1 # SPDX-License-Identifier: GPL-2.0-only
2 config ARM64
3 	def_bool y
4 	select ACPI_APMT if ACPI
5 	select ACPI_CCA_REQUIRED if ACPI
6 	select ACPI_GENERIC_GSI if ACPI
7 	select ACPI_GTDT if ACPI
8 	select ACPI_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_CORRECT_STACKTRACE_ON_KRETPROBE
18 	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
19 	select ARCH_ENABLE_MEMORY_HOTPLUG
20 	select ARCH_ENABLE_MEMORY_HOTREMOVE
21 	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
22 	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
23 	select ARCH_HAS_CACHE_LINE_SIZE
24 	select ARCH_HAS_CURRENT_STACK_POINTER
25 	select ARCH_HAS_DEBUG_VIRTUAL
26 	select ARCH_HAS_DEBUG_VM_PGTABLE
27 	select ARCH_HAS_DMA_OPS if XEN
28 	select ARCH_HAS_DMA_PREP_COHERENT
29 	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
30 	select ARCH_HAS_FAST_MULTIPLIER
31 	select ARCH_HAS_FORTIFY_SOURCE
32 	select ARCH_HAS_GCOV_PROFILE_ALL
33 	select ARCH_HAS_GIGANTIC_PAGE
34 	select ARCH_HAS_KCOV
35 	select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON
36 	select ARCH_HAS_KEEPINITRD
37 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
38 	select ARCH_HAS_MEM_ENCRYPT
39 	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
40 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
41 	select ARCH_HAS_PTE_DEVMAP
42 	select ARCH_HAS_PTE_SPECIAL
43 	select ARCH_HAS_HW_PTE_YOUNG
44 	select ARCH_HAS_SETUP_DMA_OPS
45 	select ARCH_HAS_SET_DIRECT_MAP
46 	select ARCH_HAS_SET_MEMORY
47 	select ARCH_STACKWALK
48 	select ARCH_HAS_STRICT_KERNEL_RWX
49 	select ARCH_HAS_STRICT_MODULE_RWX
50 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
51 	select ARCH_HAS_SYNC_DMA_FOR_CPU
52 	select ARCH_HAS_SYSCALL_WRAPPER
53 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
54 	select ARCH_HAS_ZONE_DMA_SET if EXPERT
55 	select ARCH_HAVE_ELF_PROT
56 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
57 	select ARCH_HAVE_TRACE_MMIO_ACCESS
58 	select ARCH_INLINE_READ_LOCK if !PREEMPTION
59 	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
60 	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
61 	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
62 	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
63 	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
64 	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
65 	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
66 	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
67 	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
68 	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
69 	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
70 	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
71 	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
72 	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
73 	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
74 	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
75 	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
76 	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
77 	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
78 	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
79 	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
80 	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
81 	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
82 	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
83 	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
84 	select ARCH_KEEP_MEMBLOCK
85 	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
86 	select ARCH_USE_CMPXCHG_LOCKREF
87 	select ARCH_USE_GNU_PROPERTY
88 	select ARCH_USE_MEMTEST
89 	select ARCH_USE_QUEUED_RWLOCKS
90 	select ARCH_USE_QUEUED_SPINLOCKS
91 	select ARCH_USE_SYM_ANNOTATIONS
92 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
93 	select ARCH_SUPPORTS_HUGETLBFS
94 	select ARCH_SUPPORTS_MEMORY_FAILURE
95 	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
96 	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
97 	select ARCH_SUPPORTS_LTO_CLANG_THIN
98 	select ARCH_SUPPORTS_CFI_CLANG
99 	select ARCH_SUPPORTS_ATOMIC_RMW
100 	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
101 	select ARCH_SUPPORTS_NUMA_BALANCING
102 	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
103 	select ARCH_SUPPORTS_PER_VMA_LOCK
104 	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
105 	select ARCH_SUPPORTS_RT
106 	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
107 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
108 	select ARCH_WANT_DEFAULT_BPF_JIT
109 	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
110 	select ARCH_WANT_FRAME_POINTERS
111 	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
112 	select ARCH_WANT_LD_ORPHAN_WARN
113 	select ARCH_WANTS_EXECMEM_LATE if EXECMEM
114 	select ARCH_WANTS_NO_INSTR
115 	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
116 	select ARCH_HAS_UBSAN
117 	select ARM_AMBA
118 	select ARM_ARCH_TIMER
119 	select ARM_GIC
120 	select AUDIT_ARCH_COMPAT_GENERIC
121 	select ARM_GIC_V2M if PCI
122 	select ARM_GIC_V3
123 	select ARM_GIC_V3_ITS if PCI
124 	select ARM_PSCI_FW
125 	select BUILDTIME_TABLE_SORT
126 	select CLONE_BACKWARDS
127 	select COMMON_CLK
128 	select CPU_PM if (SUSPEND || CPU_IDLE)
129 	select CPUMASK_OFFSTACK if NR_CPUS > 256
130 	select CRC32
131 	select DCACHE_WORD_ACCESS
132 	select DYNAMIC_FTRACE if FUNCTION_TRACER
133 	select DMA_BOUNCE_UNALIGNED_KMALLOC
134 	select DMA_DIRECT_REMAP
135 	select EDAC_SUPPORT
136 	select FRAME_POINTER
137 	select FUNCTION_ALIGNMENT_4B
138 	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
139 	select GENERIC_ALLOCATOR
140 	select GENERIC_ARCH_TOPOLOGY
141 	select GENERIC_CLOCKEVENTS_BROADCAST
142 	select GENERIC_CPU_AUTOPROBE
143 	select GENERIC_CPU_DEVICES
144 	select GENERIC_CPU_VULNERABILITIES
145 	select GENERIC_EARLY_IOREMAP
146 	select GENERIC_IDLE_POLL_SETUP
147 	select GENERIC_IOREMAP
148 	select GENERIC_IRQ_IPI
149 	select GENERIC_IRQ_PROBE
150 	select GENERIC_IRQ_SHOW
151 	select GENERIC_IRQ_SHOW_LEVEL
152 	select GENERIC_LIB_DEVMEM_IS_ALLOWED
153 	select GENERIC_PCI_IOMAP
154 	select GENERIC_PTDUMP
155 	select GENERIC_SCHED_CLOCK
156 	select GENERIC_SMP_IDLE_THREAD
157 	select GENERIC_TIME_VSYSCALL
158 	select GENERIC_GETTIMEOFDAY
159 	select GENERIC_VDSO_TIME_NS
160 	select HARDIRQS_SW_RESEND
161 	select HAS_IOPORT
162 	select HAVE_MOVE_PMD
163 	select HAVE_MOVE_PUD
164 	select HAVE_PCI
165 	select HAVE_ACPI_APEI if (ACPI && EFI)
166 	select HAVE_ALIGNED_STRUCT_PAGE
167 	select HAVE_ARCH_AUDITSYSCALL
168 	select HAVE_ARCH_BITREVERSE
169 	select HAVE_ARCH_COMPILER_H
170 	select HAVE_ARCH_HUGE_VMALLOC
171 	select HAVE_ARCH_HUGE_VMAP
172 	select HAVE_ARCH_JUMP_LABEL
173 	select HAVE_ARCH_JUMP_LABEL_RELATIVE
174 	select HAVE_ARCH_KASAN
175 	select HAVE_ARCH_KASAN_VMALLOC
176 	select HAVE_ARCH_KASAN_SW_TAGS
177 	select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
178 	# Some instrumentation may be unsound, hence EXPERT
179 	select HAVE_ARCH_KCSAN if EXPERT
180 	select HAVE_ARCH_KFENCE
181 	select HAVE_ARCH_KGDB
182 	select HAVE_ARCH_MMAP_RND_BITS
183 	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
184 	select HAVE_ARCH_PREL32_RELOCATIONS
185 	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
186 	select HAVE_ARCH_SECCOMP_FILTER
187 	select HAVE_ARCH_STACKLEAK
188 	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
189 	select HAVE_ARCH_TRACEHOOK
190 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
191 	select HAVE_ARCH_VMAP_STACK
192 	select HAVE_ARM_SMCCC
193 	select HAVE_ASM_MODVERSIONS
194 	select HAVE_EBPF_JIT
195 	select HAVE_C_RECORDMCOUNT
196 	select HAVE_CMPXCHG_DOUBLE
197 	select HAVE_CMPXCHG_LOCAL
198 	select HAVE_CONTEXT_TRACKING_USER
199 	select HAVE_DEBUG_KMEMLEAK
200 	select HAVE_DMA_CONTIGUOUS
201 	select HAVE_DYNAMIC_FTRACE
202 	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
203 		if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
204 		    CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
205 	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
206 		if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
207 	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
208 		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
209 		    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
210 	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
211 		if DYNAMIC_FTRACE_WITH_ARGS
212 	select HAVE_SAMPLE_FTRACE_DIRECT
213 	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
214 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
215 	select HAVE_GUP_FAST
216 	select HAVE_FTRACE_MCOUNT_RECORD
217 	select HAVE_FUNCTION_TRACER
218 	select HAVE_FUNCTION_ERROR_INJECTION
219 	select HAVE_FUNCTION_GRAPH_TRACER
220 	select HAVE_FUNCTION_GRAPH_RETVAL
221 	select HAVE_GCC_PLUGINS
222 	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
223 		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
224 	select HAVE_HW_BREAKPOINT if PERF_EVENTS
225 	select HAVE_IOREMAP_PROT
226 	select HAVE_IRQ_TIME_ACCOUNTING
227 	select HAVE_MOD_ARCH_SPECIFIC
228 	select HAVE_NMI
229 	select HAVE_PERF_EVENTS
230 	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
231 	select HAVE_PERF_REGS
232 	select HAVE_PERF_USER_STACK_DUMP
233 	select HAVE_PREEMPT_DYNAMIC_KEY
234 	select HAVE_REGS_AND_STACK_ACCESS_API
235 	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
236 	select HAVE_FUNCTION_ARG_ACCESS_API
237 	select MMU_GATHER_RCU_TABLE_FREE
238 	select HAVE_RSEQ
239 	select HAVE_RUST if RUSTC_SUPPORTS_ARM64
240 	select HAVE_STACKPROTECTOR
241 	select HAVE_SYSCALL_TRACEPOINTS
242 	select HAVE_KPROBES
243 	select HAVE_KRETPROBES
244 	select HAVE_GENERIC_VDSO
245 	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
246 	select IRQ_DOMAIN
247 	select IRQ_FORCED_THREADING
248 	select KASAN_VMALLOC if KASAN
249 	select LOCK_MM_AND_FIND_VMA
250 	select MODULES_USE_ELF_RELA
251 	select NEED_DMA_MAP_STATE
252 	select NEED_SG_DMA_LENGTH
253 	select OF
254 	select OF_EARLY_FLATTREE
255 	select PCI_DOMAINS_GENERIC if PCI
256 	select PCI_ECAM if (ACPI && PCI)
257 	select PCI_SYSCALL if PCI
258 	select POWER_RESET
259 	select POWER_SUPPLY
260 	select SPARSE_IRQ
261 	select SWIOTLB
262 	select SYSCTL_EXCEPTION_TRACE
263 	select THREAD_INFO_IN_TASK
264 	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
265 	select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
266 	select TRACE_IRQFLAGS_SUPPORT
267 	select TRACE_IRQFLAGS_NMI_SUPPORT
268 	select HAVE_SOFTIRQ_ON_OWN_STACK
269 	select USER_STACKTRACE_SUPPORT
270 	select VDSO_GETRANDOM
271 	help
272 	  ARM 64-bit (AArch64) Linux support.
273 
274 config RUSTC_SUPPORTS_ARM64
275 	def_bool y
276 	depends on CPU_LITTLE_ENDIAN
277 	# Shadow call stack is only supported on certain rustc versions.
