1# SPDX-License-Identifier: GPL-2.0-only
2config ARM64
3	def_bool y
4	select ACPI_APMT if ACPI
5	select ACPI_CCA_REQUIRED if ACPI
6	select ACPI_GENERIC_GSI if ACPI
7	select ACPI_GTDT if ACPI
8	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
9	select ACPI_IORT if ACPI
10	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
11	select ACPI_MCFG if (ACPI && PCI)
12	select ACPI_SPCR_TABLE if ACPI
13	select ACPI_PPTT if ACPI
14	select ARCH_HAS_DEBUG_WX
15	select ARCH_BINFMT_ELF_EXTRA_PHDRS
16	select ARCH_BINFMT_ELF_STATE
17	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
18	select ARCH_ENABLE_MEMORY_HOTPLUG
19	select ARCH_ENABLE_MEMORY_HOTREMOVE
20	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
21	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
22	select ARCH_HAS_CACHE_LINE_SIZE
23	select ARCH_HAS_CC_PLATFORM
24	select ARCH_HAS_CRC32
25	select ARCH_HAS_CRC_T10DIF if KERNEL_MODE_NEON
26	select ARCH_HAS_CURRENT_STACK_POINTER
27	select ARCH_HAS_DEBUG_VIRTUAL
28	select ARCH_HAS_DEBUG_VM_PGTABLE
29	select ARCH_HAS_DMA_OPS if XEN
30	select ARCH_HAS_DMA_PREP_COHERENT
31	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
32	select ARCH_HAS_FAST_MULTIPLIER
33	select ARCH_HAS_FORTIFY_SOURCE
34	select ARCH_HAS_GCOV_PROFILE_ALL
35	select ARCH_HAS_GIGANTIC_PAGE
36	select ARCH_HAS_KCOV
37	select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON
38	select ARCH_HAS_KEEPINITRD
39	select ARCH_HAS_MEMBARRIER_SYNC_CORE
40	select ARCH_HAS_MEM_ENCRYPT
41	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
42	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
43	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
44	select ARCH_HAS_PTE_DEVMAP
45	select ARCH_HAS_PTE_SPECIAL
46	select ARCH_HAS_HW_PTE_YOUNG
47	select ARCH_HAS_SETUP_DMA_OPS
48	select ARCH_HAS_SET_DIRECT_MAP
49	select ARCH_HAS_SET_MEMORY
50	select ARCH_HAS_MEM_ENCRYPT
51	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
52	select ARCH_STACKWALK
53	select ARCH_HAS_STRICT_KERNEL_RWX
54	select ARCH_HAS_STRICT_MODULE_RWX
55	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
56	select ARCH_HAS_SYNC_DMA_FOR_CPU
57	select ARCH_HAS_SYSCALL_WRAPPER
58	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
59	select ARCH_HAS_ZONE_DMA_SET if EXPERT
60	select ARCH_HAVE_ELF_PROT
61	select ARCH_HAVE_NMI_SAFE_CMPXCHG
62	select ARCH_HAVE_TRACE_MMIO_ACCESS
63	select ARCH_INLINE_READ_LOCK if !PREEMPTION
64	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
65	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
66	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
67	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
68	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
69	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
70	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
71	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
72	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
73	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
74	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
75	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
76	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
77	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
78	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
79	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
80	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
81	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
82	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
83	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
84	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
85	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
86	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
87	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
88	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
89	select ARCH_KEEP_MEMBLOCK
90	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
91	select ARCH_USE_CMPXCHG_LOCKREF
92	select ARCH_USE_GNU_PROPERTY
93	select ARCH_USE_MEMTEST
94	select ARCH_USE_QUEUED_RWLOCKS
95	select ARCH_USE_QUEUED_SPINLOCKS
96	select ARCH_USE_SYM_ANNOTATIONS
97	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
98	select ARCH_SUPPORTS_HUGETLBFS
99	select ARCH_SUPPORTS_MEMORY_FAILURE
100	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
101	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
102	select ARCH_SUPPORTS_LTO_CLANG_THIN
103	select ARCH_SUPPORTS_CFI_CLANG
104	select ARCH_SUPPORTS_ATOMIC_RMW
105	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
106	select ARCH_SUPPORTS_NUMA_BALANCING
107	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
108	select ARCH_SUPPORTS_PER_VMA_LOCK
109	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
110	select ARCH_SUPPORTS_RT
111	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
112	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
113	select ARCH_WANT_DEFAULT_BPF_JIT
114	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
115	select ARCH_WANT_FRAME_POINTERS
116	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
117	select ARCH_WANT_LD_ORPHAN_WARN
118	select ARCH_WANTS_EXECMEM_LATE
119	select ARCH_WANTS_NO_INSTR
120	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
121	select ARCH_HAS_UBSAN
122	select ARM_AMBA
123	select ARM_ARCH_TIMER
124	select ARM_GIC
125	select AUDIT_ARCH_COMPAT_GENERIC
126	select ARM_GIC_V2M if PCI
127	select ARM_GIC_V3
128	select ARM_GIC_V3_ITS if PCI
129	select ARM_PSCI_FW
130	select BUILDTIME_TABLE_SORT
131	select CLONE_BACKWARDS
132	select COMMON_CLK
133	select CPU_PM if (SUSPEND || CPU_IDLE)
134	select CPUMASK_OFFSTACK if NR_CPUS > 256
135	select CRC32
136	select DCACHE_WORD_ACCESS
137	select DYNAMIC_FTRACE if FUNCTION_TRACER
138	select DMA_BOUNCE_UNALIGNED_KMALLOC
139	select DMA_DIRECT_REMAP
140	select EDAC_SUPPORT
141	select FRAME_POINTER
142	select FUNCTION_ALIGNMENT_4B
143	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
144	select GENERIC_ALLOCATOR
145	select GENERIC_ARCH_TOPOLOGY
146	select GENERIC_CLOCKEVENTS_BROADCAST
147	select GENERIC_CPU_AUTOPROBE
148	select GENERIC_CPU_DEVICES
149	select GENERIC_CPU_VULNERABILITIES
150	select GENERIC_EARLY_IOREMAP
151	select GENERIC_IDLE_POLL_SETUP
152	select GENERIC_IOREMAP
153	select GENERIC_IRQ_IPI
154	select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
155	select GENERIC_IRQ_PROBE
156	select GENERIC_IRQ_SHOW
157	select GENERIC_IRQ_SHOW_LEVEL
158	select GENERIC_LIB_DEVMEM_IS_ALLOWED
159	select GENERIC_PCI_IOMAP
160	select GENERIC_PTDUMP
161	select GENERIC_SCHED_CLOCK
162	select GENERIC_SMP_IDLE_THREAD
163	select GENERIC_TIME_VSYSCALL
164	select GENERIC_GETTIMEOFDAY
165	select GENERIC_VDSO_TIME_NS
166	select HARDIRQS_SW_RESEND
167	select HAS_IOPORT
168	select HAVE_MOVE_PMD
169	select HAVE_MOVE_PUD
170	select HAVE_PCI
171	select HAVE_ACPI_APEI if (ACPI && EFI)
172	select HAVE_ALIGNED_STRUCT_PAGE
173	select HAVE_ARCH_AUDITSYSCALL
174	select HAVE_ARCH_BITREVERSE
175	select HAVE_ARCH_COMPILER_H
176	select HAVE_ARCH_HUGE_VMALLOC
177	select HAVE_ARCH_HUGE_VMAP
178	select HAVE_ARCH_JUMP_LABEL
179	select HAVE_ARCH_JUMP_LABEL_RELATIVE
180	select HAVE_ARCH_KASAN
181	select HAVE_ARCH_KASAN_VMALLOC
182	select HAVE_ARCH_KASAN_SW_TAGS
183	select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
184	# Some instrumentation may be unsound, hence EXPERT
185	select HAVE_ARCH_KCSAN if EXPERT
186	select HAVE_ARCH_KFENCE
187	select HAVE_ARCH_KGDB
188	select HAVE_ARCH_MMAP_RND_BITS
189	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
190	select HAVE_ARCH_PREL32_RELOCATIONS
191	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
192	select HAVE_ARCH_SECCOMP_FILTER
193	select HAVE_ARCH_STACKLEAK
194	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
195	select HAVE_ARCH_TRACEHOOK
196	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
197	select HAVE_ARCH_VMAP_STACK
198	select HAVE_ARM_SMCCC
199	select HAVE_ASM_MODVERSIONS
200	select HAVE_EBPF_JIT
201	select HAVE_C_RECORDMCOUNT
202	select HAVE_CMPXCHG_DOUBLE
203	select HAVE_CMPXCHG_LOCAL
204	select HAVE_CONTEXT_TRACKING_USER
205	select HAVE_DEBUG_KMEMLEAK
206	select HAVE_DMA_CONTIGUOUS
207	select HAVE_DYNAMIC_FTRACE
208	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
209		if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
210		    CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
211	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
212		if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
213	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
214		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
215		    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
216	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
217		if DYNAMIC_FTRACE_WITH_ARGS
218	select HAVE_SAMPLE_FTRACE_DIRECT
219	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
220	select HAVE_EFFICIENT_UNALIGNED_ACCESS
221	select HAVE_GUP_FAST
222	select HAVE_FTRACE_GRAPH_FUNC
223	select HAVE_FTRACE_MCOUNT_RECORD
224	select HAVE_FUNCTION_TRACER
225	select HAVE_FUNCTION_ERROR_INJECTION
226	select HAVE_FUNCTION_GRAPH_FREGS
227	select HAVE_FUNCTION_GRAPH_TRACER
228	select HAVE_GCC_PLUGINS
229	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
230		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
231	select HAVE_HW_BREAKPOINT if PERF_EVENTS
232	select HAVE_IOREMAP_PROT
233	select HAVE_IRQ_TIME_ACCOUNTING
234	select HAVE_MOD_ARCH_SPECIFIC
235	select HAVE_NMI
236	select HAVE_PERF_EVENTS
237	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
238	select HAVE_PERF_REGS
239	select HAVE_PERF_USER_STACK_DUMP
240	select HAVE_PREEMPT_DYNAMIC_KEY
241	select HAVE_REGS_AND_STACK_ACCESS_API
242	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
243	select HAVE_FUNCTION_ARG_ACCESS_API
244	select MMU_GATHER_RCU_TABLE_FREE
245	select HAVE_RSEQ
246	select HAVE_RUST if RUSTC_SUPPORTS_ARM64
247	select HAVE_STACKPROTECTOR
248	select HAVE_SYSCALL_TRACEPOINTS
249	select HAVE_KPROBES
250	select HAVE_KRETPROBES
251	select HAVE_GENERIC_VDSO
252	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
253	select IRQ_DOMAIN
254	select IRQ_FORCED_THREADING
255	select KASAN_VMALLOC if KASAN
256	select LOCK_MM_AND_FIND_VMA
257	select MODULES_USE_ELF_RELA
258	select NEED_DMA_MAP_STATE
259	select NEED_SG_DMA_LENGTH
260	select OF
261	select OF_EARLY_FLATTREE
262	select PCI_DOMAINS_GENERIC if PCI
263	select PCI_ECAM if (ACPI && PCI)
264	select PCI_SYSCALL if PCI
265	select POWER_RESET
266	select POWER_SUPPLY
267	select SPARSE_IRQ
268	select SWIOTLB
269	select SYSCTL_EXCEPTION_TRACE
270	select THREAD_INFO_IN_TASK
271	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
272	select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
273	select TRACE_IRQFLAGS_SUPPORT
274	select TRACE_IRQFLAGS_NMI_SUPPORT
275	select HAVE_SOFTIRQ_ON_OWN_STACK
276	select USER_STACKTRACE_SUPPORT
277	select VDSO_GETRANDOM
278	help
279	  ARM 64-bit (AArch64) Linux support.
280
281config RUSTC_SUPPORTS_ARM64
282	def_bool y
283	depends on CPU_LITTLE_ENDIAN
284	# Shadow call stack is only supported on certain rustc versions.
