xref: /linux/arch/arm64/Kconfig (revision bf76f23aa1c178e9115eba17f699fa726aed669b)
1# SPDX-License-Identifier: GPL-2.0-only
2config ARM64
3	def_bool y
4	select ACPI_APMT if ACPI
5	select ACPI_CCA_REQUIRED if ACPI
6	select ACPI_GENERIC_GSI if ACPI
7	select ACPI_GTDT if ACPI
8	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
9	select ACPI_IORT if ACPI
10	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
11	select ACPI_MCFG if (ACPI && PCI)
12	select ACPI_SPCR_TABLE if ACPI
13	select ACPI_PPTT if ACPI
14	select ARCH_HAS_DEBUG_WX
15	select ARCH_BINFMT_ELF_EXTRA_PHDRS
16	select ARCH_BINFMT_ELF_STATE
17	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
18	select ARCH_ENABLE_MEMORY_HOTPLUG
19	select ARCH_ENABLE_MEMORY_HOTREMOVE
20	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
21	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
22	select ARCH_HAS_CACHE_LINE_SIZE
23	select ARCH_HAS_CC_PLATFORM
24	select ARCH_HAS_CURRENT_STACK_POINTER
25	select ARCH_HAS_DEBUG_VIRTUAL
26	select ARCH_HAS_DEBUG_VM_PGTABLE
27	select ARCH_HAS_DMA_OPS if XEN
28	select ARCH_HAS_DMA_PREP_COHERENT
29	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
30	select ARCH_HAS_FAST_MULTIPLIER
31	select ARCH_HAS_FORTIFY_SOURCE
32	select ARCH_HAS_GCOV_PROFILE_ALL
33	select ARCH_HAS_GIGANTIC_PAGE
34	select ARCH_HAS_KCOV
35	select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON
36	select ARCH_HAS_KEEPINITRD
37	select ARCH_HAS_MEMBARRIER_SYNC_CORE
38	select ARCH_HAS_MEM_ENCRYPT
39	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
40	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
41	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
42	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
43	select ARCH_HAS_PREEMPT_LAZY
44	select ARCH_HAS_PTDUMP
45	select ARCH_HAS_PTE_DEVMAP
46	select ARCH_HAS_PTE_SPECIAL
47	select ARCH_HAS_HW_PTE_YOUNG
48	select ARCH_HAS_SETUP_DMA_OPS
49	select ARCH_HAS_SET_DIRECT_MAP
50	select ARCH_HAS_SET_MEMORY
51	select ARCH_HAS_MEM_ENCRYPT
52	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
53	select ARCH_STACKWALK
54	select ARCH_HAS_STRICT_KERNEL_RWX
55	select ARCH_HAS_STRICT_MODULE_RWX
56	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
57	select ARCH_HAS_SYNC_DMA_FOR_CPU
58	select ARCH_HAS_SYSCALL_WRAPPER
59	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
60	select ARCH_HAS_ZONE_DMA_SET if EXPERT
61	select ARCH_HAVE_ELF_PROT
62	select ARCH_HAVE_NMI_SAFE_CMPXCHG
63	select ARCH_HAVE_TRACE_MMIO_ACCESS
64	select ARCH_INLINE_READ_LOCK if !PREEMPTION
65	select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
66	select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
67	select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
68	select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
69	select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
70	select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
71	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
72	select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
73	select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
74	select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
75	select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
76	select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
77	select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
78	select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
79	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
80	select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
81	select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
82	select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
83	select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
84	select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
85	select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
86	select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
87	select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
88	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
89	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
90	select ARCH_KEEP_MEMBLOCK
91	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
92	select ARCH_USE_CMPXCHG_LOCKREF
93	select ARCH_USE_GNU_PROPERTY
94	select ARCH_USE_MEMTEST
95	select ARCH_USE_QUEUED_RWLOCKS
96	select ARCH_USE_QUEUED_SPINLOCKS
97	select ARCH_USE_SYM_ANNOTATIONS
98	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
99	select ARCH_SUPPORTS_HUGETLBFS
100	select ARCH_SUPPORTS_MEMORY_FAILURE
101	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
102	select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN
103	select ARCH_SUPPORTS_LTO_CLANG_THIN
104	select ARCH_SUPPORTS_CFI_CLANG
105	select ARCH_SUPPORTS_ATOMIC_RMW
106	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
107	select ARCH_SUPPORTS_NUMA_BALANCING
108	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
109	select ARCH_SUPPORTS_PER_VMA_LOCK
110	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
111	select ARCH_SUPPORTS_RT
112	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
113	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
114	select ARCH_WANT_DEFAULT_BPF_JIT
115	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
116	select ARCH_WANT_FRAME_POINTERS
117	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
118	select ARCH_WANT_LD_ORPHAN_WARN
119	select ARCH_WANTS_EXECMEM_LATE
120	select ARCH_WANTS_NO_INSTR
121	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
122	select ARCH_HAS_UBSAN
123	select ARM_AMBA
124	select ARM_ARCH_TIMER
125	select ARM_GIC
126	select AUDIT_ARCH_COMPAT_GENERIC
127	select ARM_GIC_V2M if PCI
128	select ARM_GIC_V3
129	select ARM_GIC_V3_ITS if PCI
130	select ARM_PSCI_FW
131	select BUILDTIME_TABLE_SORT
132	select CLONE_BACKWARDS
133	select COMMON_CLK
134	select CPU_PM if (SUSPEND || CPU_IDLE)
135	select CPUMASK_OFFSTACK if NR_CPUS > 256
136	select DCACHE_WORD_ACCESS
137	select DYNAMIC_FTRACE if FUNCTION_TRACER
138	select DMA_BOUNCE_UNALIGNED_KMALLOC
139	select DMA_DIRECT_REMAP
140	select EDAC_SUPPORT
141	select FRAME_POINTER
142	select FUNCTION_ALIGNMENT_4B
143	select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS
144	select GENERIC_ALLOCATOR
145	select GENERIC_ARCH_TOPOLOGY
146	select GENERIC_CLOCKEVENTS_BROADCAST
147	select GENERIC_CPU_AUTOPROBE
148	select GENERIC_CPU_DEVICES
149	select GENERIC_CPU_VULNERABILITIES
150	select GENERIC_EARLY_IOREMAP
151	select GENERIC_IDLE_POLL_SETUP
152	select GENERIC_IOREMAP
153	select GENERIC_IRQ_IPI
154	select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
155	select GENERIC_IRQ_PROBE
156	select GENERIC_IRQ_SHOW
157	select GENERIC_IRQ_SHOW_LEVEL
158	select GENERIC_LIB_DEVMEM_IS_ALLOWED
159	select GENERIC_PCI_IOMAP
160	select GENERIC_SCHED_CLOCK
161	select GENERIC_SMP_IDLE_THREAD
162	select GENERIC_TIME_VSYSCALL
163	select GENERIC_GETTIMEOFDAY
164	select GENERIC_VDSO_DATA_STORE
165	select GENERIC_VDSO_TIME_NS
166	select HARDIRQS_SW_RESEND
167	select HAS_IOPORT
168	select HAVE_MOVE_PMD
169	select HAVE_MOVE_PUD
170	select HAVE_PCI
171	select HAVE_ACPI_APEI if (ACPI && EFI)
172	select HAVE_ALIGNED_STRUCT_PAGE
173	select HAVE_ARCH_AUDITSYSCALL
174	select HAVE_ARCH_BITREVERSE
175	select HAVE_ARCH_COMPILER_H
176	select HAVE_ARCH_HUGE_VMALLOC
177	select HAVE_ARCH_HUGE_VMAP
178	select HAVE_ARCH_JUMP_LABEL
179	select HAVE_ARCH_JUMP_LABEL_RELATIVE
180	select HAVE_ARCH_KASAN
181	select HAVE_ARCH_KASAN_VMALLOC
182	select HAVE_ARCH_KASAN_SW_TAGS
183	select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE
184	# Some instrumentation may be unsound, hence EXPERT
185	select HAVE_ARCH_KCSAN if EXPERT
186	select HAVE_ARCH_KFENCE
187	select HAVE_ARCH_KGDB
188	select HAVE_ARCH_KSTACK_ERASE
189	select HAVE_ARCH_MMAP_RND_BITS
190	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
191	select HAVE_ARCH_PREL32_RELOCATIONS
192	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
193	select HAVE_ARCH_SECCOMP_FILTER
194	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
195	select HAVE_ARCH_TRACEHOOK
196	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
197	select HAVE_ARCH_VMAP_STACK
198	select HAVE_ARM_SMCCC
199	select HAVE_ASM_MODVERSIONS
