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_MEMBARRIER_SYNC_CORE
39 select ARCH_HAS_MEM_ENCRYPT
40 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
41 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
42 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
43 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
44 select ARCH_HAS_PREEMPT_LAZY
45 select ARCH_HAS_PTDUMP
46 select ARCH_HAS_PTE_SPECIAL
47 select ARCH_HAS_HW_PTE_YOUNG
48 select ARCH_HAS_SETUP_DMA_OPS
49 select ARCH_HAS_SET_DIRECT_MAP
50 select ARCH_HAS_SET_MEMORY
51 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
52 select ARCH_STACKWALK
53 select ARCH_HAS_STRICT_KERNEL_RWX
54 select ARCH_HAS_STRICT_MODULE_RWX
55 select ARCH_HAS_SYNC_DMA_FOR_DEVICE
56 select ARCH_HAS_SYNC_DMA_FOR_CPU
57 select ARCH_HAS_SYSCALL_WRAPPER
58 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
59 select ARCH_HAS_ZONE_DMA_SET if EXPERT
60 select ARCH_HAVE_ELF_PROT
61 select ARCH_HAVE_NMI_SAFE_CMPXCHG
62 select ARCH_HAVE_TRACE_MMIO_ACCESS
63 select ARCH_INLINE_READ_LOCK if !PREEMPTION
64 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
65 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
66 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
67 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
68 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
69 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
70 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
71 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
72 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
73 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
74 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
75 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
76 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
77 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
78 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
79 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
80 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
81 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
82 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
83 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
84 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
85 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
86 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
87 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
88 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
89 select ARCH_KEEP_MEMBLOCK
90 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
91 select ARCH_USE_CMPXCHG_LOCKREF
92 select ARCH_USE_GNU_PROPERTY
93 select ARCH_USE_MEMTEST
94 select ARCH_USE_QUEUED_RWLOCKS
95 select ARCH_USE_QUEUED_SPINLOCKS
96 select ARCH_USE_SYM_ANNOTATIONS
97 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
98 select ARCH_SUPPORTS_HUGETLBFS
99 select ARCH_SUPPORTS_MEMORY_FAILURE
100 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
101 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
102 select ARCH_SUPPORTS_LTO_CLANG_THIN
103 select ARCH_SUPPORTS_CFI
104 select ARCH_SUPPORTS_ATOMIC_RMW
105 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
106 select ARCH_SUPPORTS_NUMA_BALANCING
107 select ARCH_SUPPORTS_PAGE_TABLE_CHECK
108 select ARCH_SUPPORTS_PER_VMA_LOCK
109 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
110 select ARCH_SUPPORTS_RT
111 select ARCH_SUPPORTS_SCHED_SMT
112 select ARCH_SUPPORTS_SCHED_CLUSTER
113 select ARCH_SUPPORTS_SCHED_MC
114 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
115 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
116 select ARCH_WANT_DEFAULT_BPF_JIT
117 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
118 select ARCH_WANT_FRAME_POINTERS
119 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
120 select ARCH_WANT_LD_ORPHAN_WARN
121 select ARCH_WANTS_EXECMEM_LATE
122 select ARCH_WANTS_NO_INSTR
123 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
124 select ARCH_HAS_UBSAN
125 select ARM_AMBA
126 select ARM_ARCH_TIMER
127 select ARM_GIC
128 select AUDIT_ARCH_COMPAT_GENERIC
129 select ARM_GIC_V2M if PCI
130 select ARM_GIC_V3
131 select ARM_GIC_V3_ITS if PCI
132 select ARM_GIC_V5
133 select ARM_PSCI_FW
134 select BUILDTIME_TABLE_SORT
135 select CLONE_BACKWARDS
136 select COMMON_CLK
137 select CPU_PM if (SUSPEND || CPU_IDLE)
138 select CPUMASK_OFFSTACK if NR_CPUS > 256
139 select DCACHE_WORD_ACCESS
140 select HAVE_EXTRA_IPI_TRACEPOINTS
141 select DYNAMIC_FTRACE if FUNCTION_TRACER
142 select DMA_BOUNCE_UNALIGNED_KMALLOC
143 select DMA_DIRECT_REMAP
144 select EDAC_SUPPORT
145 select FRAME_POINTER
146 select FUNCTION_ALIGNMENT_4B
147 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
148 select GENERIC_ALLOCATOR
149 select GENERIC_ARCH_TOPOLOGY
150 select GENERIC_CLOCKEVENTS_BROADCAST
151 select GENERIC_CPU_AUTOPROBE
152 select GENERIC_CPU_CACHE_MAINTENANCE
153 select GENERIC_CPU_DEVICES
154 select GENERIC_CPU_VULNERABILITIES
155 select GENERIC_EARLY_IOREMAP
156 select GENERIC_IDLE_POLL_SETUP
157 select GENERIC_IOREMAP
158 select GENERIC_IRQ_ENTRY
159 select GENERIC_IRQ_IPI
160 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
161 select GENERIC_IRQ_PROBE
162 select GENERIC_IRQ_SHOW
163 select GENERIC_IRQ_SHOW_LEVEL
164 select GENERIC_LIB_DEVMEM_IS_ALLOWED
165 select GENERIC_PCI_IOMAP
166 select GENERIC_SCHED_CLOCK
167 select GENERIC_SMP_IDLE_THREAD
168 select GENERIC_TIME_VSYSCALL
169 select GENERIC_GETTIMEOFDAY
170 select HARDIRQS_SW_RESEND
171 select HAS_IOPORT
172 select HAVE_MOVE_PMD
173 select HAVE_MOVE_PUD
174 select HAVE_PCI
175 select HAVE_ACPI_APEI if (ACPI && EFI)
176 select HAVE_ALIGNED_STRUCT_PAGE
177 select HAVE_ARCH_AUDITSYSCALL
178 select HAVE_ARCH_BITREVERSE
179 select HAVE_ARCH_COMPILER_H
180 select HAVE_ARCH_HUGE_VMALLOC
181 select HAVE_ARCH_HUGE_VMAP
182 select HAVE_ARCH_JUMP_LABEL
183 select HAVE_ARCH_JUMP_LABEL_RELATIVE
184 select HAVE_ARCH_KASAN
185 select HAVE_ARCH_KASAN_VMALLOC
186 select HAVE_ARCH_KASAN_SW_TAGS
187 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
188 # Some instrumentation may be unsound, hence EXPERT
189 select HAVE_ARCH_KCSAN if EXPERT
190 select HAVE_ARCH_KFENCE
191 select HAVE_ARCH_KGDB
192 select HAVE_ARCH_KSTACK_ERASE
193 select HAVE_ARCH_MMAP_RND_BITS
194 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
195 select HAVE_ARCH_PREL32_RELOCATIONS
196 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
197 select HAVE_ARCH_SECCOMP_FILTER
198 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
199 select HAVE_ARCH_TRACEHOOK
200 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
201 select HAVE_ARCH_VMAP_STACK
202 select HAVE_ARM_SMCCC
203 select HAVE_ASM_MODVERSIONS
204 select HAVE_EBPF_JIT
205 select HAVE_C_RECORDMCOUNT
206 select HAVE_CMPXCHG_DOUBLE
207 select HAVE_CMPXCHG_LOCAL
208 select HAVE_CONTEXT_TRACKING_USER
209 select HAVE_DEBUG_KMEMLEAK
210 select HAVE_DMA_CONTIGUOUS
211 select HAVE_DYNAMIC_FTRACE
212 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
213 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
214 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
215 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
216 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
217 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
218 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \
219 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
220 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
221 if DYNAMIC_FTRACE_WITH_ARGS
222 select HAVE_SAMPLE_FTRACE_DIRECT
223 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
224 select HAVE_BUILDTIME_MCOUNT_SORT
225 select HAVE_EFFICIENT_UNALIGNED_ACCESS
226 select HAVE_GUP_FAST
227 select HAVE_FTRACE_GRAPH_FUNC
228 select HAVE_FUNCTION_TRACER
229 select HAVE_FUNCTION_ERROR_INJECTION
230 select HAVE_FUNCTION_GRAPH_FREGS
231 select HAVE_FUNCTION_GRAPH_TRACER
232 select HAVE_GCC_PLUGINS
233 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
234 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
235 select HAVE_HW_BREAKPOINT if PERF_EVENTS
236 select HAVE_IOREMAP_PROT
237 select HAVE_IRQ_TIME_ACCOUNTING
238 select HAVE_LIVEPATCH
239 select HAVE_MOD_ARCH_SPECIFIC
240 select HAVE_NMI
241 select HAVE_PERF_EVENTS
242 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
243 select HAVE_PERF_REGS
244 select HAVE_PERF_USER_STACK_DUMP
245 select HAVE_PREEMPT_DYNAMIC_KEY
246 select HAVE_REGS_AND_STACK_ACCESS_API
247 select HAVE_RELIABLE_STACKTRACE
248 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
249 select HAVE_FUNCTION_ARG_ACCESS_API
250 select MMU_GATHER_RCU_TABLE_FREE
251 select HAVE_RSEQ
252 select HAVE_RUST if RUSTC_SUPPORTS_ARM64
253 select HAVE_STACKPROTECTOR
254 select HAVE_SYSCALL_TRACEPOINTS
255 select HAVE_KPROBES
256 select HAVE_KRETPROBES
257 select HAVE_GENERIC_VDSO
258 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
259 select HOTPLUG_SMT if HOTPLUG_CPU
260 select IRQ_DOMAIN
261 select IRQ_FORCED_THREADING
262 select JUMP_LABEL
263 select KASAN_VMALLOC if KASAN
264 select LOCK_MM_AND_FIND_VMA
265 select MODULES_USE_ELF_RELA
266 select NEED_DMA_MAP_STATE
267 select NEED_SG_DMA_LENGTH
268 select OF
269 select OF_EARLY_FLATTREE
270 select PCI_DOMAINS_GENERIC if PCI
271 select PCI_ECAM if (ACPI && PCI)
272 select PCI_SYSCALL if PCI
273 select POWER_RESET
274 select POWER_SUPPLY
275 select SPARSE_IRQ
276 select SWIOTLB
277 select SYSCTL_EXCEPTION_TRACE
278 select THREAD_INFO_IN_TASK
279 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
280 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
281 select TRACE_IRQFLAGS_SUPPORT
282 select TRACE_IRQFLAGS_NMI_SUPPORT
283 select HAVE_SOFTIRQ_ON_OWN_STACK
284 select USER_STACKTRACE_SUPPORT
285 select VDSO_GETRANDOM
286 select VMAP_STACK
287 help
288 ARM 64-bit (AArch64) Linux support.
289
290config RUSTC_SUPPORTS_ARM64
291 def_bool y
292 depends on CPU_LITTLE_ENDIAN
293 # Shadow call stack is only supported on certain rustc versions.