285	#
286	# When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is
287	# required due to use of the -Zfixed-x18 flag.
288	#
289	# Otherwise, rustc version 1.82+ is required due to use of the
290	# -Zsanitizer=shadow-call-stack flag.
291	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS
292
293config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
294	def_bool CC_IS_CLANG
295	# https://github.com/ClangBuiltLinux/linux/issues/1507
296	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
297
298config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
299	def_bool CC_IS_GCC
300	depends on $(cc-option,-fpatchable-function-entry=2)
301
302config 64BIT
303	def_bool y
304
305config MMU
306	def_bool y
307
308config ARM64_CONT_PTE_SHIFT
309	int
310	default 5 if PAGE_SIZE_64KB
311	default 7 if PAGE_SIZE_16KB
312	default 4
313
314config ARM64_CONT_PMD_SHIFT
315	int
316	default 5 if PAGE_SIZE_64KB
317	default 5 if PAGE_SIZE_16KB
318	default 4
319
320config ARCH_MMAP_RND_BITS_MIN
321	default 14 if PAGE_SIZE_64KB
322	default 16 if PAGE_SIZE_16KB
323	default 18
324
325# max bits determined by the following formula:
326#  VA_BITS - PAGE_SHIFT - 3
327config ARCH_MMAP_RND_BITS_MAX
328	default 19 if ARM64_VA_BITS=36
329	default 24 if ARM64_VA_BITS=39
330	default 27 if ARM64_VA_BITS=42
331	default 30 if ARM64_VA_BITS=47
332	default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
333	default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
334	default 33 if ARM64_VA_BITS=48
335	default 14 if ARM64_64K_PAGES
336	default 16 if ARM64_16K_PAGES
337	default 18
338
339config ARCH_MMAP_RND_COMPAT_BITS_MIN
340	default 7 if ARM64_64K_PAGES
341	default 9 if ARM64_16K_PAGES
342	default 11
343
344config ARCH_MMAP_RND_COMPAT_BITS_MAX
345	default 16
346
347config NO_IOPORT_MAP
348	def_bool y if !PCI
349
350config STACKTRACE_SUPPORT
351	def_bool y
352
353config ILLEGAL_POINTER_VALUE
354	hex
355	default 0xdead000000000000
356
357config LOCKDEP_SUPPORT
358	def_bool y
359
360config GENERIC_BUG
361	def_bool y
362	depends on BUG
363
364config GENERIC_BUG_RELATIVE_POINTERS
365	def_bool y
366	depends on GENERIC_BUG
367
368config GENERIC_HWEIGHT
369	def_bool y
370
371config GENERIC_CSUM
372	def_bool y
373
374config GENERIC_CALIBRATE_DELAY
375	def_bool y
376
377config SMP
378	def_bool y
379
380config KERNEL_MODE_NEON
381	def_bool y
382
383config FIX_EARLYCON_MEM
384	def_bool y
385
386config PGTABLE_LEVELS
387	int
388	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
389	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
390	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
391	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
392	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
393	default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
394	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
395	default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
396
397config ARCH_SUPPORTS_UPROBES
398	def_bool y
399
400config ARCH_PROC_KCORE_TEXT
401	def_bool y
402
403config BROKEN_GAS_INST
404	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
405
406config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
407	bool
408	# Clang's __builtin_return_address() strips the PAC since 12.0.0
409	# https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
410	default y if CC_IS_CLANG
411	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
412	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
413	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
414	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
415	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
416	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
417	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
418	default n
419
420config KASAN_SHADOW_OFFSET
421	hex
422	depends on KASAN_GENERIC || KASAN_SW_TAGS
423	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
424	default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
425	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
426	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
427	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
428	default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
429	default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
430	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
431	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
432	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
433	default 0xffffffffffffffff
434
435config UNWIND_TABLES
436	bool
437
438source "arch/arm64/Kconfig.platforms"
439
440menu "Kernel Features"
441
442menu "ARM errata workarounds via the alternatives framework"
443
444config AMPERE_ERRATUM_AC03_CPU_38
445        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
446	default y
447	help
448	  This option adds an alternative code sequence to work around Ampere
449	  errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
450
451	  The affected design reports FEAT_HAFDBS as not implemented in
452	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
453	  as required by the architecture. The unadvertised HAFDBS
454	  implementation suffers from an additional erratum where hardware
455	  A/D updates can occur after a PTE has been marked invalid.
456
457	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
458	  which avoids enabling unadvertised hardware Access Flag management
459	  at stage-2.
460
461	  If unsure, say Y.
462
463config ARM64_WORKAROUND_CLEAN_CACHE
464	bool
465
466config ARM64_ERRATUM_826319
467	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
468	default y
469	select ARM64_WORKAROUND_CLEAN_CACHE
470	help
471	  This option adds an alternative code sequence to work around ARM
472	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
473	  AXI master interface and an L2 cache.
474
475	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
476	  and is unable to accept a certain write via this interface, it will
477	  not progress on read data presented on the read data channel and the
478	  system can deadlock.
479
480	  The workaround promotes data cache clean instructions to
481	  data cache clean-and-invalidate.
482	  Please note that this does not necessarily enable the workaround,
483	  as it depends on the alternative framework, which will only patch
484	  the kernel if an affected CPU is detected.
485
486	  If unsure, say Y.
487
488config ARM64_ERRATUM_827319
489	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
490	default y
491	select ARM64_WORKAROUND_CLEAN_CACHE
492	help
493	  This option adds an alternative code sequence to work around ARM
494	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
495	  master interface and an L2 cache.
496
497	  Under certain conditions this erratum can cause a clean line eviction
498	  to occur at the same time as another transaction to the same address
499	  on the AMBA 5 CHI interface, which can cause data corruption if the
500	  interconnect reorders the two transactions.
501
502	  The workaround promotes data cache clean instructions to
503	  data cache clean-and-invalidate.
504	  Please note that this does not necessarily enable the workaround,
505	  as it depends on the alternative framework, which will only patch
506	  the kernel if an affected CPU is detected.
507
508	  If unsure, say Y.
509
510config ARM64_ERRATUM_824069
511	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
512	default y
513	select ARM64_WORKAROUND_CLEAN_CACHE
514	help
515	  This option adds an alternative code sequence to work around ARM
516	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
517	  to a coherent interconnect.
518
519	  If a Cortex-A53 processor is executing a store or prefetch for
520	  write instruction at the same time as a processor in another
521	  cluster is executing a cache maintenance operation to the same
522	  address, then this erratum might cause a clean cache line to be
523	  incorrectly marked as dirty.
524
525	  The workaround promotes data cache clean instructions to
526	  data cache clean-and-invalidate.
527	  Please note that this option does not necessarily enable the
528	  workaround, as it depends on the alternative framework, which will
529	  only patch the kernel if an affected CPU is detected.
530
531	  If unsure, say Y.
532
533config ARM64_ERRATUM_819472
534	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
535	default y
536	select ARM64_WORKAROUND_CLEAN_CACHE
537	help
538	  This option adds an alternative code sequence to work around ARM
539	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
540	  present when it is connected to a coherent interconnect.
541
542	  If the processor is executing a load and store exclusive sequence at
543	  the same time as a processor in another cluster is executing a cache
544	  maintenance operation to the same address, then this erratum might
545	  cause data corruption.
546
547	  The workaround promotes data cache clean instructions to
548	  data cache clean-and-invalidate.
549	  Please note that this does not necessarily enable the workaround,
550	  as it depends on the alternative framework, which will only patch
551	  the kernel if an affected CPU is detected.
552
553	  If unsure, say Y.
554
555config ARM64_ERRATUM_832075
556	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
557	default y
558	help
559	  This option adds an alternative code sequence to work around ARM
560	  erratum 832075 on Cortex-A57 parts up to r1p2.
561
562	  Affected Cortex-A57 parts might deadlock when exclusive load/store
563	  instructions to Write-Back memory are mixed with Device loads.
564
565	  The workaround is to promote device loads to use Load-Acquire
566	  semantics.
567	  Please note that this does not necessarily enable the workaround,
568	  as it depends on the alternative framework, which will only patch
569	  the kernel if an affected CPU is detected.
570
571	  If unsure, say Y.
572
573config ARM64_ERRATUM_834220
574	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
575	depends on KVM
576	help
577	  This option adds an alternative code sequence to work around ARM
578	  erratum 834220 on Cortex-A57 parts up to r1p2.
579
580	  Affected Cortex-A57 parts might report a Stage 2 translation
581	  fault as the result of a Stage 1 fault for load crossing a
582	  page boundary when there is a permission or device memory
583	  alignment fault at Stage 1 and a translation fault at Stage 2.
584
585	  The workaround is to verify that the Stage 1 translation
586	  doesn't generate a fault before handling the Stage 2 fault.
587	  Please note that this does not necessarily enable the workaround,
588	  as it depends on the alternative framework, which will only patch
589	  the kernel if an affected CPU is detected.
