 select HAVE_MOVE_PUD
175 select HAVE_PCI
176 select HAVE_ACPI_APEI if (ACPI && EFI)
177 select HAVE_ALIGNED_STRUCT_PAGE
178 select HAVE_ARCH_AUDITSYSCALL
179 select HAVE_ARCH_BITREVERSE
180 select HAVE_ARCH_COMPILER_H
181 select HAVE_ARCH_HUGE_VMALLOC
182 select HAVE_ARCH_HUGE_VMAP
183 select HAVE_ARCH_JUMP_LABEL
184 select HAVE_ARCH_JUMP_LABEL_RELATIVE
185 select HAVE_ARCH_KASAN
186 select HAVE_ARCH_KASAN_VMALLOC
187 select HAVE_ARCH_KASAN_SW_TAGS
188 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
189 # Some instrumentation may be unsound, hence EXPERT
190 select HAVE_ARCH_KCSAN if EXPERT
191 select HAVE_ARCH_KFENCE
192 select HAVE_ARCH_KGDB
193 select HAVE_ARCH_KSTACK_ERASE
194 select HAVE_ARCH_MMAP_RND_BITS
195 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
196 select HAVE_ARCH_PREL32_RELOCATIONS
197 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
198 select HAVE_ARCH_SECCOMP_FILTER
199 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
200 select HAVE_ARCH_TRACEHOOK
201 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
202 select HAVE_ARCH_VMAP_STACK
203 select HAVE_ARM_SMCCC
204 select HAVE_ASM_MODVERSIONS
205 select HAVE_EBPF_JIT
206 select HAVE_C_RECORDMCOUNT
207 select HAVE_CMPXCHG_DOUBLE
208 select HAVE_CMPXCHG_LOCAL
209 select HAVE_CONTEXT_TRACKING_USER
210 select HAVE_DEBUG_KMEMLEAK
211 select HAVE_DMA_CONTIGUOUS
212 select HAVE_DYNAMIC_FTRACE
213 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
214 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
215 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
216 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
217 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
218 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
219 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \
220 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
221 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
222 if DYNAMIC_FTRACE_WITH_ARGS
223 select HAVE_SAMPLE_FTRACE_DIRECT
224 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
225 select HAVE_BUILDTIME_MCOUNT_SORT
226 select HAVE_EFFICIENT_UNALIGNED_ACCESS
227 select HAVE_GUP_FAST
228 select HAVE_FTRACE_GRAPH_FUNC
229 select HAVE_FUNCTION_TRACER
230 select HAVE_FUNCTION_ERROR_INJECTION
231 select HAVE_FUNCTION_GRAPH_FREGS
232 select HAVE_FUNCTION_GRAPH_TRACER
233 select HAVE_GCC_PLUGINS
234 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
235 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
236 select HAVE_HW_BREAKPOINT if PERF_EVENTS
237 select HAVE_IOREMAP_PROT
238 select HAVE_IRQ_TIME_ACCOUNTING
239 select HAVE_LIVEPATCH
240 select HAVE_MOD_ARCH_SPECIFIC
241 select HAVE_NMI
242 select HAVE_PERF_EVENTS
243 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
244 select HAVE_PERF_REGS
245 select HAVE_PERF_USER_STACK_DUMP
246 select HAVE_PREEMPT_DYNAMIC_KEY
247 select HAVE_REGS_AND_STACK_ACCESS_API
248 select HAVE_RELIABLE_STACKTRACE
249 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
250 select HAVE_FUNCTION_ARG_ACCESS_API
251 select MMU_GATHER_RCU_TABLE_FREE
252 select HAVE_RSEQ
253 select HAVE_RUST if RUSTC_SUPPORTS_ARM64
254 select HAVE_STACKPROTECTOR
255 select HAVE_SYSCALL_TRACEPOINTS
256 select HAVE_KPROBES
257 select HAVE_KRETPROBES
258 select HAVE_GENERIC_VDSO
259 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
260 select HOTPLUG_SMT if HOTPLUG_CPU
261 select IRQ_DOMAIN
262 select IRQ_FORCED_THREADING
263 select JUMP_LABEL
264 select KASAN_VMALLOC if KASAN
265 select LOCK_MM_AND_FIND_VMA
266 select MODULES_USE_ELF_RELA
267 select NEED_DMA_MAP_STATE
268 select NEED_SG_DMA_LENGTH
269 select OF
270 select OF_EARLY_FLATTREE
271 select PCI_DOMAINS_GENERIC if PCI
272 select PCI_ECAM if (ACPI && PCI)
273 select PCI_SYSCALL if PCI
274 select POWER_RESET
275 select POWER_SUPPLY
276 select SPARSE_IRQ
277 select SWIOTLB
278 select SYSCTL_EXCEPTION_TRACE
279 select THREAD_INFO_IN_TASK
280 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
281 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
282 select TRACE_IRQFLAGS_SUPPORT
283 select TRACE_IRQFLAGS_NMI_SUPPORT
284 select HAVE_SOFTIRQ_ON_OWN_STACK
285 select USER_STACKTRACE_SUPPORT
286 select VDSO_GETRANDOM
287 select VMAP_STACK
288 help
289 ARM 64-bit (AArch64) Linux support.
290
291config RUSTC_SUPPORTS_ARM64
292 def_bool y
293 depends on CPU_LITTLE_ENDIAN
294 # Shadow call stack is only supported on certain rustc versions.
295 #
296 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is
297 # required due to use of the -Zfixed-x18 flag.
298 #
299 # Otherwise, rustc version 1.82+ is required due to use of the
300 # -Zsanitizer=shadow-call-stack flag.
301 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS
302
303config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
304 def_bool CC_IS_CLANG
305 # https://github.com/ClangBuiltLinux/linux/issues/1507
306 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
307
308config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
309 def_bool CC_IS_GCC
310 depends on $(cc-option,-fpatchable-function-entry=2)
311
312config 64BIT
313 def_bool y
314
315config MMU
316 def_bool y
317
318config ARM64_CONT_PTE_SHIFT
319 int
320 default 5 if PAGE_SIZE_64KB
321 default 7 if PAGE_SIZE_16KB
322 default 4
323
324config ARM64_CONT_PMD_SHIFT
325 int
326 default 5 if PAGE_SIZE_64KB
327 default 5 if PAGE_SIZE_16KB
328 default 4
329
330config ARCH_MMAP_RND_BITS_MIN
331 default 14 if PAGE_SIZE_64KB
332 default 16 if PAGE_SIZE_16KB
333 default 18
334
335# max bits determined by the following formula:
336# VA_BITS - PTDESC_TABLE_SHIFT
337config ARCH_MMAP_RND_BITS_MAX
338 default 19 if ARM64_VA_BITS=36
339 default 24 if ARM64_VA_BITS=39
340 default 27 if ARM64_VA_BITS=42
341 default 30 if ARM64_VA_BITS=47
342 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES
343 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES
344 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52)
345 default 14 if ARM64_64K_PAGES
346 default 16 if ARM64_16K_PAGES
347 default 18
348
349config ARCH_MMAP_RND_COMPAT_BITS_MIN
350 default 7 if ARM64_64K_PAGES
351 default 9 if ARM64_16K_PAGES
352 default 11
353
354config ARCH_MMAP_RND_COMPAT_BITS_MAX
355 default 16
356
357config NO_IOPORT_MAP
358 def_bool y if !PCI
359
360config STACKTRACE_SUPPORT
361 def_bool y
362
363config ILLEGAL_POINTER_VALUE
364 hex
365 default 0xdead000000000000
366
367config LOCKDEP_SUPPORT
368 def_bool y
369
370config GENERIC_BUG
371 def_bool y
372 depends on BUG
373
374config GENERIC_BUG_RELATIVE_POINTERS
375 def_bool y
376 depends on GENERIC_BUG
377
378config GENERIC_HWEIGHT
379 def_bool y
380
381config GENERIC_CSUM
382 def_bool y
383
384config GENERIC_CALIBRATE_DELAY
385 def_bool y
386
387config SMP
388 def_bool y
389
390config KERNEL_MODE_NEON
391 def_bool y
392
393config FIX_EARLYCON_MEM
394 def_bool y
395
396config PGTABLE_LEVELS
397 int
398 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
399 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
400 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
401 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
402 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
403 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
404 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
405 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
406
407config ARCH_SUPPORTS_UPROBES
408 def_bool y
409
410config ARCH_PROC_KCORE_TEXT
411 def_bool y
412
413config BROKEN_GAS_INST
414 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
415
416config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
417 bool
418 # Clang's __builtin_return_address() strips the PAC since 12.0.0
419 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
420 default y if CC_IS_CLANG
421 # GCC's __builtin_return_address() strips the PAC since 11.1.0,
422 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
423 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
424 default y if CC_IS_GCC && (GCC_VERSION >= 110100)
425 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
426 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000)
427 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000)
428 default n
429
430config KASAN_SHADOW_OFFSET
431 hex
432 depends on KASAN_GENERIC || KASAN_SW_TAGS
433 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
434 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
435 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
436 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
437 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
438 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
439 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
440 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
441 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
442 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
443 default 0xffffffffffffffff
444
445config UNWIND_TABLES
446 bool
447
448source "arch/arm64/Kconfig.platforms"
449
450menu "Kernel Features"
451
452menu "ARM errata workarounds via the alternatives framework"
453
454config AMPERE_ERRATUM_AC03_CPU_38
455 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
456 default y
457 help
458 This option adds an alternative code sequence to work around Ampere
459 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
460
461 The affected design reports FEAT_HAFDBS as not implemented in
462 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
463 as required by the architecture. The unadvertised HAFDBS
464 implementation suffers from an additional erratum where hardware
465 A/D updates can occur after a PTE has been marked invalid.
466
467 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
468 which avoids enabling unadvertised hardware Access Flag management
469 at stage-2.