200	select HAVE_EBPF_JIT
201	select HAVE_C_RECORDMCOUNT
202	select HAVE_CMPXCHG_DOUBLE
203	select HAVE_CMPXCHG_LOCAL
204	select HAVE_CONTEXT_TRACKING_USER
205	select HAVE_DEBUG_KMEMLEAK
206	select HAVE_DMA_CONTIGUOUS
207	select HAVE_DYNAMIC_FTRACE
208	select HAVE_DYNAMIC_FTRACE_WITH_ARGS \
209		if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \
210		    CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS)
211	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \
212		if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS
213	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \
214		if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \
215		    (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE))
216	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
217		if DYNAMIC_FTRACE_WITH_ARGS
218	select HAVE_SAMPLE_FTRACE_DIRECT
219	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
220	select HAVE_BUILDTIME_MCOUNT_SORT
221	select HAVE_EFFICIENT_UNALIGNED_ACCESS
222	select HAVE_GUP_FAST
223	select HAVE_FTRACE_GRAPH_FUNC
224	select HAVE_FTRACE_MCOUNT_RECORD
225	select HAVE_FUNCTION_TRACER
226	select HAVE_FUNCTION_ERROR_INJECTION
227	select HAVE_FUNCTION_GRAPH_FREGS
228	select HAVE_FUNCTION_GRAPH_TRACER
229	select HAVE_GCC_PLUGINS
230	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
231		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
232	select HAVE_HW_BREAKPOINT if PERF_EVENTS
233	select HAVE_IOREMAP_PROT
234	select HAVE_IRQ_TIME_ACCOUNTING
235	select HAVE_MOD_ARCH_SPECIFIC
236	select HAVE_NMI
237	select HAVE_PERF_EVENTS
238	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
239	select HAVE_PERF_REGS
240	select HAVE_PERF_USER_STACK_DUMP
241	select HAVE_PREEMPT_DYNAMIC_KEY
242	select HAVE_REGS_AND_STACK_ACCESS_API
243	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
244	select HAVE_FUNCTION_ARG_ACCESS_API
245	select MMU_GATHER_RCU_TABLE_FREE
246	select HAVE_RSEQ
247	select HAVE_RUST if RUSTC_SUPPORTS_ARM64
248	select HAVE_STACKPROTECTOR
249	select HAVE_SYSCALL_TRACEPOINTS
250	select HAVE_KPROBES
251	select HAVE_KRETPROBES
252	select HAVE_GENERIC_VDSO
253	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
254	select HOTPLUG_SMT if HOTPLUG_CPU
255	select IRQ_DOMAIN
256	select IRQ_FORCED_THREADING
257	select JUMP_LABEL
258	select KASAN_VMALLOC if KASAN
259	select LOCK_MM_AND_FIND_VMA
260	select MODULES_USE_ELF_RELA
261	select NEED_DMA_MAP_STATE
262	select NEED_SG_DMA_LENGTH
263	select OF
264	select OF_EARLY_FLATTREE
265	select PCI_DOMAINS_GENERIC if PCI
266	select PCI_ECAM if (ACPI && PCI)
267	select PCI_SYSCALL if PCI
268	select POWER_RESET
269	select POWER_SUPPLY
270	select SPARSE_IRQ
271	select SWIOTLB
272	select SYSCTL_EXCEPTION_TRACE
273	select THREAD_INFO_IN_TASK
274	select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD
275	select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD
276	select TRACE_IRQFLAGS_SUPPORT
277	select TRACE_IRQFLAGS_NMI_SUPPORT
278	select HAVE_SOFTIRQ_ON_OWN_STACK
279	select USER_STACKTRACE_SUPPORT
280	select VDSO_GETRANDOM
281	help
282	  ARM 64-bit (AArch64) Linux support.
283
284config RUSTC_SUPPORTS_ARM64
285	def_bool y
286	depends on CPU_LITTLE_ENDIAN
287	# Shadow call stack is only supported on certain rustc versions.
288	#
289	# When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is
290	# required due to use of the -Zfixed-x18 flag.
291	#
292	# Otherwise, rustc version 1.82+ is required due to use of the
293	# -Zsanitizer=shadow-call-stack flag.
294	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS
295
296config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
297	def_bool CC_IS_CLANG
298	# https://github.com/ClangBuiltLinux/linux/issues/1507
299	depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600))
300
301config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
302	def_bool CC_IS_GCC
303	depends on $(cc-option,-fpatchable-function-entry=2)
304
305config 64BIT
306	def_bool y
307
308config MMU
309	def_bool y
310
311config ARM64_CONT_PTE_SHIFT
312	int
313	default 5 if PAGE_SIZE_64KB
314	default 7 if PAGE_SIZE_16KB
315	default 4
316
317config ARM64_CONT_PMD_SHIFT
318	int
319	default 5 if PAGE_SIZE_64KB
320	default 5 if PAGE_SIZE_16KB
321	default 4
322
323config ARCH_MMAP_RND_BITS_MIN
324	default 14 if PAGE_SIZE_64KB
325	default 16 if PAGE_SIZE_16KB
326	default 18
327
328# max bits determined by the following formula:
329#  VA_BITS - PTDESC_TABLE_SHIFT
330config ARCH_MMAP_RND_BITS_MAX
331	default 19 if ARM64_VA_BITS=36
332	default 24 if ARM64_VA_BITS=39
333	default 27 if ARM64_VA_BITS=42
334	default 30 if ARM64_VA_BITS=47
335	default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES
336	default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES
337	default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52)
338	default 14 if ARM64_64K_PAGES
339	default 16 if ARM64_16K_PAGES
340	default 18
341
342config ARCH_MMAP_RND_COMPAT_BITS_MIN
343	default 7 if ARM64_64K_PAGES
344	default 9 if ARM64_16K_PAGES
345	default 11
346
347config ARCH_MMAP_RND_COMPAT_BITS_MAX
348	default 16
349
350config NO_IOPORT_MAP
351	def_bool y if !PCI
352
353config STACKTRACE_SUPPORT
354	def_bool y
355
356config ILLEGAL_POINTER_VALUE
357	hex
358	default 0xdead000000000000
359
360config LOCKDEP_SUPPORT
361	def_bool y
362
363config GENERIC_BUG
364	def_bool y
365	depends on BUG
366
367config GENERIC_BUG_RELATIVE_POINTERS
368	def_bool y
369	depends on GENERIC_BUG
370
371config GENERIC_HWEIGHT
372	def_bool y
373
374config GENERIC_CSUM
375	def_bool y
376
377config GENERIC_CALIBRATE_DELAY
378	def_bool y
379
380config SMP
381	def_bool y
382
383config KERNEL_MODE_NEON
384	def_bool y
385
386config FIX_EARLYCON_MEM
387	def_bool y
388
389config PGTABLE_LEVELS
390	int
391	default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
392	default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
393	default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
394	default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
395	default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
396	default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52)
397	default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
398	default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52
399
400config ARCH_SUPPORTS_UPROBES
401	def_bool y
402
403config ARCH_PROC_KCORE_TEXT
404	def_bool y
405
406config BROKEN_GAS_INST
407	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)
408
409config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
410	bool
411	# Clang's __builtin_return_address() strips the PAC since 12.0.0
412	# https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
413	default y if CC_IS_CLANG
414	# GCC's __builtin_return_address() strips the PAC since 11.1.0,
415	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier
416	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891
417	default y if CC_IS_GCC && (GCC_VERSION >= 110100)
418	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)
419	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)
420	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)
421	default n
422
423config KASAN_SHADOW_OFFSET
424	hex
425	depends on KASAN_GENERIC || KASAN_SW_TAGS
426	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS
427	default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS
428	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
429	default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS
430	default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS
431	default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS
432	default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS
433	default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS
434	default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS
435	default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS
436	default 0xffffffffffffffff
437
438config UNWIND_TABLES
439	bool
440
441source "arch/arm64/Kconfig.platforms"
442
443menu "Kernel Features"
444
445menu "ARM errata workarounds via the alternatives framework"
446
447config AMPERE_ERRATUM_AC03_CPU_38
448        bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics"