590
591	  If unsure, say N.
592
593config ARM64_ERRATUM_1742098
594	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
595	depends on COMPAT
596	default y
597	help
598	  This option removes the AES hwcap for aarch32 user-space to
599	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
600
601	  Affected parts may corrupt the AES state if an interrupt is
602	  taken between a pair of AES instructions. These instructions
603	  are only present if the cryptography extensions are present.
604	  All software should have a fallback implementation for CPUs
605	  that don't implement the cryptography extensions.
606
607	  If unsure, say Y.
608
609config ARM64_ERRATUM_845719
610	bool "Cortex-A53: 845719: a load might read incorrect data"
611	depends on COMPAT
612	default y
613	help
614	  This option adds an alternative code sequence to work around ARM
615	  erratum 845719 on Cortex-A53 parts up to r0p4.
616
617	  When running a compat (AArch32) userspace on an affected Cortex-A53
618	  part, a load at EL0 from a virtual address that matches the bottom 32
619	  bits of the virtual address used by a recent load at (AArch64) EL1
620	  might return incorrect data.
621
622	  The workaround is to write the contextidr_el1 register on exception
623	  return to a 32-bit task.
624	  Please note that this does not necessarily enable the workaround,
625	  as it depends on the alternative framework, which will only patch
626	  the kernel if an affected CPU is detected.
627
628	  If unsure, say Y.
629
630config ARM64_ERRATUM_843419
631	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
632	default y
633	help
634	  This option links the kernel with '--fix-cortex-a53-843419' and
635	  enables PLT support to replace certain ADRP instructions, which can
636	  cause subsequent memory accesses to use an incorrect address on
637	  Cortex-A53 parts up to r0p4.
638
639	  If unsure, say Y.
640
641config ARM64_LD_HAS_FIX_ERRATUM_843419
642	def_bool $(ld-option,--fix-cortex-a53-843419)
643
644config ARM64_ERRATUM_1024718
645	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
646	default y
647	help
648	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
649
650	  Affected Cortex-A55 cores (all revisions) could cause incorrect
651	  update of the hardware dirty bit when the DBM/AP bits are updated
652	  without a break-before-make. The workaround is to disable the usage
653	  of hardware DBM locally on the affected cores. CPUs not affected by
654	  this erratum will continue to use the feature.
655
656	  If unsure, say Y.
657
658config ARM64_ERRATUM_1418040
659	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
660	default y
661	depends on COMPAT
662	help
663	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
664	  errata 1188873 and 1418040.
665
666	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
667	  cause register corruption when accessing the timer registers
668	  from AArch32 userspace.
669
670	  If unsure, say Y.
671
672config ARM64_WORKAROUND_SPECULATIVE_AT
673	bool
674
675config ARM64_ERRATUM_1165522
676	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
677	default y
678	select ARM64_WORKAROUND_SPECULATIVE_AT
679	help
680	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
681
682	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
683	  corrupted TLBs by speculating an AT instruction during a guest
684	  context switch.
685
686	  If unsure, say Y.
687
688config ARM64_ERRATUM_1319367
689	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
690	default y
691	select ARM64_WORKAROUND_SPECULATIVE_AT
692	help
693	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
694	  and A72 erratum 1319367
695
696	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
697	  speculating an AT instruction during a guest context switch.
698
699	  If unsure, say Y.
700
701config ARM64_ERRATUM_1530923
702	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
703	default y
704	select ARM64_WORKAROUND_SPECULATIVE_AT
705	help
706	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
707
708	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
709	  corrupted TLBs by speculating an AT instruction during a guest
710	  context switch.
711
712	  If unsure, say Y.
713
714config ARM64_WORKAROUND_REPEAT_TLBI
715	bool
716
717config ARM64_ERRATUM_2441007
718	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
719	select ARM64_WORKAROUND_REPEAT_TLBI
720	help
721	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
722
723	  Under very rare circumstances, affected Cortex-A55 CPUs
724	  may not handle a race between a break-before-make sequence on one
725	  CPU, and another CPU accessing the same page. This could allow a
726	  store to a page that has been unmapped.
727
728	  Work around this by adding the affected CPUs to the list that needs
729	  TLB sequences to be done twice.
730
731	  If unsure, say N.
732
733config ARM64_ERRATUM_1286807
734	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
735	select ARM64_WORKAROUND_REPEAT_TLBI
736	help
737	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
738
739	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
740	  address for a cacheable mapping of a location is being
741	  accessed by a core while another core is remapping the virtual
742	  address to a new physical page using the recommended
743	  break-before-make sequence, then under very rare circumstances
744	  TLBI+DSB completes before a read using the translation being
745	  invalidated has been observed by other observers. The
746	  workaround repeats the TLBI+DSB operation.
747
748	  If unsure, say N.
749
750config ARM64_ERRATUM_1463225
751	bool "Cortex-A76: Software Step might prevent interrupt recognition"
752	default y
753	help
754	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
755
756	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
757	  of a system call instruction (SVC) can prevent recognition of
758	  subsequent interrupts when software stepping is disabled in the
759	  exception handler of the system call and either kernel debugging
760	  is enabled or VHE is in use.
761
762	  Work around the erratum by triggering a dummy step exception
763	  when handling a system call from a task that is being stepped
764	  in a VHE configuration of the kernel.
765
766	  If unsure, say Y.
767
768config ARM64_ERRATUM_1542419
769	bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
770	help
771	  This option adds a workaround for ARM Neoverse-N1 erratum
772	  1542419.
773
774	  Affected Neoverse-N1 cores could execute a stale instruction when
775	  modified by another CPU. The workaround depends on a firmware
776	  counterpart.
777
778	  Workaround the issue by hiding the DIC feature from EL0. This
779	  forces user-space to perform cache maintenance.
780
781	  If unsure, say N.
782
783config ARM64_ERRATUM_1508412
784	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
785	default y
786	help
787	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
788
789	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
790	  of a store-exclusive or read of PAR_EL1 and a load with device or
791	  non-cacheable memory attributes. The workaround depends on a firmware
792	  counterpart.
793
794	  KVM guests must also have the workaround implemented or they can
795	  deadlock the system.
796
797	  Work around the issue by inserting DMB SY barriers around PAR_EL1
798	  register reads and warning KVM users. The DMB barrier is sufficient
799	  to prevent a speculative PAR_EL1 read.
800
801	  If unsure, say Y.
802
803config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
804	bool
805
806config ARM64_ERRATUM_2051678
807	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
808	default y
809	help
810	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
811	  Affected Cortex-A510 might not respect the ordering rules for
812	  hardware update of the page table's dirty bit. The workaround
813	  is to not enable the feature on affected CPUs.
814
815	  If unsure, say Y.
816
817config ARM64_ERRATUM_2077057
818	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
819	default y
820	help
821	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
822	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
823	  expected, but a Pointer Authentication trap is taken instead. The
824	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
825	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
826
827	  This can only happen when EL2 is stepping EL1.
828
829	  When these conditions occur, the SPSR_EL2 value is unchanged from the
830	  previous guest entry, and can be restored from the in-memory copy.
831
832	  If unsure, say Y.
833
834config ARM64_ERRATUM_2658417
835	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
836	default y
837	help
838	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
839	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
840	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
841	  A510 CPUs are using shared neon hardware. As the sharing is not
842	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
843	  user-space should not be using these instructions.
844
845	  If unsure, say Y.
846
847config ARM64_ERRATUM_2119858
848	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
849	default y
850	depends on CORESIGHT_TRBE
851	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
852	help
853	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
854
855	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
856	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
857	  the event of a WRAP event.
858
859	  Work around the issue by always making sure we move the TRBPTR_EL1 by
860	  256 bytes before enabling the buffer and filling the first 256 bytes of
861	  the buffer with ETM ignore packets upon disabling.
862
863	  If unsure, say Y.
864
865config ARM64_ERRATUM_2139208
866	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
867	default y
868	depends on CORESIGHT_TRBE
869	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
870	help
871	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
872
873	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
874	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
875	  the event of a WRAP event.
876
877	  Work around the issue by always making sure we move the TRBPTR_EL1 by
878	  256 bytes before enabling the buffer and filling the first 256 bytes of
879	  the buffer with ETM ignore packets upon disabling.
880
881	  If unsure, say Y.
882
883config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
884	bool
885
886config ARM64_ERRATUM_2054223
887	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
888	default y
889	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
890	help
891	  Enable workaround for ARM Cortex-A710 erratum 2054223
892
893	  Affected cores may fail to flush the trace data on a TSB instruction, when
894	  the PE is in trace prohibited state. This will cause losing a few bytes
895	  of the trace cached.
896
897	  Workaround is to issue two TSB consecutively on affected cores.
898
899	  If unsure, say Y.
900
901config ARM64_ERRATUM_2067961
902	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
903	default y
904	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
905	help
906	  Enable workaround for ARM Neoverse-N2 erratum 2067961
907
908	  Affected cores may fail to flush the trace data on a TSB instruction, when
909	  the PE is in trace prohibited state. This will cause losing a few bytes
910	  of the trace cached.
911
912	  Workaround is to issue two TSB consecutively on affected cores.
913
914	  If unsure, say Y.
915
916config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
917	bool
918
919config ARM64_ERRATUM_2253138
920	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
921	depends on CORESIGHT_TRBE
922	default y
923	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
924	help
925	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
926
927	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
928	  for TRBE. Under some conditions, the TRBE might generate a write to the next
929	  virtually addressed page following the last page of the TRBE address space
930	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
931
932	  Work around this in the driver by always making sure that there is a
933	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
934
935	  If unsure, say Y.
936
937config ARM64_ERRATUM_2224489
938	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
939	depends on CORESIGHT_TRBE
940	default y
941	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
942	help
943	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
944
945	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
946	  for TRBE. Under some conditions, the TRBE might generate a write to the next
947	  virtually addressed page following the last page of the TRBE address space
948	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
949
950	  Work around this in the driver by always making sure that there is a
951	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
952
953	  If unsure, say Y.
954
955config ARM64_ERRATUM_2441009
956	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
957	select ARM64_WORKAROUND_REPEAT_TLBI
958	help
959	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
960
961	  Under very rare circumstances, affected Cortex-A510 CPUs
962	  may not handle a race between a break-before-make sequence on one
963	  CPU, and another CPU accessing the same page. This could allow a
964	  store to a page that has been unmapped.
965
966	  Work around this by adding the affected CPUs to the list that needs
967	  TLB sequences to be done twice.
968
969	  If unsure, say N.
970
971config ARM64_ERRATUM_2064142
972	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
973	depends on CORESIGHT_TRBE
974	default y
975	help
976	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
977
978	  Affected Cortex-A510 core might fail to write into system registers after the
979	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
980	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
981	  and TRBTRG_EL1 will be ignored and will not be effected.