294 #
295 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is
296 # required due to use of the -Zfixed-x18 flag.
297 #
298 # Otherwise, rustc version 1.82+ is required due to use of the
299 # -Zsanitizer=shadow-call-stack flag.
300 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS
301
302config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
303 def_bool CC_IS_CLANG
304 # https://github.com/ClangBuiltLinux/linux/issues/1507
305 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
306
307config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
308 def_bool CC_IS_GCC
309 depends on $(cc-option,-fpatchable-function-entry=2)
310
311config 64BIT
312 def_bool y
313
314config MMU
315 def_bool y
316
317config ARM64_CONT_PTE_SHIFT
318 int
319 default 5 if PAGE_SIZE_64KB
320 default 7 if PAGE_SIZE_16KB
321 default 4
322
323config ARM64_CONT_PMD_SHIFT
324 int
325 default 5 if PAGE_SIZE_64KB
326 default 5 if PAGE_SIZE_16KB
327 default 4
328
329config ARCH_MMAP_RND_BITS_MIN
330 default 14 if PAGE_SIZE_64KB
331 default 16 if PAGE_SIZE_16KB
332 default 18
333
334# max bits determined by the following formula:
335# VA_BITS - PTDESC_TABLE_SHIFT
336config ARCH_MMAP_RND_BITS_MAX
337 default 19 if ARM64_VA_BITS=36
338 default 24 if ARM64_VA_BITS=39
339 default 27 if ARM64_VA_BITS=42
340 default 30 if ARM64_VA_BITS=47
341 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES
342 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES
343 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52)
344 default 14 if ARM64_64K_PAGES
345 default 16 if ARM64_16K_PAGES
346 default 18
347
348config ARCH_MMAP_RND_COMPAT_BITS_MIN
349 default 7 if ARM64_64K_PAGES
350 default 9 if ARM64_16K_PAGES
351 default 11
352
353config ARCH_MMAP_RND_COMPAT_BITS_MAX
354 default 16
355
356config NO_IOPORT_MAP
357 def_bool y if !PCI
358
359config STACKTRACE_SUPPORT
360 def_bool y
361
362config ILLEGAL_POINTER_VALUE
363 hex
364 default 0xdead000000000000
365
366config LOCKDEP_SUPPORT
367 def_bool y
368
369config GENERIC_BUG
370 def_bool y
371 depends on BUG
372
373config GENERIC_BUG_RELATIVE_POINTERS
374 def_bool y
375 depends on GENERIC_BUG
376
377config GENERIC_HWEIGHT
378 def_bool y
379
380config GENERIC_CSUM
381 def_bool y
382
383config GENERIC_CALIBRATE_DELAY
384 def_bool y
385
386config SMP
387 def_bool y
388
389config KERNEL_MODE_NEON
390 def_bool y
391
392config FIX_EARLYCON_MEM
393 def_bool y
394
395config PGTABLE_LEVELS
396 int
397 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
398 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
399 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
400 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
401 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
402 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
403 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
404 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
405
406config ARCH_SUPPORTS_UPROBES
407 def_bool y
408
409config ARCH_PROC_KCORE_TEXT
410 def_bool y
411
412config BROKEN_GAS_INST
413 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
414
415config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
416 bool
417 # Clang's __builtin_return_address() strips the PAC since 12.0.0
418 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
419 default y if CC_IS_CLANG
420 # GCC's __builtin_return_address() strips the PAC since 11.1.0,
421 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
422 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
423 default y if CC_IS_GCC && (GCC_VERSION >= 110100)
424 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
425 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000)
426 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000)
427 default n
428
429config KASAN_SHADOW_OFFSET
430 hex
431 depends on KASAN_GENERIC || KASAN_SW_TAGS
432 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
433 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
434 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
435 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
436 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
437 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
438 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
439 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
440 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
441 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
442 default 0xffffffffffffffff
443
444config UNWIND_TABLES
445 bool
446
447source "arch/arm64/Kconfig.platforms"
448
449menu "Kernel Features"
450
451menu "ARM errata workarounds via the alternatives framework"
452
453config AMPERE_ERRATUM_AC03_CPU_38
454 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
455 default y
456 help
457 This option adds an alternative code sequence to work around Ampere
458 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
459
460 The affected design reports FEAT_HAFDBS as not implemented in
461 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
462 as required by the architecture. The unadvertised HAFDBS
463 implementation suffers from an additional erratum where hardware
464 A/D updates can occur after a PTE has been marked invalid.
465
466 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
467 which avoids enabling unadvertised hardware Access Flag management
468 at stage-2.
469
470 If unsure, say Y.
471
472config AMPERE_ERRATUM_AC04_CPU_23
473 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations."
474 default y
475 help
476 This option adds an alternative code sequence to work around Ampere
477 errata AC04_CPU_23 on AmpereOne.
478
479 Updates to HCR_EL2 can rarely corrupt simultaneous translations for
480 data addresses initiated by load/store instructions. Only
481 instruction initiated translations are vulnerable, not translations
482 from prefetches for example. A DSB before the store to HCR_EL2 is
483 sufficient to prevent older instructions from hitting the window
484 for corruption, and an ISB after is sufficient to prevent younger
485 instructions from hitting the window for corruption.
486
487 If unsure, say Y.
488
489config ARM64_WORKAROUND_CLEAN_CACHE
490 bool
491
492config ARM64_ERRATUM_826319
493 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
494 default y
495 select ARM64_WORKAROUND_CLEAN_CACHE
496 help
497 This option adds an alternative code sequence to work around ARM
498 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
499 AXI master interface and an L2 cache.
500
501 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
502 and is unable to accept a certain write via this interface, it will
503 not progress on read data presented on the read data channel and the
504 system can deadlock.
505
506 The workaround promotes data cache clean instructions to
507 data cache clean-and-invalidate.
508 Please note that this does not necessarily enable the workaround,
509 as it depends on the alternative framework, which will only patch
510 the kernel if an affected CPU is detected.
511
512 If unsure, say Y.
513
514config ARM64_ERRATUM_827319
515 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
516 default y
517 select ARM64_WORKAROUND_CLEAN_CACHE
518 help
519 This option adds an alternative code sequence to work around ARM
520 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
521 master interface and an L2 cache.
522
523 Under certain conditions this erratum can cause a clean line eviction
524 to occur at the same time as another transaction to the same address
525 on the AMBA 5 CHI interface, which can cause data corruption if the
526 interconnect reorders the two transactions.
527
528 The workaround promotes data cache clean instructions to
529 data cache clean-and-invalidate.
530 Please note that this does not necessarily enable the workaround,
531 as it depends on the alternative framework, which will only patch
532 the kernel if an affected CPU is detected.
533
534 If unsure, say Y.
535
536config ARM64_ERRATUM_824069
537 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
538 default y
539 select ARM64_WORKAROUND_CLEAN_CACHE
540 help
541 This option adds an alternative code sequence to work around ARM
542 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
543 to a coherent interconnect.
544
545 If a Cortex-A53 processor is executing a store or prefetch for
546 write instruction at the same time as a processor in another
547 cluster is executing a cache maintenance operation to the same
548 address, then this erratum might cause a clean cache line to be
549 incorrectly marked as dirty.
550
551 The workaround promotes data cache clean instructions to
552 data cache clean-and-invalidate.
553 Please note that this option does not necessarily enable the
554 workaround, as it depends on the alternative framework, which will
555 only patch the kernel if an affected CPU is detected.
556
557 If unsure, say Y.
558
559config ARM64_ERRATUM_819472
560 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
561 default y
562 select ARM64_WORKAROUND_CLEAN_CACHE
563 help
564 This option adds an alternative code sequence to work around ARM
565 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
566 present when it is connected to a coherent interconnect.
567
568 If the processor is executing a load and store exclusive sequence at
569 the same time as a processor in another cluster is executing a cache
570 maintenance operation to the same address, then this erratum might
571 cause data corruption.
572
573 The workaround promotes data cache clean instructions to
574 data cache clean-and-invalidate.
575 Please note that this does not necessarily enable the workaround,
576 as it depends on the alternative framework, which will only patch
577 the kernel if an affected CPU is detected.
578
579 If unsure, say Y.
580
581config ARM64_ERRATUM_832075
582 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
583 default y
584 help
585 This option adds an alternative code sequence to work around ARM
586 erratum 832075 on Cortex-A57 parts up to r1p2.
587
588 Affected Cortex-A57 parts might deadlock when exclusive load/store
589 instructions to Write-Back memory are mixed with Device loads.
590
591 The workaround is to promote device loads to use Load-Acquire
592 semantics.
593 Please note that this does not necessarily enable the workaround,
594 as it depends on the alternative framework, which will only patch
595 the kernel if an affected CPU is detected.
596
597 If unsure, say Y.
598
599config ARM64_ERRATUM_834220
600 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
601 depends on KVM
602 help
603 This option adds an alternative code sequence to work around ARM
604 erratum 834220 on Cortex-A57 parts up to r1p2.
605
606 Affected Cortex-A57 parts might report a Stage 2 translation
607 fault as the result of a Stage 1 fault for load crossing a
608 page boundary when there is a permission or device memory
609 alignment fault at Stage 1 and a translation fault at Stage 2.
610
611 The workaround is to verify that the Stage 1 translation
612 doesn't generate a fault before handling the Stage 2 fault.
613 Please note that this does not necessarily enable the workaround,
614 as it depends on the alternative framework, which will only patch
615 the kernel if an affected CPU is detected.
616
617 If unsure, say N.
618
619config ARM64_ERRATUM_1742098
620 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
621 depends on COMPAT
622 default y
623 help
624 This option removes the AES hwcap for aarch32 user-space to
625 workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
626
627 Affected parts may corrupt the AES state if an interrupt is
628 taken between a pair of AES instructions. These instructions
629 are only present if the cryptography extensions are present.
630 All software should have a fallback implementation for CPUs
631 that don't implement the cryptography extensions.
632
633 If unsure, say Y.
634
635config ARM64_ERRATUM_845719
636 bool "Cortex-A53: 845719: a load might read incorrect data"
637 depends on COMPAT
638 default y
639 help
640 This option adds an alternative code sequence to work around ARM
641 erratum 845719 on Cortex-A53 parts up to r0p4.