449	default y
450	help
451	  This option adds an alternative code sequence to work around Ampere
452	  errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
453
454	  The affected design reports FEAT_HAFDBS as not implemented in
455	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
456	  as required by the architecture. The unadvertised HAFDBS
457	  implementation suffers from an additional erratum where hardware
458	  A/D updates can occur after a PTE has been marked invalid.
459
460	  The workaround forces KVM to explicitly set VTCR_EL2.HA to 0,
461	  which avoids enabling unadvertised hardware Access Flag management
462	  at stage-2.
463
464	  If unsure, say Y.
465
466config AMPERE_ERRATUM_AC04_CPU_23
467        bool "AmpereOne: AC04_CPU_23:  Failure to synchronize writes to HCR_EL2 may corrupt address translations."
468	default y
469	help
470	  This option adds an alternative code sequence to work around Ampere
471	  errata AC04_CPU_23 on AmpereOne.
472
473	  Updates to HCR_EL2 can rarely corrupt simultaneous translations for
474	  data addresses initiated by load/store instructions. Only
475	  instruction initiated translations are vulnerable, not translations
476	  from prefetches for example. A DSB before the store to HCR_EL2 is
477	  sufficient to prevent older instructions from hitting the window
478	  for corruption, and an ISB after is sufficient to prevent younger
479	  instructions from hitting the window for corruption.
480
481	  If unsure, say Y.
482
483config ARM64_WORKAROUND_CLEAN_CACHE
484	bool
485
486config ARM64_ERRATUM_826319
487	bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
488	default y
489	select ARM64_WORKAROUND_CLEAN_CACHE
490	help
491	  This option adds an alternative code sequence to work around ARM
492	  erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
493	  AXI master interface and an L2 cache.
494
495	  If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
496	  and is unable to accept a certain write via this interface, it will
497	  not progress on read data presented on the read data channel and the
498	  system can deadlock.
499
500	  The workaround promotes data cache clean instructions to
501	  data cache clean-and-invalidate.
502	  Please note that this does not necessarily enable the workaround,
503	  as it depends on the alternative framework, which will only patch
504	  the kernel if an affected CPU is detected.
505
506	  If unsure, say Y.
507
508config ARM64_ERRATUM_827319
509	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
510	default y
511	select ARM64_WORKAROUND_CLEAN_CACHE
512	help
513	  This option adds an alternative code sequence to work around ARM
514	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
515	  master interface and an L2 cache.
516
517	  Under certain conditions this erratum can cause a clean line eviction
518	  to occur at the same time as another transaction to the same address
519	  on the AMBA 5 CHI interface, which can cause data corruption if the
520	  interconnect reorders the two transactions.
521
522	  The workaround promotes data cache clean instructions to
523	  data cache clean-and-invalidate.
524	  Please note that this does not necessarily enable the workaround,
525	  as it depends on the alternative framework, which will only patch
526	  the kernel if an affected CPU is detected.
527
528	  If unsure, say Y.
529
530config ARM64_ERRATUM_824069
531	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
532	default y
533	select ARM64_WORKAROUND_CLEAN_CACHE
534	help
535	  This option adds an alternative code sequence to work around ARM
536	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
537	  to a coherent interconnect.
538
539	  If a Cortex-A53 processor is executing a store or prefetch for
540	  write instruction at the same time as a processor in another
541	  cluster is executing a cache maintenance operation to the same
542	  address, then this erratum might cause a clean cache line to be
543	  incorrectly marked as dirty.
544
545	  The workaround promotes data cache clean instructions to
546	  data cache clean-and-invalidate.
547	  Please note that this option does not necessarily enable the
548	  workaround, as it depends on the alternative framework, which will
549	  only patch the kernel if an affected CPU is detected.
550
551	  If unsure, say Y.
552
553config ARM64_ERRATUM_819472
554	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
555	default y
556	select ARM64_WORKAROUND_CLEAN_CACHE
557	help
558	  This option adds an alternative code sequence to work around ARM
559	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
560	  present when it is connected to a coherent interconnect.
561
562	  If the processor is executing a load and store exclusive sequence at
563	  the same time as a processor in another cluster is executing a cache
564	  maintenance operation to the same address, then this erratum might
565	  cause data corruption.
566
567	  The workaround promotes data cache clean instructions to
568	  data cache clean-and-invalidate.
569	  Please note that this does not necessarily enable the workaround,
570	  as it depends on the alternative framework, which will only patch
571	  the kernel if an affected CPU is detected.
572
573	  If unsure, say Y.
574
575config ARM64_ERRATUM_832075
576	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
577	default y
578	help
579	  This option adds an alternative code sequence to work around ARM
580	  erratum 832075 on Cortex-A57 parts up to r1p2.
581
582	  Affected Cortex-A57 parts might deadlock when exclusive load/store
583	  instructions to Write-Back memory are mixed with Device loads.
584
585	  The workaround is to promote device loads to use Load-Acquire
586	  semantics.
587	  Please note that this does not necessarily enable the workaround,
588	  as it depends on the alternative framework, which will only patch
589	  the kernel if an affected CPU is detected.
590
591	  If unsure, say Y.
592
593config ARM64_ERRATUM_834220
594	bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)"
595	depends on KVM
596	help
597	  This option adds an alternative code sequence to work around ARM
598	  erratum 834220 on Cortex-A57 parts up to r1p2.
599
600	  Affected Cortex-A57 parts might report a Stage 2 translation
601	  fault as the result of a Stage 1 fault for load crossing a
602	  page boundary when there is a permission or device memory
603	  alignment fault at Stage 1 and a translation fault at Stage 2.
604
605	  The workaround is to verify that the Stage 1 translation
606	  doesn't generate a fault before handling the Stage 2 fault.
607	  Please note that this does not necessarily enable the workaround,
608	  as it depends on the alternative framework, which will only patch
609	  the kernel if an affected CPU is detected.
610
611	  If unsure, say N.
612
613config ARM64_ERRATUM_1742098
614	bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence"
615	depends on COMPAT
616	default y
617	help
618	  This option removes the AES hwcap for aarch32 user-space to
619	  workaround erratum 1742098 on Cortex-A57 and Cortex-A72.