278 	#
279 	# When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is
280 	# required due to use of the -Zfixed-x18 flag.
281 	#
282 	# Otherwise, rustc version 1.82+ is required due to use of the
283 	# -Zsanitizer=shadow-call-stack flag.
284 	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS
285 
286 config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
287 	def_bool CC_IS_CLANG
288 	# https://github.com/ClangBuiltLinux/linux/issues/1507
289 	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
290 
291 config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
292 	def_bool CC_IS_GCC
293 	depends on $(cc-option,-fpatchable-function-entry=2)
294 
295 config 64BIT
296 	def_bool y
297 
298 config MMU
299 	def_bool y
300 
301 config ARM64_CONT_PTE_SHIFT
302 	int
303 	default 5 if PAGE_SIZE_64KB
304 	default 7 if PAGE_SIZE_16KB
305 	default 4
306 
307 config ARM64_CONT_PMD_SHIFT
308 	int
309 	default 5 if PAGE_SIZE_64KB
310 	default 5 if PAGE_SIZE_16KB
311 	default 4
312 
313 config ARCH_MMAP_RND_BITS_MIN
314 	default 14 if PAGE_SIZE_64KB
315 	default 16 if PAGE_SIZE_16KB
316 	default 18
317 
318 # max bits determined by the following formula:
319 #  VA_BITS - PAGE_SHIFT - 3
320 config ARCH_MMAP_RND_BITS_MAX
321 	default 19 if ARM64_VA_BITS=36
322 	default 24 if ARM64_VA_BITS=39
323 	default 27 if ARM64_VA_BITS=42
324 	default 30 if ARM64_VA_BITS=47
325 	default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
326 	default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
327 	default 33 if ARM64_VA_BITS=48
328 	default 14 if ARM64_64K_PAGES
329 	default 16 if ARM64_16K_PAGES
330 	default 18
331 
332 config ARCH_MMAP_RND_COMPAT_BITS_MIN
333 	default 7 if ARM64_64K_PAGES
334 	default 9 if ARM64_16K_PAGES
335 	default 11
336 
337 config ARCH_MMAP_RND_COMPAT_BITS_MAX
338 	default 16
339 
340 config NO_IOPORT_MAP
341 	def_bool y if !PCI
342 
343 config STACKTRACE_SUPPORT
344 	def_bool y
345 
346 config ILLEGAL_POINTER_VALUE
347 	hex
348 	default 0xdead000000000000
349 
350 config LOCKDEP_SUPPORT
351 	def_bool y
352 
353 config GENERIC_BUG
354 	def_bool y
355 	depends on BUG
356 
357 config GENERIC_BUG_RELATIVE_POINTERS
358 	def_bool y
359 	depends on GENERIC_BUG
360 
361 config GENERIC_HWEIGHT
362 	def_bool y
363 
364 config GENERIC_CSUM
365 	def_bool y
366 
367 config GENERIC_CALIBRATE_DELAY
368 	def_bool y
369 
370 config SMP
371 	def_bool y
372 
373 config KERNEL_MODE_NEON
374 	def_bool y
375 
376 config FIX_EARLYCON_MEM
377 	def_bool y
378 
379 config PGTABLE_LEVELS
380 	int
381 	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
382 	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
383 	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
384 	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
385 	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
386 	default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
387 	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
388 	default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
389 
390 config ARCH_SUPPORTS_UPROBES
391 	def_bool y
392 
393 config ARCH_PROC_KCORE_TEXT
394 	def_bool y
395 
396 config BROKEN_GAS_INST
397 	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
398 
399 config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
400 	bool
401 	# Clang's __builtin_return_address() strips the PAC since 12.0.0
402 	# https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
403 	default y if CC_IS_CLANG
404 	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
405 	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
406 	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
407 	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
408 	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
409 	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
410 	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
411 	default n
412 
413 config KASAN_SHADOW_OFFSET
414 	hex
415 	depends on KASAN_GENERIC || KASAN_SW_TAGS
416 	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
417 	default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
418 	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
419 	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
420 	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
421 	default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
422 	default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
423 	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
424 	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
425 	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
426 	default 0xffffffffffffffff
427 
428 config UNWIND_TABLES
429 	bool
430 
431 source "arch/arm64/Kconfig.platforms"
432 
433 menu "Kernel Features"
434 
435 menu "ARM errata workarounds via the alternatives framework"
436 
437 config AMPERE_ERRATUM_AC03_CPU_38
438         bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
439 	default y
440 	help
441 	  This option adds an alternative code sequence to work around Ampere
442 	  errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
443 
444 	  The affected design reports FEAT_HAFDBS as not implemented in
445 	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
446 	  as required by the architecture. The unadvertised HAFDBS
447 	  implementation suffers from an additional erratum where hardware
448 	  A/D updates can occur after a PTE has been marked invalid.
449 
450 	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
451 	  which avoids enabling unadvertised hardware Access Flag management
452 	  at stage-2.
453 
454 	  If unsure, say Y.
455 
456 config ARM64_WORKAROUND_CLEAN_CACHE
457 	bool
458 
459 config ARM64_ERRATUM_826319
460 	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
461 	default y
462 	select ARM64_WORKAROUND_CLEAN_CACHE
463 	help
464 	  This option adds an alternative code sequence to work around ARM
465 	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
466 	  AXI master interface and an L2 cache.
467 
468 	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
469 	  and is unable to accept a certain write via this interface, it will
470 	  not progress on read data presented on the read data channel and the
471 	  system can deadlock.
472 
473 	  The workaround promotes data cache clean instructions to
474 	  data cache clean-and-invalidate.
475 	  Please note that this does not necessarily enable the workaround,
476 	  as it depends on the alternative framework, which will only patch
477 	  the kernel if an affected CPU is detected.
478 
479 	  If unsure, say Y.
480 
481 config ARM64_ERRATUM_827319
482 	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
483 	default y
484 	select ARM64_WORKAROUND_CLEAN_CACHE
485 	help
486 	  This option adds an alternative code sequence to work around ARM
487 	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
488 	  master interface and an L2 cache.
489 
490 	  Under certain conditions this erratum can cause a clean line eviction
491 	  to occur at the same time as another transaction to the same address
492 	  on the AMBA 5 CHI interface, which can cause data corruption if the
493 	  interconnect reorders the two transactions.
494 
495 	  The workaround promotes data cache clean instructions to
496 	  data cache clean-and-invalidate.
497 	  Please note that this does not necessarily enable the workaround,
498 	  as it depends on the alternative framework, which will only patch
499 	  the kernel if an affected CPU is detected.
500 
501 	  If unsure, say Y.
502 
503 config ARM64_ERRATUM_824069
504 	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
505 	default y
506 	select ARM64_WORKAROUND_CLEAN_CACHE
507 	help
508 	  This option adds an alternative code sequence to work around ARM
509 	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
510 	  to a coherent interconnect.
511 
512 	  If a Cortex-A53 processor is executing a store or prefetch for
513 	  write instruction at the same time as a processor in another
514 	  cluster is executing a cache maintenance operation to the same
515 	  address, then this erratum might cause a clean cache line to be
516 	  incorrectly marked as dirty.
517 
518 	  The workaround promotes data cache clean instructions to
519 	  data cache clean-and-invalidate.
520 	  Please note that this option does not necessarily enable the
521 	  workaround, as it depends on the alternative framework, which will
522 	  only patch the kernel if an affected CPU is detected.
523 
524 	  If unsure, say Y.
525 
526 config ARM64_ERRATUM_819472
527 	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
528 	default y
529 	select ARM64_WORKAROUND_CLEAN_CACHE
530 	help
531 	  This option adds an alternative code sequence to work around ARM
532 	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
533 	  present when it is connected to a coherent interconnect.
534 
535 	  If the processor is executing a load and store exclusive sequence at
536 	  the same time as a processor in another cluster is executing a cache
537 	  maintenance operation to the same address, then this erratum might
538 	  cause data corruption.
539 
540 	  The workaround promotes data cache clean instructions to
541 	  data cache clean-and-invalidate.
542 	  Please note that this does not necessarily enable the workaround,
543 	  as it depends on the alternative framework, which will only patch
544 	  the kernel if an affected CPU is detected.
545 
546 	  If unsure, say Y.
547 
548 config ARM64_ERRATUM_832075
549 	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
550 	default y
551 	help
552 	  This option adds an alternative code sequence to work around ARM
553 	  erratum 832075 on Cortex-A57 parts up to r1p2.
554 
555 	  Affected Cortex-A57 parts might deadlock when exclusive load/store
556 	  instructions to Write-Back memory are mixed with Device loads.
557 
558 	  The workaround is to promote device loads to use Load-Acquire
559 	  semantics.
560 	  Please note that this does not necessarily enable the workaround,
561 	  as it depends on the alternative framework, which will only patch
562 	  the kernel if an affected CPU is detected.
563 
564 	  If unsure, say Y.
565 
566 config ARM64_ERRATUM_834220
567 	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
568 	depends on KVM
569 	help
570 	  This option adds an alternative code sequence to work around ARM
571 	  erratum 834220 on Cortex-A57 parts up to r1p2.
572 
573 	  Affected Cortex-A57 parts might report a Stage 2 translation
574 	  fault as the result of a Stage 1 fault for load crossing a
575 	  page boundary when there is a permission or device memory
576 	  alignment fault at Stage 1 and a translation fault at Stage 2.
577 
578 	  The workaround is to verify that the Stage 1 translation
579 	  doesn't generate a fault before handling the Stage 2 fault.
580 	  Please note that this does not necessarily enable the workaround,
581 	  as it depends on the alternative framework, which will only patch
582 	  the kernel if an affected CPU is detected.