642
643 When running a compat (AArch32) userspace on an affected Cortex-A53
644 part, a load at EL0 from a virtual address that matches the bottom 32
645 bits of the virtual address used by a recent load at (AArch64) EL1
646 might return incorrect data.
647
648 The workaround is to write the contextidr_el1 register on exception
649 return to a 32-bit task.
650 Please note that this does not necessarily enable the workaround,
651 as it depends on the alternative framework, which will only patch
652 the kernel if an affected CPU is detected.
653
654 If unsure, say Y.
655
656config ARM64_ERRATUM_843419
657 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
658 default y
659 help
660 This option links the kernel with '--fix-cortex-a53-843419' and
661 enables PLT support to replace certain ADRP instructions, which can
662 cause subsequent memory accesses to use an incorrect address on
663 Cortex-A53 parts up to r0p4.
664
665 If unsure, say Y.
666
667config ARM64_ERRATUM_1024718
668 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
669 default y
670 help
671 This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
672
673 Affected Cortex-A55 cores (all revisions) could cause incorrect
674 update of the hardware dirty bit when the DBM/AP bits are updated
675 without a break-before-make. The workaround is to disable the usage
676 of hardware DBM locally on the affected cores. CPUs not affected by
677 this erratum will continue to use the feature.
678
679 If unsure, say Y.
680
681config ARM64_ERRATUM_1418040
682 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
683 default y
684 depends on COMPAT
685 help
686 This option adds a workaround for ARM Cortex-A76/Neoverse-N1
687 errata 1188873 and 1418040.
688
689 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
690 cause register corruption when accessing the timer registers
691 from AArch32 userspace.
692
693 If unsure, say Y.
694
695config ARM64_WORKAROUND_SPECULATIVE_AT
696 bool
697
698config ARM64_ERRATUM_1165522
699 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
700 default y
701 select ARM64_WORKAROUND_SPECULATIVE_AT
702 help
703 This option adds a workaround for ARM Cortex-A76 erratum 1165522.
704
705 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
706 corrupted TLBs by speculating an AT instruction during a guest
707 context switch.
708
709 If unsure, say Y.
710
711config ARM64_ERRATUM_1319367
712 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
713 default y
714 select ARM64_WORKAROUND_SPECULATIVE_AT
715 help
716 This option adds work arounds for ARM Cortex-A57 erratum 1319537
717 and A72 erratum 1319367
718
719 Cortex-A57 and A72 cores could end-up with corrupted TLBs by
720 speculating an AT instruction during a guest context switch.
721
722 If unsure, say Y.
723
724config ARM64_ERRATUM_1530923
725 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
726 default y
727 select ARM64_WORKAROUND_SPECULATIVE_AT
728 help
729 This option adds a workaround for ARM Cortex-A55 erratum 1530923.
730
731 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
732 corrupted TLBs by speculating an AT instruction during a guest
733 context switch.
734
735 If unsure, say Y.
736
737config ARM64_WORKAROUND_REPEAT_TLBI
738 bool
739
740config ARM64_ERRATUM_2441007
741 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
742 select ARM64_WORKAROUND_REPEAT_TLBI
743 help
744 This option adds a workaround for ARM Cortex-A55 erratum #2441007.
745
746 Under very rare circumstances, affected Cortex-A55 CPUs
747 may not handle a race between a break-before-make sequence on one
748 CPU, and another CPU accessing the same page. This could allow a
749 store to a page that has been unmapped.
750
751 Work around this by adding the affected CPUs to the list that needs
752 TLB sequences to be done twice.
753
754 If unsure, say N.
755
756config ARM64_ERRATUM_1286807
757 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
758 select ARM64_WORKAROUND_REPEAT_TLBI
759 help
760 This option adds a workaround for ARM Cortex-A76 erratum 1286807.
761
762 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
763 address for a cacheable mapping of a location is being
764 accessed by a core while another core is remapping the virtual
765 address to a new physical page using the recommended
766 break-before-make sequence, then under very rare circumstances
767 TLBI+DSB completes before a read using the translation being
768 invalidated has been observed by other observers. The
769 workaround repeats the TLBI+DSB operation.
770
771 If unsure, say N.
772
773config ARM64_ERRATUM_1463225
774 bool "Cortex-A76: Software Step might prevent interrupt recognition"
775 default y
776 help
777 This option adds a workaround for Arm Cortex-A76 erratum 1463225.
778
779 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
780 of a system call instruction (SVC) can prevent recognition of
781 subsequent interrupts when software stepping is disabled in the
782 exception handler of the system call and either kernel debugging
783 is enabled or VHE is in use.
784
785 Work around the erratum by triggering a dummy step exception
786 when handling a system call from a task that is being stepped
787 in a VHE configuration of the kernel.
788
789 If unsure, say Y.
790
791config ARM64_ERRATUM_1542419
792 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
793 help
794 This option adds a workaround for ARM Neoverse-N1 erratum
795 1542419.
796
797 Affected Neoverse-N1 cores could execute a stale instruction when
798 modified by another CPU. The workaround depends on a firmware
799 counterpart.
800
801 Workaround the issue by hiding the DIC feature from EL0. This
802 forces user-space to perform cache maintenance.
803
804 If unsure, say N.
805
806config ARM64_ERRATUM_1508412
807 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
808 default y
809 help
810 This option adds a workaround for Arm Cortex-A77 erratum 1508412.
811
812 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
813 of a store-exclusive or read of PAR_EL1 and a load with device or
814 non-cacheable memory attributes. The workaround depends on a firmware
815 counterpart.
816
817 KVM guests must also have the workaround implemented or they can
818 deadlock the system.
819
820 Work around the issue by inserting DMB SY barriers around PAR_EL1
821 register reads and warning KVM users. The DMB barrier is sufficient
822 to prevent a speculative PAR_EL1 read.
823
824 If unsure, say Y.
825
826config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
827 bool
828
829config ARM64_ERRATUM_2051678
830 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
831 default y
832 help
833 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
834 Affected Cortex-A510 might not respect the ordering rules for
835 hardware update of the page table's dirty bit. The workaround
836 is to not enable the feature on affected CPUs.
837
838 If unsure, say Y.
839
840config ARM64_ERRATUM_2077057
841 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
842 default y
843 help
844 This option adds the workaround for ARM Cortex-A510 erratum 2077057.
845 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
846 expected, but a Pointer Authentication trap is taken instead. The
847 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
848 EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
849
850 This can only happen when EL2 is stepping EL1.
851
852 When these conditions occur, the SPSR_EL2 value is unchanged from the
853 previous guest entry, and can be restored from the in-memory copy.
854
855 If unsure, say Y.
856
857config ARM64_ERRATUM_2658417
858 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
859 default y
860 help
861 This option adds the workaround for ARM Cortex-A510 erratum 2658417.
862 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
863 BFMMLA or VMMLA instructions in rare circumstances when a pair of
864 A510 CPUs are using shared neon hardware. As the sharing is not
865 discoverable by the kernel, hide the BF16 HWCAP to indicate that
866 user-space should not be using these instructions.
867
868 If unsure, say Y.
869
870config ARM64_ERRATUM_2119858
871 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
872 default y
873 depends on CORESIGHT_TRBE
874 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
875 help
876 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
877
878 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
879 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
880 the event of a WRAP event.
881
882 Work around the issue by always making sure we move the TRBPTR_EL1 by
883 256 bytes before enabling the buffer and filling the first 256 bytes of
884 the buffer with ETM ignore packets upon disabling.
885
886 If unsure, say Y.
887
888config ARM64_ERRATUM_2139208
889 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
890 default y
891 depends on CORESIGHT_TRBE
892 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
893 help
894 This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
895
896 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
897 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
898 the event of a WRAP event.
899
900 Work around the issue by always making sure we move the TRBPTR_EL1 by
901 256 bytes before enabling the buffer and filling the first 256 bytes of
902 the buffer with ETM ignore packets upon disabling.
903
904 If unsure, say Y.
905
906config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
907 bool
908
909config ARM64_ERRATUM_2054223
910 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
911 default y
912 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
913 help
914 Enable workaround for ARM Cortex-A710 erratum 2054223
915
916 Affected cores may fail to flush the trace data on a TSB instruction, when
917 the PE is in trace prohibited state. This will cause losing a few bytes
918 of the trace cached.
919
920 Workaround is to issue two TSB consecutively on affected cores.
921
922 If unsure, say Y.
923
924config ARM64_ERRATUM_2067961
925 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
926 default y
927 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
928 help
929 Enable workaround for ARM Neoverse-N2 erratum 2067961
930
931 Affected cores may fail to flush the trace data on a TSB instruction, when
932 the PE is in trace prohibited state. This will cause losing a few bytes
933 of the trace cached.
934
935 Workaround is to issue two TSB consecutively on affected cores.
936
937 If unsure, say Y.
938
939config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
940 bool
941
942config ARM64_ERRATUM_2253138
943 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
944 depends on CORESIGHT_TRBE
945 default y
946 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
947 help
948 This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
949
950 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
951 for TRBE. Under some conditions, the TRBE might generate a write to the next
952 virtually addressed page following the last page of the TRBE address space
953 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
954
955 Work around this in the driver by always making sure that there is a
956 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
957
958 If unsure, say Y.
959
960config ARM64_ERRATUM_2224489
961 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
962 depends on CORESIGHT_TRBE
963 default y
964 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
965 help
966 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
967
968 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
969 for TRBE. Under some conditions, the TRBE might generate a write to the next
970 virtually addressed page following the last page of the TRBE address space
971 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
972
973 Work around this in the driver by always making sure that there is a
974 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
975
976 If unsure, say Y.
977
978config ARM64_ERRATUM_2441009
979 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
980 select ARM64_WORKAROUND_REPEAT_TLBI
981 help
982 This option adds a workaround for ARM Cortex-A510 erratum #2441009.
983
984 Under very rare circumstances, affected Cortex-A510 CPUs
985 may not handle a race between a break-before-make sequence on one
986 CPU, and another CPU accessing the same page. This could allow a
987 store to a page that has been unmapped.
988
989 Work around this by adding the affected CPUs to the list that needs
990 TLB sequences to be done twice.
991
992 If unsure, say N.
993
994config ARM64_ERRATUM_2064142
995 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
996 depends on CORESIGHT_TRBE
997 default y
998 help
999 This option adds the workaround for ARM Cortex-A510 erratum 2064142.
1000
1001 Affected Cortex-A510 core might fail to write into system registers after the
1002 TRBE has been disabled. Under some conditions after the TRBE has been disabled
1003 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
1004 and TRBTRG_EL1 will be ignored and will not be effected.