470
471 If unsure, say Y.
472
473config AMPERE_ERRATUM_AC04_CPU_23
474 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations."
475 default y
476 help
477 This option adds an alternative code sequence to work around Ampere
478 errata AC04_CPU_23 on AmpereOne.
479
480 Updates to HCR_EL2 can rarely corrupt simultaneous translations for
481 data addresses initiated by load/store instructions. Only
482 instruction initiated translations are vulnerable, not translations
483 from prefetches for example. A DSB before the store to HCR_EL2 is
484 sufficient to prevent older instructions from hitting the window
485 for corruption, and an ISB after is sufficient to prevent younger
486 instructions from hitting the window for corruption.
487
488 If unsure, say Y.
489
490config ARM64_WORKAROUND_CLEAN_CACHE
491 bool
492
493config ARM64_ERRATUM_826319
494 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
495 default y
496 select ARM64_WORKAROUND_CLEAN_CACHE
497 help
498 This option adds an alternative code sequence to work around ARM
499 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
500 AXI master interface and an L2 cache.
501
502 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
503 and is unable to accept a certain write via this interface, it will
504 not progress on read data presented on the read data channel and the
505 system can deadlock.
506
507 The workaround promotes data cache clean instructions to
508 data cache clean-and-invalidate.
509 Please note that this does not necessarily enable the workaround,
510 as it depends on the alternative framework, which will only patch
511 the kernel if an affected CPU is detected.
512
513 If unsure, say Y.
514
515config ARM64_ERRATUM_827319
516 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
517 default y
518 select ARM64_WORKAROUND_CLEAN_CACHE
519 help
520 This option adds an alternative code sequence to work around ARM
521 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
522 master interface and an L2 cache.
523
524 Under certain conditions this erratum can cause a clean line eviction
525 to occur at the same time as another transaction to the same address
526 on the AMBA 5 CHI interface, which can cause data corruption if the
527 interconnect reorders the two transactions.
528
529 The workaround promotes data cache clean instructions to
530 data cache clean-and-invalidate.
531 Please note that this does not necessarily enable the workaround,
532 as it depends on the alternative framework, which will only patch
533 the kernel if an affected CPU is detected.
534
535 If unsure, say Y.
536
537config ARM64_ERRATUM_824069
538 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
539 default y
540 select ARM64_WORKAROUND_CLEAN_CACHE
541 help
542 This option adds an alternative code sequence to work around ARM
543 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
544 to a coherent interconnect.
545
546 If a Cortex-A53 processor is executing a store or prefetch for
547 write instruction at the same time as a processor in another
548 cluster is executing a cache maintenance operation to the same
549 address, then this erratum might cause a clean cache line to be
550 incorrectly marked as dirty.
551
552 The workaround promotes data cache clean instructions to
553 data cache clean-and-invalidate.
554 Please note that this option does not necessarily enable the
555 workaround, as it depends on the alternative framework, which will
556 only patch the kernel if an affected CPU is detected.
557
558 If unsure, say Y.
559
560config ARM64_ERRATUM_819472
561 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
562 default y
563 select ARM64_WORKAROUND_CLEAN_CACHE
564 help
565 This option adds an alternative code sequence to work around ARM
566 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
567 present when it is connected to a coherent interconnect.
568
569 If the processor is executing a load and store exclusive sequence at
570 the same time as a processor in another cluster is executing a cache
571 maintenance operation to the same address, then this erratum might
572 cause data corruption.
573
574 The workaround promotes data cache clean instructions to
575 data cache clean-and-invalidate.
576 Please note that this does not necessarily enable the workaround,
577 as it depends on the alternative framework, which will only patch
578 the kernel if an affected CPU is detected.
579
580 If unsure, say Y.
581
582config ARM64_ERRATUM_832075
583 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
584 default y
585 help
586 This option adds an alternative code sequence to work around ARM
587 erratum 832075 on Cortex-A57 parts up to r1p2.
588
589 Affected Cortex-A57 parts might deadlock when exclusive load/store
590 instructions to Write-Back memory are mixed with Device loads.
591
592 The workaround is to promote device loads to use Load-Acquire
593 semantics.
594 Please note that this does not necessarily enable the workaround,
595 as it depends on the alternative framework, which will only patch
596 the kernel if an affected CPU is detected.
597
598 If unsure, say Y.
599
600config ARM64_ERRATUM_834220
601 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
602 depends on KVM
603 help
604 This option adds an alternative code sequence to work around ARM
605 erratum 834220 on Cortex-A57 parts up to r1p2.
606
607 Affected Cortex-A57 parts might report a Stage 2 translation
608 fault as the result of a Stage 1 fault for load crossing a
609 page boundary when there is a permission or device memory
610 alignment fault at Stage 1 and a translation fault at Stage 2.
611
612 The workaround is to verify that the Stage 1 translation
613 doesn't generate a fault before handling the Stage 2 fault.
614 Please note that this does not necessarily enable the workaround,
615 as it depends on the alternative framework, which will only patch
616 the kernel if an affected CPU is detected.
617
618 If unsure, say N.
619
620config ARM64_ERRATUM_1742098
621 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
622 depends on COMPAT
623 default y
624 help
625 This option removes the AES hwcap for aarch32 user-space to
626 workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
627
628 Affected parts may corrupt the AES state if an interrupt is
629 taken between a pair of AES instructions. These instructions
630 are only present if the cryptography extensions are present.
631 All software should have a fallback implementation for CPUs
632 that don't implement the cryptography extensions.
633
634 If unsure, say Y.
635
636config ARM64_ERRATUM_845719
637 bool "Cortex-A53: 845719: a load might read incorrect data"
638 depends on COMPAT
639 default y
640 help
641 This option adds an alternative code sequence to work around ARM
642 erratum 845719 on Cortex-A53 parts up to r0p4.
643
644 When running a compat (AArch32) userspace on an affected Cortex-A53
645 part, a load at EL0 from a virtual address that matches the bottom 32
646 bits of the virtual address used by a recent load at (AArch64) EL1
647 might return incorrect data.
648
649 The workaround is to write the contextidr_el1 register on exception
650 return to a 32-bit task.
651 Please note that this does not necessarily enable the workaround,
652 as it depends on the alternative framework, which will only patch
653 the kernel if an affected CPU is detected.
654
655 If unsure, say Y.
656
657config ARM64_ERRATUM_843419
658 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
659 default y
660 help
661 This option links the kernel with '--fix-cortex-a53-843419' and
662 enables PLT support to replace certain ADRP instructions, which can
663 cause subsequent memory accesses to use an incorrect address on
664 Cortex-A53 parts up to r0p4.
665
666 If unsure, say Y.
667
668config ARM64_ERRATUM_1024718
669 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
670 default y
671 help
672 This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
673
674 Affected Cortex-A55 cores (all revisions) could cause incorrect
675 update of the hardware dirty bit when the DBM/AP bits are updated
676 without a break-before-make. The workaround is to disable the usage
677 of hardware DBM locally on the affected cores. CPUs not affected by
678 this erratum will continue to use the feature.
679
680 If unsure, say Y.
681
682config ARM64_ERRATUM_1418040
683 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
684 default y
685 depends on COMPAT
686 help
687 This option adds a workaround for ARM Cortex-A76/Neoverse-N1
688 errata 1188873 and 1418040.
689
690 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
691 cause register corruption when accessing the timer registers
692 from AArch32 userspace.
693
694 If unsure, say Y.
695
696config ARM64_WORKAROUND_SPECULATIVE_AT
697 bool
698
699config ARM64_ERRATUM_1165522
700 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
701 default y
702 select ARM64_WORKAROUND_SPECULATIVE_AT
703 help
704 This option adds a workaround for ARM Cortex-A76 erratum 1165522.
705
706 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
707 corrupted TLBs by speculating an AT instruction during a guest
708 context switch.
709
710 If unsure, say Y.
711
712config ARM64_ERRATUM_1319367
713 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
714 default y
715 select ARM64_WORKAROUND_SPECULATIVE_AT
716 help
717 This option adds work arounds for ARM Cortex-A57 erratum 1319537
718 and A72 erratum 1319367
719
720 Cortex-A57 and A72 cores could end-up with corrupted TLBs by
721 speculating an AT instruction during a guest context switch.
722
723 If unsure, say Y.
724
725config ARM64_ERRATUM_1530923
726 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
727 default y
728 select ARM64_WORKAROUND_SPECULATIVE_AT
729 help
730 This option adds a workaround for ARM Cortex-A55 erratum 1530923.
731
732 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
733 corrupted TLBs by speculating an AT instruction during a guest
734 context switch.
735
736 If unsure, say Y.
737
738config ARM64_WORKAROUND_REPEAT_TLBI
739 bool
740
741config ARM64_ERRATUM_2441007
742 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
743 select ARM64_WORKAROUND_REPEAT_TLBI
744 help
745 This option adds a workaround for ARM Cortex-A55 erratum #2441007.
746
747 Under very rare circumstances, affected Cortex-A55 CPUs
748 may not handle a race between a break-before-make sequence on one
749 CPU, and another CPU accessing the same page. This could allow a
750 store to a page that has been unmapped.
751
752 Work around this by adding the affected CPUs to the list that needs
753 TLB sequences to be done twice.
754
755 If unsure, say N.
756
757config ARM64_ERRATUM_1286807
758 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
759 select ARM64_WORKAROUND_REPEAT_TLBI
760 help
761 This option adds a workaround for ARM Cortex-A76 erratum 1286807.
762
763 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
764 address for a cacheable mapping of a location is being
765 accessed by a core while another core is remapping the virtual
766 address to a new physical page using the recommended
767 break-before-make sequence, then under very rare circumstances
768 TLBI+DSB completes before a read using the translation being
769 invalidated has been observed by other observers. The
770 workaround repeats the TLBI+DSB operation.