583 
584 	  If unsure, say N.
585 
586 config ARM64_ERRATUM_1742098
587 	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
588 	depends on COMPAT
589 	default y
590 	help
591 	  This option removes the AES hwcap for aarch32 user-space to
592 	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
593 
594 	  Affected parts may corrupt the AES state if an interrupt is
595 	  taken between a pair of AES instructions. These instructions
596 	  are only present if the cryptography extensions are present.
597 	  All software should have a fallback implementation for CPUs
598 	  that don't implement the cryptography extensions.
599 
600 	  If unsure, say Y.
601 
602 config ARM64_ERRATUM_845719
603 	bool "Cortex-A53: 845719: a load might read incorrect data"
604 	depends on COMPAT
605 	default y
606 	help
607 	  This option adds an alternative code sequence to work around ARM
608 	  erratum 845719 on Cortex-A53 parts up to r0p4.
609 
610 	  When running a compat (AArch32) userspace on an affected Cortex-A53
611 	  part, a load at EL0 from a virtual address that matches the bottom 32
612 	  bits of the virtual address used by a recent load at (AArch64) EL1
613 	  might return incorrect data.
614 
615 	  The workaround is to write the contextidr_el1 register on exception
616 	  return to a 32-bit task.
617 	  Please note that this does not necessarily enable the workaround,
618 	  as it depends on the alternative framework, which will only patch
619 	  the kernel if an affected CPU is detected.
620 
621 	  If unsure, say Y.
622 
623 config ARM64_ERRATUM_843419
624 	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
625 	default y
626 	help
627 	  This option links the kernel with '--fix-cortex-a53-843419' and
628 	  enables PLT support to replace certain ADRP instructions, which can
629 	  cause subsequent memory accesses to use an incorrect address on
630 	  Cortex-A53 parts up to r0p4.
631 
632 	  If unsure, say Y.
633 
634 config ARM64_LD_HAS_FIX_ERRATUM_843419
635 	def_bool $(ld-option,--fix-cortex-a53-843419)
636 
637 config ARM64_ERRATUM_1024718
638 	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
639 	default y
640 	help
641 	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
642 
643 	  Affected Cortex-A55 cores (all revisions) could cause incorrect
644 	  update of the hardware dirty bit when the DBM/AP bits are updated
645 	  without a break-before-make. The workaround is to disable the usage
646 	  of hardware DBM locally on the affected cores. CPUs not affected by
647 	  this erratum will continue to use the feature.
648 
649 	  If unsure, say Y.
650 
651 config ARM64_ERRATUM_1418040
652 	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
653 	default y
654 	depends on COMPAT
655 	help
656 	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
657 	  errata 1188873 and 1418040.
658 
659 	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
660 	  cause register corruption when accessing the timer registers
661 	  from AArch32 userspace.
662 
663 	  If unsure, say Y.
664 
665 config ARM64_WORKAROUND_SPECULATIVE_AT
666 	bool
667 
668 config ARM64_ERRATUM_1165522
669 	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
670 	default y
671 	select ARM64_WORKAROUND_SPECULATIVE_AT
672 	help
673 	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
674 
675 	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
676 	  corrupted TLBs by speculating an AT instruction during a guest
677 	  context switch.
678 
679 	  If unsure, say Y.
680 
681 config ARM64_ERRATUM_1319367
682 	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
683 	default y
684 	select ARM64_WORKAROUND_SPECULATIVE_AT
685 	help
686 	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
687 	  and A72 erratum 1319367
688 
689 	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
690 	  speculating an AT instruction during a guest context switch.
691 
692 	  If unsure, say Y.
693 
694 config ARM64_ERRATUM_1530923
695 	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
696 	default y
697 	select ARM64_WORKAROUND_SPECULATIVE_AT
698 	help
699 	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
700 
701 	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
702 	  corrupted TLBs by speculating an AT instruction during a guest
703 	  context switch.
704 
705 	  If unsure, say Y.
706 
707 config ARM64_WORKAROUND_REPEAT_TLBI
708 	bool
709 
710 config ARM64_ERRATUM_2441007
711 	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
712 	select ARM64_WORKAROUND_REPEAT_TLBI
713 	help
714 	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
715 
716 	  Under very rare circumstances, affected Cortex-A55 CPUs
717 	  may not handle a race between a break-before-make sequence on one
718 	  CPU, and another CPU accessing the same page. This could allow a
719 	  store to a page that has been unmapped.
720 
721 	  Work around this by adding the affected CPUs to the list that needs
722 	  TLB sequences to be done twice.
723 
724 	  If unsure, say N.
725 
726 config ARM64_ERRATUM_1286807
727 	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
728 	select ARM64_WORKAROUND_REPEAT_TLBI
729 	help
730 	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
731 
732 	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
733 	  address for a cacheable mapping of a location is being
734 	  accessed by a core while another core is remapping the virtual
735 	  address to a new physical page using the recommended
736 	  break-before-make sequence, then under very rare circumstances
737 	  TLBI+DSB completes before a read using the translation being
738 	  invalidated has been observed by other observers. The
739 	  workaround repeats the TLBI+DSB operation.
740 
741 	  If unsure, say N.
742 
743 config ARM64_ERRATUM_1463225
744 	bool "Cortex-A76: Software Step might prevent interrupt recognition"
745 	default y
746 	help
747 	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
748 
749 	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
750 	  of a system call instruction (SVC) can prevent recognition of
751 	  subsequent interrupts when software stepping is disabled in the
752 	  exception handler of the system call and either kernel debugging
753 	  is enabled or VHE is in use.
754 
755 	  Work around the erratum by triggering a dummy step exception
756 	  when handling a system call from a task that is being stepped
757 	  in a VHE configuration of the kernel.
758 
759 	  If unsure, say Y.
760 
761 config ARM64_ERRATUM_1542419
762 	bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
763 	help
764 	  This option adds a workaround for ARM Neoverse-N1 erratum
765 	  1542419.
766 
767 	  Affected Neoverse-N1 cores could execute a stale instruction when
768 	  modified by another CPU. The workaround depends on a firmware
769 	  counterpart.
770 
771 	  Workaround the issue by hiding the DIC feature from EL0. This
772 	  forces user-space to perform cache maintenance.
773 
774 	  If unsure, say N.
775 
776 config ARM64_ERRATUM_1508412
777 	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
778 	default y
779 	help
780 	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
781 
782 	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
783 	  of a store-exclusive or read of PAR_EL1 and a load with device or
784 	  non-cacheable memory attributes. The workaround depends on a firmware
785 	  counterpart.
786 
787 	  KVM guests must also have the workaround implemented or they can
788 	  deadlock the system.
789 
790 	  Work around the issue by inserting DMB SY barriers around PAR_EL1
791 	  register reads and warning KVM users. The DMB barrier is sufficient
792 	  to prevent a speculative PAR_EL1 read.
793 
794 	  If unsure, say Y.
795 
796 config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
797 	bool
798 
799 config ARM64_ERRATUM_2051678
800 	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
801 	default y
802 	help
803 	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
804 	  Affected Cortex-A510 might not respect the ordering rules for
805 	  hardware update of the page table's dirty bit. The workaround
806 	  is to not enable the feature on affected CPUs.
807 
808 	  If unsure, say Y.
809 
810 config ARM64_ERRATUM_2077057
811 	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
812 	default y
813 	help
814 	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
815 	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
816 	  expected, but a Pointer Authentication trap is taken instead. The
817 	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
818 	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
819 
820 	  This can only happen when EL2 is stepping EL1.
821 
822 	  When these conditions occur, the SPSR_EL2 value is unchanged from the
823 	  previous guest entry, and can be restored from the in-memory copy.
824 
825 	  If unsure, say Y.
826 
827 config ARM64_ERRATUM_2658417
828 	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
829 	default y
830 	help
831 	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
832 	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
833 	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
834 	  A510 CPUs are using shared neon hardware. As the sharing is not
835 	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
836 	  user-space should not be using these instructions.
837 
838 	  If unsure, say Y.
839 
840 config ARM64_ERRATUM_2119858
841 	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
842 	default y
843 	depends on CORESIGHT_TRBE
844 	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
845 	help
846 	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
847 
848 	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
849 	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
850 	  the event of a WRAP event.
851 
852 	  Work around the issue by always making sure we move the TRBPTR_EL1 by
853 	  256 bytes before enabling the buffer and filling the first 256 bytes of
854 	  the buffer with ETM ignore packets upon disabling.
855 
856 	  If unsure, say Y.
857 
858 config ARM64_ERRATUM_2139208
859 	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
860 	default y
861 	depends on CORESIGHT_TRBE
862 	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
863 	help
864 	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
865 
866 	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
867 	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
868 	  the event of a WRAP event.
869 
870 	  Work around the issue by always making sure we move the TRBPTR_EL1 by
871 	  256 bytes before enabling the buffer and filling the first 256 bytes of
872 	  the buffer with ETM ignore packets upon disabling.
873 
874 	  If unsure, say Y.
875 
876 config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
877 	bool
878 
879 config ARM64_ERRATUM_2054223
880 	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
881 	default y
882 	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
883 	help
884 	  Enable workaround for ARM Cortex-A710 erratum 2054223
885 
886 	  Affected cores may fail to flush the trace data on a TSB instruction, when
887 	  the PE is in trace prohibited state. This will cause losing a few bytes
888 	  of the trace cached.
889 
890 	  Workaround is to issue two TSB consecutively on affected cores.
891 
892 	  If unsure, say Y.
893 
894 config ARM64_ERRATUM_2067961
895 	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
896 	default y
897 	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
898 	help
899 	  Enable workaround for ARM Neoverse-N2 erratum 2067961
900 
901 	  Affected cores may fail to flush the trace data on a TSB instruction, when
902 	  the PE is in trace prohibited state. This will cause losing a few bytes
903 	  of the trace cached.
904 
905 	  Workaround is to issue two TSB consecutively on affected cores.
906 
907 	  If unsure, say Y.
908 
909 config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
910 	bool
911 
912 config ARM64_ERRATUM_2253138
913 	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
914 	depends on CORESIGHT_TRBE
915 	default y
916 	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
917 	help
918 	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
919 
920 	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
921 	  for TRBE. Under some conditions, the TRBE might generate a write to the next
922 	  virtually addressed page following the last page of the TRBE address space
923 	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
924 
925 	  Work around this in the driver by always making sure that there is a
926 	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
927 
928 	  If unsure, say Y.
929 
930 config ARM64_ERRATUM_2224489
931 	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
932 	depends on CORESIGHT_TRBE
933 	default y
934 	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
935 	help
936 	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
937 
938 	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
939 	  for TRBE. Under some conditions, the TRBE might generate a write to the next
940 	  virtually addressed page following the last page of the TRBE address space
941 	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
942 
943 	  Work around this in the driver by always making sure that there is a
944 	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
945 
946 	  If unsure, say Y.
947 
948 config ARM64_ERRATUM_2441009
949 	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
950 	select ARM64_WORKAROUND_REPEAT_TLBI
951 	help
952 	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
953 
954 	  Under very rare circumstances, affected Cortex-A510 CPUs
955 	  may not handle a race between a break-before-make sequence on one
956 	  CPU, and another CPU accessing the same page. This could allow a
957 	  store to a page that has been unmapped.