1005
1006 Work around this in the driver by executing TSB CSYNC and DSB after collection
1007 is stopped and before performing a system register write to one of the affected
1008 registers.
1009
1010 If unsure, say Y.
1011
1012config ARM64_ERRATUM_2038923
1013 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
1014 depends on CORESIGHT_TRBE
1015 default y
1016 help
1017 This option adds the workaround for ARM Cortex-A510 erratum 2038923.
1018
1019 Affected Cortex-A510 core might cause an inconsistent view on whether trace is
1020 prohibited within the CPU. As a result, the trace buffer or trace buffer state
1021 might be corrupted. This happens after TRBE buffer has been enabled by setting
1022 TRBLIMITR_EL1.E, followed by just a single context synchronization event before
1023 execution changes from a context, in which trace is prohibited to one where it
1024 isn't, or vice versa. In these mentioned conditions, the view of whether trace
1025 is prohibited is inconsistent between parts of the CPU, and the trace buffer or
1026 the trace buffer state might be corrupted.
1027
1028 Work around this in the driver by preventing an inconsistent view of whether the
1029 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
1030 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
1031 two ISB instructions if no ERET is to take place.
1032
1033 If unsure, say Y.
1034
1035config ARM64_ERRATUM_1902691
1036 bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1037 depends on CORESIGHT_TRBE
1038 default y
1039 help
1040 This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1041
1042 Affected Cortex-A510 core might cause trace data corruption, when being written
1043 into the memory. Effectively TRBE is broken and hence cannot be used to capture
1044 trace data.
1045
1046 Work around this problem in the driver by just preventing TRBE initialization on
1047 affected cpus. The firmware must have disabled the access to TRBE for the kernel
1048 on such implementations. This will cover the kernel for any firmware that doesn't
1049 do this already.
1050
1051 If unsure, say Y.
1052
1053config ARM64_ERRATUM_2457168
1054 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1055 depends on ARM64_AMU_EXTN
1056 default y
1057 help
1058 This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1059
1060 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1061 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1062 incorrectly giving a significantly higher output value.
1063
1064 Work around this problem by returning 0 when reading the affected counter in
1065 key locations that results in disabling all users of this counter. This effect
1066 is the same to firmware disabling affected counters.
1067
1068 If unsure, say Y.
1069
1070config ARM64_ERRATUM_2645198
1071 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1072 default y
1073 help
1074 This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1075
1076 If a Cortex-A715 cpu sees a page mapping permissions change from executable
1077 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1078 next instruction abort caused by permission fault.
1079
1080 Only user-space does executable to non-executable permission transition via
1081 mprotect() system call. Workaround the problem by doing a break-before-make
1082 TLB invalidation, for all changes to executable user space mappings.
1083
1084 If unsure, say Y.
1085
1086config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1087 bool
1088
1089config ARM64_ERRATUM_2966298
1090 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1091 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1092 default y
1093 help
1094 This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1095
1096 On an affected Cortex-A520 core, a speculatively executed unprivileged
1097 load might leak data from a privileged level via a cache side channel.
1098
1099 Work around this problem by executing a TLBI before returning to EL0.
1100
1101 If unsure, say Y.
1102
1103config ARM64_ERRATUM_3117295
1104 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1105 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1106 default y
1107 help
1108 This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1109
1110 On an affected Cortex-A510 core, a speculatively executed unprivileged
1111 load might leak data from a privileged level via a cache side channel.
1112
1113 Work around this problem by executing a TLBI before returning to EL0.
1114
1115 If unsure, say Y.
1116
1117config ARM64_ERRATUM_3194386
1118 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1119 default y
1120 help
1121 This option adds the workaround for the following errata:
1122
1123 * ARM Cortex-A76 erratum 3324349
1124 * ARM Cortex-A77 erratum 3324348
1125 * ARM Cortex-A78 erratum 3324344
1126 * ARM Cortex-A78C erratum 3324346
1127 * ARM Cortex-A78C erratum 3324347
1128 * ARM Cortex-A710 erratam 3324338
1129 * ARM Cortex-A715 errartum 3456084
1130 * ARM Cortex-A720 erratum 3456091
1131 * ARM Cortex-A725 erratum 3456106
1132 * ARM Cortex-X1 erratum 3324344
1133 * ARM Cortex-X1C erratum 3324346
1134 * ARM Cortex-X2 erratum 3324338
1135 * ARM Cortex-X3 erratum 3324335
1136 * ARM Cortex-X4 erratum 3194386
1137 * ARM Cortex-X925 erratum 3324334
1138 * ARM Neoverse-N1 erratum 3324349
1139 * ARM Neoverse N2 erratum 3324339
1140 * ARM Neoverse-N3 erratum 3456111
1141 * ARM Neoverse-V1 erratum 3324341
1142 * ARM Neoverse V2 erratum 3324336
1143 * ARM Neoverse-V3 erratum 3312417
1144 * ARM Neoverse-V3AE erratum 3312417
1145
1146 On affected cores "MSR SSBS, #0" instructions may not affect
1147 subsequent speculative instructions, which may permit unexepected
1148 speculative store bypassing.
1149
1150 Work around this problem by placing a Speculation Barrier (SB) or
1151 Instruction Synchronization Barrier (ISB) after kernel changes to
1152 SSBS. The presence of the SSBS special-purpose register is hidden
1153 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1154 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1155
1156 If unsure, say Y.
1157
1158config CAVIUM_ERRATUM_22375
1159 bool "Cavium erratum 22375, 24313"
1160 default y
1161 help
1162 Enable workaround for errata 22375 and 24313.
1163
1164 This implements two gicv3-its errata workarounds for ThunderX. Both
1165 with a small impact affecting only ITS table allocation.
1166
1167 erratum 22375: only alloc 8MB table size
1168 erratum 24313: ignore memory access type
1169
1170 The fixes are in ITS initialization and basically ignore memory access
1171 type and table size provided by the TYPER and BASER registers.
1172
1173 If unsure, say Y.
1174
1175config CAVIUM_ERRATUM_23144
1176 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1177 depends on NUMA
1178 default y
1179 help
1180 ITS SYNC command hang for cross node io and collections/cpu mapping.
1181
1182 If unsure, say Y.
1183
1184config CAVIUM_ERRATUM_23154
1185 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1186 default y
1187 help
1188 The ThunderX GICv3 implementation requires a modified version for
1189 reading the IAR status to ensure data synchronization
1190 (access to icc_iar1_el1 is not sync'ed before and after).
1191
1192 It also suffers from erratum 38545 (also present on Marvell's
1193 OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1194 spuriously presented to the CPU interface.
1195
1196 If unsure, say Y.
1197
1198config CAVIUM_ERRATUM_27456
1199 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1200 default y
1201 help
1202 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1203 instructions may cause the icache to become corrupted if it
1204 contains data for a non-current ASID. The fix is to
1205 invalidate the icache when changing the mm context.
1206
1207 If unsure, say Y.
1208
1209config CAVIUM_ERRATUM_30115
1210 bool "Cavium erratum 30115: Guest may disable interrupts in host"
1211 default y
1212 help
1213 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1214 1.2, and T83 Pass 1.0, KVM guest execution may disable
1215 interrupts in host. Trapping both GICv3 group-0 and group-1
1216 accesses sidesteps the issue.
1217
1218 If unsure, say Y.
1219
1220config CAVIUM_TX2_ERRATUM_219
1221 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1222 default y
1223 help
1224 On Cavium ThunderX2, a load, store or prefetch instruction between a
1225 TTBR update and the corresponding context synchronizing operation can
1226 cause a spurious Data Abort to be delivered to any hardware thread in
1227 the CPU core.
1228
1229 Work around the issue by avoiding the problematic code sequence and
1230 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1231 trap handler performs the corresponding register access, skips the
1232 instruction and ensures context synchronization by virtue of the
1233 exception return.
1234
1235 If unsure, say Y.
1236
1237config FUJITSU_ERRATUM_010001
1238 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1239 default y
1240 help
1241 This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1242 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1243 accesses may cause undefined fault (Data abort, DFSC=0b111111).
1244 This fault occurs under a specific hardware condition when a
1245 load/store instruction performs an address translation using:
1246 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1247 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1248 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1249 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1250
1251 The workaround is to ensure these bits are clear in TCR_ELx.
1252 The workaround only affects the Fujitsu-A64FX.
1253
1254 If unsure, say Y.
1255
1256config HISILICON_ERRATUM_161600802
1257 bool "Hip07 161600802: Erroneous redistributor VLPI base"
1258 default y
1259 help
1260 The HiSilicon Hip07 SoC uses the wrong redistributor base
1261 when issued ITS commands such as VMOVP and VMAPP, and requires
1262 a 128kB offset to be applied to the target address in this commands.
1263
1264 If unsure, say Y.
1265
1266config HISILICON_ERRATUM_162100801
1267 bool "Hip09 162100801 erratum support"
1268 default y
1269 help
1270 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches
1271 during unmapping operation, which will cause some vSGIs lost.
1272 To fix the issue, invalidate related vPE cache through GICR_INVALLR
1273 after VMOVP.
1274
1275 If unsure, say Y.
1276
1277config QCOM_FALKOR_ERRATUM_1003
1278 bool "Falkor E1003: Incorrect translation due to ASID change"
1279 default y
1280 help
1281 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1282 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1283 in TTBR1_EL1, this situation only occurs in the entry trampoline and
1284 then only for entries in the walk cache, since the leaf translation
1285 is unchanged. Work around the erratum by invalidating the walk cache
1286 entries for the trampoline before entering the kernel proper.
1287
1288config QCOM_FALKOR_ERRATUM_1009
1289 bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1290 default y
1291 select ARM64_WORKAROUND_REPEAT_TLBI
1292 help
1293 On Falkor v1, the CPU may prematurely complete a DSB following a
1294 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1295 one more time to fix the issue.
1296
1297 If unsure, say Y.
1298
1299config QCOM_QDF2400_ERRATUM_0065
1300 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1301 default y
1302 help
1303 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1304 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1305 been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1306
1307 If unsure, say Y.
1308
1309config QCOM_FALKOR_ERRATUM_E1041
1310 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1311 default y
1312 help
1313 Falkor CPU may speculatively fetch instructions from an improper
1314 memory location when MMU translation is changed from SCTLR_ELn[M]=1
1315 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1316
1317 If unsure, say Y.
1318
1319config NVIDIA_CARMEL_CNP_ERRATUM
1320 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1321 default y
1322 help
1323 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1324 invalidate shared TLB entries installed by a different core, as it would
1325 on standard ARM cores.