982
983	  Work around this in the driver by executing TSB CSYNC and DSB after collection
984	  is stopped and before performing a system register write to one of the affected
985	  registers.
986
987	  If unsure, say Y.
988
989config ARM64_ERRATUM_2038923
990	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
991	depends on CORESIGHT_TRBE
992	default y
993	help
994	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
995
996	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
997	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
998	  might be corrupted. This happens after TRBE buffer has been enabled by setting
999	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
1000	  execution changes from a context, in which trace is prohibited to one where it
1001	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
1002	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
1003	  the trace buffer state might be corrupted.
1004
1005	  Work around this in the driver by preventing an inconsistent view of whether the
1006	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
1007	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
1008	  two ISB instructions if no ERET is to take place.
1009
1010	  If unsure, say Y.
1011
1012config ARM64_ERRATUM_1902691
1013	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1014	depends on CORESIGHT_TRBE
1015	default y
1016	help
1017	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1018
1019	  Affected Cortex-A510 core might cause trace data corruption, when being written
1020	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
1021	  trace data.
1022
1023	  Work around this problem in the driver by just preventing TRBE initialization on
1024	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1025	  on such implementations. This will cover the kernel for any firmware that doesn't
1026	  do this already.
1027
1028	  If unsure, say Y.
1029
1030config ARM64_ERRATUM_2457168
1031	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1032	depends on ARM64_AMU_EXTN
1033	default y
1034	help
1035	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1036
1037	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1038	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1039	  incorrectly giving a significantly higher output value.
1040
1041	  Work around this problem by returning 0 when reading the affected counter in
1042	  key locations that results in disabling all users of this counter. This effect
1043	  is the same to firmware disabling affected counters.
1044
1045	  If unsure, say Y.
1046
1047config ARM64_ERRATUM_2645198
1048	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1049	default y
1050	help
1051	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1052
1053	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1054	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1055	  next instruction abort caused by permission fault.
1056
1057	  Only user-space does executable to non-executable permission transition via
1058	  mprotect() system call. Workaround the problem by doing a break-before-make
1059	  TLB invalidation, for all changes to executable user space mappings.
1060
1061	  If unsure, say Y.
1062
1063config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1064	bool
1065
1066config ARM64_ERRATUM_2966298
1067	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1068	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1069	default y
1070	help
1071	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1072
1073	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1074	  load might leak data from a privileged level via a cache side channel.
1075
1076	  Work around this problem by executing a TLBI before returning to EL0.
1077
1078	  If unsure, say Y.
1079
1080config ARM64_ERRATUM_3117295
1081	bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1082	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1083	default y
1084	help
1085	  This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1086
1087	  On an affected Cortex-A510 core, a speculatively executed unprivileged
1088	  load might leak data from a privileged level via a cache side channel.
1089
1090	  Work around this problem by executing a TLBI before returning to EL0.
1091
1092	  If unsure, say Y.
1093
1094config ARM64_ERRATUM_3194386
1095	bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1096	default y
1097	help
1098	  This option adds the workaround for the following errata:
1099
1100	  * ARM Cortex-A76 erratum 3324349
1101	  * ARM Cortex-A77 erratum 3324348
1102	  * ARM Cortex-A78 erratum 3324344
1103	  * ARM Cortex-A78C erratum 3324346
1104	  * ARM Cortex-A78C erratum 3324347
1105	  * ARM Cortex-A710 erratam 3324338
1106	  * ARM Cortex-A715 errartum 3456084
1107	  * ARM Cortex-A720 erratum 3456091
1108	  * ARM Cortex-A725 erratum 3456106
1109	  * ARM Cortex-X1 erratum 3324344
1110	  * ARM Cortex-X1C erratum 3324346
1111	  * ARM Cortex-X2 erratum 3324338
1112	  * ARM Cortex-X3 erratum 3324335
1113	  * ARM Cortex-X4 erratum 3194386
1114	  * ARM Cortex-X925 erratum 3324334
1115	  * ARM Neoverse-N1 erratum 3324349
1116	  * ARM Neoverse N2 erratum 3324339
1117	  * ARM Neoverse-N3 erratum 3456111
1118	  * ARM Neoverse-V1 erratum 3324341
1119	  * ARM Neoverse V2 erratum 3324336
1120	  * ARM Neoverse-V3 erratum 3312417
1121
1122	  On affected cores "MSR SSBS, #0" instructions may not affect
1123	  subsequent speculative instructions, which may permit unexepected
1124	  speculative store bypassing.
1125
1126	  Work around this problem by placing a Speculation Barrier (SB) or
1127	  Instruction Synchronization Barrier (ISB) after kernel changes to
1128	  SSBS. The presence of the SSBS special-purpose register is hidden
1129	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1130	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1131
1132	  If unsure, say Y.
1133
1134config CAVIUM_ERRATUM_22375
1135	bool "Cavium erratum 22375, 24313"
1136	default y
1137	help
1138	  Enable workaround for errata 22375 and 24313.
1139
1140	  This implements two gicv3-its errata workarounds for ThunderX. Both
1141	  with a small impact affecting only ITS table allocation.
1142
1143	    erratum 22375: only alloc 8MB table size
1144	    erratum 24313: ignore memory access type
1145
1146	  The fixes are in ITS initialization and basically ignore memory access
1147	  type and table size provided by the TYPER and BASER registers.
1148
1149	  If unsure, say Y.
1150
1151config CAVIUM_ERRATUM_23144
1152	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1153	depends on NUMA
1154	default y
1155	help
1156	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1157
1158	  If unsure, say Y.
1159
1160config CAVIUM_ERRATUM_23154
1161	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1162	default y
1163	help
1164	  The ThunderX GICv3 implementation requires a modified version for
1165	  reading the IAR status to ensure data synchronization
1166	  (access to icc_iar1_el1 is not sync'ed before and after).
1167
1168	  It also suffers from erratum 38545 (also present on Marvell's
1169	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1170	  spuriously presented to the CPU interface.
1171
1172	  If unsure, say Y.
1173
1174config CAVIUM_ERRATUM_27456
1175	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1176	default y
1177	help
1178	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1179	  instructions may cause the icache to become corrupted if it
1180	  contains data for a non-current ASID.  The fix is to
1181	  invalidate the icache when changing the mm context.
1182
1183	  If unsure, say Y.
1184
1185config CAVIUM_ERRATUM_30115
1186	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1187	default y
1188	help
1189	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1190	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1191	  interrupts in host. Trapping both GICv3 group-0 and group-1
1192	  accesses sidesteps the issue.
1193
1194	  If unsure, say Y.
1195
1196config CAVIUM_TX2_ERRATUM_219
1197	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1198	default y
1199	help
1200	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1201	  TTBR update and the corresponding context synchronizing operation can
1202	  cause a spurious Data Abort to be delivered to any hardware thread in
1203	  the CPU core.
1204
1205	  Work around the issue by avoiding the problematic code sequence and
1206	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1207	  trap handler performs the corresponding register access, skips the
1208	  instruction and ensures context synchronization by virtue of the
1209	  exception return.
1210
1211	  If unsure, say Y.
1212
1213config FUJITSU_ERRATUM_010001
1214	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1215	default y
1216	help
1217	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1218	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1219	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1220	  This fault occurs under a specific hardware condition when a
1221	  load/store instruction performs an address translation using:
1222	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1223	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1224	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1225	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1226
1227	  The workaround is to ensure these bits are clear in TCR_ELx.
1228	  The workaround only affects the Fujitsu-A64FX.
1229
1230	  If unsure, say Y.
1231
1232config HISILICON_ERRATUM_161600802
1233	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1234	default y
1235	help
1236	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1237	  when issued ITS commands such as VMOVP and VMAPP, and requires
1238	  a 128kB offset to be applied to the target address in this commands.
1239
1240	  If unsure, say Y.
1241
1242config HISILICON_ERRATUM_162100801
1243	bool "Hip09 162100801 erratum support"
1244	default y
1245	help
1246	  When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches
1247	  during unmapping operation, which will cause some vSGIs lost.
1248	  To fix the issue, invalidate related vPE cache through GICR_INVALLR
1249	  after VMOVP.
1250
1251	  If unsure, say Y.
1252
1253config QCOM_FALKOR_ERRATUM_1003
1254	bool "Falkor E1003: Incorrect translation due to ASID change"
1255	default y
1256	help
1257	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1258	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1259	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1260	  then only for entries in the walk cache, since the leaf translation
1261	  is unchanged. Work around the erratum by invalidating the walk cache
1262	  entries for the trampoline before entering the kernel proper.
1263
1264config QCOM_FALKOR_ERRATUM_1009
1265	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1266	default y
1267	select ARM64_WORKAROUND_REPEAT_TLBI
1268	help
1269	  On Falkor v1, the CPU may prematurely complete a DSB following a
1270	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1271	  one more time to fix the issue.
1272
1273	  If unsure, say Y.
1274
1275config QCOM_QDF2400_ERRATUM_0065
1276	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1277	default y
1278	help
1279	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1280	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1281	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1282
1283	  If unsure, say Y.
1284
1285config QCOM_FALKOR_ERRATUM_E1041
1286	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1287	default y
1288	help
1289	  Falkor CPU may speculatively fetch instructions from an improper
1290	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1291	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1292
1293	  If unsure, say Y.
1294
1295config NVIDIA_CARMEL_CNP_ERRATUM
1296	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1297	default y
1298	help
1299	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1300	  invalidate shared TLB entries installed by a different core, as it would
1301	  on standard ARM cores.
1302
1303	  If unsure, say Y.
1304
1305config ROCKCHIP_ERRATUM_3568002
1306	bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB"
1307	default y
1308	help
1309	  The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI
1310	  addressing limited to the first 32bit of physical address space.
1311
1312	  If unsure, say Y.
1313
1314config ROCKCHIP_ERRATUM_3588001
1315	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1316	default y
1317	help
1318	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1319	  This means, that its sharability feature may not be used, even though it
1320	  is supported by the IP itself.