958 
959 	  Work around this by adding the affected CPUs to the list that needs
960 	  TLB sequences to be done twice.
961 
962 	  If unsure, say N.
963 
964 config ARM64_ERRATUM_2064142
965 	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
966 	depends on CORESIGHT_TRBE
967 	default y
968 	help
969 	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
970 
971 	  Affected Cortex-A510 core might fail to write into system registers after the
972 	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
973 	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
974 	  and TRBTRG_EL1 will be ignored and will not be effected.
975 
976 	  Work around this in the driver by executing TSB CSYNC and DSB after collection
977 	  is stopped and before performing a system register write to one of the affected
978 	  registers.
979 
980 	  If unsure, say Y.
981 
982 config ARM64_ERRATUM_2038923
983 	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
984 	depends on CORESIGHT_TRBE
985 	default y
986 	help
987 	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
988 
989 	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
990 	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
991 	  might be corrupted. This happens after TRBE buffer has been enabled by setting
992 	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
993 	  execution changes from a context, in which trace is prohibited to one where it
994 	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
995 	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
996 	  the trace buffer state might be corrupted.
997 
998 	  Work around this in the driver by preventing an inconsistent view of whether the
999 	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
1000 	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
1001 	  two ISB instructions if no ERET is to take place.
1002 
1003 	  If unsure, say Y.
1004 
1005 config ARM64_ERRATUM_1902691
1006 	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1007 	depends on CORESIGHT_TRBE
1008 	default y
1009 	help
1010 	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1011 
1012 	  Affected Cortex-A510 core might cause trace data corruption, when being written
1013 	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
1014 	  trace data.
1015 
1016 	  Work around this problem in the driver by just preventing TRBE initialization on
1017 	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1018 	  on such implementations. This will cover the kernel for any firmware that doesn't
1019 	  do this already.
1020 
1021 	  If unsure, say Y.
1022 
1023 config ARM64_ERRATUM_2457168
1024 	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1025 	depends on ARM64_AMU_EXTN
1026 	default y
1027 	help
1028 	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1029 
1030 	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1031 	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1032 	  incorrectly giving a significantly higher output value.
1033 
1034 	  Work around this problem by returning 0 when reading the affected counter in
1035 	  key locations that results in disabling all users of this counter. This effect
1036 	  is the same to firmware disabling affected counters.
1037 
1038 	  If unsure, say Y.
1039 
1040 config ARM64_ERRATUM_2645198
1041 	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1042 	default y
1043 	help
1044 	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1045 
1046 	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1047 	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1048 	  next instruction abort caused by permission fault.
1049 
1050 	  Only user-space does executable to non-executable permission transition via
1051 	  mprotect() system call. Workaround the problem by doing a break-before-make
1052 	  TLB invalidation, for all changes to executable user space mappings.
1053 
1054 	  If unsure, say Y.
1055 
1056 config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1057 	bool
1058 
1059 config ARM64_ERRATUM_2966298
1060 	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1061 	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1062 	default y
1063 	help
1064 	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1065 
1066 	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1067 	  load might leak data from a privileged level via a cache side channel.
1068 
1069 	  Work around this problem by executing a TLBI before returning to EL0.
1070 
1071 	  If unsure, say Y.
1072 
1073 config ARM64_ERRATUM_3117295
1074 	bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1075 	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1076 	default y
1077 	help
1078 	  This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1079 
1080 	  On an affected Cortex-A510 core, a speculatively executed unprivileged
1081 	  load might leak data from a privileged level via a cache side channel.
1082 
1083 	  Work around this problem by executing a TLBI before returning to EL0.
1084 
1085 	  If unsure, say Y.
1086 
1087 config ARM64_ERRATUM_3194386
1088 	bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1089 	default y
1090 	help
1091 	  This option adds the workaround for the following errata:
1092 
1093 	  * ARM Cortex-A76 erratum 3324349
1094 	  * ARM Cortex-A77 erratum 3324348
1095 	  * ARM Cortex-A78 erratum 3324344
1096 	  * ARM Cortex-A78C erratum 3324346
1097 	  * ARM Cortex-A78C erratum 3324347
1098 	  * ARM Cortex-A710 erratam 3324338
1099 	  * ARM Cortex-A715 errartum 3456084
1100 	  * ARM Cortex-A720 erratum 3456091
1101 	  * ARM Cortex-A725 erratum 3456106
1102 	  * ARM Cortex-X1 erratum 3324344
1103 	  * ARM Cortex-X1C erratum 3324346
1104 	  * ARM Cortex-X2 erratum 3324338
1105 	  * ARM Cortex-X3 erratum 3324335
1106 	  * ARM Cortex-X4 erratum 3194386
1107 	  * ARM Cortex-X925 erratum 3324334
1108 	  * ARM Neoverse-N1 erratum 3324349
1109 	  * ARM Neoverse N2 erratum 3324339
1110 	  * ARM Neoverse-N3 erratum 3456111
1111 	  * ARM Neoverse-V1 erratum 3324341
1112 	  * ARM Neoverse V2 erratum 3324336
1113 	  * ARM Neoverse-V3 erratum 3312417
1114 
1115 	  On affected cores "MSR SSBS, #0" instructions may not affect
1116 	  subsequent speculative instructions, which may permit unexepected
1117 	  speculative store bypassing.
1118 
1119 	  Work around this problem by placing a Speculation Barrier (SB) or
1120 	  Instruction Synchronization Barrier (ISB) after kernel changes to
1121 	  SSBS. The presence of the SSBS special-purpose register is hidden
1122 	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1123 	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1124 
1125 	  If unsure, say Y.
1126 
1127 config CAVIUM_ERRATUM_22375
1128 	bool "Cavium erratum 22375, 24313"
1129 	default y
1130 	help
1131 	  Enable workaround for errata 22375 and 24313.
1132 
1133 	  This implements two gicv3-its errata workarounds for ThunderX. Both
1134 	  with a small impact affecting only ITS table allocation.
1135 
1136 	    erratum 22375: only alloc 8MB table size
1137 	    erratum 24313: ignore memory access type
1138 
1139 	  The fixes are in ITS initialization and basically ignore memory access
1140 	  type and table size provided by the TYPER and BASER registers.
1141 
1142 	  If unsure, say Y.
1143 
1144 config CAVIUM_ERRATUM_23144
1145 	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1146 	depends on NUMA
1147 	default y
1148 	help
1149 	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1150 
1151 	  If unsure, say Y.
1152 
1153 config CAVIUM_ERRATUM_23154
1154 	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1155 	default y
1156 	help
1157 	  The ThunderX GICv3 implementation requires a modified version for
1158 	  reading the IAR status to ensure data synchronization
1159 	  (access to icc_iar1_el1 is not sync'ed before and after).
1160 
1161 	  It also suffers from erratum 38545 (also present on Marvell's
1162 	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1163 	  spuriously presented to the CPU interface.
1164 
1165 	  If unsure, say Y.
1166 
1167 config CAVIUM_ERRATUM_27456
1168 	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1169 	default y
1170 	help
1171 	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1172 	  instructions may cause the icache to become corrupted if it
1173 	  contains data for a non-current ASID.  The fix is to
1174 	  invalidate the icache when changing the mm context.
1175 
1176 	  If unsure, say Y.
1177 
1178 config CAVIUM_ERRATUM_30115
1179 	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1180 	default y
1181 	help
1182 	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1183 	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1184 	  interrupts in host. Trapping both GICv3 group-0 and group-1
1185 	  accesses sidesteps the issue.
1186 
1187 	  If unsure, say Y.
1188 
1189 config CAVIUM_TX2_ERRATUM_219
1190 	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1191 	default y
1192 	help
1193 	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1194 	  TTBR update and the corresponding context synchronizing operation can
1195 	  cause a spurious Data Abort to be delivered to any hardware thread in
1196 	  the CPU core.
1197 
1198 	  Work around the issue by avoiding the problematic code sequence and
1199 	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1200 	  trap handler performs the corresponding register access, skips the
1201 	  instruction and ensures context synchronization by virtue of the
1202 	  exception return.
1203 
1204 	  If unsure, say Y.
1205 
1206 config FUJITSU_ERRATUM_010001
1207 	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1208 	default y
1209 	help
1210 	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1211 	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1212 	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1213 	  This fault occurs under a specific hardware condition when a
1214 	  load/store instruction performs an address translation using:
1215 	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1216 	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1217 	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1218 	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1219 
1220 	  The workaround is to ensure these bits are clear in TCR_ELx.
1221 	  The workaround only affects the Fujitsu-A64FX.
1222 
1223 	  If unsure, say Y.
1224 
1225 config HISILICON_ERRATUM_161600802
1226 	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1227 	default y
1228 	help
1229 	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1230 	  when issued ITS commands such as VMOVP and VMAPP, and requires
1231 	  a 128kB offset to be applied to the target address in this commands.
1232 
1233 	  If unsure, say Y.
1234 
1235 config QCOM_FALKOR_ERRATUM_1003
1236 	bool "Falkor E1003: Incorrect translation due to ASID change"
1237 	default y
1238 	help
1239 	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1240 	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1241 	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1242 	  then only for entries in the walk cache, since the leaf translation
1243 	  is unchanged. Work around the erratum by invalidating the walk cache
1244 	  entries for the trampoline before entering the kernel proper.
1245 
1246 config QCOM_FALKOR_ERRATUM_1009
1247 	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1248 	default y
1249 	select ARM64_WORKAROUND_REPEAT_TLBI
1250 	help
1251 	  On Falkor v1, the CPU may prematurely complete a DSB following a
1252 	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1253 	  one more time to fix the issue.
1254 
1255 	  If unsure, say Y.
1256 
1257 config QCOM_QDF2400_ERRATUM_0065
1258 	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1259 	default y
1260 	help
1261 	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1262 	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1263 	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1264 
1265 	  If unsure, say Y.
1266 
1267 config QCOM_FALKOR_ERRATUM_E1041
1268 	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1269 	default y
1270 	help
1271 	  Falkor CPU may speculatively fetch instructions from an improper
1272 	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1273 	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1274 
1275 	  If unsure, say Y.
1276 
1277 config NVIDIA_CARMEL_CNP_ERRATUM
1278 	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1279 	default y
1280 	help
1281 	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1282 	  invalidate shared TLB entries installed by a different core, as it would
1283 	  on standard ARM cores.