1326
1327 If unsure, say Y.
1328
1329config ROCKCHIP_ERRATUM_3568002
1330 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB"
1331 default y
1332 help
1333 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI
1334 addressing limited to the first 32bit of physical address space.
1335
1336 If unsure, say Y.
1337
1338config ROCKCHIP_ERRATUM_3588001
1339 bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1340 default y
1341 help
1342 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1343 This means, that its sharability feature may not be used, even though it
1344 is supported by the IP itself.
1345
1346 If unsure, say Y.
1347
1348config SOCIONEXT_SYNQUACER_PREITS
1349 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1350 default y
1351 help
1352 Socionext Synquacer SoCs implement a separate h/w block to generate
1353 MSI doorbell writes with non-zero values for the device ID.
1354
1355 If unsure, say Y.
1356
1357endmenu # "ARM errata workarounds via the alternatives framework"
1358
1359choice
1360 prompt "Page size"
1361 default ARM64_4K_PAGES
1362 help
1363 Page size (translation granule) configuration.
1364
1365config ARM64_4K_PAGES
1366 bool "4KB"
1367 select HAVE_PAGE_SIZE_4KB
1368 help
1369 This feature enables 4KB pages support.
1370
1371config ARM64_16K_PAGES
1372 bool "16KB"
1373 select HAVE_PAGE_SIZE_16KB
1374 help
1375 The system will use 16KB pages support. AArch32 emulation
1376 requires applications compiled with 16K (or a multiple of 16K)
1377 aligned segments.
1378
1379config ARM64_64K_PAGES
1380 bool "64KB"
1381 select HAVE_PAGE_SIZE_64KB
1382 help
1383 This feature enables 64KB pages support (4KB by default)
1384 allowing only two levels of page tables and faster TLB
1385 look-up. AArch32 emulation requires applications compiled
1386 with 64K aligned segments.
1387
1388endchoice
1389
1390choice
1391 prompt "Virtual address space size"
1392 default ARM64_VA_BITS_52
1393 help
1394 Allows choosing one of multiple possible virtual address
1395 space sizes. The level of translation table is determined by
1396 a combination of page size and virtual address space size.
1397
1398config ARM64_VA_BITS_36
1399 bool "36-bit" if EXPERT
1400 depends on PAGE_SIZE_16KB
1401
1402config ARM64_VA_BITS_39
1403 bool "39-bit"
1404 depends on PAGE_SIZE_4KB
1405
1406config ARM64_VA_BITS_42
1407 bool "42-bit"
1408 depends on PAGE_SIZE_64KB
1409
1410config ARM64_VA_BITS_47
1411 bool "47-bit"
1412 depends on PAGE_SIZE_16KB
1413
1414config ARM64_VA_BITS_48
1415 bool "48-bit"
1416
1417config ARM64_VA_BITS_52
1418 bool "52-bit"
1419 help
1420 Enable 52-bit virtual addressing for userspace when explicitly
1421 requested via a hint to mmap(). The kernel will also use 52-bit
1422 virtual addresses for its own mappings (provided HW support for
1423 this feature is available, otherwise it reverts to 48-bit).
1424
1425 NOTE: Enabling 52-bit virtual addressing in conjunction with
1426 ARMv8.3 Pointer Authentication will result in the PAC being
1427 reduced from 7 bits to 3 bits, which may have a significant
1428 impact on its susceptibility to brute-force attacks.
1429
1430 If unsure, select 48-bit virtual addressing instead.
1431
1432endchoice
1433
1434config ARM64_FORCE_52BIT
1435 bool "Force 52-bit virtual addresses for userspace"
1436 depends on ARM64_VA_BITS_52 && EXPERT
1437 help
1438 For systems with 52-bit userspace VAs enabled, the kernel will attempt
1439 to maintain compatibility with older software by providing 48-bit VAs
1440 unless a hint is supplied to mmap.
1441
1442 This configuration option disables the 48-bit compatibility logic, and
1443 forces all userspace addresses to be 52-bit on HW that supports it. One
1444 should only enable this configuration option for stress testing userspace
1445 memory management code. If unsure say N here.
1446
1447config ARM64_VA_BITS
1448 int
1449 default 36 if ARM64_VA_BITS_36
1450 default 39 if ARM64_VA_BITS_39
1451 default 42 if ARM64_VA_BITS_42
1452 default 47 if ARM64_VA_BITS_47
1453 default 48 if ARM64_VA_BITS_48
1454 default 52 if ARM64_VA_BITS_52
1455
1456choice
1457 prompt "Physical address space size"
1458 default ARM64_PA_BITS_48
1459 help
1460 Choose the maximum physical address range that the kernel will
1461 support.
1462
1463config ARM64_PA_BITS_48
1464 bool "48-bit"
1465 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1466
1467config ARM64_PA_BITS_52
1468 bool "52-bit"
1469 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1470 help
1471 Enable support for a 52-bit physical address space, introduced as
1472 part of the ARMv8.2-LPA extension.
1473
1474 With this enabled, the kernel will also continue to work on CPUs that
1475 do not support ARMv8.2-LPA, but with some added memory overhead (and
1476 minor performance overhead).
1477
1478endchoice
1479
1480config ARM64_PA_BITS
1481 int
1482 default 48 if ARM64_PA_BITS_48
1483 default 52 if ARM64_PA_BITS_52
1484
1485config ARM64_LPA2
1486 def_bool y
1487 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1488
1489choice
1490 prompt "Endianness"
1491 default CPU_LITTLE_ENDIAN
1492 help
1493 Select the endianness of data accesses performed by the CPU. Userspace
1494 applications will need to be compiled and linked for the endianness
1495 that is selected here.
1496
1497config CPU_BIG_ENDIAN
1498 bool "Build big-endian kernel"
1499 depends on BROKEN
1500 help
1501 Say Y if you plan on running a kernel with a big-endian userspace.
1502
1503config CPU_LITTLE_ENDIAN
1504 bool "Build little-endian kernel"
1505 help
1506 Say Y if you plan on running a kernel with a little-endian userspace.
1507 This is usually the case for distributions targeting arm64.
1508
1509endchoice
1510
1511config NR_CPUS
1512 int "Maximum number of CPUs (2-4096)"
1513 range 2 4096
1514 default "512"
1515
1516config HOTPLUG_CPU
1517 bool "Support for hot-pluggable CPUs"
1518 select GENERIC_IRQ_MIGRATION
1519 help
1520 Say Y here to experiment with turning CPUs off and on. CPUs
1521 can be controlled through /sys/devices/system/cpu.
1522
1523# Common NUMA Features
1524config NUMA
1525 bool "NUMA Memory Allocation and Scheduler Support"
1526 select GENERIC_ARCH_NUMA
1527 select OF_NUMA
1528 select HAVE_SETUP_PER_CPU_AREA
1529 select NEED_PER_CPU_EMBED_FIRST_CHUNK
1530 select NEED_PER_CPU_PAGE_FIRST_CHUNK
1531 select USE_PERCPU_NUMA_NODE_ID
1532 help
1533 Enable NUMA (Non-Uniform Memory Access) support.
1534
1535 The kernel will try to allocate memory used by a CPU on the
1536 local memory of the CPU and add some more
1537 NUMA awareness to the kernel.
1538
1539config NODES_SHIFT
1540 int "Maximum NUMA Nodes (as a power of 2)"
1541 range 1 10
1542 default "4"
1543 depends on NUMA
1544 help
1545 Specify the maximum number of NUMA Nodes available on the target
1546 system. Increases memory reserved to accommodate various tables.
1547
1548source "kernel/Kconfig.hz"
1549
1550config ARCH_SPARSEMEM_ENABLE
1551 def_bool y
1552 select SPARSEMEM_VMEMMAP_ENABLE
1553
1554config HW_PERF_EVENTS
1555 def_bool y
1556 depends on ARM_PMU
1557
1558# Supported by clang >= 7.0 or GCC >= 12.0.0
1559config CC_HAVE_SHADOW_CALL_STACK
1560 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1561
1562config PARAVIRT
1563 bool "Enable paravirtualization code"
1564 help
1565 This changes the kernel so it can modify itself when it is run
1566 under a hypervisor, potentially improving performance significantly
1567 over full virtualization.
1568
1569config PARAVIRT_TIME_ACCOUNTING
1570 bool "Paravirtual steal time accounting"
1571 select PARAVIRT
1572 help
1573 Select this option to enable fine granularity task steal time
1574 accounting. Time spent executing other tasks in parallel with
1575 the current vCPU is discounted from the vCPU power. To account for
1576 that, there can be a small performance impact.
1577
1578 If in doubt, say N here.
1579
1580config ARCH_SUPPORTS_KEXEC
1581 def_bool PM_SLEEP_SMP
1582
1583config ARCH_SUPPORTS_KEXEC_FILE
1584 def_bool y
1585
1586config ARCH_SELECTS_KEXEC_FILE
1587 def_bool y
1588 depends on KEXEC_FILE
1589 select HAVE_IMA_KEXEC if IMA
1590
1591config ARCH_SUPPORTS_KEXEC_SIG
1592 def_bool y
1593
1594config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1595 def_bool y
1596
1597config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1598 def_bool y
1599
1600config ARCH_SUPPORTS_KEXEC_HANDOVER
1601 def_bool y
1602
1603config ARCH_SUPPORTS_CRASH_DUMP
1604 def_bool y
1605
1606config ARCH_DEFAULT_CRASH_DUMP
1607 def_bool y
1608
1609config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1610 def_bool CRASH_RESERVE
1611
1612config TRANS_TABLE
1613 def_bool y
1614 depends on HIBERNATION || KEXEC_CORE
1615
1616config XEN_DOM0
1617 def_bool y
1618 depends on XEN
1619
1620config XEN
1621 bool "Xen guest support on ARM64"
1622 depends on ARM64 && OF
1623 select SWIOTLB_XEN
1624 select PARAVIRT
1625 help
1626 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1627
1628# include/linux/mmzone.h requires the following to be true:
1629#
1630# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1631#
1632# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1633#
1634# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER |
1635# ----+-------------------+--------------+----------------------+-------------------------+
1636# 4K | 27 | 12 | 15 | 10 |
1637# 16K | 27 | 14 | 13 | 11 |
1638# 64K | 29 | 16 | 13 | 13 |
1639config ARCH_FORCE_MAX_ORDER
1640 int
1641 default "13" if ARM64_64K_PAGES
1642 default "11" if ARM64_16K_PAGES
1643 default "10"
1644 help
1645 The kernel page allocator limits the size of maximal physically
1646 contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1647 defines the maximal power of two of number of pages that can be
1648 allocated as a single contiguous block. This option allows
1649 overriding the default setting when ability to allocate very
1650 large blocks of physically contiguous memory is required.
