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