1284 
1285 	  If unsure, say Y.
1286 
1287 config ROCKCHIP_ERRATUM_3588001
1288 	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1289 	default y
1290 	help
1291 	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1292 	  This means, that its sharability feature may not be used, even though it
1293 	  is supported by the IP itself.
1294 
1295 	  If unsure, say Y.
1296 
1297 config SOCIONEXT_SYNQUACER_PREITS
1298 	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1299 	default y
1300 	help
1301 	  Socionext Synquacer SoCs implement a separate h/w block to generate
1302 	  MSI doorbell writes with non-zero values for the device ID.
1303 
1304 	  If unsure, say Y.
1305 
1306 endmenu # "ARM errata workarounds via the alternatives framework"
1307 
1308 choice
1309 	prompt "Page size"
1310 	default ARM64_4K_PAGES
1311 	help
1312 	  Page size (translation granule) configuration.
1313 
1314 config ARM64_4K_PAGES
1315 	bool "4KB"
1316 	select HAVE_PAGE_SIZE_4KB
1317 	help
1318 	  This feature enables 4KB pages support.
1319 
1320 config ARM64_16K_PAGES
1321 	bool "16KB"
1322 	select HAVE_PAGE_SIZE_16KB
1323 	help
1324 	  The system will use 16KB pages support. AArch32 emulation
1325 	  requires applications compiled with 16K (or a multiple of 16K)
1326 	  aligned segments.
1327 
1328 config ARM64_64K_PAGES
1329 	bool "64KB"
1330 	select HAVE_PAGE_SIZE_64KB
1331 	help
1332 	  This feature enables 64KB pages support (4KB by default)
1333 	  allowing only two levels of page tables and faster TLB
1334 	  look-up. AArch32 emulation requires applications compiled
1335 	  with 64K aligned segments.
1336 
1337 endchoice
1338 
1339 choice
1340 	prompt "Virtual address space size"
1341 	default ARM64_VA_BITS_52
1342 	help
1343 	  Allows choosing one of multiple possible virtual address
1344 	  space sizes. The level of translation table is determined by
1345 	  a combination of page size and virtual address space size.
1346 
1347 config ARM64_VA_BITS_36
1348 	bool "36-bit" if EXPERT
1349 	depends on PAGE_SIZE_16KB
1350 
1351 config ARM64_VA_BITS_39
1352 	bool "39-bit"
1353 	depends on PAGE_SIZE_4KB
1354 
1355 config ARM64_VA_BITS_42
1356 	bool "42-bit"
1357 	depends on PAGE_SIZE_64KB
1358 
1359 config ARM64_VA_BITS_47
1360 	bool "47-bit"
1361 	depends on PAGE_SIZE_16KB
1362 
1363 config ARM64_VA_BITS_48
1364 	bool "48-bit"
1365 
1366 config ARM64_VA_BITS_52
1367 	bool "52-bit"
1368 	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1369 	help
1370 	  Enable 52-bit virtual addressing for userspace when explicitly
1371 	  requested via a hint to mmap(). The kernel will also use 52-bit
1372 	  virtual addresses for its own mappings (provided HW support for
1373 	  this feature is available, otherwise it reverts to 48-bit).
1374 
1375 	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1376 	  ARMv8.3 Pointer Authentication will result in the PAC being
1377 	  reduced from 7 bits to 3 bits, which may have a significant
1378 	  impact on its susceptibility to brute-force attacks.
1379 
1380 	  If unsure, select 48-bit virtual addressing instead.
1381 
1382 endchoice
1383 
1384 config ARM64_FORCE_52BIT
1385 	bool "Force 52-bit virtual addresses for userspace"
1386 	depends on ARM64_VA_BITS_52 && EXPERT
1387 	help
1388 	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1389 	  to maintain compatibility with older software by providing 48-bit VAs
1390 	  unless a hint is supplied to mmap.
1391 
1392 	  This configuration option disables the 48-bit compatibility logic, and
1393 	  forces all userspace addresses to be 52-bit on HW that supports it. One
1394 	  should only enable this configuration option for stress testing userspace
1395 	  memory management code. If unsure say N here.
1396 
1397 config ARM64_VA_BITS
1398 	int
1399 	default 36 if ARM64_VA_BITS_36
1400 	default 39 if ARM64_VA_BITS_39
1401 	default 42 if ARM64_VA_BITS_42
1402 	default 47 if ARM64_VA_BITS_47
1403 	default 48 if ARM64_VA_BITS_48
1404 	default 52 if ARM64_VA_BITS_52
1405 
1406 choice
1407 	prompt "Physical address space size"
1408 	default ARM64_PA_BITS_48
1409 	help
1410 	  Choose the maximum physical address range that the kernel will
1411 	  support.
1412 
1413 config ARM64_PA_BITS_48
1414 	bool "48-bit"
1415 	depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1416 
1417 config ARM64_PA_BITS_52
1418 	bool "52-bit"
1419 	depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1420 	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
1421 	help
1422 	  Enable support for a 52-bit physical address space, introduced as
1423 	  part of the ARMv8.2-LPA extension.
1424 
1425 	  With this enabled, the kernel will also continue to work on CPUs that
1426 	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1427 	  minor performance overhead).
1428 
1429 endchoice
1430 
1431 config ARM64_PA_BITS
1432 	int
1433 	default 48 if ARM64_PA_BITS_48
1434 	default 52 if ARM64_PA_BITS_52
1435 
1436 config ARM64_LPA2
1437 	def_bool y
1438 	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1439 
1440 choice
1441 	prompt "Endianness"
1442 	default CPU_LITTLE_ENDIAN
1443 	help
1444 	  Select the endianness of data accesses performed by the CPU. Userspace
1445 	  applications will need to be compiled and linked for the endianness
1446 	  that is selected here.
1447 
1448 config CPU_BIG_ENDIAN
1449 	bool "Build big-endian kernel"
1450 	# https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1451 	depends on AS_IS_GNU || AS_VERSION >= 150000
1452 	help
1453 	  Say Y if you plan on running a kernel with a big-endian userspace.
1454 
1455 config CPU_LITTLE_ENDIAN
1456 	bool "Build little-endian kernel"
1457 	help
1458 	  Say Y if you plan on running a kernel with a little-endian userspace.
1459 	  This is usually the case for distributions targeting arm64.
1460 
1461 endchoice
1462 
1463 config SCHED_MC
1464 	bool "Multi-core scheduler support"
1465 	help
1466 	  Multi-core scheduler support improves the CPU scheduler's decision
1467 	  making when dealing with multi-core CPU chips at a cost of slightly
1468 	  increased overhead in some places. If unsure say N here.
1469 
1470 config SCHED_CLUSTER
1471 	bool "Cluster scheduler support"
1472 	help
1473 	  Cluster scheduler support improves the CPU scheduler's decision
1474 	  making when dealing with machines that have clusters of CPUs.
1475 	  Cluster usually means a couple of CPUs which are placed closely
1476 	  by sharing mid-level caches, last-level cache tags or internal
1477 	  busses.
1478 
1479 config SCHED_SMT
1480 	bool "SMT scheduler support"
1481 	help
1482 	  Improves the CPU scheduler's decision making when dealing with
1483 	  MultiThreading at a cost of slightly increased overhead in some
1484 	  places. If unsure say N here.
1485 
1486 config NR_CPUS
1487 	int "Maximum number of CPUs (2-4096)"
1488 	range 2 4096
1489 	default "512"
1490 
1491 config HOTPLUG_CPU
1492 	bool "Support for hot-pluggable CPUs"
1493 	select GENERIC_IRQ_MIGRATION
1494 	help
1495 	  Say Y here to experiment with turning CPUs off and on.  CPUs
1496 	  can be controlled through /sys/devices/system/cpu.
1497 
1498 # Common NUMA Features
1499 config NUMA
1500 	bool "NUMA Memory Allocation and Scheduler Support"
1501 	select GENERIC_ARCH_NUMA
1502 	select OF_NUMA
1503 	select HAVE_SETUP_PER_CPU_AREA
1504 	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1505 	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1506 	select USE_PERCPU_NUMA_NODE_ID
1507 	help
1508 	  Enable NUMA (Non-Uniform Memory Access) support.
1509 
1510 	  The kernel will try to allocate memory used by a CPU on the
1511 	  local memory of the CPU and add some more
1512 	  NUMA awareness to the kernel.
1513 
1514 config NODES_SHIFT
1515 	int "Maximum NUMA Nodes (as a power of 2)"
1516 	range 1 10
1517 	default "4"
1518 	depends on NUMA
1519 	help
1520 	  Specify the maximum number of NUMA Nodes available on the target
1521 	  system.  Increases memory reserved to accommodate various tables.
1522 
1523 source "kernel/Kconfig.hz"
1524 
1525 config ARCH_SPARSEMEM_ENABLE
1526 	def_bool y
1527 	select SPARSEMEM_VMEMMAP_ENABLE
1528 	select SPARSEMEM_VMEMMAP
1529 
1530 config HW_PERF_EVENTS
1531 	def_bool y
1532 	depends on ARM_PMU
1533 
1534 # Supported by clang >= 7.0 or GCC >= 12.0.0
1535 config CC_HAVE_SHADOW_CALL_STACK
1536 	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1537 
1538 config PARAVIRT
1539 	bool "Enable paravirtualization code"
1540 	help
1541 	  This changes the kernel so it can modify itself when it is run
1542 	  under a hypervisor, potentially improving performance significantly
1543 	  over full virtualization.
1544 
1545 config PARAVIRT_TIME_ACCOUNTING
1546 	bool "Paravirtual steal time accounting"
1547 	select PARAVIRT
1548 	help
1549 	  Select this option to enable fine granularity task steal time
1550 	  accounting. Time spent executing other tasks in parallel with
1551 	  the current vCPU is discounted from the vCPU power. To account for
1552 	  that, there can be a small performance impact.