1651
1652 The maximal size of allocation cannot exceed the size of the
1653 section, so the value of MAX_PAGE_ORDER should satisfy
1654
1655 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1656
1657 Don't change if unsure.
1658
1659config UNMAP_KERNEL_AT_EL0
1660 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1661 default y
1662 help
1663 Speculation attacks against some high-performance processors can
1664 be used to bypass MMU permission checks and leak kernel data to
1665 userspace. This can be defended against by unmapping the kernel
1666 when running in userspace, mapping it back in on exception entry
1667 via a trampoline page in the vector table.
1668
1669 If unsure, say Y.
1670
1671config MITIGATE_SPECTRE_BRANCH_HISTORY
1672 bool "Mitigate Spectre style attacks against branch history" if EXPERT
1673 default y
1674 help
1675 Speculation attacks against some high-performance processors can
1676 make use of branch history to influence future speculation.
1677 When taking an exception from user-space, a sequence of branches
1678 or a firmware call overwrites the branch history.
1679
1680config ARM64_SW_TTBR0_PAN
1681 bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1682 depends on !KCSAN
1683 select ARM64_PAN
1684 help
1685 Enabling this option prevents the kernel from accessing
1686 user-space memory directly by pointing TTBR0_EL1 to a reserved
1687 zeroed area and reserved ASID. The user access routines
1688 restore the valid TTBR0_EL1 temporarily.
1689
1690config ARM64_TAGGED_ADDR_ABI
1691 bool "Enable the tagged user addresses syscall ABI"
1692 default y
1693 help
1694 When this option is enabled, user applications can opt in to a
1695 relaxed ABI via prctl() allowing tagged addresses to be passed
1696 to system calls as pointer arguments. For details, see
1697 Documentation/arch/arm64/tagged-address-abi.rst.
1698
1699menuconfig COMPAT
1700 bool "Kernel support for 32-bit EL0"
1701 depends on ARM64_4K_PAGES || EXPERT
1702 select HAVE_UID16
1703 select OLD_SIGSUSPEND3
1704 select COMPAT_OLD_SIGACTION
1705 help
1706 This option enables support for a 32-bit EL0 running under a 64-bit
1707 kernel at EL1. AArch32-specific components such as system calls,
1708 the user helper functions, VFP support and the ptrace interface are
1709 handled appropriately by the kernel.
1710
1711 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1712 that you will only be able to execute AArch32 binaries that were compiled
1713 with page size aligned segments.
1714
1715 If you want to execute 32-bit userspace applications, say Y.
1716
1717if COMPAT
1718
1719config KUSER_HELPERS
1720 bool "Enable kuser helpers page for 32-bit applications"
1721 default y
1722 help
1723 Warning: disabling this option may break 32-bit user programs.
1724
1725 Provide kuser helpers to compat tasks. The kernel provides
1726 helper code to userspace in read only form at a fixed location
1727 to allow userspace to be independent of the CPU type fitted to
1728 the system. This permits binaries to be run on ARMv4 through
1729 to ARMv8 without modification.
1730
1731 See Documentation/arch/arm/kernel_user_helpers.rst for details.
1732
1733 However, the fixed address nature of these helpers can be used
1734 by ROP (return orientated programming) authors when creating
1735 exploits.
1736
1737 If all of the binaries and libraries which run on your platform
1738 are built specifically for your platform, and make no use of
1739 these helpers, then you can turn this option off to hinder
1740 such exploits. However, in that case, if a binary or library
1741 relying on those helpers is run, it will not function correctly.
1742
1743 Say N here only if you are absolutely certain that you do not
1744 need these helpers; otherwise, the safe option is to say Y.
1745
1746config COMPAT_VDSO
1747 bool "Enable vDSO for 32-bit applications"
1748 depends on !CPU_BIG_ENDIAN
1749 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1750 default y
1751 help
1752 Place in the process address space of 32-bit applications an
1753 ELF shared object providing fast implementations of gettimeofday
1754 and clock_gettime.
1755
1756 You must have a 32-bit build of glibc 2.22 or later for programs
1757 to seamlessly take advantage of this.
1758
1759config THUMB2_COMPAT_VDSO
1760 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1761 depends on COMPAT_VDSO
1762 default y
1763 help
1764 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1765 otherwise with '-marm'.
1766
1767config COMPAT_ALIGNMENT_FIXUPS
1768 bool "Fix up misaligned multi-word loads and stores in user space"
1769
1770menuconfig ARMV8_DEPRECATED
1771 bool "Emulate deprecated/obsolete ARMv8 instructions"
1772 depends on SYSCTL
1773 help
1774 Legacy software support may require certain instructions
1775 that have been deprecated or obsoleted in the architecture.
1776
1777 Enable this config to enable selective emulation of these
1778 features.
1779
1780 If unsure, say Y
1781
1782if ARMV8_DEPRECATED
1783
1784config SWP_EMULATION
1785 bool "Emulate SWP/SWPB instructions"
1786 help
1787 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1788 they are always undefined. Say Y here to enable software
1789 emulation of these instructions for userspace using LDXR/STXR.
1790 This feature can be controlled at runtime with the abi.swp
1791 sysctl which is disabled by default.
1792
1793 In some older versions of glibc [<=2.8] SWP is used during futex
1794 trylock() operations with the assumption that the code will not
1795 be preempted. This invalid assumption may be more likely to fail
1796 with SWP emulation enabled, leading to deadlock of the user
1797 application.
1798
1799 NOTE: when accessing uncached shared regions, LDXR/STXR rely
1800 on an external transaction monitoring block called a global
1801 monitor to maintain update atomicity. If your system does not
1802 implement a global monitor, this option can cause programs that
1803 perform SWP operations to uncached memory to deadlock.
1804
1805 If unsure, say Y
1806
1807config CP15_BARRIER_EMULATION
1808 bool "Emulate CP15 Barrier instructions"
1809 help
1810 The CP15 barrier instructions - CP15ISB, CP15DSB, and
1811 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1812 strongly recommended to use the ISB, DSB, and DMB
1813 instructions instead.
1814
1815 Say Y here to enable software emulation of these
1816 instructions for AArch32 userspace code. When this option is
1817 enabled, CP15 barrier usage is traced which can help
1818 identify software that needs updating. This feature can be
1819 controlled at runtime with the abi.cp15_barrier sysctl.
1820
1821 If unsure, say Y
1822
1823config SETEND_EMULATION
1824 bool "Emulate SETEND instruction"
1825 help
1826 The SETEND instruction alters the data-endianness of the
1827 AArch32 EL0, and is deprecated in ARMv8.
1828
1829 Say Y here to enable software emulation of the instruction
1830 for AArch32 userspace code. This feature can be controlled
1831 at runtime with the abi.setend sysctl.
1832
1833 Note: All the cpus on the system must have mixed endian support at EL0
1834 for this feature to be enabled. If a new CPU - which doesn't support mixed
1835 endian - is hotplugged in after this feature has been enabled, there could
1836 be unexpected results in the applications.
1837
1838 If unsure, say Y
1839endif # ARMV8_DEPRECATED
1840
1841endif # COMPAT
1842
1843menu "ARMv8.1 architectural features"
1844
1845config ARM64_HW_AFDBM
1846 bool "Support for hardware updates of the Access and Dirty page flags"
1847 default y
1848 help
1849 The ARMv8.1 architecture extensions introduce support for
1850 hardware updates of the access and dirty information in page
1851 table entries. When enabled in TCR_EL1 (HA and HD bits) on
1852 capable processors, accesses to pages with PTE_AF cleared will
1853 set this bit instead of raising an access flag fault.
1854 Similarly, writes to read-only pages with the DBM bit set will
1855 clear the read-only bit (AP[2]) instead of raising a
1856 permission fault.
1857
1858 Kernels built with this configuration option enabled continue
1859 to work on pre-ARMv8.1 hardware and the performance impact is
1860 minimal. If unsure, say Y.
1861
1862config ARM64_PAN
1863 bool "Enable support for Privileged Access Never (PAN)"
1864 default y
1865 help
1866 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1867 prevents the kernel or hypervisor from accessing user-space (EL0)
1868 memory directly.
1869
1870 Choosing this option will cause any unprotected (not using
1871 copy_to_user et al) memory access to fail with a permission fault.
1872
1873 The feature is detected at runtime, and will remain as a 'nop'
1874 instruction if the cpu does not implement the feature.
1875
1876config ARM64_LSE_ATOMICS
1877 bool
1878 default ARM64_USE_LSE_ATOMICS
1879
1880config ARM64_USE_LSE_ATOMICS
1881 bool "Atomic instructions"
1882 default y
1883 help
1884 As part of the Large System Extensions, ARMv8.1 introduces new
1885 atomic instructions that are designed specifically to scale in
1886 very large systems.
1887
1888 Say Y here to make use of these instructions for the in-kernel
1889 atomic routines. This incurs a small overhead on CPUs that do
1890 not support these instructions.
1891
1892endmenu # "ARMv8.1 architectural features"
1893
1894menu "ARMv8.2 architectural features"
1895
1896config ARM64_PMEM
1897 bool "Enable support for persistent memory"
1898 select ARCH_HAS_PMEM_API
1899 select ARCH_HAS_UACCESS_FLUSHCACHE
1900 help
1901 Say Y to enable support for the persistent memory API based on the
1902 ARMv8.2 DCPoP feature.
1903
1904 The feature is detected at runtime, and the kernel will use DC CVAC
1905 operations if DC CVAP is not supported (following the behaviour of
1906 DC CVAP itself if the system does not define a point of persistence).
1907
1908config ARM64_RAS_EXTN
1909 bool "Enable support for RAS CPU Extensions"
1910 default y
1911 help
1912 CPUs that support the Reliability, Availability and Serviceability
1913 (RAS) Extensions, part of ARMv8.2 are able to track faults and
1914 errors, classify them and report them to software.
1915
1916 On CPUs with these extensions system software can use additional
1917 barriers to determine if faults are pending and read the
1918 classification from a new set of registers.
1919
1920 Selecting this feature will allow the kernel to use these barriers
1921 and access the new registers if the system supports the extension.