620
621	  Affected parts may corrupt the AES state if an interrupt is
622	  taken between a pair of AES instructions. These instructions
623	  are only present if the cryptography extensions are present.
624	  All software should have a fallback implementation for CPUs
625	  that don't implement the cryptography extensions.
626
627	  If unsure, say Y.
628
629config ARM64_ERRATUM_845719
630	bool "Cortex-A53: 845719: a load might read incorrect data"
631	depends on COMPAT
632	default y
633	help
634	  This option adds an alternative code sequence to work around ARM
635	  erratum 845719 on Cortex-A53 parts up to r0p4.
636
637	  When running a compat (AArch32) userspace on an affected Cortex-A53
638	  part, a load at EL0 from a virtual address that matches the bottom 32
639	  bits of the virtual address used by a recent load at (AArch64) EL1
640	  might return incorrect data.
641
642	  The workaround is to write the contextidr_el1 register on exception
643	  return to a 32-bit task.
644	  Please note that this does not necessarily enable the workaround,
645	  as it depends on the alternative framework, which will only patch
646	  the kernel if an affected CPU is detected.
647
648	  If unsure, say Y.
649
650config ARM64_ERRATUM_843419
651	bool "Cortex-A53: 843419: A load or store might access an incorrect address"
652	default y
653	help
654	  This option links the kernel with '--fix-cortex-a53-843419' and
655	  enables PLT support to replace certain ADRP instructions, which can
656	  cause subsequent memory accesses to use an incorrect address on
657	  Cortex-A53 parts up to r0p4.
658
659	  If unsure, say Y.
660
661config ARM64_ERRATUM_1024718
662	bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
663	default y
664	help
665	  This option adds a workaround for ARM Cortex-A55 Erratum 1024718.
666
667	  Affected Cortex-A55 cores (all revisions) could cause incorrect
668	  update of the hardware dirty bit when the DBM/AP bits are updated
669	  without a break-before-make. The workaround is to disable the usage
670	  of hardware DBM locally on the affected cores. CPUs not affected by
671	  this erratum will continue to use the feature.
672
673	  If unsure, say Y.
674
675config ARM64_ERRATUM_1418040
676	bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result"
677	default y
678	depends on COMPAT
679	help
680	  This option adds a workaround for ARM Cortex-A76/Neoverse-N1
681	  errata 1188873 and 1418040.
682
683	  Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could
684	  cause register corruption when accessing the timer registers
685	  from AArch32 userspace.
686
687	  If unsure, say Y.
688
689config ARM64_WORKAROUND_SPECULATIVE_AT
690	bool
691
692config ARM64_ERRATUM_1165522
693	bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
694	default y
695	select ARM64_WORKAROUND_SPECULATIVE_AT
696	help
697	  This option adds a workaround for ARM Cortex-A76 erratum 1165522.
698
699	  Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with
700	  corrupted TLBs by speculating an AT instruction during a guest
701	  context switch.
702
703	  If unsure, say Y.
704
705config ARM64_ERRATUM_1319367
706	bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
707	default y
708	select ARM64_WORKAROUND_SPECULATIVE_AT
709	help
710	  This option adds work arounds for ARM Cortex-A57 erratum 1319537
711	  and A72 erratum 1319367
712
713	  Cortex-A57 and A72 cores could end-up with corrupted TLBs by
714	  speculating an AT instruction during a guest context switch.
715
716	  If unsure, say Y.
717
718config ARM64_ERRATUM_1530923
719	bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation"
720	default y
721	select ARM64_WORKAROUND_SPECULATIVE_AT
722	help
723	  This option adds a workaround for ARM Cortex-A55 erratum 1530923.
724
725	  Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with
726	  corrupted TLBs by speculating an AT instruction during a guest
727	  context switch.
728
729	  If unsure, say Y.
730
731config ARM64_WORKAROUND_REPEAT_TLBI
732	bool
733
734config ARM64_ERRATUM_2441007
735	bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
736	select ARM64_WORKAROUND_REPEAT_TLBI
737	help
738	  This option adds a workaround for ARM Cortex-A55 erratum #2441007.
739
740	  Under very rare circumstances, affected Cortex-A55 CPUs
741	  may not handle a race between a break-before-make sequence on one
742	  CPU, and another CPU accessing the same page. This could allow a
743	  store to a page that has been unmapped.
744
745	  Work around this by adding the affected CPUs to the list that needs
746	  TLB sequences to be done twice.
747
748	  If unsure, say N.
749
750config ARM64_ERRATUM_1286807
751	bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)"
752	select ARM64_WORKAROUND_REPEAT_TLBI
753	help
754	  This option adds a workaround for ARM Cortex-A76 erratum 1286807.
755
756	  On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
757	  address for a cacheable mapping of a location is being
758	  accessed by a core while another core is remapping the virtual
759	  address to a new physical page using the recommended
760	  break-before-make sequence, then under very rare circumstances
761	  TLBI+DSB completes before a read using the translation being
762	  invalidated has been observed by other observers. The
763	  workaround repeats the TLBI+DSB operation.
764
765	  If unsure, say N.
766
767config ARM64_ERRATUM_1463225
768	bool "Cortex-A76: Software Step might prevent interrupt recognition"
769	default y
770	help
771	  This option adds a workaround for Arm Cortex-A76 erratum 1463225.
772
773	  On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping
774	  of a system call instruction (SVC) can prevent recognition of
775	  subsequent interrupts when software stepping is disabled in the
776	  exception handler of the system call and either kernel debugging
777	  is enabled or VHE is in use.
778
779	  Work around the erratum by triggering a dummy step exception
780	  when handling a system call from a task that is being stepped
781	  in a VHE configuration of the kernel.
782
783	  If unsure, say Y.
784
785config ARM64_ERRATUM_1542419
786	bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)"
787	help
788	  This option adds a workaround for ARM Neoverse-N1 erratum
789	  1542419.
790
791	  Affected Neoverse-N1 cores could execute a stale instruction when
792	  modified by another CPU. The workaround depends on a firmware
793	  counterpart.
794
795	  Workaround the issue by hiding the DIC feature from EL0. This
796	  forces user-space to perform cache maintenance.
797
798	  If unsure, say N.
799
800config ARM64_ERRATUM_1508412
801	bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read"
802	default y
803	help
804	  This option adds a workaround for Arm Cortex-A77 erratum 1508412.
805
806	  Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence
807	  of a store-exclusive or read of PAR_EL1 and a load with device or
808	  non-cacheable memory attributes. The workaround depends on a firmware
809	  counterpart.
810
811	  KVM guests must also have the workaround implemented or they can
812	  deadlock the system.
813
814	  Work around the issue by inserting DMB SY barriers around PAR_EL1
815	  register reads and warning KVM users. The DMB barrier is sufficient
816	  to prevent a speculative PAR_EL1 read.
817
818	  If unsure, say Y.
819
820config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
821	bool
822
823config ARM64_ERRATUM_2051678
824	bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit"
825	default y
826	help
827	  This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678.
828	  Affected Cortex-A510 might not respect the ordering rules for
829	  hardware update of the page table's dirty bit. The workaround
830	  is to not enable the feature on affected CPUs.
831
832	  If unsure, say Y.
833
834config ARM64_ERRATUM_2077057
835	bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2"
836	default y
837	help
838	  This option adds the workaround for ARM Cortex-A510 erratum 2077057.
839	  Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is
840	  expected, but a Pointer Authentication trap is taken instead. The
841	  erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
842	  EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
843
844	  This can only happen when EL2 is stepping EL1.
845
846	  When these conditions occur, the SPSR_EL2 value is unchanged from the
847	  previous guest entry, and can be restored from the in-memory copy.