771
772 If unsure, say N.
773
774config ARM64_ERRATUM_1463225
775 bool "Cortex-A76: Software Step might prevent interrupt recognition"
776 default y
777 help
778 This option adds a workaround for Arm Cortex-A76 erratum 1463225.
779
780 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
781 of a system call instruction (SVC) can prevent recognition of
782 subsequent interrupts when software stepping is disabled in the
783 exception handler of the system call and either kernel debugging
784 is enabled or VHE is in use.
785
786 Work around the erratum by triggering a dummy step exception
787 when handling a system call from a task that is being stepped
788 in a VHE configuration of the kernel.
789
790 If unsure, say Y.
791
792config ARM64_ERRATUM_1542419
793 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
794 help
795 This option adds a workaround for ARM Neoverse-N1 erratum
796 1542419.
797
798 Affected Neoverse-N1 cores could execute a stale instruction when
799 modified by another CPU. The workaround depends on a firmware
800 counterpart.
801
802 Workaround the issue by hiding the DIC feature from EL0. This
803 forces user-space to perform cache maintenance.
804
805 If unsure, say N.
806
807config ARM64_ERRATUM_1508412
808 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
809 default y
810 help
811 This option adds a workaround for Arm Cortex-A77 erratum 1508412.
812
813 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
814 of a store-exclusive or read of PAR_EL1 and a load with device or
815 non-cacheable memory attributes. The workaround depends on a firmware
816 counterpart.
817
818 KVM guests must also have the workaround implemented or they can
819 deadlock the system.
820
821 Work around the issue by inserting DMB SY barriers around PAR_EL1
822 register reads and warning KVM users. The DMB barrier is sufficient
823 to prevent a speculative PAR_EL1 read.
824
825 If unsure, say Y.
826
827config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
828 bool
829
830config ARM64_ERRATUM_2051678
831 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
832 default y
833 help
834 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
835 Affected Cortex-A510 might not respect the ordering rules for
836 hardware update of the page table's dirty bit. The workaround
837 is to not enable the feature on affected CPUs.
838
839 If unsure, say Y.
840
841config ARM64_ERRATUM_2077057
842 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
843 default y
844 help
845 This option adds the workaround for ARM Cortex-A510 erratum 2077057.
846 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
847 expected, but a Pointer Authentication trap is taken instead. The
848 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
849 EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
850
851 This can only happen when EL2 is stepping EL1.
852
853 When these conditions occur, the SPSR_EL2 value is unchanged from the
854 previous guest entry, and can be restored from the in-memory copy.
855
856 If unsure, say Y.
857
858config ARM64_ERRATUM_2658417
859 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
860 default y
861 help
862 This option adds the workaround for ARM Cortex-A510 erratum 2658417.
863 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
864 BFMMLA or VMMLA instructions in rare circumstances when a pair of
865 A510 CPUs are using shared neon hardware. As the sharing is not
866 discoverable by the kernel, hide the BF16 HWCAP to indicate that
867 user-space should not be using these instructions.
868
869 If unsure, say Y.
870
871config ARM64_ERRATUM_2119858
872 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
873 default y
874 depends on CORESIGHT_TRBE
875 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
876 help
877 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
878
879 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
880 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
881 the event of a WRAP event.
882
883 Work around the issue by always making sure we move the TRBPTR_EL1 by
884 256 bytes before enabling the buffer and filling the first 256 bytes of
885 the buffer with ETM ignore packets upon disabling.
886
887 If unsure, say Y.
888
889config ARM64_ERRATUM_2139208
890 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
891 default y
892 depends on CORESIGHT_TRBE
893 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
894 help
895 This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
896
897 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
898 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
899 the event of a WRAP event.
900
901 Work around the issue by always making sure we move the TRBPTR_EL1 by
902 256 bytes before enabling the buffer and filling the first 256 bytes of
903 the buffer with ETM ignore packets upon disabling.
904
905 If unsure, say Y.
906
907config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
908 bool
909
910config ARM64_ERRATUM_2054223
911 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
912 default y
913 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
914 help
915 Enable workaround for ARM Cortex-A710 erratum 2054223
916
917 Affected cores may fail to flush the trace data on a TSB instruction, when
918 the PE is in trace prohibited state. This will cause losing a few bytes
919 of the trace cached.
920
921 Workaround is to issue two TSB consecutively on affected cores.
922
923 If unsure, say Y.
924
925config ARM64_ERRATUM_2067961
926 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
927 default y
928 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
929 help
930 Enable workaround for ARM Neoverse-N2 erratum 2067961
931
932 Affected cores may fail to flush the trace data on a TSB instruction, when
933 the PE is in trace prohibited state. This will cause losing a few bytes
934 of the trace cached.
935
936 Workaround is to issue two TSB consecutively on affected cores.
937
938 If unsure, say Y.
939
940config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
941 bool
942
943config ARM64_ERRATUM_2253138
944 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
945 depends on CORESIGHT_TRBE
946 default y
947 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
948 help
949 This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
950
951 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
952 for TRBE. Under some conditions, the TRBE might generate a write to the next
953 virtually addressed page following the last page of the TRBE address space
954 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
955
956 Work around this in the driver by always making sure that there is a
957 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
958
959 If unsure, say Y.
960
961config ARM64_ERRATUM_2224489
962 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
963 depends on CORESIGHT_TRBE
964 default y
965 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
966 help
967 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
968
969 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
970 for TRBE. Under some conditions, the TRBE might generate a write to the next
971 virtually addressed page following the last page of the TRBE address space
972 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
973
974 Work around this in the driver by always making sure that there is a
975 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
976
977 If unsure, say Y.
978
979config ARM64_ERRATUM_2441009
980 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
981 select ARM64_WORKAROUND_REPEAT_TLBI
982 help
983 This option adds a workaround for ARM Cortex-A510 erratum #2441009.
984
985 Under very rare circumstances, affected Cortex-A510 CPUs
986 may not handle a race between a break-before-make sequence on one
987 CPU, and another CPU accessing the same page. This could allow a
988 store to a page that has been unmapped.
989
990 Work around this by adding the affected CPUs to the list that needs
991 TLB sequences to be done twice.
992
993 If unsure, say N.
994
995config ARM64_ERRATUM_2064142
996 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
997 depends on CORESIGHT_TRBE
998 default y
999 help
1000 This option adds the workaround for ARM Cortex-A510 erratum 2064142.
1001
1002 Affected Cortex-A510 core might fail to write into system registers after the
1003 TRBE has been disabled. Under some conditions after the TRBE has been disabled
1004 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
1005 and TRBTRG_EL1 will be ignored and will not be effected.
1006
1007 Work around this in the driver by executing TSB CSYNC and DSB after collection
1008 is stopped and before performing a system register write to one of the affected
1009 registers.
1010
1011 If unsure, say Y.
1012
1013config ARM64_ERRATUM_2038923
1014 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
1015 depends on CORESIGHT_TRBE
1016 default y
1017 help
1018 This option adds the workaround for ARM Cortex-A510 erratum 2038923.
1019
1020 Affected Cortex-A510 core might cause an inconsistent view on whether trace is
1021 prohibited within the CPU. As a result, the trace buffer or trace buffer state
1022 might be corrupted. This happens after TRBE buffer has been enabled by setting
1023 TRBLIMITR_EL1.E, followed by just a single context synchronization event before
1024 execution changes from a context, in which trace is prohibited to one where it
1025 isn't, or vice versa. In these mentioned conditions, the view of whether trace
1026 is prohibited is inconsistent between parts of the CPU, and the trace buffer or
1027 the trace buffer state might be corrupted.
1028
1029 Work around this in the driver by preventing an inconsistent view of whether the
1030 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
1031 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
1032 two ISB instructions if no ERET is to take place.
1033
1034 If unsure, say Y.
1035
1036config ARM64_ERRATUM_1902691
1037 bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1038 depends on CORESIGHT_TRBE
1039 default y
1040 help
1041 This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1042
1043 Affected Cortex-A510 core might cause trace data corruption, when being written
1044 into the memory. Effectively TRBE is broken and hence cannot be used to capture
1045 trace data.
1046
1047 Work around this problem in the driver by just preventing TRBE initialization on
1048 affected cpus. The firmware must have disabled the access to TRBE for the kernel
1049 on such implementations. This will cover the kernel for any firmware that doesn't
1050 do this already.
1051
1052 If unsure, say Y.
1053
1054config ARM64_ERRATUM_2457168
1055 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1056 depends on ARM64_AMU_EXTN
1057 default y
1058 help
1059 This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1060
1061 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1062 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1063 incorrectly giving a significantly higher output value.
1064
1065 Work around this problem by returning 0 when reading the affected counter in
1066 key locations that results in disabling all users of this counter. This effect
1067 is the same to firmware disabling affected counters.
1068
1069 If unsure, say Y.
1070
1071config ARM64_ERRATUM_2645198
1072 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1073 default y
1074 help
1075 This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1076
1077 If a Cortex-A715 cpu sees a page mapping permissions change from executable
1078 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1079 next instruction abort caused by permission fault.
1080
1081 Only user-space does executable to non-executable permission transition via
1082 mprotect() system call. Workaround the problem by doing a break-before-make
1083 TLB invalidation, for all changes to executable user space mappings.
1084
1085 If unsure, say Y.
1086
1087config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1088 bool
1089
1090config ARM64_ERRATUM_2966298
1091 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1092 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1093 default y
1094 help
1095 This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1096
1097 On an affected Cortex-A520 core, a speculatively executed unprivileged
1098 load might leak data from a privileged level via a cache side channel.
1099
1100 Work around this problem by executing a TLBI before returning to EL0.
1101
1102 If unsure, say Y.
1103
1104config ARM64_ERRATUM_3117295
1105 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1106 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1107 default y
1108 help
1109 This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1110
1111 On an affected Cortex-A510 core, a speculatively executed unprivileged
1112 load might leak data from a privileged level via a cache side channel.