1922 Platform RAS features may additionally depend on firmware support.
1923
1924config ARM64_CNP
1925 bool "Enable support for Common Not Private (CNP) translations"
1926 default y
1927 help
1928 Common Not Private (CNP) allows translation table entries to
1929 be shared between different PEs in the same inner shareable
1930 domain, so the hardware can use this fact to optimise the
1931 caching of such entries in the TLB.
1932
1933 Selecting this option allows the CNP feature to be detected
1934 at runtime, and does not affect PEs that do not implement
1935 this feature.
1936
1937endmenu # "ARMv8.2 architectural features"
1938
1939menu "ARMv8.3 architectural features"
1940
1941config ARM64_PTR_AUTH
1942 bool "Enable support for pointer authentication"
1943 default y
1944 help
1945 Pointer authentication (part of the ARMv8.3 Extensions) provides
1946 instructions for signing and authenticating pointers against secret
1947 keys, which can be used to mitigate Return Oriented Programming (ROP)
1948 and other attacks.
1949
1950 This option enables these instructions at EL0 (i.e. for userspace).
1951 Choosing this option will cause the kernel to initialise secret keys
1952 for each process at exec() time, with these keys being
1953 context-switched along with the process.
1954
1955 The feature is detected at runtime. If the feature is not present in
1956 hardware it will not be advertised to userspace/KVM guest nor will it
1957 be enabled.
1958
1959 If the feature is present on the boot CPU but not on a late CPU, then
1960 the late CPU will be parked. Also, if the boot CPU does not have
1961 address auth and the late CPU has then the late CPU will still boot
1962 but with the feature disabled. On such a system, this option should
1963 not be selected.
1964
1965config ARM64_PTR_AUTH_KERNEL
1966 bool "Use pointer authentication for kernel"
1967 default y
1968 depends on ARM64_PTR_AUTH
1969 # Modern compilers insert a .note.gnu.property section note for PAC
1970 # which is only understood by binutils starting with version 2.33.1.
1971 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1972 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1973 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1974 help
1975 If the compiler supports the -mbranch-protection or
1976 -msign-return-address flag (e.g. GCC 7 or later), then this option
1977 will cause the kernel itself to be compiled with return address
1978 protection. In this case, and if the target hardware is known to
1979 support pointer authentication, then CONFIG_STACKPROTECTOR can be
1980 disabled with minimal loss of protection.
1981
1982 This feature works with FUNCTION_GRAPH_TRACER option only if
1983 DYNAMIC_FTRACE_WITH_ARGS is enabled.
1984
1985config CC_HAS_BRANCH_PROT_PAC_RET
1986 # GCC 9 or later, clang 8 or later
1987 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1988
1989config AS_HAS_CFI_NEGATE_RA_STATE
1990 # binutils 2.34+
1991 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1992
1993endmenu # "ARMv8.3 architectural features"
1994
1995menu "ARMv8.4 architectural features"
1996
1997config ARM64_AMU_EXTN
1998 bool "Enable support for the Activity Monitors Unit CPU extension"
1999 default y
2000 help
2001 The activity monitors extension is an optional extension introduced
2002 by the ARMv8.4 CPU architecture. This enables support for version 1
2003 of the activity monitors architecture, AMUv1.
2004
2005 To enable the use of this extension on CPUs that implement it, say Y.
2006
2007 Note that for architectural reasons, firmware _must_ implement AMU
2008 support when running on CPUs that present the activity monitors
2009 extension. The required support is present in:
2010 * Version 1.5 and later of the ARM Trusted Firmware
2011
2012 For kernels that have this configuration enabled but boot with broken
2013 firmware, you may need to say N here until the firmware is fixed.
2014 Otherwise you may experience firmware panics or lockups when
2015 accessing the counter registers. Even if you are not observing these
2016 symptoms, the values returned by the register reads might not
2017 correctly reflect reality. Most commonly, the value read will be 0,
2018 indicating that the counter is not enabled.
2019
2020config ARM64_TLB_RANGE
2021 bool "Enable support for tlbi range feature"
2022 default y
2023 help
2024 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2025 range of input addresses.
2026
2027config ARM64_MPAM
2028 bool "Enable support for MPAM"
2029 select ARM64_MPAM_DRIVER if EXPERT # does nothing yet
2030 select ACPI_MPAM if ACPI
2031 help
2032 Memory System Resource Partitioning and Monitoring (MPAM) is an
2033 optional extension to the Arm architecture that allows each
2034 transaction issued to the memory system to be labelled with a
2035 Partition identifier (PARTID) and Performance Monitoring Group
2036 identifier (PMG).
2037
2038 Memory system components, such as the caches, can be configured with
2039 policies to control how much of various physical resources (such as
2040 memory bandwidth or cache memory) the transactions labelled with each
2041 PARTID can consume. Depending on the capabilities of the hardware,
2042 the PARTID and PMG can also be used as filtering criteria to measure
2043 the memory system resource consumption of different parts of a
2044 workload.
2045
2046 Use of this extension requires CPU support, support in the
2047 Memory System Components (MSC), and a description from firmware
2048 of where the MSCs are in the address space.
2049
2050 MPAM is exposed to user-space via the resctrl pseudo filesystem.
2051
2052endmenu # "ARMv8.4 architectural features"
2053
2054menu "ARMv8.5 architectural features"
2055
2056config AS_HAS_ARMV8_5
2057 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2058
2059config ARM64_BTI
2060 bool "Branch Target Identification support"
2061 default y
2062 help
2063 Branch Target Identification (part of the ARMv8.5 Extensions)
2064 provides a mechanism to limit the set of locations to which computed
2065 branch instructions such as BR or BLR can jump.
2066
2067 To make use of BTI on CPUs that support it, say Y.
2068
2069 BTI is intended to provide complementary protection to other control
2070 flow integrity protection mechanisms, such as the Pointer
2071 authentication mechanism provided as part of the ARMv8.3 Extensions.
2072 For this reason, it does not make sense to enable this option without
2073 also enabling support for pointer authentication. Thus, when
2074 enabling this option you should also select ARM64_PTR_AUTH=y.
2075
2076 Userspace binaries must also be specifically compiled to make use of
2077 this mechanism. If you say N here or the hardware does not support
2078 BTI, such binaries can still run, but you get no additional
2079 enforcement of branch destinations.
2080
2081config ARM64_BTI_KERNEL
2082 bool "Use Branch Target Identification for kernel"
2083 default y
2084 depends on ARM64_BTI
2085 depends on ARM64_PTR_AUTH_KERNEL
2086 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2087 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2088 depends on !CC_IS_GCC || GCC_VERSION >= 100100
2089 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2090 depends on !CC_IS_GCC
2091 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2092 help
2093 Build the kernel with Branch Target Identification annotations
2094 and enable enforcement of this for kernel code. When this option
2095 is enabled and the system supports BTI all kernel code including
2096 modular code must have BTI enabled.
2097
2098config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2099 # GCC 9 or later, clang 8 or later
2100 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2101
2102config ARM64_E0PD
2103 bool "Enable support for E0PD"
2104 default y
2105 help
2106 E0PD (part of the ARMv8.5 extensions) allows us to ensure
2107 that EL0 accesses made via TTBR1 always fault in constant time,
2108 providing similar benefits to KASLR as those provided by KPTI, but
2109 with lower overhead and without disrupting legitimate access to
2110 kernel memory such as SPE.
2111
2112 This option enables E0PD for TTBR1 where available.
2113
2114config ARM64_AS_HAS_MTE
2115 # Initial support for MTE went in binutils 2.32.0, checked with
2116 # ".arch armv8.5-a+memtag" below. However, this was incomplete
2117 # as a late addition to the final architecture spec (LDGM/STGM)
2118 # is only supported in the newer 2.32.x and 2.33 binutils
2119 # versions, hence the extra "stgm" instruction check below.
2120 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2121
2122config ARM64_MTE
2123 bool "Memory Tagging Extension support"
2124 default y
2125 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2126 depends on AS_HAS_ARMV8_5
2127 # Required for tag checking in the uaccess routines
2128 select ARM64_PAN
2129 select ARCH_HAS_SUBPAGE_FAULTS
2130 select ARCH_USES_HIGH_VMA_FLAGS
2131 select ARCH_USES_PG_ARCH_2
2132 select ARCH_USES_PG_ARCH_3
2133 help
2134 Memory Tagging (part of the ARMv8.5 Extensions) provides
2135 architectural support for run-time, always-on detection of
2136 various classes of memory error to aid with software debugging
2137 to eliminate vulnerabilities arising from memory-unsafe
2138 languages.
2139
2140 This option enables the support for the Memory Tagging
2141 Extension at EL0 (i.e. for userspace).
2142
2143 Selecting this option allows the feature to be detected at
2144 runtime. Any secondary CPU not implementing this feature will
2145 not be allowed a late bring-up.
2146
2147 Userspace binaries that want to use this feature must
2148 explicitly opt in. The mechanism for the userspace is
2149 described in:
2150
2151 Documentation/arch/arm64/memory-tagging-extension.rst.
2152
2153endmenu # "ARMv8.5 architectural features"
2154
2155menu "ARMv8.7 architectural features"
2156
2157config ARM64_EPAN
2158 bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2159 default y
2160 depends on ARM64_PAN
2161 help
2162 Enhanced Privileged Access Never (EPAN) allows Privileged
2163 Access Never to be used with Execute-only mappings.
2164
2165 The feature is detected at runtime, and will remain disabled
2166 if the cpu does not implement the feature.
2167endmenu # "ARMv8.7 architectural features"
2168
2169config AS_HAS_MOPS
2170 def_bool $(as-instr,.arch_extension mops)
2171
2172menu "ARMv8.9 architectural features"
2173
2174config ARM64_POE
2175 prompt "Permission Overlay Extension"
2176 def_bool y
2177 select ARCH_USES_HIGH_VMA_FLAGS
2178 select ARCH_HAS_PKEYS
2179 help
2180 The Permission Overlay Extension is used to implement Memory
2181 Protection Keys. Memory Protection Keys provides a mechanism for
2182 enforcing page-based protections, but without requiring modification
2183 of the page tables when an application changes protection domains.
2184
2185 For details, see Documentation/core-api/protection-keys.rst
2186
2187 If unsure, say y.
2188
2189config ARCH_PKEY_BITS
2190 int
2191 default 3
2192
2193config ARM64_HAFT
2194 bool "Support for Hardware managed Access Flag for Table Descriptors"
2195 depends on ARM64_HW_AFDBM
2196 default y
2197 help
2198 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access
2199 Flag for Table descriptors. When enabled an architectural executed
2200 memory access will update the Access Flag in each Table descriptor
2201 which is accessed during the translation table walk and for which
2202 the Access Flag is 0. The Access Flag of the Table descriptor use
2203 the same bit of PTE_AF.