1553 
1554 	  If in doubt, say N here.
1555 
1556 config ARCH_SUPPORTS_KEXEC
1557 	def_bool PM_SLEEP_SMP
1558 
1559 config ARCH_SUPPORTS_KEXEC_FILE
1560 	def_bool y
1561 
1562 config ARCH_SELECTS_KEXEC_FILE
1563 	def_bool y
1564 	depends on KEXEC_FILE
1565 	select HAVE_IMA_KEXEC if IMA
1566 
1567 config ARCH_SUPPORTS_KEXEC_SIG
1568 	def_bool y
1569 
1570 config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1571 	def_bool y
1572 
1573 config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1574 	def_bool y
1575 
1576 config ARCH_SUPPORTS_CRASH_DUMP
1577 	def_bool y
1578 
1579 config ARCH_DEFAULT_CRASH_DUMP
1580 	def_bool y
1581 
1582 config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1583 	def_bool CRASH_RESERVE
1584 
1585 config TRANS_TABLE
1586 	def_bool y
1587 	depends on HIBERNATION || KEXEC_CORE
1588 
1589 config XEN_DOM0
1590 	def_bool y
1591 	depends on XEN
1592 
1593 config XEN
1594 	bool "Xen guest support on ARM64"
1595 	depends on ARM64 && OF
1596 	select SWIOTLB_XEN
1597 	select PARAVIRT
1598 	help
1599 	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1600 
1601 # include/linux/mmzone.h requires the following to be true:
1602 #
1603 #   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1604 #
1605 # so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1606 #
1607 #     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1608 # ----+-------------------+--------------+----------------------+-------------------------+
1609 # 4K  |       27          |      12      |       15             |         10              |
1610 # 16K |       27          |      14      |       13             |         11              |
1611 # 64K |       29          |      16      |       13             |         13              |
1612 config ARCH_FORCE_MAX_ORDER
1613 	int
1614 	default "13" if ARM64_64K_PAGES
1615 	default "11" if ARM64_16K_PAGES
1616 	default "10"
1617 	help
1618 	  The kernel page allocator limits the size of maximal physically
1619 	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1620 	  defines the maximal power of two of number of pages that can be
1621 	  allocated as a single contiguous block. This option allows
1622 	  overriding the default setting when ability to allocate very
1623 	  large blocks of physically contiguous memory is required.
1624 
1625 	  The maximal size of allocation cannot exceed the size of the
1626 	  section, so the value of MAX_PAGE_ORDER should satisfy
1627 
1628 	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1629 
1630 	  Don't change if unsure.
1631 
1632 config UNMAP_KERNEL_AT_EL0
1633 	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1634 	default y
1635 	help
1636 	  Speculation attacks against some high-performance processors can
1637 	  be used to bypass MMU permission checks and leak kernel data to
1638 	  userspace. This can be defended against by unmapping the kernel
1639 	  when running in userspace, mapping it back in on exception entry
1640 	  via a trampoline page in the vector table.
1641 
1642 	  If unsure, say Y.
1643 
1644 config MITIGATE_SPECTRE_BRANCH_HISTORY
1645 	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1646 	default y
1647 	help
1648 	  Speculation attacks against some high-performance processors can
1649 	  make use of branch history to influence future speculation.
1650 	  When taking an exception from user-space, a sequence of branches
1651 	  or a firmware call overwrites the branch history.
1652 
1653 config RODATA_FULL_DEFAULT_ENABLED
1654 	bool "Apply r/o permissions of VM areas also to their linear aliases"
1655 	default y
1656 	help
1657 	  Apply read-only attributes of VM areas to the linear alias of
1658 	  the backing pages as well. This prevents code or read-only data
1659 	  from being modified (inadvertently or intentionally) via another
1660 	  mapping of the same memory page. This additional enhancement can
1661 	  be turned off at runtime by passing rodata=[off|on] (and turned on
1662 	  with rodata=full if this option is set to 'n')
1663 
1664 	  This requires the linear region to be mapped down to pages,
1665 	  which may adversely affect performance in some cases.
1666 
1667 config ARM64_SW_TTBR0_PAN
1668 	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1669 	depends on !KCSAN
1670 	help
1671 	  Enabling this option prevents the kernel from accessing
1672 	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1673 	  zeroed area and reserved ASID. The user access routines
1674 	  restore the valid TTBR0_EL1 temporarily.
1675 
1676 config ARM64_TAGGED_ADDR_ABI
1677 	bool "Enable the tagged user addresses syscall ABI"
1678 	default y
1679 	help
1680 	  When this option is enabled, user applications can opt in to a
1681 	  relaxed ABI via prctl() allowing tagged addresses to be passed
1682 	  to system calls as pointer arguments. For details, see
1683 	  Documentation/arch/arm64/tagged-address-abi.rst.
1684 
1685 menuconfig COMPAT
1686 	bool "Kernel support for 32-bit EL0"
1687 	depends on ARM64_4K_PAGES || EXPERT
1688 	select HAVE_UID16
1689 	select OLD_SIGSUSPEND3
1690 	select COMPAT_OLD_SIGACTION
1691 	help
1692 	  This option enables support for a 32-bit EL0 running under a 64-bit
1693 	  kernel at EL1. AArch32-specific components such as system calls,
1694 	  the user helper functions, VFP support and the ptrace interface are
1695 	  handled appropriately by the kernel.
1696 
1697 	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1698 	  that you will only be able to execute AArch32 binaries that were compiled
1699 	  with page size aligned segments.
1700 
1701 	  If you want to execute 32-bit userspace applications, say Y.
1702 
1703 if COMPAT
1704 
1705 config KUSER_HELPERS
1706 	bool "Enable kuser helpers page for 32-bit applications"
1707 	default y
1708 	help
1709 	  Warning: disabling this option may break 32-bit user programs.
1710 
1711 	  Provide kuser helpers to compat tasks. The kernel provides
1712 	  helper code to userspace in read only form at a fixed location
1713 	  to allow userspace to be independent of the CPU type fitted to
1714 	  the system. This permits binaries to be run on ARMv4 through
1715 	  to ARMv8 without modification.
1716 
1717 	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1718 
1719 	  However, the fixed address nature of these helpers can be used
1720 	  by ROP (return orientated programming) authors when creating
1721 	  exploits.
1722 
1723 	  If all of the binaries and libraries which run on your platform
1724 	  are built specifically for your platform, and make no use of
1725 	  these helpers, then you can turn this option off to hinder
1726 	  such exploits. However, in that case, if a binary or library
1727 	  relying on those helpers is run, it will not function correctly.
1728 
1729 	  Say N here only if you are absolutely certain that you do not
1730 	  need these helpers; otherwise, the safe option is to say Y.
1731 
1732 config COMPAT_VDSO
1733 	bool "Enable vDSO for 32-bit applications"
1734 	depends on !CPU_BIG_ENDIAN
1735 	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1736 	select GENERIC_COMPAT_VDSO
1737 	default y
1738 	help
1739 	  Place in the process address space of 32-bit applications an
1740 	  ELF shared object providing fast implementations of gettimeofday
1741 	  and clock_gettime.
1742 
1743 	  You must have a 32-bit build of glibc 2.22 or later for programs
1744 	  to seamlessly take advantage of this.
1745 
1746 config THUMB2_COMPAT_VDSO
1747 	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1748 	depends on COMPAT_VDSO
1749 	default y
1750 	help
1751 	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1752 	  otherwise with '-marm'.
1753 
1754 config COMPAT_ALIGNMENT_FIXUPS
1755 	bool "Fix up misaligned multi-word loads and stores in user space"
1756 
1757 menuconfig ARMV8_DEPRECATED
1758 	bool "Emulate deprecated/obsolete ARMv8 instructions"
1759 	depends on SYSCTL
1760 	help
1761 	  Legacy software support may require certain instructions
1762 	  that have been deprecated or obsoleted in the architecture.
1763 
1764 	  Enable this config to enable selective emulation of these
1765 	  features.
1766 
1767 	  If unsure, say Y
1768 
1769 if ARMV8_DEPRECATED
1770 
1771 config SWP_EMULATION
1772 	bool "Emulate SWP/SWPB instructions"
1773 	help
1774 	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1775 	  they are always undefined. Say Y here to enable software
1776 	  emulation of these instructions for userspace using LDXR/STXR.
1777 	  This feature can be controlled at runtime with the abi.swp
1778 	  sysctl which is disabled by default.
1779 
1780 	  In some older versions of glibc [<=2.8] SWP is used during futex
1781 	  trylock() operations with the assumption that the code will not
1782 	  be preempted. This invalid assumption may be more likely to fail
1783 	  with SWP emulation enabled, leading to deadlock of the user
1784 	  application.
1785 
1786 	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1787 	  on an external transaction monitoring block called a global
1788 	  monitor to maintain update atomicity. If your system does not
1789 	  implement a global monitor, this option can cause programs that
1790 	  perform SWP operations to uncached memory to deadlock.
1791 
1792 	  If unsure, say Y
1793 
1794 config CP15_BARRIER_EMULATION
1795 	bool "Emulate CP15 Barrier instructions"
1796 	help
1797 	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1798 	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1799 	  strongly recommended to use the ISB, DSB, and DMB
1800 	  instructions instead.
1801 
1802 	  Say Y here to enable software emulation of these
1803 	  instructions for AArch32 userspace code. When this option is
1804 	  enabled, CP15 barrier usage is traced which can help
1805 	  identify software that needs updating. This feature can be
1806 	  controlled at runtime with the abi.cp15_barrier sysctl.
1807 
1808 	  If unsure, say Y
1809 
1810 config SETEND_EMULATION
1811 	bool "Emulate SETEND instruction"
1812 	help
1813 	  The SETEND instruction alters the data-endianness of the
1814 	  AArch32 EL0, and is deprecated in ARMv8.
1815 
1816 	  Say Y here to enable software emulation of the instruction
1817 	  for AArch32 userspace code. This feature can be controlled
1818 	  at runtime with the abi.setend sysctl.
1819 
1820 	  Note: All the cpus on the system must have mixed endian support at EL0
1821 	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1822 	  endian - is hotplugged in after this feature has been enabled, there could
1823 	  be unexpected results in the applications.
1824 
1825 	  If unsure, say Y
1826 endif # ARMV8_DEPRECATED
1827 
1828 endif # COMPAT
1829 
1830 menu "ARMv8.1 architectural features"
1831 
1832 config ARM64_HW_AFDBM
1833 	bool "Support for hardware updates of the Access and Dirty page flags"
1834 	default y
1835 	help
1836 	  The ARMv8.1 architecture extensions introduce support for
1837 	  hardware updates of the access and dirty information in page
1838 	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1839 	  capable processors, accesses to pages with PTE_AF cleared will
1840 	  set this bit instead of raising an access flag fault.
1841 	  Similarly, writes to read-only pages with the DBM bit set will
1842 	  clear the read-only bit (AP[2]) instead of raising a
1843 	  permission fault.
1844 
1845 	  Kernels built with this configuration option enabled continue
1846 	  to work on pre-ARMv8.1 hardware and the performance impact is
1847 	  minimal. If unsure, say Y.
1848 
1849 config ARM64_PAN
1850 	bool "Enable support for Privileged Access Never (PAN)"
1851 	default y
1852 	help
1853 	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1854 	  prevents the kernel or hypervisor from accessing user-space (EL0)
1855 	  memory directly.