848
849	  If unsure, say Y.
850
851config ARM64_ERRATUM_2658417
852	bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result"
853	default y
854	help
855	  This option adds the workaround for ARM Cortex-A510 erratum 2658417.
856	  Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for
857	  BFMMLA or VMMLA instructions in rare circumstances when a pair of
858	  A510 CPUs are using shared neon hardware. As the sharing is not
859	  discoverable by the kernel, hide the BF16 HWCAP to indicate that
860	  user-space should not be using these instructions.
861
862	  If unsure, say Y.
863
864config ARM64_ERRATUM_2119858
865	bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode"
866	default y
867	depends on CORESIGHT_TRBE
868	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
869	help
870	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858.
871
872	  Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace
873	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
874	  the event of a WRAP event.
875
876	  Work around the issue by always making sure we move the TRBPTR_EL1 by
877	  256 bytes before enabling the buffer and filling the first 256 bytes of
878	  the buffer with ETM ignore packets upon disabling.
879
880	  If unsure, say Y.
881
882config ARM64_ERRATUM_2139208
883	bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode"
884	default y
885	depends on CORESIGHT_TRBE
886	select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
887	help
888	  This option adds the workaround for ARM Neoverse-N2 erratum 2139208.
889
890	  Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace
891	  data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in
892	  the event of a WRAP event.
893
894	  Work around the issue by always making sure we move the TRBPTR_EL1 by
895	  256 bytes before enabling the buffer and filling the first 256 bytes of
896	  the buffer with ETM ignore packets upon disabling.
897
898	  If unsure, say Y.
899
900config ARM64_WORKAROUND_TSB_FLUSH_FAILURE
901	bool
902
903config ARM64_ERRATUM_2054223
904	bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace"
905	default y
906	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
907	help
908	  Enable workaround for ARM Cortex-A710 erratum 2054223
909
910	  Affected cores may fail to flush the trace data on a TSB instruction, when
911	  the PE is in trace prohibited state. This will cause losing a few bytes
912	  of the trace cached.
913
914	  Workaround is to issue two TSB consecutively on affected cores.
915
916	  If unsure, say Y.
917
918config ARM64_ERRATUM_2067961
919	bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace"
920	default y
921	select ARM64_WORKAROUND_TSB_FLUSH_FAILURE
922	help
923	  Enable workaround for ARM Neoverse-N2 erratum 2067961
924
925	  Affected cores may fail to flush the trace data on a TSB instruction, when
926	  the PE is in trace prohibited state. This will cause losing a few bytes
927	  of the trace cached.
928
929	  Workaround is to issue two TSB consecutively on affected cores.
930
931	  If unsure, say Y.
932
933config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
934	bool
935
936config ARM64_ERRATUM_2253138
937	bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range"
938	depends on CORESIGHT_TRBE
939	default y
940	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
941	help
942	  This option adds the workaround for ARM Neoverse-N2 erratum 2253138.
943
944	  Affected Neoverse-N2 cores might write to an out-of-range address, not reserved
945	  for TRBE. Under some conditions, the TRBE might generate a write to the next
946	  virtually addressed page following the last page of the TRBE address space
947	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
948
949	  Work around this in the driver by always making sure that there is a
950	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
951
952	  If unsure, say Y.
953
954config ARM64_ERRATUM_2224489
955	bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range"
956	depends on CORESIGHT_TRBE
957	default y
958	select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
959	help
960	  This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489.
961
962	  Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved
963	  for TRBE. Under some conditions, the TRBE might generate a write to the next
964	  virtually addressed page following the last page of the TRBE address space
965	  (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base.
966
967	  Work around this in the driver by always making sure that there is a
968	  page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE.
969
970	  If unsure, say Y.
971
972config ARM64_ERRATUM_2441009
973	bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)"
974	select ARM64_WORKAROUND_REPEAT_TLBI
975	help
976	  This option adds a workaround for ARM Cortex-A510 erratum #2441009.
977
978	  Under very rare circumstances, affected Cortex-A510 CPUs
979	  may not handle a race between a break-before-make sequence on one
980	  CPU, and another CPU accessing the same page. This could allow a
981	  store to a page that has been unmapped.
982
983	  Work around this by adding the affected CPUs to the list that needs
984	  TLB sequences to be done twice.
985
986	  If unsure, say N.
987
988config ARM64_ERRATUM_2064142
989	bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled"
990	depends on CORESIGHT_TRBE
991	default y
992	help
993	  This option adds the workaround for ARM Cortex-A510 erratum 2064142.
994
995	  Affected Cortex-A510 core might fail to write into system registers after the
996	  TRBE has been disabled. Under some conditions after the TRBE has been disabled
997	  writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1,
998	  and TRBTRG_EL1 will be ignored and will not be effected.
999
1000	  Work around this in the driver by executing TSB CSYNC and DSB after collection
1001	  is stopped and before performing a system register write to one of the affected
1002	  registers.
1003
1004	  If unsure, say Y.
1005
1006config ARM64_ERRATUM_2038923
1007	bool "Cortex-A510: 2038923: workaround TRBE corruption with enable"
1008	depends on CORESIGHT_TRBE
1009	default y
1010	help
1011	  This option adds the workaround for ARM Cortex-A510 erratum 2038923.
1012
1013	  Affected Cortex-A510 core might cause an inconsistent view on whether trace is
1014	  prohibited within the CPU. As a result, the trace buffer or trace buffer state
1015	  might be corrupted. This happens after TRBE buffer has been enabled by setting
1016	  TRBLIMITR_EL1.E, followed by just a single context synchronization event before
1017	  execution changes from a context, in which trace is prohibited to one where it
1018	  isn't, or vice versa. In these mentioned conditions, the view of whether trace
1019	  is prohibited is inconsistent between parts of the CPU, and the trace buffer or
1020	  the trace buffer state might be corrupted.
1021
1022	  Work around this in the driver by preventing an inconsistent view of whether the
1023	  trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a
1024	  change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or
1025	  two ISB instructions if no ERET is to take place.
1026
1027	  If unsure, say Y.
1028
1029config ARM64_ERRATUM_1902691
1030	bool "Cortex-A510: 1902691: workaround TRBE trace corruption"
1031	depends on CORESIGHT_TRBE
1032	default y
1033	help
1034	  This option adds the workaround for ARM Cortex-A510 erratum 1902691.
1035
1036	  Affected Cortex-A510 core might cause trace data corruption, when being written
1037	  into the memory. Effectively TRBE is broken and hence cannot be used to capture
1038	  trace data.
1039
1040	  Work around this problem in the driver by just preventing TRBE initialization on
1041	  affected cpus. The firmware must have disabled the access to TRBE for the kernel
1042	  on such implementations. This will cover the kernel for any firmware that doesn't
1043	  do this already.
1044
1045	  If unsure, say Y.
1046
1047config ARM64_ERRATUM_2457168
1048	bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly"
1049	depends on ARM64_AMU_EXTN
1050	default y
1051	help
1052	  This option adds the workaround for ARM Cortex-A510 erratum 2457168.
1053
1054	  The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate
1055	  as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments
1056	  incorrectly giving a significantly higher output value.
1057
1058	  Work around this problem by returning 0 when reading the affected counter in
1059	  key locations that results in disabling all users of this counter. This effect
1060	  is the same to firmware disabling affected counters.
1061
1062	  If unsure, say Y.
1063
1064config ARM64_ERRATUM_2645198
1065	bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption"
1066	default y
1067	help
1068	  This option adds the workaround for ARM Cortex-A715 erratum 2645198.
1069
1070	  If a Cortex-A715 cpu sees a page mapping permissions change from executable
1071	  to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
1072	  next instruction abort caused by permission fault.