1113
1114 Work around this problem by executing a TLBI before returning to EL0.
1115
1116 If unsure, say Y.
1117
1118config ARM64_ERRATUM_3194386
1119 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1120 default y
1121 help
1122 This option adds the workaround for the following errata:
1123
1124 * ARM Cortex-A76 erratum 3324349
1125 * ARM Cortex-A77 erratum 3324348
1126 * ARM Cortex-A78 erratum 3324344
1127 * ARM Cortex-A78C erratum 3324346
1128 * ARM Cortex-A78C erratum 3324347
1129 * ARM Cortex-A710 erratam 3324338
1130 * ARM Cortex-A715 errartum 3456084
1131 * ARM Cortex-A720 erratum 3456091
1132 * ARM Cortex-A725 erratum 3456106
1133 * ARM Cortex-X1 erratum 3324344
1134 * ARM Cortex-X1C erratum 3324346
1135 * ARM Cortex-X2 erratum 3324338
1136 * ARM Cortex-X3 erratum 3324335
1137 * ARM Cortex-X4 erratum 3194386
1138 * ARM Cortex-X925 erratum 3324334
1139 * ARM Neoverse-N1 erratum 3324349
1140 * ARM Neoverse N2 erratum 3324339
1141 * ARM Neoverse-N3 erratum 3456111
1142 * ARM Neoverse-V1 erratum 3324341
1143 * ARM Neoverse V2 erratum 3324336
1144 * ARM Neoverse-V3 erratum 3312417
1145 * ARM Neoverse-V3AE erratum 3312417
1146
1147 On affected cores "MSR SSBS, #0" instructions may not affect
1148 subsequent speculative instructions, which may permit unexepected
1149 speculative store bypassing.
1150
1151 Work around this problem by placing a Speculation Barrier (SB) or
1152 Instruction Synchronization Barrier (ISB) after kernel changes to
1153 SSBS. The presence of the SSBS special-purpose register is hidden
1154 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1155 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1156
1157 If unsure, say Y.
1158
1159config ARM64_ERRATUM_4311569
1160 bool "SI L1: 4311569: workaround for premature CMO completion erratum"
1161 default y
1162 help
1163 This option adds the workaround for ARM SI L1 erratum 4311569.
1164
1165 The erratum of SI L1 can cause an early response to a combined write
1166 and cache maintenance operation (WR+CMO) before the operation is fully
1167 completed to the Point of Serialization (POS).
1168 This can result in a non-I/O coherent agent observing stale data,
1169 potentially leading to system instability or incorrect behavior.
1170
1171 Enabling this option implements a software workaround by inserting a
1172 second loop of Cache Maintenance Operation (CMO) immediately following the
1173 end of function to do CMOs. This ensures that the data is correctly serialized
1174 before the buffer is handed off to a non-coherent agent.
1175
1176 If unsure, say Y.
1177
1178config CAVIUM_ERRATUM_22375
1179 bool "Cavium erratum 22375, 24313"
1180 default y
1181 help
1182 Enable workaround for errata 22375 and 24313.
1183
1184 This implements two gicv3-its errata workarounds for ThunderX. Both
1185 with a small impact affecting only ITS table allocation.
1186
1187 erratum 22375: only alloc 8MB table size
1188 erratum 24313: ignore memory access type
1189
1190 The fixes are in ITS initialization and basically ignore memory access
1191 type and table size provided by the TYPER and BASER registers.
1192
1193 If unsure, say Y.
1194
1195config CAVIUM_ERRATUM_23144
1196 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1197 depends on NUMA
1198 default y
1199 help
1200 ITS SYNC command hang for cross node io and collections/cpu mapping.
1201
1202 If unsure, say Y.
1203
1204config CAVIUM_ERRATUM_23154
1205 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1206 default y
1207 help
1208 The ThunderX GICv3 implementation requires a modified version for
1209 reading the IAR status to ensure data synchronization
1210 (access to icc_iar1_el1 is not sync'ed before and after).
1211
1212 It also suffers from erratum 38545 (also present on Marvell's
1213 OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1214 spuriously presented to the CPU interface.
1215
1216 If unsure, say Y.
1217
1218config CAVIUM_ERRATUM_27456
1219 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1220 default y
1221 help
1222 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1223 instructions may cause the icache to become corrupted if it
1224 contains data for a non-current ASID. The fix is to
1225 invalidate the icache when changing the mm context.
1226
1227 If unsure, say Y.
1228
1229config CAVIUM_ERRATUM_30115
1230 bool "Cavium erratum 30115: Guest may disable interrupts in host"
1231 default y
1232 help
1233 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1234 1.2, and T83 Pass 1.0, KVM guest execution may disable
1235 interrupts in host. Trapping both GICv3 group-0 and group-1
1236 accesses sidesteps the issue.
1237
1238 If unsure, say Y.
1239
1240config CAVIUM_TX2_ERRATUM_219
1241 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1242 default y
1243 help
1244 On Cavium ThunderX2, a load, store or prefetch instruction between a
1245 TTBR update and the corresponding context synchronizing operation can
1246 cause a spurious Data Abort to be delivered to any hardware thread in
1247 the CPU core.
1248
1249 Work around the issue by avoiding the problematic code sequence and
1250 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1251 trap handler performs the corresponding register access, skips the
1252 instruction and ensures context synchronization by virtue of the
1253 exception return.
1254
1255 If unsure, say Y.
1256
1257config FUJITSU_ERRATUM_010001
1258 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1259 default y
1260 help
1261 This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1262 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1263 accesses may cause undefined fault (Data abort, DFSC=0b111111).
1264 This fault occurs under a specific hardware condition when a
1265 load/store instruction performs an address translation using:
1266 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1267 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1268 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1269 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1270
1271 The workaround is to ensure these bits are clear in TCR_ELx.
1272 The workaround only affects the Fujitsu-A64FX.
1273
1274 If unsure, say Y.
1275
1276config HISILICON_ERRATUM_161600802
1277 bool "Hip07 161600802: Erroneous redistributor VLPI base"
1278 default y
1279 help
1280 The HiSilicon Hip07 SoC uses the wrong redistributor base
1281 when issued ITS commands such as VMOVP and VMAPP, and requires
1282 a 128kB offset to be applied to the target address in this commands.
1283
1284 If unsure, say Y.
1285
1286config HISILICON_ERRATUM_162100801
1287 bool "Hip09 162100801 erratum support"
1288 default y
1289 help
1290 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches
1291 during unmapping operation, which will cause some vSGIs lost.
1292 To fix the issue, invalidate related vPE cache through GICR_INVALLR
1293 after VMOVP.
1294
1295 If unsure, say Y.
1296
1297config QCOM_FALKOR_ERRATUM_1003
1298 bool "Falkor E1003: Incorrect translation due to ASID change"
1299 default y
1300 help
1301 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1302 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1303 in TTBR1_EL1, this situation only occurs in the entry trampoline and
1304 then only for entries in the walk cache, since the leaf translation
1305 is unchanged. Work around the erratum by invalidating the walk cache
1306 entries for the trampoline before entering the kernel proper.
1307
1308config QCOM_FALKOR_ERRATUM_1009
1309 bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1310 default y
1311 select ARM64_WORKAROUND_REPEAT_TLBI
1312 help
1313 On Falkor v1, the CPU may prematurely complete a DSB following a
1314 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1315 one more time to fix the issue.
1316
1317 If unsure, say Y.
1318
1319config QCOM_QDF2400_ERRATUM_0065
1320 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1321 default y
1322 help
1323 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1324 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1325 been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1326
1327 If unsure, say Y.
1328
1329config QCOM_FALKOR_ERRATUM_E1041
1330 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1331 default y
1332 help
1333 Falkor CPU may speculatively fetch instructions from an improper
1334 memory location when MMU translation is changed from SCTLR_ELn[M]=1
1335 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1336
1337 If unsure, say Y.
1338
1339config NVIDIA_CARMEL_CNP_ERRATUM
1340 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1341 default y
1342 help
1343 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1344 invalidate shared TLB entries installed by a different core, as it would
1345 on standard ARM cores.
1346
1347 If unsure, say Y.
1348
1349config ROCKCHIP_ERRATUM_3568002
1350 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB"
1351 default y
1352 help
1353 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI
1354 addressing limited to the first 32bit of physical address space.
1355
1356 If unsure, say Y.
1357
1358config ROCKCHIP_ERRATUM_3588001
1359 bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1360 default y
1361 help
1362 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1363 This means, that its sharability feature may not be used, even though it
1364 is supported by the IP itself.
1365
1366 If unsure, say Y.
1367
1368config SOCIONEXT_SYNQUACER_PREITS
1369 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1370 default y
1371 help
1372 Socionext Synquacer SoCs implement a separate h/w block to generate
1373 MSI doorbell writes with non-zero values for the device ID.
1374
1375 If unsure, say Y.
1376
1377endmenu # "ARM errata workarounds via the alternatives framework"
1378
1379choice
1380 prompt "Page size"
1381 default ARM64_4K_PAGES
1382 help
1383 Page size (translation granule) configuration.
1384
1385config ARM64_4K_PAGES
1386 bool "4KB"
1387 select HAVE_PAGE_SIZE_4KB
1388 help
1389 This feature enables 4KB pages support.
1390
1391config ARM64_16K_PAGES
1392 bool "16KB"
1393 select HAVE_PAGE_SIZE_16KB
1394 help
1395 The system will use 16KB pages support. AArch32 emulation
1396 requires applications compiled with 16K (or a multiple of 16K)
1397 aligned segments.
1398
1399config ARM64_64K_PAGES
1400 bool "64KB"
1401 select HAVE_PAGE_SIZE_64KB
1402 help
1403 This feature enables 64KB pages support (4KB by default)
1404 allowing only two levels of page tables and faster TLB
1405 look-up. AArch32 emulation requires applications compiled
1406 with 64K aligned segments.