1321
1322	  If unsure, say Y.
1323
1324config SOCIONEXT_SYNQUACER_PREITS
1325	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1326	default y
1327	help
1328	  Socionext Synquacer SoCs implement a separate h/w block to generate
1329	  MSI doorbell writes with non-zero values for the device ID.
1330
1331	  If unsure, say Y.
1332
1333endmenu # "ARM errata workarounds via the alternatives framework"
1334
1335choice
1336	prompt "Page size"
1337	default ARM64_4K_PAGES
1338	help
1339	  Page size (translation granule) configuration.
1340
1341config ARM64_4K_PAGES
1342	bool "4KB"
1343	select HAVE_PAGE_SIZE_4KB
1344	help
1345	  This feature enables 4KB pages support.
1346
1347config ARM64_16K_PAGES
1348	bool "16KB"
1349	select HAVE_PAGE_SIZE_16KB
1350	help
1351	  The system will use 16KB pages support. AArch32 emulation
1352	  requires applications compiled with 16K (or a multiple of 16K)
1353	  aligned segments.
1354
1355config ARM64_64K_PAGES
1356	bool "64KB"
1357	select HAVE_PAGE_SIZE_64KB
1358	help
1359	  This feature enables 64KB pages support (4KB by default)
1360	  allowing only two levels of page tables and faster TLB
1361	  look-up. AArch32 emulation requires applications compiled
1362	  with 64K aligned segments.
1363
1364endchoice
1365
1366choice
1367	prompt "Virtual address space size"
1368	default ARM64_VA_BITS_52
1369	help
1370	  Allows choosing one of multiple possible virtual address
1371	  space sizes. The level of translation table is determined by
1372	  a combination of page size and virtual address space size.
1373
1374config ARM64_VA_BITS_36
1375	bool "36-bit" if EXPERT
1376	depends on PAGE_SIZE_16KB
1377
1378config ARM64_VA_BITS_39
1379	bool "39-bit"
1380	depends on PAGE_SIZE_4KB
1381
1382config ARM64_VA_BITS_42
1383	bool "42-bit"
1384	depends on PAGE_SIZE_64KB
1385
1386config ARM64_VA_BITS_47
1387	bool "47-bit"
1388	depends on PAGE_SIZE_16KB
1389
1390config ARM64_VA_BITS_48
1391	bool "48-bit"
1392
1393config ARM64_VA_BITS_52
1394	bool "52-bit"
1395	help
1396	  Enable 52-bit virtual addressing for userspace when explicitly
1397	  requested via a hint to mmap(). The kernel will also use 52-bit
1398	  virtual addresses for its own mappings (provided HW support for
1399	  this feature is available, otherwise it reverts to 48-bit).
1400
1401	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1402	  ARMv8.3 Pointer Authentication will result in the PAC being
1403	  reduced from 7 bits to 3 bits, which may have a significant
1404	  impact on its susceptibility to brute-force attacks.
1405
1406	  If unsure, select 48-bit virtual addressing instead.
1407
1408endchoice
1409
1410config ARM64_FORCE_52BIT
1411	bool "Force 52-bit virtual addresses for userspace"
1412	depends on ARM64_VA_BITS_52 && EXPERT
1413	help
1414	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1415	  to maintain compatibility with older software by providing 48-bit VAs
1416	  unless a hint is supplied to mmap.
1417
1418	  This configuration option disables the 48-bit compatibility logic, and
1419	  forces all userspace addresses to be 52-bit on HW that supports it. One
1420	  should only enable this configuration option for stress testing userspace
1421	  memory management code. If unsure say N here.
1422
1423config ARM64_VA_BITS
1424	int
1425	default 36 if ARM64_VA_BITS_36
1426	default 39 if ARM64_VA_BITS_39
1427	default 42 if ARM64_VA_BITS_42
1428	default 47 if ARM64_VA_BITS_47
1429	default 48 if ARM64_VA_BITS_48
1430	default 52 if ARM64_VA_BITS_52
1431
1432choice
1433	prompt "Physical address space size"
1434	default ARM64_PA_BITS_48
1435	help
1436	  Choose the maximum physical address range that the kernel will
1437	  support.
1438
1439config ARM64_PA_BITS_48
1440	bool "48-bit"
1441	depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1442
1443config ARM64_PA_BITS_52
1444	bool "52-bit"
1445	depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1446	help
1447	  Enable support for a 52-bit physical address space, introduced as
1448	  part of the ARMv8.2-LPA extension.
1449
1450	  With this enabled, the kernel will also continue to work on CPUs that
1451	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1452	  minor performance overhead).
1453
1454endchoice
1455
1456config ARM64_PA_BITS
1457	int
1458	default 48 if ARM64_PA_BITS_48
1459	default 52 if ARM64_PA_BITS_52
1460
1461config ARM64_LPA2
1462	def_bool y
1463	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1464
1465choice
1466	prompt "Endianness"
1467	default CPU_LITTLE_ENDIAN
1468	help
1469	  Select the endianness of data accesses performed by the CPU. Userspace
1470	  applications will need to be compiled and linked for the endianness
1471	  that is selected here.
1472
1473config CPU_BIG_ENDIAN
1474	bool "Build big-endian kernel"
1475	# https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1476	depends on AS_IS_GNU || AS_VERSION >= 150000
1477	help
1478	  Say Y if you plan on running a kernel with a big-endian userspace.
1479
1480config CPU_LITTLE_ENDIAN
1481	bool "Build little-endian kernel"
1482	help
1483	  Say Y if you plan on running a kernel with a little-endian userspace.
1484	  This is usually the case for distributions targeting arm64.
1485
1486endchoice
1487
1488config SCHED_MC
1489	bool "Multi-core scheduler support"
1490	help
1491	  Multi-core scheduler support improves the CPU scheduler's decision
1492	  making when dealing with multi-core CPU chips at a cost of slightly
1493	  increased overhead in some places. If unsure say N here.
1494
1495config SCHED_CLUSTER
1496	bool "Cluster scheduler support"
1497	help
1498	  Cluster scheduler support improves the CPU scheduler's decision
1499	  making when dealing with machines that have clusters of CPUs.
1500	  Cluster usually means a couple of CPUs which are placed closely
1501	  by sharing mid-level caches, last-level cache tags or internal
1502	  busses.
1503
1504config SCHED_SMT
1505	bool "SMT scheduler support"
1506	help
1507	  Improves the CPU scheduler's decision making when dealing with
1508	  MultiThreading at a cost of slightly increased overhead in some
1509	  places. If unsure say N here.
1510
1511config NR_CPUS
1512	int "Maximum number of CPUs (2-4096)"
1513	range 2 4096
1514	default "512"
1515
1516config HOTPLUG_CPU
1517	bool "Support for hot-pluggable CPUs"
1518	select GENERIC_IRQ_MIGRATION
1519	help
1520	  Say Y here to experiment with turning CPUs off and on.  CPUs
1521	  can be controlled through /sys/devices/system/cpu.
1522
1523# Common NUMA Features
1524config NUMA
1525	bool "NUMA Memory Allocation and Scheduler Support"
1526	select GENERIC_ARCH_NUMA
1527	select OF_NUMA
1528	select HAVE_SETUP_PER_CPU_AREA
1529	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1530	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1531	select USE_PERCPU_NUMA_NODE_ID
1532	help
1533	  Enable NUMA (Non-Uniform Memory Access) support.
1534
1535	  The kernel will try to allocate memory used by a CPU on the
1536	  local memory of the CPU and add some more
1537	  NUMA awareness to the kernel.
1538
1539config NODES_SHIFT
1540	int "Maximum NUMA Nodes (as a power of 2)"
1541	range 1 10
1542	default "4"
1543	depends on NUMA
1544	help
1545	  Specify the maximum number of NUMA Nodes available on the target
1546	  system.  Increases memory reserved to accommodate various tables.
1547
1548source "kernel/Kconfig.hz"
1549
1550config ARCH_SPARSEMEM_ENABLE
1551	def_bool y
1552	select SPARSEMEM_VMEMMAP_ENABLE
1553	select SPARSEMEM_VMEMMAP
1554
1555config HW_PERF_EVENTS
1556	def_bool y
1557	depends on ARM_PMU
1558
1559# Supported by clang >= 7.0 or GCC >= 12.0.0
1560config CC_HAVE_SHADOW_CALL_STACK
1561	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1562
1563config PARAVIRT
1564	bool "Enable paravirtualization code"
1565	help
1566	  This changes the kernel so it can modify itself when it is run
1567	  under a hypervisor, potentially improving performance significantly
1568	  over full virtualization.
1569
1570config PARAVIRT_TIME_ACCOUNTING
1571	bool "Paravirtual steal time accounting"
1572	select PARAVIRT
1573	help
1574	  Select this option to enable fine granularity task steal time
1575	  accounting. Time spent executing other tasks in parallel with
1576	  the current vCPU is discounted from the vCPU power. To account for
1577	  that, there can be a small performance impact.
1578
1579	  If in doubt, say N here.
1580
1581config ARCH_SUPPORTS_KEXEC
1582	def_bool PM_SLEEP_SMP
1583
1584config ARCH_SUPPORTS_KEXEC_FILE
1585	def_bool y
1586
1587config ARCH_SELECTS_KEXEC_FILE
1588	def_bool y
1589	depends on KEXEC_FILE
1590	select HAVE_IMA_KEXEC if IMA
1591
1592config ARCH_SUPPORTS_KEXEC_SIG
1593	def_bool y
1594
1595config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1596	def_bool y
1597
1598config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1599	def_bool y
1600
1601config ARCH_SUPPORTS_CRASH_DUMP
1602	def_bool y
1603
1604config ARCH_DEFAULT_CRASH_DUMP
1605	def_bool y
1606
1607config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1608	def_bool CRASH_RESERVE
1609
1610config TRANS_TABLE
1611	def_bool y
1612	depends on HIBERNATION || KEXEC_CORE
1613
1614config XEN_DOM0
1615	def_bool y
1616	depends on XEN
1617
1618config XEN
1619	bool "Xen guest support on ARM64"
1620	depends on ARM64 && OF
1621	select SWIOTLB_XEN
1622	select PARAVIRT
1623	help
1624	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1625
1626# include/linux/mmzone.h requires the following to be true:
1627#
1628#   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1629#
1630# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1631#
1632#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1633# ----+-------------------+--------------+----------------------+-------------------------+
1634# 4K  |       27          |      12      |       15             |         10              |
1635# 16K |       27          |      14      |       13             |         11              |
1636# 64K |       29          |      16      |       13             |         13              |
1637config ARCH_FORCE_MAX_ORDER
1638	int
1639	default "13" if ARM64_64K_PAGES
1640	default "11" if ARM64_16K_PAGES
1641	default "10"
1642	help
1643	  The kernel page allocator limits the size of maximal physically
1644	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1645	  defines the maximal power of two of number of pages that can be
1646	  allocated as a single contiguous block. This option allows
1647	  overriding the default setting when ability to allocate very
1648	  large blocks of physically contiguous memory is required.