1073
1074	  Only user-space does executable to non-executable permission transition via
1075	  mprotect() system call. Workaround the problem by doing a break-before-make
1076	  TLB invalidation, for all changes to executable user space mappings.
1077
1078	  If unsure, say Y.
1079
1080config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1081	bool
1082
1083config ARM64_ERRATUM_2966298
1084	bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load"
1085	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1086	default y
1087	help
1088	  This option adds the workaround for ARM Cortex-A520 erratum 2966298.
1089
1090	  On an affected Cortex-A520 core, a speculatively executed unprivileged
1091	  load might leak data from a privileged level via a cache side channel.
1092
1093	  Work around this problem by executing a TLBI before returning to EL0.
1094
1095	  If unsure, say Y.
1096
1097config ARM64_ERRATUM_3117295
1098	bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load"
1099	select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
1100	default y
1101	help
1102	  This option adds the workaround for ARM Cortex-A510 erratum 3117295.
1103
1104	  On an affected Cortex-A510 core, a speculatively executed unprivileged
1105	  load might leak data from a privileged level via a cache side channel.
1106
1107	  Work around this problem by executing a TLBI before returning to EL0.
1108
1109	  If unsure, say Y.
1110
1111config ARM64_ERRATUM_3194386
1112	bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
1113	default y
1114	help
1115	  This option adds the workaround for the following errata:
1116
1117	  * ARM Cortex-A76 erratum 3324349
1118	  * ARM Cortex-A77 erratum 3324348
1119	  * ARM Cortex-A78 erratum 3324344
1120	  * ARM Cortex-A78C erratum 3324346
1121	  * ARM Cortex-A78C erratum 3324347
1122	  * ARM Cortex-A710 erratam 3324338
1123	  * ARM Cortex-A715 errartum 3456084
1124	  * ARM Cortex-A720 erratum 3456091
1125	  * ARM Cortex-A725 erratum 3456106
1126	  * ARM Cortex-X1 erratum 3324344
1127	  * ARM Cortex-X1C erratum 3324346
1128	  * ARM Cortex-X2 erratum 3324338
1129	  * ARM Cortex-X3 erratum 3324335
1130	  * ARM Cortex-X4 erratum 3194386
1131	  * ARM Cortex-X925 erratum 3324334
1132	  * ARM Neoverse-N1 erratum 3324349
1133	  * ARM Neoverse N2 erratum 3324339
1134	  * ARM Neoverse-N3 erratum 3456111
1135	  * ARM Neoverse-V1 erratum 3324341
1136	  * ARM Neoverse V2 erratum 3324336
1137	  * ARM Neoverse-V3 erratum 3312417
1138
1139	  On affected cores "MSR SSBS, #0" instructions may not affect
1140	  subsequent speculative instructions, which may permit unexepected
1141	  speculative store bypassing.
1142
1143	  Work around this problem by placing a Speculation Barrier (SB) or
1144	  Instruction Synchronization Barrier (ISB) after kernel changes to
1145	  SSBS. The presence of the SSBS special-purpose register is hidden
1146	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
1147	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
1148
1149	  If unsure, say Y.
1150
1151config CAVIUM_ERRATUM_22375
1152	bool "Cavium erratum 22375, 24313"
1153	default y
1154	help
1155	  Enable workaround for errata 22375 and 24313.
1156
1157	  This implements two gicv3-its errata workarounds for ThunderX. Both
1158	  with a small impact affecting only ITS table allocation.
1159
1160	    erratum 22375: only alloc 8MB table size
1161	    erratum 24313: ignore memory access type
1162
1163	  The fixes are in ITS initialization and basically ignore memory access
1164	  type and table size provided by the TYPER and BASER registers.
1165
1166	  If unsure, say Y.
1167
1168config CAVIUM_ERRATUM_23144
1169	bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
1170	depends on NUMA
1171	default y
1172	help
1173	  ITS SYNC command hang for cross node io and collections/cpu mapping.
1174
1175	  If unsure, say Y.
1176
1177config CAVIUM_ERRATUM_23154
1178	bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation"
1179	default y
1180	help
1181	  The ThunderX GICv3 implementation requires a modified version for
1182	  reading the IAR status to ensure data synchronization
1183	  (access to icc_iar1_el1 is not sync'ed before and after).
1184
1185	  It also suffers from erratum 38545 (also present on Marvell's
1186	  OcteonTX and OcteonTX2), resulting in deactivated interrupts being
1187	  spuriously presented to the CPU interface.
1188
1189	  If unsure, say Y.
1190
1191config CAVIUM_ERRATUM_27456
1192	bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
1193	default y
1194	help
1195	  On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
1196	  instructions may cause the icache to become corrupted if it
1197	  contains data for a non-current ASID.  The fix is to
1198	  invalidate the icache when changing the mm context.
1199
1200	  If unsure, say Y.
1201
1202config CAVIUM_ERRATUM_30115
1203	bool "Cavium erratum 30115: Guest may disable interrupts in host"
1204	default y
1205	help
1206	  On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
1207	  1.2, and T83 Pass 1.0, KVM guest execution may disable
1208	  interrupts in host. Trapping both GICv3 group-0 and group-1
1209	  accesses sidesteps the issue.
1210
1211	  If unsure, say Y.
1212
1213config CAVIUM_TX2_ERRATUM_219
1214	bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails"
1215	default y
1216	help
1217	  On Cavium ThunderX2, a load, store or prefetch instruction between a
1218	  TTBR update and the corresponding context synchronizing operation can
1219	  cause a spurious Data Abort to be delivered to any hardware thread in
1220	  the CPU core.
1221
1222	  Work around the issue by avoiding the problematic code sequence and
1223	  trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The
1224	  trap handler performs the corresponding register access, skips the
1225	  instruction and ensures context synchronization by virtue of the
1226	  exception return.
1227
1228	  If unsure, say Y.
1229
1230config FUJITSU_ERRATUM_010001
1231	bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly"
1232	default y
1233	help
1234	  This option adds a workaround for Fujitsu-A64FX erratum E#010001.
1235	  On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory
1236	  accesses may cause undefined fault (Data abort, DFSC=0b111111).
1237	  This fault occurs under a specific hardware condition when a
1238	  load/store instruction performs an address translation using:
1239	  case-1  TTBR0_EL1 with TCR_EL1.NFD0 == 1.
1240	  case-2  TTBR0_EL2 with TCR_EL2.NFD0 == 1.
1241	  case-3  TTBR1_EL1 with TCR_EL1.NFD1 == 1.
1242	  case-4  TTBR1_EL2 with TCR_EL2.NFD1 == 1.
1243
1244	  The workaround is to ensure these bits are clear in TCR_ELx.
1245	  The workaround only affects the Fujitsu-A64FX.
1246
1247	  If unsure, say Y.
1248
1249config HISILICON_ERRATUM_161600802
1250	bool "Hip07 161600802: Erroneous redistributor VLPI base"
1251	default y
1252	help
1253	  The HiSilicon Hip07 SoC uses the wrong redistributor base
1254	  when issued ITS commands such as VMOVP and VMAPP, and requires
1255	  a 128kB offset to be applied to the target address in this commands.
1256
1257	  If unsure, say Y.
1258
1259config HISILICON_ERRATUM_162100801
1260	bool "Hip09 162100801 erratum support"
1261	default y
1262	help
1263	  When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches
1264	  during unmapping operation, which will cause some vSGIs lost.
1265	  To fix the issue, invalidate related vPE cache through GICR_INVALLR
1266	  after VMOVP.