1407
1408endchoice
1409
1410choice
1411 prompt "Virtual address space size"
1412 default ARM64_VA_BITS_52
1413 help
1414 Allows choosing one of multiple possible virtual address
1415 space sizes. The level of translation table is determined by
1416 a combination of page size and virtual address space size.
1417
1418config ARM64_VA_BITS_36
1419 bool "36-bit" if EXPERT
1420 depends on PAGE_SIZE_16KB
1421
1422config ARM64_VA_BITS_39
1423 bool "39-bit"
1424 depends on PAGE_SIZE_4KB
1425
1426config ARM64_VA_BITS_42
1427 bool "42-bit"
1428 depends on PAGE_SIZE_64KB
1429
1430config ARM64_VA_BITS_47
1431 bool "47-bit"
1432 depends on PAGE_SIZE_16KB
1433
1434config ARM64_VA_BITS_48
1435 bool "48-bit"
1436
1437config ARM64_VA_BITS_52
1438 bool "52-bit"
1439 help
1440 Enable 52-bit virtual addressing for userspace when explicitly
1441 requested via a hint to mmap(). The kernel will also use 52-bit
1442 virtual addresses for its own mappings (provided HW support for
1443 this feature is available, otherwise it reverts to 48-bit).
1444
1445 NOTE: Enabling 52-bit virtual addressing in conjunction with
1446 ARMv8.3 Pointer Authentication will result in the PAC being
1447 reduced from 7 bits to 3 bits, which may have a significant
1448 impact on its susceptibility to brute-force attacks.
1449
1450 If unsure, select 48-bit virtual addressing instead.
1451
1452endchoice
1453
1454config ARM64_FORCE_52BIT
1455 bool "Force 52-bit virtual addresses for userspace"
1456 depends on ARM64_VA_BITS_52 && EXPERT
1457 help
1458 For systems with 52-bit userspace VAs enabled, the kernel will attempt
1459 to maintain compatibility with older software by providing 48-bit VAs
1460 unless a hint is supplied to mmap.
1461
1462 This configuration option disables the 48-bit compatibility logic, and
1463 forces all userspace addresses to be 52-bit on HW that supports it. One
1464 should only enable this configuration option for stress testing userspace
1465 memory management code. If unsure say N here.
1466
1467config ARM64_VA_BITS
1468 int
1469 default 36 if ARM64_VA_BITS_36
1470 default 39 if ARM64_VA_BITS_39
1471 default 42 if ARM64_VA_BITS_42
1472 default 47 if ARM64_VA_BITS_47
1473 default 48 if ARM64_VA_BITS_48
1474 default 52 if ARM64_VA_BITS_52
1475
1476choice
1477 prompt "Physical address space size"
1478 default ARM64_PA_BITS_48
1479 help
1480 Choose the maximum physical address range that the kernel will
1481 support.
1482
1483config ARM64_PA_BITS_48
1484 bool "48-bit"
1485 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1486
1487config ARM64_PA_BITS_52
1488 bool "52-bit"
1489 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1490 help
1491 Enable support for a 52-bit physical address space, introduced as
1492 part of the ARMv8.2-LPA extension.
1493
1494 With this enabled, the kernel will also continue to work on CPUs that
1495 do not support ARMv8.2-LPA, but with some added memory overhead (and
1496 minor performance overhead).
1497
1498endchoice
1499
1500config ARM64_PA_BITS
1501 int
1502 default 48 if ARM64_PA_BITS_48
1503 default 52 if ARM64_PA_BITS_52
1504
1505config ARM64_LPA2
1506 def_bool y
1507 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1508
1509choice
1510 prompt "Endianness"
1511 default CPU_LITTLE_ENDIAN
1512 help
1513 Select the endianness of data accesses performed by the CPU. Userspace
1514 applications will need to be compiled and linked for the endianness
1515 that is selected here.
1516
1517config CPU_BIG_ENDIAN
1518 bool "Build big-endian kernel"
1519 depends on BROKEN
1520 help
1521 Say Y if you plan on running a kernel with a big-endian userspace.
1522
1523config CPU_LITTLE_ENDIAN
1524 bool "Build little-endian kernel"
1525 help
1526 Say Y if you plan on running a kernel with a little-endian userspace.
1527 This is usually the case for distributions targeting arm64.
1528
1529endchoice
1530
1531config NR_CPUS
1532 int "Maximum number of CPUs (2-4096)"
1533 range 2 4096
1534 default "512"
1535
1536config HOTPLUG_CPU
1537 bool "Support for hot-pluggable CPUs"
1538 select GENERIC_IRQ_MIGRATION
1539 help
1540 Say Y here to experiment with turning CPUs off and on. CPUs
1541 can be controlled through /sys/devices/system/cpu.
1542
1543# Common NUMA Features
1544config NUMA
1545 bool "NUMA Memory Allocation and Scheduler Support"
1546 select GENERIC_ARCH_NUMA
1547 select OF_NUMA
1548 select HAVE_SETUP_PER_CPU_AREA
1549 select NEED_PER_CPU_EMBED_FIRST_CHUNK
1550 select NEED_PER_CPU_PAGE_FIRST_CHUNK
1551 select USE_PERCPU_NUMA_NODE_ID
1552 help
1553 Enable NUMA (Non-Uniform Memory Access) support.
1554
1555 The kernel will try to allocate memory used by a CPU on the
1556 local memory of the CPU and add some more
1557 NUMA awareness to the kernel.
1558
1559config NODES_SHIFT
1560 int "Maximum NUMA Nodes (as a power of 2)"
1561 range 1 10
1562 default "4"
1563 depends on NUMA
1564 help
1565 Specify the maximum number of NUMA Nodes available on the target
1566 system. Increases memory reserved to accommodate various tables.
1567
1568source "kernel/Kconfig.hz"
1569
1570config ARCH_SPARSEMEM_ENABLE
1571 def_bool y
1572 select SPARSEMEM_VMEMMAP_ENABLE
1573
1574config HW_PERF_EVENTS
1575 def_bool y
1576 depends on ARM_PMU
1577
1578# Supported by clang >= 7.0 or GCC >= 12.0.0
1579config CC_HAVE_SHADOW_CALL_STACK
1580 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1581
1582config PARAVIRT
1583 bool "Enable paravirtualization code"
1584 select HAVE_PV_STEAL_CLOCK_GEN
1585 help
1586 This changes the kernel so it can modify itself when it is run
1587 under a hypervisor, potentially improving performance significantly
1588 over full virtualization.
1589
1590config PARAVIRT_TIME_ACCOUNTING
1591 bool "Paravirtual steal time accounting"
1592 select PARAVIRT
1593 help
1594 Select this option to enable fine granularity task steal time
1595 accounting. Time spent executing other tasks in parallel with
1596 the current vCPU is discounted from the vCPU power. To account for
1597 that, there can be a small performance impact.
1598
1599 If in doubt, say N here.
1600
1601config ARCH_SUPPORTS_KEXEC
1602 def_bool PM_SLEEP_SMP
1603
1604config ARCH_SUPPORTS_KEXEC_FILE
1605 def_bool y
1606
1607config ARCH_SELECTS_KEXEC_FILE
1608 def_bool y
1609 depends on KEXEC_FILE
1610 select HAVE_IMA_KEXEC if IMA
1611
1612config ARCH_SUPPORTS_KEXEC_SIG
1613 def_bool y
1614
1615config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1616 def_bool y
1617
1618config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1619 def_bool y
1620
1621config ARCH_SUPPORTS_KEXEC_HANDOVER
1622 def_bool y
1623
1624config ARCH_SUPPORTS_CRASH_DUMP
1625 def_bool y
1626
1627config ARCH_DEFAULT_CRASH_DUMP
1628 def_bool y
1629
1630config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1631 def_bool CRASH_RESERVE
1632
1633config TRANS_TABLE
1634 def_bool y
1635 depends on HIBERNATION || KEXEC_CORE
1636
1637config XEN_DOM0
1638 def_bool y
1639 depends on XEN
1640
1641config XEN
1642 bool "Xen guest support on ARM64"
1643 depends on ARM64 && OF
1644 select SWIOTLB_XEN
1645 select PARAVIRT
1646 help
1647 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1648
1649# include/linux/mmzone.h requires the following to be true:
1650#
1651# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1652#
1653# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1654#
1655# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER |
1656# ----+-------------------+--------------+----------------------+-------------------------+
1657# 4K | 27 | 12 | 15 | 10 |
1658# 16K | 27 | 14 | 13 | 11 |
1659# 64K | 29 | 16 | 13 | 13 |
1660config ARCH_FORCE_MAX_ORDER
1661 int
1662 default "13" if ARM64_64K_PAGES
1663 default "11" if ARM64_16K_PAGES
1664 default "10"
1665 help
1666 The kernel page allocator limits the size of maximal physically
1667 contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1668 defines the maximal power of two of number of pages that can be
1669 allocated as a single contiguous block. This option allows
1670 overriding the default setting when ability to allocate very
1671 large blocks of physically contiguous memory is required.
1672
1673 The maximal size of allocation cannot exceed the size of the
1674 section, so the value of MAX_PAGE_ORDER should satisfy
1675
1676 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1677
1678 Don't change if unsure.
1679
1680config UNMAP_KERNEL_AT_EL0
1681 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1682 default y
1683 help
1684 Speculation attacks against some high-performance processors can
1685 be used to bypass MMU permission checks and leak kernel data to
1686 userspace. This can be defended against by unmapping the kernel
1687 when running in userspace, mapping it back in on exception entry
1688 via a trampoline page in the vector table.
1689
1690 If unsure, say Y.
1691
1692config MITIGATE_SPECTRE_BRANCH_HISTORY
1693 bool "Mitigate Spectre style attacks against branch history" if EXPERT
1694 default y
1695 help
1696 Speculation attacks against some high-performance processors can
1697 make use of branch history to influence future speculation.