1856 
1857 	  Choosing this option will cause any unprotected (not using
1858 	  copy_to_user et al) memory access to fail with a permission fault.
1859 
1860 	  The feature is detected at runtime, and will remain as a 'nop'
1861 	  instruction if the cpu does not implement the feature.
1862 
1863 config AS_HAS_LSE_ATOMICS
1864 	def_bool $(as-instr,.arch_extension lse)
1865 
1866 config ARM64_LSE_ATOMICS
1867 	bool
1868 	default ARM64_USE_LSE_ATOMICS
1869 	depends on AS_HAS_LSE_ATOMICS
1870 
1871 config ARM64_USE_LSE_ATOMICS
1872 	bool "Atomic instructions"
1873 	default y
1874 	help
1875 	  As part of the Large System Extensions, ARMv8.1 introduces new
1876 	  atomic instructions that are designed specifically to scale in
1877 	  very large systems.
1878 
1879 	  Say Y here to make use of these instructions for the in-kernel
1880 	  atomic routines. This incurs a small overhead on CPUs that do
1881 	  not support these instructions and requires the kernel to be
1882 	  built with binutils >= 2.25 in order for the new instructions
1883 	  to be used.
1884 
1885 endmenu # "ARMv8.1 architectural features"
1886 
1887 menu "ARMv8.2 architectural features"
1888 
1889 config AS_HAS_ARMV8_2
1890 	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1891 
1892 config AS_HAS_SHA3
1893 	def_bool $(as-instr,.arch armv8.2-a+sha3)
1894 
1895 config ARM64_PMEM
1896 	bool "Enable support for persistent memory"
1897 	select ARCH_HAS_PMEM_API
1898 	select ARCH_HAS_UACCESS_FLUSHCACHE
1899 	help
1900 	  Say Y to enable support for the persistent memory API based on the
1901 	  ARMv8.2 DCPoP feature.
1902 
1903 	  The feature is detected at runtime, and the kernel will use DC CVAC
1904 	  operations if DC CVAP is not supported (following the behaviour of
1905 	  DC CVAP itself if the system does not define a point of persistence).
1906 
1907 config ARM64_RAS_EXTN
1908 	bool "Enable support for RAS CPU Extensions"
1909 	default y
1910 	help
1911 	  CPUs that support the Reliability, Availability and Serviceability
1912 	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1913 	  errors, classify them and report them to software.
1914 
1915 	  On CPUs with these extensions system software can use additional
1916 	  barriers to determine if faults are pending and read the
1917 	  classification from a new set of registers.
1918 
1919 	  Selecting this feature will allow the kernel to use these barriers
1920 	  and access the new registers if the system supports the extension.
1921 	  Platform RAS features may additionally depend on firmware support.
1922 
1923 config ARM64_CNP
1924 	bool "Enable support for Common Not Private (CNP) translations"
1925 	default y
1926 	depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN
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 
1937 endmenu # "ARMv8.2 architectural features"
1938 
1939 menu "ARMv8.3 architectural features"
1940 
1941 config 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 
1965 config ARM64_PTR_AUTH_KERNEL
1966 	bool "Use pointer authentication for kernel"
1967 	default y
1968 	depends on ARM64_PTR_AUTH
1969 	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1970 	# Modern compilers insert a .note.gnu.property section note for PAC
1971 	# which is only understood by binutils starting with version 2.33.1.
1972 	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1973 	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1974 	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
1975 	help
1976 	  If the compiler supports the -mbranch-protection or
1977 	  -msign-return-address flag (e.g. GCC 7 or later), then this option
1978 	  will cause the kernel itself to be compiled with return address
1979 	  protection. In this case, and if the target hardware is known to
1980 	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
1981 	  disabled with minimal loss of protection.
1982 
1983 	  This feature works with FUNCTION_GRAPH_TRACER option only if
1984 	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
1985 
1986 config CC_HAS_BRANCH_PROT_PAC_RET
1987 	# GCC 9 or later, clang 8 or later
1988 	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
1989 
1990 config CC_HAS_SIGN_RETURN_ADDRESS
1991 	# GCC 7, 8
1992 	def_bool $(cc-option,-msign-return-address=all)
1993 
1994 config AS_HAS_ARMV8_3
1995 	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
1996 
1997 config AS_HAS_CFI_NEGATE_RA_STATE
1998 	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
1999 
2000 config AS_HAS_LDAPR
2001 	def_bool $(as-instr,.arch_extension rcpc)
2002 
2003 endmenu # "ARMv8.3 architectural features"
2004 
2005 menu "ARMv8.4 architectural features"
2006 
2007 config ARM64_AMU_EXTN
2008 	bool "Enable support for the Activity Monitors Unit CPU extension"
2009 	default y
2010 	help
2011 	  The activity monitors extension is an optional extension introduced
2012 	  by the ARMv8.4 CPU architecture. This enables support for version 1
2013 	  of the activity monitors architecture, AMUv1.
2014 
2015 	  To enable the use of this extension on CPUs that implement it, say Y.
2016 
2017 	  Note that for architectural reasons, firmware _must_ implement AMU
2018 	  support when running on CPUs that present the activity monitors
2019 	  extension. The required support is present in:
2020 	    * Version 1.5 and later of the ARM Trusted Firmware
2021 
2022 	  For kernels that have this configuration enabled but boot with broken
2023 	  firmware, you may need to say N here until the firmware is fixed.
2024 	  Otherwise you may experience firmware panics or lockups when
2025 	  accessing the counter registers. Even if you are not observing these
2026 	  symptoms, the values returned by the register reads might not
2027 	  correctly reflect reality. Most commonly, the value read will be 0,
2028 	  indicating that the counter is not enabled.
2029 
2030 config AS_HAS_ARMV8_4
2031 	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
2032 
2033 config ARM64_TLB_RANGE
2034 	bool "Enable support for tlbi range feature"
2035 	default y
2036 	depends on AS_HAS_ARMV8_4
2037 	help
2038 	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2039 	  range of input addresses.
2040 
2041 	  The feature introduces new assembly instructions, and they were
2042 	  support when binutils >= 2.30.
2043 
2044 endmenu # "ARMv8.4 architectural features"
2045 
2046 menu "ARMv8.5 architectural features"
2047 
2048 config AS_HAS_ARMV8_5
2049 	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2050 
2051 config ARM64_BTI
2052 	bool "Branch Target Identification support"
2053 	default y
2054 	help
2055 	  Branch Target Identification (part of the ARMv8.5 Extensions)
2056 	  provides a mechanism to limit the set of locations to which computed
2057 	  branch instructions such as BR or BLR can jump.
2058 
2059 	  To make use of BTI on CPUs that support it, say Y.
2060 
2061 	  BTI is intended to provide complementary protection to other control
2062 	  flow integrity protection mechanisms, such as the Pointer
2063 	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2064 	  For this reason, it does not make sense to enable this option without
2065 	  also enabling support for pointer authentication.  Thus, when
2066 	  enabling this option you should also select ARM64_PTR_AUTH=y.
2067 
2068 	  Userspace binaries must also be specifically compiled to make use of
2069 	  this mechanism.  If you say N here or the hardware does not support
2070 	  BTI, such binaries can still run, but you get no additional
2071 	  enforcement of branch destinations.
2072 
2073 config ARM64_BTI_KERNEL
2074 	bool "Use Branch Target Identification for kernel"
2075 	default y
2076 	depends on ARM64_BTI
2077 	depends on ARM64_PTR_AUTH_KERNEL
2078 	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2079 	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2080 	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2081 	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2082 	depends on !CC_IS_GCC
2083 	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2084 	help
2085 	  Build the kernel with Branch Target Identification annotations
2086 	  and enable enforcement of this for kernel code. When this option
2087 	  is enabled and the system supports BTI all kernel code including
2088 	  modular code must have BTI enabled.
2089 
2090 config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2091 	# GCC 9 or later, clang 8 or later
2092 	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2093 
2094 config ARM64_E0PD
2095 	bool "Enable support for E0PD"
2096 	default y
2097 	help
2098 	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2099 	  that EL0 accesses made via TTBR1 always fault in constant time,
2100 	  providing similar benefits to KASLR as those provided by KPTI, but
2101 	  with lower overhead and without disrupting legitimate access to
2102 	  kernel memory such as SPE.
2103 
2104 	  This option enables E0PD for TTBR1 where available.
2105 
2106 config ARM64_AS_HAS_MTE
2107 	# Initial support for MTE went in binutils 2.32.0, checked with
2108 	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2109 	# as a late addition to the final architecture spec (LDGM/STGM)
2110 	# is only supported in the newer 2.32.x and 2.33 binutils
2111 	# versions, hence the extra "stgm" instruction check below.
2112 	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2113 
2114 config ARM64_MTE
2115 	bool "Memory Tagging Extension support"
2116 	default y
2117 	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2118 	depends on AS_HAS_ARMV8_5
2119 	depends on AS_HAS_LSE_ATOMICS
2120 	# Required for tag checking in the uaccess routines
2121 	depends on ARM64_PAN
2122 	select ARCH_HAS_SUBPAGE_FAULTS
2123 	select ARCH_USES_HIGH_VMA_FLAGS
2124 	select ARCH_USES_PG_ARCH_2
2125 	select ARCH_USES_PG_ARCH_3
2126 	help
2127 	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2128 	  architectural support for run-time, always-on detection of
2129 	  various classes of memory error to aid with software debugging
2130 	  to eliminate vulnerabilities arising from memory-unsafe
2131 	  languages.
2132 
2133 	  This option enables the support for the Memory Tagging
2134 	  Extension at EL0 (i.e. for userspace).
2135 
2136 	  Selecting this option allows the feature to be detected at
2137 	  runtime. Any secondary CPU not implementing this feature will
2138 	  not be allowed a late bring-up.
2139 
2140 	  Userspace binaries that want to use this feature must
2141 	  explicitly opt in. The mechanism for the userspace is
2142 	  described in:
2143 
2144 	  Documentation/arch/arm64/memory-tagging-extension.rst.
2145 
2146 endmenu # "ARMv8.5 architectural features"
2147 
2148 menu "ARMv8.7 architectural features"
2149 
2150 config ARM64_EPAN
2151 	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2152 	default y
2153 	depends on ARM64_PAN
2154 	help
2155 	  Enhanced Privileged Access Never (EPAN) allows Privileged
2156 	  Access Never to be used with Execute-only mappings.
2157 
2158 	  The feature is detected at runtime, and will remain disabled
2159 	  if the cpu does not implement the feature.