1267
1268	  If unsure, say Y.
1269
1270config QCOM_FALKOR_ERRATUM_1003
1271	bool "Falkor E1003: Incorrect translation due to ASID change"
1272	default y
1273	help
1274	  On Falkor v1, an incorrect ASID may be cached in the TLB when ASID
1275	  and BADDR are changed together in TTBRx_EL1. Since we keep the ASID
1276	  in TTBR1_EL1, this situation only occurs in the entry trampoline and
1277	  then only for entries in the walk cache, since the leaf translation
1278	  is unchanged. Work around the erratum by invalidating the walk cache
1279	  entries for the trampoline before entering the kernel proper.
1280
1281config QCOM_FALKOR_ERRATUM_1009
1282	bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
1283	default y
1284	select ARM64_WORKAROUND_REPEAT_TLBI
1285	help
1286	  On Falkor v1, the CPU may prematurely complete a DSB following a
1287	  TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
1288	  one more time to fix the issue.
1289
1290	  If unsure, say Y.
1291
1292config QCOM_QDF2400_ERRATUM_0065
1293	bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
1294	default y
1295	help
1296	  On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
1297	  ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
1298	  been indicated as 16Bytes (0xf), not 8Bytes (0x7).
1299
1300	  If unsure, say Y.
1301
1302config QCOM_FALKOR_ERRATUM_E1041
1303	bool "Falkor E1041: Speculative instruction fetches might cause errant memory access"
1304	default y
1305	help
1306	  Falkor CPU may speculatively fetch instructions from an improper
1307	  memory location when MMU translation is changed from SCTLR_ELn[M]=1
1308	  to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem.
1309
1310	  If unsure, say Y.
1311
1312config NVIDIA_CARMEL_CNP_ERRATUM
1313	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
1314	default y
1315	help
1316	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
1317	  invalidate shared TLB entries installed by a different core, as it would
1318	  on standard ARM cores.
1319
1320	  If unsure, say Y.
1321
1322config ROCKCHIP_ERRATUM_3568002
1323	bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB"
1324	default y
1325	help
1326	  The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI
1327	  addressing limited to the first 32bit of physical address space.
1328
1329	  If unsure, say Y.
1330
1331config ROCKCHIP_ERRATUM_3588001
1332	bool "Rockchip 3588001: GIC600 can not support shareability attributes"
1333	default y
1334	help
1335	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite.
1336	  This means, that its sharability feature may not be used, even though it
1337	  is supported by the IP itself.
1338
1339	  If unsure, say Y.
1340
1341config SOCIONEXT_SYNQUACER_PREITS
1342	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
1343	default y
1344	help
1345	  Socionext Synquacer SoCs implement a separate h/w block to generate
1346	  MSI doorbell writes with non-zero values for the device ID.
1347
1348	  If unsure, say Y.
1349
1350endmenu # "ARM errata workarounds via the alternatives framework"
1351
1352choice
1353	prompt "Page size"
1354	default ARM64_4K_PAGES
1355	help
1356	  Page size (translation granule) configuration.
1357
1358config ARM64_4K_PAGES
1359	bool "4KB"
1360	select HAVE_PAGE_SIZE_4KB
1361	help
1362	  This feature enables 4KB pages support.
1363
1364config ARM64_16K_PAGES
1365	bool "16KB"
1366	select HAVE_PAGE_SIZE_16KB
1367	help
1368	  The system will use 16KB pages support. AArch32 emulation
1369	  requires applications compiled with 16K (or a multiple of 16K)
1370	  aligned segments.
1371
1372config ARM64_64K_PAGES
1373	bool "64KB"
1374	select HAVE_PAGE_SIZE_64KB
1375	help
1376	  This feature enables 64KB pages support (4KB by default)
1377	  allowing only two levels of page tables and faster TLB
1378	  look-up. AArch32 emulation requires applications compiled
1379	  with 64K aligned segments.
1380
1381endchoice
1382
1383choice
1384	prompt "Virtual address space size"
1385	default ARM64_VA_BITS_52
1386	help
1387	  Allows choosing one of multiple possible virtual address
1388	  space sizes. The level of translation table is determined by
1389	  a combination of page size and virtual address space size.
1390
1391config ARM64_VA_BITS_36
1392	bool "36-bit" if EXPERT
1393	depends on PAGE_SIZE_16KB
1394
1395config ARM64_VA_BITS_39
1396	bool "39-bit"
1397	depends on PAGE_SIZE_4KB
1398
1399config ARM64_VA_BITS_42
1400	bool "42-bit"
1401	depends on PAGE_SIZE_64KB
1402
1403config ARM64_VA_BITS_47
1404	bool "47-bit"
1405	depends on PAGE_SIZE_16KB
1406
1407config ARM64_VA_BITS_48
1408	bool "48-bit"
1409
1410config ARM64_VA_BITS_52
1411	bool "52-bit"
1412	help
1413	  Enable 52-bit virtual addressing for userspace when explicitly
1414	  requested via a hint to mmap(). The kernel will also use 52-bit
1415	  virtual addresses for its own mappings (provided HW support for
1416	  this feature is available, otherwise it reverts to 48-bit).
1417
1418	  NOTE: Enabling 52-bit virtual addressing in conjunction with
1419	  ARMv8.3 Pointer Authentication will result in the PAC being
1420	  reduced from 7 bits to 3 bits, which may have a significant
1421	  impact on its susceptibility to brute-force attacks.
1422
1423	  If unsure, select 48-bit virtual addressing instead.
1424
1425endchoice
1426
1427config ARM64_FORCE_52BIT
1428	bool "Force 52-bit virtual addresses for userspace"
1429	depends on ARM64_VA_BITS_52 && EXPERT
1430	help
1431	  For systems with 52-bit userspace VAs enabled, the kernel will attempt
1432	  to maintain compatibility with older software by providing 48-bit VAs
1433	  unless a hint is supplied to mmap.
1434
1435	  This configuration option disables the 48-bit compatibility logic, and
1436	  forces all userspace addresses to be 52-bit on HW that supports it. One
1437	  should only enable this configuration option for stress testing userspace
1438	  memory management code. If unsure say N here.
1439
1440config ARM64_VA_BITS
1441	int
1442	default 36 if ARM64_VA_BITS_36
1443	default 39 if ARM64_VA_BITS_39
1444	default 42 if ARM64_VA_BITS_42
1445	default 47 if ARM64_VA_BITS_47
1446	default 48 if ARM64_VA_BITS_48
1447	default 52 if ARM64_VA_BITS_52
1448
1449choice
1450	prompt "Physical address space size"
1451	default ARM64_PA_BITS_48
1452	help
1453	  Choose the maximum physical address range that the kernel will
1454	  support.
1455
1456config ARM64_PA_BITS_48
1457	bool "48-bit"
1458	depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52
1459
1460config ARM64_PA_BITS_52
1461	bool "52-bit"
1462	depends on ARM64_64K_PAGES || ARM64_VA_BITS_52
1463	help
1464	  Enable support for a 52-bit physical address space, introduced as
1465	  part of the ARMv8.2-LPA extension.
1466
1467	  With this enabled, the kernel will also continue to work on CPUs that
1468	  do not support ARMv8.2-LPA, but with some added memory overhead (and
1469	  minor performance overhead).
1470
1471endchoice
1472
1473config ARM64_PA_BITS
1474	int
1475	default 48 if ARM64_PA_BITS_48
1476	default 52 if ARM64_PA_BITS_52
1477
1478config ARM64_LPA2
1479	def_bool y
1480	depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES
1481
1482choice
1483	prompt "Endianness"
1484	default CPU_LITTLE_ENDIAN
1485	help
1486	  Select the endianness of data accesses performed by the CPU. Userspace
1487	  applications will need to be compiled and linked for the endianness
1488	  that is selected here.