1698 When taking an exception from user-space, a sequence of branches
1699 or a firmware call overwrites the branch history.
1700
1701config ARM64_SW_TTBR0_PAN
1702 bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1703 depends on !KCSAN
1704 help
1705 Enabling this option prevents the kernel from accessing
1706 user-space memory directly by pointing TTBR0_EL1 to a reserved
1707 zeroed area and reserved ASID. The user access routines
1708 restore the valid TTBR0_EL1 temporarily.
1709
1710config ARM64_TAGGED_ADDR_ABI
1711 bool "Enable the tagged user addresses syscall ABI"
1712 default y
1713 help
1714 When this option is enabled, user applications can opt in to a
1715 relaxed ABI via prctl() allowing tagged addresses to be passed
1716 to system calls as pointer arguments. For details, see
1717 Documentation/arch/arm64/tagged-address-abi.rst.
1718
1719menuconfig COMPAT
1720 bool "Kernel support for 32-bit EL0"
1721 depends on ARM64_4K_PAGES || EXPERT
1722 select HAVE_UID16
1723 select OLD_SIGSUSPEND3
1724 select COMPAT_OLD_SIGACTION
1725 help
1726 This option enables support for a 32-bit EL0 running under a 64-bit
1727 kernel at EL1. AArch32-specific components such as system calls,
1728 the user helper functions, VFP support and the ptrace interface are
1729 handled appropriately by the kernel.
1730
1731 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1732 that you will only be able to execute AArch32 binaries that were compiled
1733 with page size aligned segments.
1734
1735 If you want to execute 32-bit userspace applications, say Y.
1736
1737if COMPAT
1738
1739config KUSER_HELPERS
1740 bool "Enable kuser helpers page for 32-bit applications"
1741 default y
1742 help
1743 Warning: disabling this option may break 32-bit user programs.
1744
1745 Provide kuser helpers to compat tasks. The kernel provides
1746 helper code to userspace in read only form at a fixed location
1747 to allow userspace to be independent of the CPU type fitted to
1748 the system. This permits binaries to be run on ARMv4 through
1749 to ARMv8 without modification.
1750
1751 See Documentation/arch/arm/kernel_user_helpers.rst for details.
1752
1753 However, the fixed address nature of these helpers can be used
1754 by ROP (return orientated programming) authors when creating
1755 exploits.
1756
1757 If all of the binaries and libraries which run on your platform
1758 are built specifically for your platform, and make no use of
1759 these helpers, then you can turn this option off to hinder
1760 such exploits. However, in that case, if a binary or library
1761 relying on those helpers is run, it will not function correctly.
1762
1763 Say N here only if you are absolutely certain that you do not
1764 need these helpers; otherwise, the safe option is to say Y.
1765
1766config COMPAT_VDSO
1767 bool "Enable vDSO for 32-bit applications"
1768 depends on !CPU_BIG_ENDIAN
1769 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1770 default y
1771 help
1772 Place in the process address space of 32-bit applications an
1773 ELF shared object providing fast implementations of gettimeofday
1774 and clock_gettime.
1775
1776 You must have a 32-bit build of glibc 2.22 or later for programs
1777 to seamlessly take advantage of this.
1778
1779config THUMB2_COMPAT_VDSO
1780 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1781 depends on COMPAT_VDSO
1782 default y
1783 help
1784 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1785 otherwise with '-marm'.
1786
1787config COMPAT_ALIGNMENT_FIXUPS
1788 bool "Fix up misaligned multi-word loads and stores in user space"
1789
1790menuconfig ARMV8_DEPRECATED
1791 bool "Emulate deprecated/obsolete ARMv8 instructions"
1792 depends on SYSCTL
1793 help
1794 Legacy software support may require certain instructions
1795 that have been deprecated or obsoleted in the architecture.
1796
1797 Enable this config to enable selective emulation of these
1798 features.
1799
1800 If unsure, say Y
1801
1802if ARMV8_DEPRECATED
1803
1804config SWP_EMULATION
1805 bool "Emulate SWP/SWPB instructions"
1806 help
1807 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1808 they are always undefined. Say Y here to enable software
1809 emulation of these instructions for userspace using LDXR/STXR.
1810 This feature can be controlled at runtime with the abi.swp
1811 sysctl which is disabled by default.
1812
1813 In some older versions of glibc [<=2.8] SWP is used during futex
1814 trylock() operations with the assumption that the code will not
1815 be preempted. This invalid assumption may be more likely to fail
1816 with SWP emulation enabled, leading to deadlock of the user
1817 application.
1818
1819 NOTE: when accessing uncached shared regions, LDXR/STXR rely
1820 on an external transaction monitoring block called a global
1821 monitor to maintain update atomicity. If your system does not
1822 implement a global monitor, this option can cause programs that
1823 perform SWP operations to uncached memory to deadlock.
1824
1825 If unsure, say Y
1826
1827config CP15_BARRIER_EMULATION
1828 bool "Emulate CP15 Barrier instructions"
1829 help
1830 The CP15 barrier instructions - CP15ISB, CP15DSB, and
1831 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1832 strongly recommended to use the ISB, DSB, and DMB
1833 instructions instead.
1834
1835 Say Y here to enable software emulation of these
1836 instructions for AArch32 userspace code. When this option is
1837 enabled, CP15 barrier usage is traced which can help
1838 identify software that needs updating. This feature can be
1839 controlled at runtime with the abi.cp15_barrier sysctl.
1840
1841 If unsure, say Y
1842
1843config SETEND_EMULATION
1844 bool "Emulate SETEND instruction"
1845 help
1846 The SETEND instruction alters the data-endianness of the
1847 AArch32 EL0, and is deprecated in ARMv8.
1848
1849 Say Y here to enable software emulation of the instruction
1850 for AArch32 userspace code. This feature can be controlled
1851 at runtime with the abi.setend sysctl.
1852
1853 Note: All the cpus on the system must have mixed endian support at EL0
1854 for this feature to be enabled. If a new CPU - which doesn't support mixed
1855 endian - is hotplugged in after this feature has been enabled, there could
1856 be unexpected results in the applications.
1857
1858 If unsure, say Y
1859endif # ARMV8_DEPRECATED
1860
1861endif # COMPAT
1862
1863menu "ARMv8.1 architectural features"
1864
1865config ARM64_HW_AFDBM
1866 bool "Support for hardware updates of the Access and Dirty page flags"
1867 default y
1868 help
1869 The ARMv8.1 architecture extensions introduce support for
1870 hardware updates of the access and dirty information in page
1871 table entries. When enabled in TCR_EL1 (HA and HD bits) on
1872 capable processors, accesses to pages with PTE_AF cleared will
1873 set this bit instead of raising an access flag fault.
1874 Similarly, writes to read-only pages with the DBM bit set will
1875 clear the read-only bit (AP[2]) instead of raising a
1876 permission fault.
1877
1878 Kernels built with this configuration option enabled continue
1879 to work on pre-ARMv8.1 hardware and the performance impact is
1880 minimal. If unsure, say Y.
1881
1882endmenu # "ARMv8.1 architectural features"
1883
1884menu "ARMv8.2 architectural features"
1885
1886config ARM64_PMEM
1887 bool "Enable support for persistent memory"
1888 select ARCH_HAS_PMEM_API
1889 select ARCH_HAS_UACCESS_FLUSHCACHE
1890 help
1891 Say Y to enable support for the persistent memory API based on the
1892 ARMv8.2 DCPoP feature.
1893
1894 The feature is detected at runtime, and the kernel will use DC CVAC
1895 operations if DC CVAP is not supported (following the behaviour of
1896 DC CVAP itself if the system does not define a point of persistence).
1897
1898config ARM64_RAS_EXTN
1899 bool "Enable support for RAS CPU Extensions"
1900 default y
1901 help
1902 CPUs that support the Reliability, Availability and Serviceability
1903 (RAS) Extensions, part of ARMv8.2 are able to track faults and
1904 errors, classify them and report them to software.
1905
1906 On CPUs with these extensions system software can use additional
1907 barriers to determine if faults are pending and read the
1908 classification from a new set of registers.
1909
1910 Selecting this feature will allow the kernel to use these barriers
1911 and access the new registers if the system supports the extension.
1912 Platform RAS features may additionally depend on firmware support.
1913
1914config ARM64_CNP
1915 bool "Enable support for Common Not Private (CNP) translations"
1916 default y
1917 help
1918 Common Not Private (CNP) allows translation table entries to
1919 be shared between different PEs in the same inner shareable
1920 domain, so the hardware can use this fact to optimise the
1921 caching of such entries in the TLB.
1922
1923 Selecting this option allows the CNP feature to be detected
1924 at runtime, and does not affect PEs that do not implement
1925 this feature.
1926
1927endmenu # "ARMv8.2 architectural features"
1928
1929menu "ARMv8.3 architectural features"
1930
1931config ARM64_PTR_AUTH
1932 bool "Enable support for pointer authentication"
1933 default y
1934 help
1935 Pointer authentication (part of the ARMv8.3 Extensions) provides
1936 instructions for signing and authenticating pointers against secret
1937 keys, which can be used to mitigate Return Oriented Programming (ROP)
1938 and other attacks.
1939
1940 This option enables these instructions at EL0 (i.e. for userspace).
1941 Choosing this option will cause the kernel to initialise secret keys
1942 for each process at exec() time, with these keys being
1943 context-switched along with the process.
1944
1945 The feature is detected at runtime. If the feature is not present in
1946 hardware it will not be advertised to userspace/KVM guest nor will it
1947 be enabled.
1948
1949 If the feature is present on the boot CPU but not on a late CPU, then
1950 the late CPU will be parked. Also, if the boot CPU does not have
1951 address auth and the late CPU has then the late CPU will still boot
1952 but with the feature disabled. On such a system, this option should
1953 not be selected.