2204
2205 The feature will only be enabled if all the CPUs in the system
2206 support this feature. If unsure, say Y.
2207
2208endmenu # "ARMv8.9 architectural features"
2209
2210menu "ARMv9.4 architectural features"
2211
2212config ARM64_GCS
2213 bool "Enable support for Guarded Control Stack (GCS)"
2214 default y
2215 select ARCH_HAS_USER_SHADOW_STACK
2216 select ARCH_USES_HIGH_VMA_FLAGS
2217 help
2218 Guarded Control Stack (GCS) provides support for a separate
2219 stack with restricted access which contains only return
2220 addresses. This can be used to harden against some attacks
2221 by comparing return address used by the program with what is
2222 stored in the GCS, and may also be used to efficiently obtain
2223 the call stack for applications such as profiling.
2224
2225 The feature is detected at runtime, and will remain disabled
2226 if the system does not implement the feature.
2227
2228endmenu # "ARMv9.4 architectural features"
2229
2230config ARM64_SVE
2231 bool "ARM Scalable Vector Extension support"
2232 default y
2233 help
2234 The Scalable Vector Extension (SVE) is an extension to the AArch64
2235 execution state which complements and extends the SIMD functionality
2236 of the base architecture to support much larger vectors and to enable
2237 additional vectorisation opportunities.
2238
2239 To enable use of this extension on CPUs that implement it, say Y.
2240
2241 On CPUs that support the SVE2 extensions, this option will enable
2242 those too.
2243
2244 Note that for architectural reasons, firmware _must_ implement SVE
2245 support when running on SVE capable hardware. The required support
2246 is present in:
2247
2248 * version 1.5 and later of the ARM Trusted Firmware
2249 * the AArch64 boot wrapper since commit 5e1261e08abf
2250 ("bootwrapper: SVE: Enable SVE for EL2 and below").
2251
2252 For other firmware implementations, consult the firmware documentation
2253 or vendor.
2254
2255 If you need the kernel to boot on SVE-capable hardware with broken
2256 firmware, you may need to say N here until you get your firmware
2257 fixed. Otherwise, you may experience firmware panics or lockups when
2258 booting the kernel. If unsure and you are not observing these
2259 symptoms, you should assume that it is safe to say Y.
2260
2261config ARM64_SME
2262 bool "ARM Scalable Matrix Extension support"
2263 default y
2264 depends on ARM64_SVE
2265 help
2266 The Scalable Matrix Extension (SME) is an extension to the AArch64
2267 execution state which utilises a substantial subset of the SVE
2268 instruction set, together with the addition of new architectural
2269 register state capable of holding two dimensional matrix tiles to
2270 enable various matrix operations.
2271
2272config ARM64_PSEUDO_NMI
2273 bool "Support for NMI-like interrupts"
2274 select ARM_GIC_V3
2275 help
2276 Adds support for mimicking Non-Maskable Interrupts through the use of
2277 GIC interrupt priority. This support requires version 3 or later of
2278 ARM GIC.
2279
2280 This high priority configuration for interrupts needs to be
2281 explicitly enabled by setting the kernel parameter
2282 "irqchip.gicv3_pseudo_nmi" to 1.
2283
2284 If unsure, say N
2285
2286if ARM64_PSEUDO_NMI
2287config ARM64_DEBUG_PRIORITY_MASKING
2288 bool "Debug interrupt priority masking"
2289 help
2290 This adds runtime checks to functions enabling/disabling
2291 interrupts when using priority masking. The additional checks verify
2292 the validity of ICC_PMR_EL1 when calling concerned functions.
2293
2294 If unsure, say N
2295endif # ARM64_PSEUDO_NMI
2296
2297config RELOCATABLE
2298 bool "Build a relocatable kernel image" if EXPERT
2299 select ARCH_HAS_RELR
2300 default y
2301 help
2302 This builds the kernel as a Position Independent Executable (PIE),
2303 which retains all relocation metadata required to relocate the
2304 kernel binary at runtime to a different virtual address than the
2305 address it was linked at.
2306 Since AArch64 uses the RELA relocation format, this requires a
2307 relocation pass at runtime even if the kernel is loaded at the
2308 same address it was linked at.
2309
2310config RANDOMIZE_BASE
2311 bool "Randomize the address of the kernel image"
2312 select RELOCATABLE
2313 help
2314 Randomizes the virtual address at which the kernel image is
2315 loaded, as a security feature that deters exploit attempts
2316 relying on knowledge of the location of kernel internals.
2317
2318 It is the bootloader's job to provide entropy, by passing a
2319 random u64 value in /chosen/kaslr-seed at kernel entry.
2320
2321 When booting via the UEFI stub, it will invoke the firmware's
2322 EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2323 to the kernel proper. In addition, it will randomise the physical
2324 location of the kernel Image as well.
2325
2326 If unsure, say N.
2327
2328config RANDOMIZE_MODULE_REGION_FULL
2329 bool "Randomize the module region over a 2 GB range"
2330 depends on RANDOMIZE_BASE
2331 default y
2332 help
2333 Randomizes the location of the module region inside a 2 GB window
2334 covering the core kernel. This way, it is less likely for modules
2335 to leak information about the location of core kernel data structures
2336 but it does imply that function calls between modules and the core
2337 kernel will need to be resolved via veneers in the module PLT.
2338
2339 When this option is not set, the module region will be randomized over
2340 a limited range that contains the [_stext, _etext] interval of the
2341 core kernel, so branch relocations are almost always in range unless
2342 the region is exhausted. In this particular case of region
2343 exhaustion, modules might be able to fall back to a larger 2GB area.
2344
2345config CC_HAVE_STACKPROTECTOR_SYSREG
2346 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2347
2348config STACKPROTECTOR_PER_TASK
2349 def_bool y
2350 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2351
2352config UNWIND_PATCH_PAC_INTO_SCS
2353 bool "Enable shadow call stack dynamically using code patching"
2354 depends on CC_IS_CLANG
2355 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2356 depends on SHADOW_CALL_STACK
2357 select UNWIND_TABLES
2358 select DYNAMIC_SCS
2359
2360config ARM64_CONTPTE
2361 bool "Contiguous PTE mappings for user memory" if EXPERT
2362 depends on TRANSPARENT_HUGEPAGE
2363 default y
2364 help
2365 When enabled, user mappings are configured using the PTE contiguous
2366 bit, for any mappings that meet the size and alignment requirements.
2367 This reduces TLB pressure and improves performance.
2368
2369endmenu # "Kernel Features"
2370
2371menu "Boot options"
2372
2373config ARM64_ACPI_PARKING_PROTOCOL
2374 bool "Enable support for the ARM64 ACPI parking protocol"
2375 depends on ACPI
2376 help
2377 Enable support for the ARM64 ACPI parking protocol. If disabled
2378 the kernel will not allow booting through the ARM64 ACPI parking
2379 protocol even if the corresponding data is present in the ACPI
2380 MADT table.
2381
2382config CMDLINE
2383 string "Default kernel command string"
2384 default ""
2385 help
2386 Provide a set of default command-line options at build time by
2387 entering them here. As a minimum, you should specify the the
2388 root device (e.g. root=/dev/nfs).
2389
2390choice
2391 prompt "Kernel command line type"
2392 depends on CMDLINE != ""
2393 default CMDLINE_FROM_BOOTLOADER
2394 help
2395 Choose how the kernel will handle the provided default kernel
2396 command line string.
2397
2398config CMDLINE_FROM_BOOTLOADER
2399 bool "Use bootloader kernel arguments if available"
2400 help
2401 Uses the command-line options passed by the boot loader. If
2402 the boot loader doesn't provide any, the default kernel command
2403 string provided in CMDLINE will be used.
2404
2405config CMDLINE_FORCE
2406 bool "Always use the default kernel command string"
2407 help
2408 Always use the default kernel command string, even if the boot
2409 loader passes other arguments to the kernel.
2410 This is useful if you cannot or don't want to change the
2411 command-line options your boot loader passes to the kernel.
2412
2413endchoice
2414
2415config EFI_STUB
2416 bool
2417
2418config EFI
2419 bool "UEFI runtime support"
2420 depends on OF && !CPU_BIG_ENDIAN
2421 depends on KERNEL_MODE_NEON
2422 select ARCH_SUPPORTS_ACPI
2423 select LIBFDT
2424 select UCS2_STRING
2425 select EFI_PARAMS_FROM_FDT
2426 select EFI_RUNTIME_WRAPPERS
2427 select EFI_STUB
2428 select EFI_GENERIC_STUB
2429 imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2430 default y
2431 help
2432 This option provides support for runtime services provided
2433 by UEFI firmware (such as non-volatile variables, realtime
2434 clock, and platform reset). A UEFI stub is also provided to
2435 allow the kernel to be booted as an EFI application. This
2436 is only useful on systems that have UEFI firmware.
2437
2438config COMPRESSED_INSTALL
2439 bool "Install compressed image by default"
2440 help
2441 This makes the regular "make install" install the compressed
2442 image we built, not the legacy uncompressed one.
2443
2444 You can check that a compressed image works for you by doing
2445 "make zinstall" first, and verifying that everything is fine
2446 in your environment before making "make install" do this for
2447 you.
2448
2449config DMI
2450 bool "Enable support for SMBIOS (DMI) tables"
2451 depends on EFI
2452 default y
2453 help
2454 This enables SMBIOS/DMI feature for systems.
2455
2456 This option is only useful on systems that have UEFI firmware.
2457 However, even with this option, the resultant kernel should
2458 continue to boot on existing non-UEFI platforms.
2459
2460endmenu # "Boot options"
2461
2462menu "Power management options"
2463
2464source "kernel/power/Kconfig"
2465
2466config ARCH_HIBERNATION_POSSIBLE
2467 def_bool y
2468 depends on CPU_PM
2469
2470config ARCH_HIBERNATION_HEADER
2471 def_bool y
2472 depends on HIBERNATION
2473
2474config ARCH_SUSPEND_POSSIBLE
2475 def_bool y
2476
2477endmenu # "Power management options"
2478
2479menu "CPU Power Management"
2480
2481source "drivers/cpuidle/Kconfig"
2482
2483source "drivers/cpufreq/Kconfig"
2484
2485endmenu # "CPU Power Management"
2486
2487source "drivers/acpi/Kconfig"
2488
2489source "arch/arm64/kvm/Kconfig"
2490
2491source "kernel/livepatch/Kconfig"