2160 endmenu # "ARMv8.7 architectural features"
2161 
2162 menu "ARMv8.9 architectural features"
2163 
2164 config ARM64_POE
2165 	prompt "Permission Overlay Extension"
2166 	def_bool y
2167 	select ARCH_USES_HIGH_VMA_FLAGS
2168 	select ARCH_HAS_PKEYS
2169 	help
2170 	  The Permission Overlay Extension is used to implement Memory
2171 	  Protection Keys. Memory Protection Keys provides a mechanism for
2172 	  enforcing page-based protections, but without requiring modification
2173 	  of the page tables when an application changes protection domains.
2174 
2175 	  For details, see Documentation/core-api/protection-keys.rst
2176 
2177 	  If unsure, say y.
2178 
2179 config ARCH_PKEY_BITS
2180 	int
2181 	default 3
2182 
2183 endmenu # "ARMv8.9 architectural features"
2184 
2185 config ARM64_SVE
2186 	bool "ARM Scalable Vector Extension support"
2187 	default y
2188 	help
2189 	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2190 	  execution state which complements and extends the SIMD functionality
2191 	  of the base architecture to support much larger vectors and to enable
2192 	  additional vectorisation opportunities.
2193 
2194 	  To enable use of this extension on CPUs that implement it, say Y.
2195 
2196 	  On CPUs that support the SVE2 extensions, this option will enable
2197 	  those too.
2198 
2199 	  Note that for architectural reasons, firmware _must_ implement SVE
2200 	  support when running on SVE capable hardware.  The required support
2201 	  is present in:
2202 
2203 	    * version 1.5 and later of the ARM Trusted Firmware
2204 	    * the AArch64 boot wrapper since commit 5e1261e08abf
2205 	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2206 
2207 	  For other firmware implementations, consult the firmware documentation
2208 	  or vendor.
2209 
2210 	  If you need the kernel to boot on SVE-capable hardware with broken
2211 	  firmware, you may need to say N here until you get your firmware
2212 	  fixed.  Otherwise, you may experience firmware panics or lockups when
2213 	  booting the kernel.  If unsure and you are not observing these
2214 	  symptoms, you should assume that it is safe to say Y.
2215 
2216 config ARM64_SME
2217 	bool "ARM Scalable Matrix Extension support"
2218 	default y
2219 	depends on ARM64_SVE
2220 	depends on BROKEN
2221 	help
2222 	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2223 	  execution state which utilises a substantial subset of the SVE
2224 	  instruction set, together with the addition of new architectural
2225 	  register state capable of holding two dimensional matrix tiles to
2226 	  enable various matrix operations.
2227 
2228 config ARM64_PSEUDO_NMI
2229 	bool "Support for NMI-like interrupts"
2230 	select ARM_GIC_V3
2231 	help
2232 	  Adds support for mimicking Non-Maskable Interrupts through the use of
2233 	  GIC interrupt priority. This support requires version 3 or later of
2234 	  ARM GIC.
2235 
2236 	  This high priority configuration for interrupts needs to be
2237 	  explicitly enabled by setting the kernel parameter
2238 	  "irqchip.gicv3_pseudo_nmi" to 1.
2239 
2240 	  If unsure, say N
2241 
2242 if ARM64_PSEUDO_NMI
2243 config ARM64_DEBUG_PRIORITY_MASKING
2244 	bool "Debug interrupt priority masking"
2245 	help
2246 	  This adds runtime checks to functions enabling/disabling
2247 	  interrupts when using priority masking. The additional checks verify
2248 	  the validity of ICC_PMR_EL1 when calling concerned functions.
2249 
2250 	  If unsure, say N
2251 endif # ARM64_PSEUDO_NMI
2252 
2253 config RELOCATABLE
2254 	bool "Build a relocatable kernel image" if EXPERT
2255 	select ARCH_HAS_RELR
2256 	default y
2257 	help
2258 	  This builds the kernel as a Position Independent Executable (PIE),
2259 	  which retains all relocation metadata required to relocate the
2260 	  kernel binary at runtime to a different virtual address than the
2261 	  address it was linked at.
2262 	  Since AArch64 uses the RELA relocation format, this requires a
2263 	  relocation pass at runtime even if the kernel is loaded at the
2264 	  same address it was linked at.
2265 
2266 config RANDOMIZE_BASE
2267 	bool "Randomize the address of the kernel image"
2268 	select RELOCATABLE
2269 	help
2270 	  Randomizes the virtual address at which the kernel image is
2271 	  loaded, as a security feature that deters exploit attempts
2272 	  relying on knowledge of the location of kernel internals.
2273 
2274 	  It is the bootloader's job to provide entropy, by passing a
2275 	  random u64 value in /chosen/kaslr-seed at kernel entry.
2276 
2277 	  When booting via the UEFI stub, it will invoke the firmware's
2278 	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2279 	  to the kernel proper. In addition, it will randomise the physical
2280 	  location of the kernel Image as well.
2281 
2282 	  If unsure, say N.
2283 
2284 config RANDOMIZE_MODULE_REGION_FULL
2285 	bool "Randomize the module region over a 2 GB range"
2286 	depends on RANDOMIZE_BASE
2287 	default y
2288 	help
2289 	  Randomizes the location of the module region inside a 2 GB window
2290 	  covering the core kernel. This way, it is less likely for modules
2291 	  to leak information about the location of core kernel data structures
2292 	  but it does imply that function calls between modules and the core
2293 	  kernel will need to be resolved via veneers in the module PLT.
2294 
2295 	  When this option is not set, the module region will be randomized over
2296 	  a limited range that contains the [_stext, _etext] interval of the
2297 	  core kernel, so branch relocations are almost always in range unless
2298 	  the region is exhausted. In this particular case of region
2299 	  exhaustion, modules might be able to fall back to a larger 2GB area.
2300 
2301 config CC_HAVE_STACKPROTECTOR_SYSREG
2302 	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2303 
2304 config STACKPROTECTOR_PER_TASK
2305 	def_bool y
2306 	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2307 
2308 config UNWIND_PATCH_PAC_INTO_SCS
2309 	bool "Enable shadow call stack dynamically using code patching"
2310 	# needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated
2311 	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2312 	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2313 	depends on SHADOW_CALL_STACK
2314 	select UNWIND_TABLES
2315 	select DYNAMIC_SCS
2316 
2317 config ARM64_CONTPTE
2318 	bool "Contiguous PTE mappings for user memory" if EXPERT
2319 	depends on TRANSPARENT_HUGEPAGE
2320 	default y
2321 	help
2322 	  When enabled, user mappings are configured using the PTE contiguous
2323 	  bit, for any mappings that meet the size and alignment requirements.
2324 	  This reduces TLB pressure and improves performance.
2325 
2326 endmenu # "Kernel Features"
2327 
2328 menu "Boot options"
2329 
2330 config ARM64_ACPI_PARKING_PROTOCOL
2331 	bool "Enable support for the ARM64 ACPI parking protocol"
2332 	depends on ACPI
2333 	help
2334 	  Enable support for the ARM64 ACPI parking protocol. If disabled
2335 	  the kernel will not allow booting through the ARM64 ACPI parking
2336 	  protocol even if the corresponding data is present in the ACPI
2337 	  MADT table.
2338 
2339 config CMDLINE
2340 	string "Default kernel command string"
2341 	default ""
2342 	help
2343 	  Provide a set of default command-line options at build time by
2344 	  entering them here. As a minimum, you should specify the the
2345 	  root device (e.g. root=/dev/nfs).
2346 
2347 choice
2348 	prompt "Kernel command line type"
2349 	depends on CMDLINE != ""
2350 	default CMDLINE_FROM_BOOTLOADER
2351 	help
2352 	  Choose how the kernel will handle the provided default kernel
2353 	  command line string.
2354 
2355 config CMDLINE_FROM_BOOTLOADER
2356 	bool "Use bootloader kernel arguments if available"
2357 	help
2358 	  Uses the command-line options passed by the boot loader. If
2359 	  the boot loader doesn't provide any, the default kernel command
2360 	  string provided in CMDLINE will be used.
2361 
2362 config CMDLINE_FORCE
2363 	bool "Always use the default kernel command string"
2364 	help
2365 	  Always use the default kernel command string, even if the boot
2366 	  loader passes other arguments to the kernel.
2367 	  This is useful if you cannot or don't want to change the
2368 	  command-line options your boot loader passes to the kernel.
2369 
2370 endchoice
2371 
2372 config EFI_STUB
2373 	bool
2374 
2375 config EFI
2376 	bool "UEFI runtime support"
2377 	depends on OF && !CPU_BIG_ENDIAN
2378 	depends on KERNEL_MODE_NEON
2379 	select ARCH_SUPPORTS_ACPI
2380 	select LIBFDT
2381 	select UCS2_STRING
2382 	select EFI_PARAMS_FROM_FDT
2383 	select EFI_RUNTIME_WRAPPERS
2384 	select EFI_STUB
2385 	select EFI_GENERIC_STUB
2386 	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2387 	default y
2388 	help
2389 	  This option provides support for runtime services provided
2390 	  by UEFI firmware (such as non-volatile variables, realtime
2391 	  clock, and platform reset). A UEFI stub is also provided to
2392 	  allow the kernel to be booted as an EFI application. This
2393 	  is only useful on systems that have UEFI firmware.
2394 
2395 config COMPRESSED_INSTALL
2396 	bool "Install compressed image by default"
2397 	help
2398 	  This makes the regular "make install" install the compressed
2399 	  image we built, not the legacy uncompressed one.
2400 
2401 	  You can check that a compressed image works for you by doing
2402 	  "make zinstall" first, and verifying that everything is fine
2403 	  in your environment before making "make install" do this for
2404 	  you.
2405 
2406 config DMI
2407 	bool "Enable support for SMBIOS (DMI) tables"
2408 	depends on EFI
2409 	default y
2410 	help
2411 	  This enables SMBIOS/DMI feature for systems.
2412 
2413 	  This option is only useful on systems that have UEFI firmware.
2414 	  However, even with this option, the resultant kernel should
2415 	  continue to boot on existing non-UEFI platforms.
2416 
2417 endmenu # "Boot options"
2418 
2419 menu "Power management options"
2420 
2421 source "kernel/power/Kconfig"
2422 
2423 config ARCH_HIBERNATION_POSSIBLE
2424 	def_bool y
2425 	depends on CPU_PM
2426 
2427 config ARCH_HIBERNATION_HEADER
2428 	def_bool y
2429 	depends on HIBERNATION
2430 
2431 config ARCH_SUSPEND_POSSIBLE
2432 	def_bool y
2433 
2434 endmenu # "Power management options"
2435 
2436 menu "CPU Power Management"
2437 
2438 source "drivers/cpuidle/Kconfig"
2439 
2440 source "drivers/cpufreq/Kconfig"
2441 
2442 endmenu # "CPU Power Management"
2443 
2444 source "drivers/acpi/Kconfig"
2445 
2446 source "arch/arm64/kvm/Kconfig"
2447 
2448