1954
1955config ARM64_PTR_AUTH_KERNEL
1956 bool "Use pointer authentication for kernel"
1957 default y
1958 depends on ARM64_PTR_AUTH
1959 # Modern compilers insert a .note.gnu.property section note for PAC
1960 # which is only understood by binutils starting with version 2.33.1.
1961 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1962 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1963 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1964 help
1965 If the compiler supports the -mbranch-protection or
1966 -msign-return-address flag (e.g. GCC 7 or later), then this option
1967 will cause the kernel itself to be compiled with return address
1968 protection. In this case, and if the target hardware is known to
1969 support pointer authentication, then CONFIG_STACKPROTECTOR can be
1970 disabled with minimal loss of protection.
1971
1972 This feature works with FUNCTION_GRAPH_TRACER option only if
1973 DYNAMIC_FTRACE_WITH_ARGS is enabled.
1974
1975config CC_HAS_BRANCH_PROT_PAC_RET
1976 # GCC 9 or later, clang 8 or later
1977 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1978
1979config AS_HAS_CFI_NEGATE_RA_STATE
1980 # binutils 2.34+
1981 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1982
1983endmenu # "ARMv8.3 architectural features"
1984
1985menu "ARMv8.4 architectural features"
1986
1987config ARM64_AMU_EXTN
1988 bool "Enable support for the Activity Monitors Unit CPU extension"
1989 default y
1990 help
1991 The activity monitors extension is an optional extension introduced
1992 by the ARMv8.4 CPU architecture. This enables support for version 1
1993 of the activity monitors architecture, AMUv1.
1994
1995 To enable the use of this extension on CPUs that implement it, say Y.
1996
1997 Note that for architectural reasons, firmware _must_ implement AMU
1998 support when running on CPUs that present the activity monitors
1999 extension. The required support is present in:
2000 * Version 1.5 and later of the ARM Trusted Firmware
2001
2002 For kernels that have this configuration enabled but boot with broken
2003 firmware, you may need to say N here until the firmware is fixed.
2004 Otherwise you may experience firmware panics or lockups when
2005 accessing the counter registers. Even if you are not observing these
2006 symptoms, the values returned by the register reads might not
2007 correctly reflect reality. Most commonly, the value read will be 0,
2008 indicating that the counter is not enabled.
2009
2010config ARM64_TLB_RANGE
2011 bool "Enable support for tlbi range feature"
2012 default y
2013 help
2014 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2015 range of input addresses.
2016
2017config ARM64_MPAM
2018 bool "Enable support for MPAM"
2019 select ARM64_MPAM_DRIVER if EXPERT # does nothing yet
2020 select ACPI_MPAM if ACPI
2021 help
2022 Memory System Resource Partitioning and Monitoring (MPAM) is an
2023 optional extension to the Arm architecture that allows each
2024 transaction issued to the memory system to be labelled with a
2025 Partition identifier (PARTID) and Performance Monitoring Group
2026 identifier (PMG).
2027
2028 Memory system components, such as the caches, can be configured with
2029 policies to control how much of various physical resources (such as
2030 memory bandwidth or cache memory) the transactions labelled with each
2031 PARTID can consume. Depending on the capabilities of the hardware,
2032 the PARTID and PMG can also be used as filtering criteria to measure
2033 the memory system resource consumption of different parts of a
2034 workload.
2035
2036 Use of this extension requires CPU support, support in the
2037 Memory System Components (MSC), and a description from firmware
2038 of where the MSCs are in the address space.
2039
2040 MPAM is exposed to user-space via the resctrl pseudo filesystem.
2041
2042endmenu # "ARMv8.4 architectural features"
2043
2044menu "ARMv8.5 architectural features"
2045
2046config AS_HAS_ARMV8_5
2047 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2048
2049config ARM64_BTI
2050 bool "Branch Target Identification support"
2051 default y
2052 help
2053 Branch Target Identification (part of the ARMv8.5 Extensions)
2054 provides a mechanism to limit the set of locations to which computed
2055 branch instructions such as BR or BLR can jump.
2056
2057 To make use of BTI on CPUs that support it, say Y.
2058
2059 BTI is intended to provide complementary protection to other control
2060 flow integrity protection mechanisms, such as the Pointer
2061 authentication mechanism provided as part of the ARMv8.3 Extensions.
2062 For this reason, it does not make sense to enable this option without
2063 also enabling support for pointer authentication. Thus, when
2064 enabling this option you should also select ARM64_PTR_AUTH=y.
2065
2066 Userspace binaries must also be specifically compiled to make use of
2067 this mechanism. If you say N here or the hardware does not support
2068 BTI, such binaries can still run, but you get no additional
2069 enforcement of branch destinations.
2070
2071config ARM64_BTI_KERNEL
2072 bool "Use Branch Target Identification for kernel"
2073 default y
2074 depends on ARM64_BTI
2075 depends on ARM64_PTR_AUTH_KERNEL
2076 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2077 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2078 depends on !CC_IS_GCC || GCC_VERSION >= 100100
2079 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2080 depends on !CC_IS_GCC
2081 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2082 help
2083 Build the kernel with Branch Target Identification annotations
2084 and enable enforcement of this for kernel code. When this option
2085 is enabled and the system supports BTI all kernel code including
2086 modular code must have BTI enabled.
2087
2088config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2089 # GCC 9 or later, clang 8 or later
2090 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2091
2092config ARM64_E0PD
2093 bool "Enable support for E0PD"
2094 default y
2095 help
2096 E0PD (part of the ARMv8.5 extensions) allows us to ensure
2097 that EL0 accesses made via TTBR1 always fault in constant time,
2098 providing similar benefits to KASLR as those provided by KPTI, but
2099 with lower overhead and without disrupting legitimate access to
2100 kernel memory such as SPE.
2101
2102 This option enables E0PD for TTBR1 where available.
2103
2104config ARM64_AS_HAS_MTE
2105 # Initial support for MTE went in binutils 2.32.0, checked with
2106 # ".arch armv8.5-a+memtag" below. However, this was incomplete
2107 # as a late addition to the final architecture spec (LDGM/STGM)
2108 # is only supported in the newer 2.32.x and 2.33 binutils
2109 # versions, hence the extra "stgm" instruction check below.
2110 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2111
2112config ARM64_MTE
2113 bool "Memory Tagging Extension support"
2114 default y
2115 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2116 depends on AS_HAS_ARMV8_5
2117 # Required for tag checking in the uaccess routines
2118 select ARCH_HAS_SUBPAGE_FAULTS
2119 select ARCH_USES_HIGH_VMA_FLAGS
2120 select ARCH_USES_PG_ARCH_2
2121 select ARCH_USES_PG_ARCH_3
2122 help
2123 Memory Tagging (part of the ARMv8.5 Extensions) provides
2124 architectural support for run-time, always-on detection of
2125 various classes of memory error to aid with software debugging
2126 to eliminate vulnerabilities arising from memory-unsafe
2127 languages.
2128
2129 This option enables the support for the Memory Tagging
2130 Extension at EL0 (i.e. for userspace).
2131
2132 Selecting this option allows the feature to be detected at
2133 runtime. Any secondary CPU not implementing this feature will
2134 not be allowed a late bring-up.
2135
2136 Userspace binaries that want to use this feature must
2137 explicitly opt in. The mechanism for the userspace is
2138 described in:
2139
2140 Documentation/arch/arm64/memory-tagging-extension.rst.
2141
2142endmenu # "ARMv8.5 architectural features"
2143
2144menu "ARMv8.7 architectural features"
2145
2146config ARM64_EPAN
2147 bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2148 default y
2149 help
2150 Enhanced Privileged Access Never (EPAN) allows Privileged
2151 Access Never to be used with Execute-only mappings.
2152
2153 The feature is detected at runtime, and will remain disabled
2154 if the cpu does not implement the feature.
2155endmenu # "ARMv8.7 architectural features"
2156
2157config AS_HAS_MOPS
2158 def_bool $(as-instr,.arch_extension mops)
2159
2160menu "ARMv8.9 architectural features"
2161
2162config ARM64_POE
2163 prompt "Permission Overlay Extension"
2164 def_bool y
2165 select ARCH_USES_HIGH_VMA_FLAGS
2166 select ARCH_HAS_PKEYS
2167 help
2168 The Permission Overlay Extension is used to implement Memory
2169 Protection Keys. Memory Protection Keys provides a mechanism for
2170 enforcing page-based protections, but without requiring modification
2171 of the page tables when an application changes protection domains.
2172
2173 For details, see Documentation/core-api/protection-keys.rst
2174
2175 If unsure, say y.
2176
2177config ARCH_PKEY_BITS
2178 int
2179 default 3
2180
2181config ARM64_HAFT
2182 bool "Support for Hardware managed Access Flag for Table Descriptors"
2183 depends on ARM64_HW_AFDBM
2184 default y
2185 help
2186 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access
2187 Flag for Table descriptors. When enabled an architectural executed
2188 memory access will update the Access Flag in each Table descriptor
2189 which is accessed during the translation table walk and for which
2190 the Access Flag is 0. The Access Flag of the Table descriptor use
2191 the same bit of PTE_AF.
2192
2193 The feature will only be enabled if all the CPUs in the system
2194 support this feature. If unsure, say Y.
2195
2196endmenu # "ARMv8.9 architectural features"
2197
2198menu "ARMv9.4 architectural features"
2199
2200config ARM64_GCS
2201 bool "Enable support for Guarded Control Stack (GCS)"
2202 default y
2203 select ARCH_HAS_USER_SHADOW_STACK
2204 select ARCH_USES_HIGH_VMA_FLAGS
2205 help
2206 Guarded Control Stack (GCS) provides support for a separate
2207 stack with restricted access which contains only return
2208 addresses. This can be used to harden against some attacks
2209 by comparing return address used by the program with what is
2210 stored in the GCS, and may also be used to efficiently obtain
2211 the call stack for applications such as profiling.