1649
1650	  The maximal size of allocation cannot exceed the size of the
1651	  section, so the value of MAX_PAGE_ORDER should satisfy
1652
1653	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1654
1655	  Don't change if unsure.
1656
1657config UNMAP_KERNEL_AT_EL0
1658	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1659	default y
1660	help
1661	  Speculation attacks against some high-performance processors can
1662	  be used to bypass MMU permission checks and leak kernel data to
1663	  userspace. This can be defended against by unmapping the kernel
1664	  when running in userspace, mapping it back in on exception entry
1665	  via a trampoline page in the vector table.
1666
1667	  If unsure, say Y.
1668
1669config MITIGATE_SPECTRE_BRANCH_HISTORY
1670	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1671	default y
1672	help
1673	  Speculation attacks against some high-performance processors can
1674	  make use of branch history to influence future speculation.
1675	  When taking an exception from user-space, a sequence of branches
1676	  or a firmware call overwrites the branch history.
1677
1678config RODATA_FULL_DEFAULT_ENABLED
1679	bool "Apply r/o permissions of VM areas also to their linear aliases"
1680	default y
1681	help
1682	  Apply read-only attributes of VM areas to the linear alias of
1683	  the backing pages as well. This prevents code or read-only data
1684	  from being modified (inadvertently or intentionally) via another
1685	  mapping of the same memory page. This additional enhancement can
1686	  be turned off at runtime by passing rodata=[off|on] (and turned on
1687	  with rodata=full if this option is set to 'n')
1688
1689	  This requires the linear region to be mapped down to pages,
1690	  which may adversely affect performance in some cases.
1691
1692config ARM64_SW_TTBR0_PAN
1693	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1694	depends on !KCSAN
1695	select ARM64_PAN
1696	help
1697	  Enabling this option prevents the kernel from accessing
1698	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1699	  zeroed area and reserved ASID. The user access routines
1700	  restore the valid TTBR0_EL1 temporarily.
1701
1702config ARM64_TAGGED_ADDR_ABI
1703	bool "Enable the tagged user addresses syscall ABI"
1704	default y
1705	help
1706	  When this option is enabled, user applications can opt in to a
1707	  relaxed ABI via prctl() allowing tagged addresses to be passed
1708	  to system calls as pointer arguments. For details, see
1709	  Documentation/arch/arm64/tagged-address-abi.rst.
1710
1711menuconfig COMPAT
1712	bool "Kernel support for 32-bit EL0"
1713	depends on ARM64_4K_PAGES || EXPERT
1714	select HAVE_UID16
1715	select OLD_SIGSUSPEND3
1716	select COMPAT_OLD_SIGACTION
1717	help
1718	  This option enables support for a 32-bit EL0 running under a 64-bit
1719	  kernel at EL1. AArch32-specific components such as system calls,
1720	  the user helper functions, VFP support and the ptrace interface are
1721	  handled appropriately by the kernel.
1722
1723	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1724	  that you will only be able to execute AArch32 binaries that were compiled
1725	  with page size aligned segments.
1726
1727	  If you want to execute 32-bit userspace applications, say Y.
1728
1729if COMPAT
1730
1731config KUSER_HELPERS
1732	bool "Enable kuser helpers page for 32-bit applications"
1733	default y
1734	help
1735	  Warning: disabling this option may break 32-bit user programs.
1736
1737	  Provide kuser helpers to compat tasks. The kernel provides
1738	  helper code to userspace in read only form at a fixed location
1739	  to allow userspace to be independent of the CPU type fitted to
1740	  the system. This permits binaries to be run on ARMv4 through
1741	  to ARMv8 without modification.
1742
1743	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1744
1745	  However, the fixed address nature of these helpers can be used
1746	  by ROP (return orientated programming) authors when creating
1747	  exploits.
1748
1749	  If all of the binaries and libraries which run on your platform
1750	  are built specifically for your platform, and make no use of
1751	  these helpers, then you can turn this option off to hinder
1752	  such exploits. However, in that case, if a binary or library
1753	  relying on those helpers is run, it will not function correctly.
1754
1755	  Say N here only if you are absolutely certain that you do not
1756	  need these helpers; otherwise, the safe option is to say Y.
1757
1758config COMPAT_VDSO
1759	bool "Enable vDSO for 32-bit applications"
1760	depends on !CPU_BIG_ENDIAN
1761	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1762	select GENERIC_COMPAT_VDSO
1763	default y
1764	help
1765	  Place in the process address space of 32-bit applications an
1766	  ELF shared object providing fast implementations of gettimeofday
1767	  and clock_gettime.
1768
1769	  You must have a 32-bit build of glibc 2.22 or later for programs
1770	  to seamlessly take advantage of this.
1771
1772config THUMB2_COMPAT_VDSO
1773	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1774	depends on COMPAT_VDSO
1775	default y
1776	help
1777	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1778	  otherwise with '-marm'.
1779
1780config COMPAT_ALIGNMENT_FIXUPS
1781	bool "Fix up misaligned multi-word loads and stores in user space"
1782
1783menuconfig ARMV8_DEPRECATED
1784	bool "Emulate deprecated/obsolete ARMv8 instructions"
1785	depends on SYSCTL
1786	help
1787	  Legacy software support may require certain instructions
1788	  that have been deprecated or obsoleted in the architecture.
1789
1790	  Enable this config to enable selective emulation of these
1791	  features.
1792
1793	  If unsure, say Y
1794
1795if ARMV8_DEPRECATED
1796
1797config SWP_EMULATION
1798	bool "Emulate SWP/SWPB instructions"
1799	help
1800	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1801	  they are always undefined. Say Y here to enable software
1802	  emulation of these instructions for userspace using LDXR/STXR.
1803	  This feature can be controlled at runtime with the abi.swp
1804	  sysctl which is disabled by default.
1805
1806	  In some older versions of glibc [<=2.8] SWP is used during futex
1807	  trylock() operations with the assumption that the code will not
1808	  be preempted. This invalid assumption may be more likely to fail
1809	  with SWP emulation enabled, leading to deadlock of the user
1810	  application.
1811
1812	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1813	  on an external transaction monitoring block called a global
1814	  monitor to maintain update atomicity. If your system does not
1815	  implement a global monitor, this option can cause programs that
1816	  perform SWP operations to uncached memory to deadlock.
1817
1818	  If unsure, say Y
1819
1820config CP15_BARRIER_EMULATION
1821	bool "Emulate CP15 Barrier instructions"
1822	help
1823	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1824	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1825	  strongly recommended to use the ISB, DSB, and DMB
1826	  instructions instead.
1827
1828	  Say Y here to enable software emulation of these
1829	  instructions for AArch32 userspace code. When this option is
1830	  enabled, CP15 barrier usage is traced which can help
1831	  identify software that needs updating. This feature can be
1832	  controlled at runtime with the abi.cp15_barrier sysctl.
1833
1834	  If unsure, say Y
1835
1836config SETEND_EMULATION
1837	bool "Emulate SETEND instruction"
1838	help
1839	  The SETEND instruction alters the data-endianness of the
1840	  AArch32 EL0, and is deprecated in ARMv8.
1841
1842	  Say Y here to enable software emulation of the instruction
1843	  for AArch32 userspace code. This feature can be controlled
1844	  at runtime with the abi.setend sysctl.
1845
1846	  Note: All the cpus on the system must have mixed endian support at EL0
1847	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1848	  endian - is hotplugged in after this feature has been enabled, there could
1849	  be unexpected results in the applications.
1850
1851	  If unsure, say Y
1852endif # ARMV8_DEPRECATED
1853
1854endif # COMPAT
1855
1856menu "ARMv8.1 architectural features"
1857
1858config ARM64_HW_AFDBM
1859	bool "Support for hardware updates of the Access and Dirty page flags"
1860	default y
1861	help
1862	  The ARMv8.1 architecture extensions introduce support for
1863	  hardware updates of the access and dirty information in page
1864	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1865	  capable processors, accesses to pages with PTE_AF cleared will
1866	  set this bit instead of raising an access flag fault.
1867	  Similarly, writes to read-only pages with the DBM bit set will
1868	  clear the read-only bit (AP[2]) instead of raising a
1869	  permission fault.
1870
1871	  Kernels built with this configuration option enabled continue
1872	  to work on pre-ARMv8.1 hardware and the performance impact is
1873	  minimal. If unsure, say Y.
1874
1875config ARM64_PAN
1876	bool "Enable support for Privileged Access Never (PAN)"
1877	default y
1878	help
1879	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1880	  prevents the kernel or hypervisor from accessing user-space (EL0)
1881	  memory directly.
1882
1883	  Choosing this option will cause any unprotected (not using
1884	  copy_to_user et al) memory access to fail with a permission fault.
1885
1886	  The feature is detected at runtime, and will remain as a 'nop'
1887	  instruction if the cpu does not implement the feature.
1888
1889config AS_HAS_LSE_ATOMICS
1890	def_bool $(as-instr,.arch_extension lse)
1891
1892config ARM64_LSE_ATOMICS
1893	bool
1894	default ARM64_USE_LSE_ATOMICS
1895	depends on AS_HAS_LSE_ATOMICS
1896
1897config ARM64_USE_LSE_ATOMICS
1898	bool "Atomic instructions"
1899	default y
1900	help
1901	  As part of the Large System Extensions, ARMv8.1 introduces new
1902	  atomic instructions that are designed specifically to scale in
1903	  very large systems.
1904
1905	  Say Y here to make use of these instructions for the in-kernel
1906	  atomic routines. This incurs a small overhead on CPUs that do
1907	  not support these instructions and requires the kernel to be
1908	  built with binutils >= 2.25 in order for the new instructions
1909	  to be used.
1910
1911endmenu # "ARMv8.1 architectural features"
1912
1913menu "ARMv8.2 architectural features"
1914
1915config AS_HAS_ARMV8_2
1916	def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a)
1917
1918config AS_HAS_SHA3
1919	def_bool $(as-instr,.arch armv8.2-a+sha3)
1920
1921config ARM64_PMEM
1922	bool "Enable support for persistent memory"
1923	select ARCH_HAS_PMEM_API
1924	select ARCH_HAS_UACCESS_FLUSHCACHE
1925	help
1926	  Say Y to enable support for the persistent memory API based on the
1927	  ARMv8.2 DCPoP feature.
1928
1929	  The feature is detected at runtime, and the kernel will use DC CVAC
1930	  operations if DC CVAP is not supported (following the behaviour of
1931	  DC CVAP itself if the system does not define a point of persistence).
1932
1933config ARM64_RAS_EXTN
1934	bool "Enable support for RAS CPU Extensions"
1935	default y
1936	help
1937	  CPUs that support the Reliability, Availability and Serviceability
1938	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1939	  errors, classify them and report them to software.