2212
2213 The feature is detected at runtime, and will remain disabled
2214 if the system does not implement the feature.
2215
2216endmenu # "ARMv9.4 architectural features"
2217
2218config ARM64_SVE
2219 bool "ARM Scalable Vector Extension support"
2220 default y
2221 help
2222 The Scalable Vector Extension (SVE) is an extension to the AArch64
2223 execution state which complements and extends the SIMD functionality
2224 of the base architecture to support much larger vectors and to enable
2225 additional vectorisation opportunities.
2226
2227 To enable use of this extension on CPUs that implement it, say Y.
2228
2229 On CPUs that support the SVE2 extensions, this option will enable
2230 those too.
2231
2232 Note that for architectural reasons, firmware _must_ implement SVE
2233 support when running on SVE capable hardware. The required support
2234 is present in:
2235
2236 * version 1.5 and later of the ARM Trusted Firmware
2237 * the AArch64 boot wrapper since commit 5e1261e08abf
2238 ("bootwrapper: SVE: Enable SVE for EL2 and below").
2239
2240 For other firmware implementations, consult the firmware documentation
2241 or vendor.
2242
2243 If you need the kernel to boot on SVE-capable hardware with broken
2244 firmware, you may need to say N here until you get your firmware
2245 fixed. Otherwise, you may experience firmware panics or lockups when
2246 booting the kernel. If unsure and you are not observing these
2247 symptoms, you should assume that it is safe to say Y.
2248
2249config ARM64_SME
2250 bool "ARM Scalable Matrix Extension support"
2251 default y
2252 depends on ARM64_SVE
2253 help
2254 The Scalable Matrix Extension (SME) is an extension to the AArch64
2255 execution state which utilises a substantial subset of the SVE
2256 instruction set, together with the addition of new architectural
2257 register state capable of holding two dimensional matrix tiles to
2258 enable various matrix operations.
2259
2260config ARM64_PSEUDO_NMI
2261 bool "Support for NMI-like interrupts"
2262 select ARM_GIC_V3
2263 help
2264 Adds support for mimicking Non-Maskable Interrupts through the use of
2265 GIC interrupt priority. This support requires version 3 or later of
2266 ARM GIC.
2267
2268 This high priority configuration for interrupts needs to be
2269 explicitly enabled by setting the kernel parameter
2270 "irqchip.gicv3_pseudo_nmi" to 1.
2271
2272 If unsure, say N
2273
2274if ARM64_PSEUDO_NMI
2275config ARM64_DEBUG_PRIORITY_MASKING
2276 bool "Debug interrupt priority masking"
2277 help
2278 This adds runtime checks to functions enabling/disabling
2279 interrupts when using priority masking. The additional checks verify
2280 the validity of ICC_PMR_EL1 when calling concerned functions.
2281
2282 If unsure, say N
2283endif # ARM64_PSEUDO_NMI
2284
2285config RELOCATABLE
2286 bool "Build a relocatable kernel image" if EXPERT
2287 select ARCH_HAS_RELR
2288 default y
2289 help
2290 This builds the kernel as a Position Independent Executable (PIE),
2291 which retains all relocation metadata required to relocate the
2292 kernel binary at runtime to a different virtual address than the
2293 address it was linked at.
2294 Since AArch64 uses the RELA relocation format, this requires a
2295 relocation pass at runtime even if the kernel is loaded at the
2296 same address it was linked at.
2297
2298config RANDOMIZE_BASE
2299 bool "Randomize the address of the kernel image"
2300 select RELOCATABLE
2301 help
2302 Randomizes the virtual address at which the kernel image is
2303 loaded, as a security feature that deters exploit attempts
2304 relying on knowledge of the location of kernel internals.
2305
2306 It is the bootloader's job to provide entropy, by passing a
2307 random u64 value in /chosen/kaslr-seed at kernel entry.
2308
2309 When booting via the UEFI stub, it will invoke the firmware's
2310 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2311 to the kernel proper. In addition, it will randomise the physical
2312 location of the kernel Image as well.
2313
2314 If unsure, say N.
2315
2316config RANDOMIZE_MODULE_REGION_FULL
2317 bool "Randomize the module region over a 2 GB range"
2318 depends on RANDOMIZE_BASE
2319 default y
2320 help
2321 Randomizes the location of the module region inside a 2 GB window
2322 covering the core kernel. This way, it is less likely for modules
2323 to leak information about the location of core kernel data structures
2324 but it does imply that function calls between modules and the core
2325 kernel will need to be resolved via veneers in the module PLT.
2326
2327 When this option is not set, the module region will be randomized over
2328 a limited range that contains the [_stext, _etext] interval of the
2329 core kernel, so branch relocations are almost always in range unless
2330 the region is exhausted. In this particular case of region
2331 exhaustion, modules might be able to fall back to a larger 2GB area.
2332
2333config CC_HAVE_STACKPROTECTOR_SYSREG
2334 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2335
2336config STACKPROTECTOR_PER_TASK
2337 def_bool y
2338 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2339
2340config UNWIND_PATCH_PAC_INTO_SCS
2341 bool "Enable shadow call stack dynamically using code patching"
2342 depends on CC_IS_CLANG
2343 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2344 depends on SHADOW_CALL_STACK
2345 select UNWIND_TABLES
2346 select DYNAMIC_SCS
2347
2348config ARM64_CONTPTE
2349 bool "Contiguous PTE mappings for user memory" if EXPERT
2350 depends on TRANSPARENT_HUGEPAGE
2351 default y
2352 help
2353 When enabled, user mappings are configured using the PTE contiguous
2354 bit, for any mappings that meet the size and alignment requirements.
2355 This reduces TLB pressure and improves performance.
2356
2357endmenu # "Kernel Features"
2358
2359menu "Boot options"
2360
2361config ARM64_ACPI_PARKING_PROTOCOL
2362 bool "Enable support for the ARM64 ACPI parking protocol"
2363 depends on ACPI
2364 help
2365 Enable support for the ARM64 ACPI parking protocol. If disabled
2366 the kernel will not allow booting through the ARM64 ACPI parking
2367 protocol even if the corresponding data is present in the ACPI
2368 MADT table.
2369
2370config CMDLINE
2371 string "Default kernel command string"
2372 default ""
2373 help
2374 Provide a set of default command-line options at build time by
2375 entering them here. As a minimum, you should specify the the
2376 root device (e.g. root=/dev/nfs).
2377
2378choice
2379 prompt "Kernel command line type"
2380 depends on CMDLINE != ""
2381 default CMDLINE_FROM_BOOTLOADER
2382 help
2383 Choose how the kernel will handle the provided default kernel
2384 command line string.
2385
2386config CMDLINE_FROM_BOOTLOADER
2387 bool "Use bootloader kernel arguments if available"
2388 help
2389 Uses the command-line options passed by the boot loader. If
2390 the boot loader doesn't provide any, the default kernel command
2391 string provided in CMDLINE will be used.
2392
2393config CMDLINE_FORCE
2394 bool "Always use the default kernel command string"
2395 help
2396 Always use the default kernel command string, even if the boot
2397 loader passes other arguments to the kernel.
2398 This is useful if you cannot or don't want to change the
2399 command-line options your boot loader passes to the kernel.
2400
2401endchoice
2402
2403config EFI_STUB
2404 bool
2405
2406config EFI
2407 bool "UEFI runtime support"
2408 depends on OF && !CPU_BIG_ENDIAN
2409 depends on KERNEL_MODE_NEON
2410 select ARCH_SUPPORTS_ACPI
2411 select LIBFDT
2412 select UCS2_STRING
2413 select EFI_PARAMS_FROM_FDT
2414 select EFI_RUNTIME_WRAPPERS
2415 select EFI_STUB
2416 select EFI_GENERIC_STUB
2417 imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2418 default y
2419 help
2420 This option provides support for runtime services provided
2421 by UEFI firmware (such as non-volatile variables, realtime
2422 clock, and platform reset). A UEFI stub is also provided to
2423 allow the kernel to be booted as an EFI application. This
2424 is only useful on systems that have UEFI firmware.
2425
2426config COMPRESSED_INSTALL
2427 bool "Install compressed image by default"
2428 help
2429 This makes the regular "make install" install the compressed
2430 image we built, not the legacy uncompressed one.
2431
2432 You can check that a compressed image works for you by doing
2433 "make zinstall" first, and verifying that everything is fine
2434 in your environment before making "make install" do this for
2435 you.
2436
2437config DMI
2438 bool "Enable support for SMBIOS (DMI) tables"
2439 depends on EFI
2440 default y
2441 help
2442 This enables SMBIOS/DMI feature for systems.
2443
2444 This option is only useful on systems that have UEFI firmware.
2445 However, even with this option, the resultant kernel should
2446 continue to boot on existing non-UEFI platforms.
2447
2448endmenu # "Boot options"
2449
2450menu "Power management options"
2451
2452source "kernel/power/Kconfig"
2453
2454config ARCH_HIBERNATION_POSSIBLE
2455 def_bool y
2456 depends on CPU_PM
2457
2458config ARCH_HIBERNATION_HEADER
2459 def_bool y
2460 depends on HIBERNATION
2461
2462config ARCH_SUSPEND_POSSIBLE
2463 def_bool y
2464
2465endmenu # "Power management options"
2466
2467menu "CPU Power Management"
2468
2469source "drivers/cpuidle/Kconfig"
2470
2471source "drivers/cpufreq/Kconfig"
2472
2473endmenu # "CPU Power Management"
2474
2475source "drivers/acpi/Kconfig"
2476
2477source "arch/arm64/kvm/Kconfig"
2478
2479source "kernel/livepatch/Kconfig"