1940
1941	  On CPUs with these extensions system software can use additional
1942	  barriers to determine if faults are pending and read the
1943	  classification from a new set of registers.
1944
1945	  Selecting this feature will allow the kernel to use these barriers
1946	  and access the new registers if the system supports the extension.
1947	  Platform RAS features may additionally depend on firmware support.
1948
1949config ARM64_CNP
1950	bool "Enable support for Common Not Private (CNP) translations"
1951	default y
1952	help
1953	  Common Not Private (CNP) allows translation table entries to
1954	  be shared between different PEs in the same inner shareable
1955	  domain, so the hardware can use this fact to optimise the
1956	  caching of such entries in the TLB.
1957
1958	  Selecting this option allows the CNP feature to be detected
1959	  at runtime, and does not affect PEs that do not implement
1960	  this feature.
1961
1962endmenu # "ARMv8.2 architectural features"
1963
1964menu "ARMv8.3 architectural features"
1965
1966config ARM64_PTR_AUTH
1967	bool "Enable support for pointer authentication"
1968	default y
1969	help
1970	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1971	  instructions for signing and authenticating pointers against secret
1972	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1973	  and other attacks.
1974
1975	  This option enables these instructions at EL0 (i.e. for userspace).
1976	  Choosing this option will cause the kernel to initialise secret keys
1977	  for each process at exec() time, with these keys being
1978	  context-switched along with the process.
1979
1980	  The feature is detected at runtime. If the feature is not present in
1981	  hardware it will not be advertised to userspace/KVM guest nor will it
1982	  be enabled.
1983
1984	  If the feature is present on the boot CPU but not on a late CPU, then
1985	  the late CPU will be parked. Also, if the boot CPU does not have
1986	  address auth and the late CPU has then the late CPU will still boot
1987	  but with the feature disabled. On such a system, this option should
1988	  not be selected.
1989
1990config ARM64_PTR_AUTH_KERNEL
1991	bool "Use pointer authentication for kernel"
1992	default y
1993	depends on ARM64_PTR_AUTH
1994	depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3
1995	# Modern compilers insert a .note.gnu.property section note for PAC
1996	# which is only understood by binutils starting with version 2.33.1.
1997	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
1998	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
1999	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2000	help
2001	  If the compiler supports the -mbranch-protection or
2002	  -msign-return-address flag (e.g. GCC 7 or later), then this option
2003	  will cause the kernel itself to be compiled with return address
2004	  protection. In this case, and if the target hardware is known to
2005	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
2006	  disabled with minimal loss of protection.
2007
2008	  This feature works with FUNCTION_GRAPH_TRACER option only if
2009	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
2010
2011config CC_HAS_BRANCH_PROT_PAC_RET
2012	# GCC 9 or later, clang 8 or later
2013	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
2014
2015config CC_HAS_SIGN_RETURN_ADDRESS
2016	# GCC 7, 8
2017	def_bool $(cc-option,-msign-return-address=all)
2018
2019config AS_HAS_ARMV8_3
2020	def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a)
2021
2022config AS_HAS_CFI_NEGATE_RA_STATE
2023	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
2024
2025config AS_HAS_LDAPR
2026	def_bool $(as-instr,.arch_extension rcpc)
2027
2028endmenu # "ARMv8.3 architectural features"
2029
2030menu "ARMv8.4 architectural features"
2031
2032config ARM64_AMU_EXTN
2033	bool "Enable support for the Activity Monitors Unit CPU extension"
2034	default y
2035	help
2036	  The activity monitors extension is an optional extension introduced
2037	  by the ARMv8.4 CPU architecture. This enables support for version 1
2038	  of the activity monitors architecture, AMUv1.
2039
2040	  To enable the use of this extension on CPUs that implement it, say Y.
2041
2042	  Note that for architectural reasons, firmware _must_ implement AMU
2043	  support when running on CPUs that present the activity monitors
2044	  extension. The required support is present in:
2045	    * Version 1.5 and later of the ARM Trusted Firmware
2046
2047	  For kernels that have this configuration enabled but boot with broken
2048	  firmware, you may need to say N here until the firmware is fixed.
2049	  Otherwise you may experience firmware panics or lockups when
2050	  accessing the counter registers. Even if you are not observing these
2051	  symptoms, the values returned by the register reads might not
2052	  correctly reflect reality. Most commonly, the value read will be 0,
2053	  indicating that the counter is not enabled.
2054
2055config AS_HAS_ARMV8_4
2056	def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a)
2057
2058config ARM64_TLB_RANGE
2059	bool "Enable support for tlbi range feature"
2060	default y
2061	depends on AS_HAS_ARMV8_4
2062	help
2063	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2064	  range of input addresses.
2065
2066	  The feature introduces new assembly instructions, and they were
2067	  support when binutils >= 2.30.
2068
2069endmenu # "ARMv8.4 architectural features"
2070
2071menu "ARMv8.5 architectural features"
2072
2073config AS_HAS_ARMV8_5
2074	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2075
2076config ARM64_BTI
2077	bool "Branch Target Identification support"
2078	default y
2079	help
2080	  Branch Target Identification (part of the ARMv8.5 Extensions)
2081	  provides a mechanism to limit the set of locations to which computed
2082	  branch instructions such as BR or BLR can jump.
2083
2084	  To make use of BTI on CPUs that support it, say Y.
2085
2086	  BTI is intended to provide complementary protection to other control
2087	  flow integrity protection mechanisms, such as the Pointer
2088	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2089	  For this reason, it does not make sense to enable this option without
2090	  also enabling support for pointer authentication.  Thus, when
2091	  enabling this option you should also select ARM64_PTR_AUTH=y.
2092
2093	  Userspace binaries must also be specifically compiled to make use of
2094	  this mechanism.  If you say N here or the hardware does not support
2095	  BTI, such binaries can still run, but you get no additional
2096	  enforcement of branch destinations.
2097
2098config ARM64_BTI_KERNEL
2099	bool "Use Branch Target Identification for kernel"
2100	default y
2101	depends on ARM64_BTI
2102	depends on ARM64_PTR_AUTH_KERNEL
2103	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2104	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2105	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2106	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2107	depends on !CC_IS_GCC
2108	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2109	help
2110	  Build the kernel with Branch Target Identification annotations
2111	  and enable enforcement of this for kernel code. When this option
2112	  is enabled and the system supports BTI all kernel code including
2113	  modular code must have BTI enabled.
2114
2115config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2116	# GCC 9 or later, clang 8 or later
2117	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2118
2119config ARM64_E0PD
2120	bool "Enable support for E0PD"
2121	default y
2122	help
2123	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2124	  that EL0 accesses made via TTBR1 always fault in constant time,
2125	  providing similar benefits to KASLR as those provided by KPTI, but
2126	  with lower overhead and without disrupting legitimate access to
2127	  kernel memory such as SPE.
2128
2129	  This option enables E0PD for TTBR1 where available.
2130
2131config ARM64_AS_HAS_MTE
2132	# Initial support for MTE went in binutils 2.32.0, checked with
2133	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2134	# as a late addition to the final architecture spec (LDGM/STGM)
2135	# is only supported in the newer 2.32.x and 2.33 binutils
2136	# versions, hence the extra "stgm" instruction check below.
2137	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2138
2139config ARM64_MTE
2140	bool "Memory Tagging Extension support"
2141	default y
2142	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2143	depends on AS_HAS_ARMV8_5
2144	depends on AS_HAS_LSE_ATOMICS
2145	# Required for tag checking in the uaccess routines
2146	select ARM64_PAN
2147	select ARCH_HAS_SUBPAGE_FAULTS
2148	select ARCH_USES_HIGH_VMA_FLAGS
2149	select ARCH_USES_PG_ARCH_2
2150	select ARCH_USES_PG_ARCH_3
2151	help
2152	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2153	  architectural support for run-time, always-on detection of
2154	  various classes of memory error to aid with software debugging
2155	  to eliminate vulnerabilities arising from memory-unsafe
2156	  languages.
2157
2158	  This option enables the support for the Memory Tagging
2159	  Extension at EL0 (i.e. for userspace).
2160
2161	  Selecting this option allows the feature to be detected at
2162	  runtime. Any secondary CPU not implementing this feature will
2163	  not be allowed a late bring-up.
2164
2165	  Userspace binaries that want to use this feature must
2166	  explicitly opt in. The mechanism for the userspace is
2167	  described in:
2168
2169	  Documentation/arch/arm64/memory-tagging-extension.rst.
2170
2171endmenu # "ARMv8.5 architectural features"
2172
2173menu "ARMv8.7 architectural features"
2174
2175config ARM64_EPAN
2176	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2177	default y
2178	depends on ARM64_PAN
2179	help
2180	  Enhanced Privileged Access Never (EPAN) allows Privileged
2181	  Access Never to be used with Execute-only mappings.
2182
2183	  The feature is detected at runtime, and will remain disabled
2184	  if the cpu does not implement the feature.
2185endmenu # "ARMv8.7 architectural features"
2186
2187config AS_HAS_MOPS
2188	def_bool $(as-instr,.arch_extension mops)
2189
2190menu "ARMv8.9 architectural features"
2191
2192config ARM64_POE
2193	prompt "Permission Overlay Extension"
2194	def_bool y
2195	select ARCH_USES_HIGH_VMA_FLAGS
2196	select ARCH_HAS_PKEYS
2197	help
2198	  The Permission Overlay Extension is used to implement Memory
2199	  Protection Keys. Memory Protection Keys provides a mechanism for
2200	  enforcing page-based protections, but without requiring modification
2201	  of the page tables when an application changes protection domains.
2202
2203	  For details, see Documentation/core-api/protection-keys.rst
2204
2205	  If unsure, say y.
2206
2207config ARCH_PKEY_BITS
2208	int
2209	default 3
2210
2211config ARM64_HAFT
2212	bool "Support for Hardware managed Access Flag for Table Descriptors"
2213	depends on ARM64_HW_AFDBM
2214	default y
2215	help
2216	  The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access
2217	  Flag for Table descriptors. When enabled an architectural executed
2218	  memory access will update the Access Flag in each Table descriptor
2219	  which is accessed during the translation table walk and for which
2220	  the Access Flag is 0. The Access Flag of the Table descriptor use
2221	  the same bit of PTE_AF.
2222
2223	  The feature will only be enabled if all the CPUs in the system
2224	  support this feature. If unsure, say Y.
2225
2226endmenu # "ARMv8.9 architectural features"
2227
2228menu "v9.4 architectural features"
2229
2230config ARM64_GCS
2231	bool "Enable support for Guarded Control Stack (GCS)"
2232	default y
2233	select ARCH_HAS_USER_SHADOW_STACK
2234	select ARCH_USES_HIGH_VMA_FLAGS
2235	depends on !UPROBES
2236	help
2237	  Guarded Control Stack (GCS) provides support for a separate
2238	  stack with restricted access which contains only return
2239	  addresses.  This can be used to harden against some attacks
2240	  by comparing return address used by the program with what is
2241	  stored in the GCS, and may also be used to efficiently obtain
2242	  the call stack for applications such as profiling.
2243
2244	  The feature is detected at runtime, and will remain disabled
2245	  if the system does not implement the feature.
2246
2247endmenu # "v9.4 architectural features"
2248
2249config ARM64_SVE
2250	bool "ARM Scalable Vector Extension support"
2251	default y
2252	help
2253	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2254	  execution state which complements and extends the SIMD functionality
2255	  of the base architecture to support much larger vectors and to enable
2256	  additional vectorisation opportunities.
2257
2258	  To enable use of this extension on CPUs that implement it, say Y.
2259
2260	  On CPUs that support the SVE2 extensions, this option will enable
2261	  those too.
2262
2263	  Note that for architectural reasons, firmware _must_ implement SVE
2264	  support when running on SVE capable hardware.  The required support
2265	  is present in:
2266
2267	    * version 1.5 and later of the ARM Trusted Firmware
2268	    * the AArch64 boot wrapper since commit 5e1261e08abf
2269	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2270
2271	  For other firmware implementations, consult the firmware documentation
2272	  or vendor.
2273
2274	  If you need the kernel to boot on SVE-capable hardware with broken
2275	  firmware, you may need to say N here until you get your firmware
2276	  fixed.  Otherwise, you may experience firmware panics or lockups when
2277	  booting the kernel.  If unsure and you are not observing these
2278	  symptoms, you should assume that it is safe to say Y.
2279
2280config ARM64_SME
2281	bool "ARM Scalable Matrix Extension support"
2282	default y
2283	depends on ARM64_SVE
2284	depends on BROKEN
2285	help
2286	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2287	  execution state which utilises a substantial subset of the SVE
2288	  instruction set, together with the addition of new architectural
2289	  register state capable of holding two dimensional matrix tiles to
2290	  enable various matrix operations.
2291
2292config ARM64_PSEUDO_NMI
2293	bool "Support for NMI-like interrupts"
2294	select ARM_GIC_V3
2295	help
2296	  Adds support for mimicking Non-Maskable Interrupts through the use of
2297	  GIC interrupt priority. This support requires version 3 or later of
2298	  ARM GIC.
2299
2300	  This high priority configuration for interrupts needs to be
2301	  explicitly enabled by setting the kernel parameter
2302	  "irqchip.gicv3_pseudo_nmi" to 1.
2303
2304	  If unsure, say N
2305
2306if ARM64_PSEUDO_NMI
2307config ARM64_DEBUG_PRIORITY_MASKING
2308	bool "Debug interrupt priority masking"
2309	help
2310	  This adds runtime checks to functions enabling/disabling
2311	  interrupts when using priority masking. The additional checks verify
2312	  the validity of ICC_PMR_EL1 when calling concerned functions.
2313
2314	  If unsure, say N
2315endif # ARM64_PSEUDO_NMI
2316
2317config RELOCATABLE
2318	bool "Build a relocatable kernel image" if EXPERT
2319	select ARCH_HAS_RELR
2320	default y
2321	help
2322	  This builds the kernel as a Position Independent Executable (PIE),
2323	  which retains all relocation metadata required to relocate the
2324	  kernel binary at runtime to a different virtual address than the
2325	  address it was linked at.
2326	  Since AArch64 uses the RELA relocation format, this requires a
2327	  relocation pass at runtime even if the kernel is loaded at the
2328	  same address it was linked at.
2329
2330config RANDOMIZE_BASE
2331	bool "Randomize the address of the kernel image"
2332	select RELOCATABLE
2333	help
2334	  Randomizes the virtual address at which the kernel image is
2335	  loaded, as a security feature that deters exploit attempts
2336	  relying on knowledge of the location of kernel internals.
2337
2338	  It is the bootloader's job to provide entropy, by passing a
2339	  random u64 value in /chosen/kaslr-seed at kernel entry.
2340
2341	  When booting via the UEFI stub, it will invoke the firmware's
2342	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2343	  to the kernel proper. In addition, it will randomise the physical
2344	  location of the kernel Image as well.
2345
2346	  If unsure, say N.
2347
2348config RANDOMIZE_MODULE_REGION_FULL
2349	bool "Randomize the module region over a 2 GB range"
2350	depends on RANDOMIZE_BASE
2351	default y
2352	help
2353	  Randomizes the location of the module region inside a 2 GB window
2354	  covering the core kernel. This way, it is less likely for modules
2355	  to leak information about the location of core kernel data structures
2356	  but it does imply that function calls between modules and the core
2357	  kernel will need to be resolved via veneers in the module PLT.
2358
2359	  When this option is not set, the module region will be randomized over
2360	  a limited range that contains the [_stext, _etext] interval of the
2361	  core kernel, so branch relocations are almost always in range unless
2362	  the region is exhausted. In this particular case of region
2363	  exhaustion, modules might be able to fall back to a larger 2GB area.
2364
2365config CC_HAVE_STACKPROTECTOR_SYSREG
2366	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2367
2368config STACKPROTECTOR_PER_TASK
2369	def_bool y
2370	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2371
2372config UNWIND_PATCH_PAC_INTO_SCS
2373	bool "Enable shadow call stack dynamically using code patching"
2374	# needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated
2375	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2376	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2377	depends on SHADOW_CALL_STACK
2378	select UNWIND_TABLES
2379	select DYNAMIC_SCS
2380
2381config ARM64_CONTPTE
2382	bool "Contiguous PTE mappings for user memory" if EXPERT
2383	depends on TRANSPARENT_HUGEPAGE
2384	default y
2385	help
2386	  When enabled, user mappings are configured using the PTE contiguous
2387	  bit, for any mappings that meet the size and alignment requirements.
2388	  This reduces TLB pressure and improves performance.
2389
2390endmenu # "Kernel Features"
2391
2392menu "Boot options"
2393
2394config ARM64_ACPI_PARKING_PROTOCOL
2395	bool "Enable support for the ARM64 ACPI parking protocol"
2396	depends on ACPI
2397	help
2398	  Enable support for the ARM64 ACPI parking protocol. If disabled
2399	  the kernel will not allow booting through the ARM64 ACPI parking
2400	  protocol even if the corresponding data is present in the ACPI
2401	  MADT table.
2402
2403config CMDLINE
2404	string "Default kernel command string"
2405	default ""
2406	help
2407	  Provide a set of default command-line options at build time by
2408	  entering them here. As a minimum, you should specify the the
2409	  root device (e.g. root=/dev/nfs).
2410
2411choice
2412	prompt "Kernel command line type"
2413	depends on CMDLINE != ""
2414	default CMDLINE_FROM_BOOTLOADER
2415	help
2416	  Choose how the kernel will handle the provided default kernel
2417	  command line string.
2418
2419config CMDLINE_FROM_BOOTLOADER
2420	bool "Use bootloader kernel arguments if available"
2421	help
2422	  Uses the command-line options passed by the boot loader. If
2423	  the boot loader doesn't provide any, the default kernel command
2424	  string provided in CMDLINE will be used.
2425
2426config CMDLINE_FORCE
2427	bool "Always use the default kernel command string"
2428	help
2429	  Always use the default kernel command string, even if the boot
2430	  loader passes other arguments to the kernel.
2431	  This is useful if you cannot or don't want to change the
2432	  command-line options your boot loader passes to the kernel.
2433
2434endchoice
2435
2436config EFI_STUB
2437	bool
2438
2439config EFI
2440	bool "UEFI runtime support"
2441	depends on OF && !CPU_BIG_ENDIAN
2442	depends on KERNEL_MODE_NEON
2443	select ARCH_SUPPORTS_ACPI
2444	select LIBFDT
2445	select UCS2_STRING
2446	select EFI_PARAMS_FROM_FDT
2447	select EFI_RUNTIME_WRAPPERS
2448	select EFI_STUB
2449	select EFI_GENERIC_STUB
2450	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2451	default y
2452	help
2453	  This option provides support for runtime services provided
2454	  by UEFI firmware (such as non-volatile variables, realtime
2455	  clock, and platform reset). A UEFI stub is also provided to
2456	  allow the kernel to be booted as an EFI application. This
2457	  is only useful on systems that have UEFI firmware.
2458
2459config COMPRESSED_INSTALL
2460	bool "Install compressed image by default"
2461	help
2462	  This makes the regular "make install" install the compressed
2463	  image we built, not the legacy uncompressed one.
2464
2465	  You can check that a compressed image works for you by doing
2466	  "make zinstall" first, and verifying that everything is fine
2467	  in your environment before making "make install" do this for
2468	  you.
2469
2470config DMI
2471	bool "Enable support for SMBIOS (DMI) tables"
2472	depends on EFI
2473	default y
2474	help
2475	  This enables SMBIOS/DMI feature for systems.
2476
2477	  This option is only useful on systems that have UEFI firmware.
2478	  However, even with this option, the resultant kernel should
2479	  continue to boot on existing non-UEFI platforms.
2480
2481endmenu # "Boot options"
2482
2483menu "Power management options"
2484
2485source "kernel/power/Kconfig"
2486
2487config ARCH_HIBERNATION_POSSIBLE
2488	def_bool y
2489	depends on CPU_PM
2490
2491config ARCH_HIBERNATION_HEADER
2492	def_bool y
2493	depends on HIBERNATION
2494
2495config ARCH_SUSPEND_POSSIBLE
2496	def_bool y
2497
2498endmenu # "Power management options"
2499
2500menu "CPU Power Management"
2501
2502source "drivers/cpuidle/Kconfig"
2503
2504source "drivers/cpufreq/Kconfig"
2505
2506endmenu # "CPU Power Management"
2507
2508source "drivers/acpi/Kconfig"
2509
2510source "arch/arm64/kvm/Kconfig"
2511
2512