1489
1490config CPU_BIG_ENDIAN
1491	bool "Build big-endian kernel"
1492	# https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c
1493	depends on AS_IS_GNU || AS_VERSION >= 150000
1494	help
1495	  Say Y if you plan on running a kernel with a big-endian userspace.
1496
1497config CPU_LITTLE_ENDIAN
1498	bool "Build little-endian kernel"
1499	help
1500	  Say Y if you plan on running a kernel with a little-endian userspace.
1501	  This is usually the case for distributions targeting arm64.
1502
1503endchoice
1504
1505config SCHED_MC
1506	bool "Multi-core scheduler support"
1507	help
1508	  Multi-core scheduler support improves the CPU scheduler's decision
1509	  making when dealing with multi-core CPU chips at a cost of slightly
1510	  increased overhead in some places. If unsure say N here.
1511
1512config SCHED_CLUSTER
1513	bool "Cluster scheduler support"
1514	help
1515	  Cluster scheduler support improves the CPU scheduler's decision
1516	  making when dealing with machines that have clusters of CPUs.
1517	  Cluster usually means a couple of CPUs which are placed closely
1518	  by sharing mid-level caches, last-level cache tags or internal
1519	  busses.
1520
1521config SCHED_SMT
1522	bool "SMT scheduler support"
1523	help
1524	  Improves the CPU scheduler's decision making when dealing with
1525	  MultiThreading at a cost of slightly increased overhead in some
1526	  places. If unsure say N here.
1527
1528config NR_CPUS
1529	int "Maximum number of CPUs (2-4096)"
1530	range 2 4096
1531	default "512"
1532
1533config HOTPLUG_CPU
1534	bool "Support for hot-pluggable CPUs"
1535	select GENERIC_IRQ_MIGRATION
1536	help
1537	  Say Y here to experiment with turning CPUs off and on.  CPUs
1538	  can be controlled through /sys/devices/system/cpu.
1539
1540# Common NUMA Features
1541config NUMA
1542	bool "NUMA Memory Allocation and Scheduler Support"
1543	select GENERIC_ARCH_NUMA
1544	select OF_NUMA
1545	select HAVE_SETUP_PER_CPU_AREA
1546	select NEED_PER_CPU_EMBED_FIRST_CHUNK
1547	select NEED_PER_CPU_PAGE_FIRST_CHUNK
1548	select USE_PERCPU_NUMA_NODE_ID
1549	help
1550	  Enable NUMA (Non-Uniform Memory Access) support.
1551
1552	  The kernel will try to allocate memory used by a CPU on the
1553	  local memory of the CPU and add some more
1554	  NUMA awareness to the kernel.
1555
1556config NODES_SHIFT
1557	int "Maximum NUMA Nodes (as a power of 2)"
1558	range 1 10
1559	default "4"
1560	depends on NUMA
1561	help
1562	  Specify the maximum number of NUMA Nodes available on the target
1563	  system.  Increases memory reserved to accommodate various tables.
1564
1565source "kernel/Kconfig.hz"
1566
1567config ARCH_SPARSEMEM_ENABLE
1568	def_bool y
1569	select SPARSEMEM_VMEMMAP_ENABLE
1570	select SPARSEMEM_VMEMMAP
1571
1572config HW_PERF_EVENTS
1573	def_bool y
1574	depends on ARM_PMU
1575
1576# Supported by clang >= 7.0 or GCC >= 12.0.0
1577config CC_HAVE_SHADOW_CALL_STACK
1578	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
1579
1580config PARAVIRT
1581	bool "Enable paravirtualization code"
1582	help
1583	  This changes the kernel so it can modify itself when it is run
1584	  under a hypervisor, potentially improving performance significantly
1585	  over full virtualization.
1586
1587config PARAVIRT_TIME_ACCOUNTING
1588	bool "Paravirtual steal time accounting"
1589	select PARAVIRT
1590	help
1591	  Select this option to enable fine granularity task steal time
1592	  accounting. Time spent executing other tasks in parallel with
1593	  the current vCPU is discounted from the vCPU power. To account for
1594	  that, there can be a small performance impact.
1595
1596	  If in doubt, say N here.
1597
1598config ARCH_SUPPORTS_KEXEC
1599	def_bool PM_SLEEP_SMP
1600
1601config ARCH_SUPPORTS_KEXEC_FILE
1602	def_bool y
1603
1604config ARCH_SELECTS_KEXEC_FILE
1605	def_bool y
1606	depends on KEXEC_FILE
1607	select HAVE_IMA_KEXEC if IMA
1608
1609config ARCH_SUPPORTS_KEXEC_SIG
1610	def_bool y
1611
1612config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
1613	def_bool y
1614
1615config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
1616	def_bool y
1617
1618config ARCH_SUPPORTS_KEXEC_HANDOVER
1619	def_bool y
1620
1621config ARCH_SUPPORTS_CRASH_DUMP
1622	def_bool y
1623
1624config ARCH_DEFAULT_CRASH_DUMP
1625	def_bool y
1626
1627config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
1628	def_bool CRASH_RESERVE
1629
1630config TRANS_TABLE
1631	def_bool y
1632	depends on HIBERNATION || KEXEC_CORE
1633
1634config XEN_DOM0
1635	def_bool y
1636	depends on XEN
1637
1638config XEN
1639	bool "Xen guest support on ARM64"
1640	depends on ARM64 && OF
1641	select SWIOTLB_XEN
1642	select PARAVIRT
1643	help
1644	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
1645
1646# include/linux/mmzone.h requires the following to be true:
1647#
1648#   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1649#
1650# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT:
1651#
1652#     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  max MAX_PAGE_ORDER  |  default MAX_PAGE_ORDER |
1653# ----+-------------------+--------------+----------------------+-------------------------+
1654# 4K  |       27          |      12      |       15             |         10              |
1655# 16K |       27          |      14      |       13             |         11              |
1656# 64K |       29          |      16      |       13             |         13              |
1657config ARCH_FORCE_MAX_ORDER
1658	int
1659	default "13" if ARM64_64K_PAGES
1660	default "11" if ARM64_16K_PAGES
1661	default "10"
1662	help
1663	  The kernel page allocator limits the size of maximal physically
1664	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1665	  defines the maximal power of two of number of pages that can be
1666	  allocated as a single contiguous block. This option allows
1667	  overriding the default setting when ability to allocate very
1668	  large blocks of physically contiguous memory is required.
1669
1670	  The maximal size of allocation cannot exceed the size of the
1671	  section, so the value of MAX_PAGE_ORDER should satisfy
1672
1673	    MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
1674
1675	  Don't change if unsure.
1676
1677config UNMAP_KERNEL_AT_EL0
1678	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
1679	default y
1680	help
1681	  Speculation attacks against some high-performance processors can
1682	  be used to bypass MMU permission checks and leak kernel data to
1683	  userspace. This can be defended against by unmapping the kernel
1684	  when running in userspace, mapping it back in on exception entry
1685	  via a trampoline page in the vector table.
1686
1687	  If unsure, say Y.
1688
1689config MITIGATE_SPECTRE_BRANCH_HISTORY
1690	bool "Mitigate Spectre style attacks against branch history" if EXPERT
1691	default y
1692	help
1693	  Speculation attacks against some high-performance processors can
1694	  make use of branch history to influence future speculation.
1695	  When taking an exception from user-space, a sequence of branches
1696	  or a firmware call overwrites the branch history.
1697
1698config RODATA_FULL_DEFAULT_ENABLED
1699	bool "Apply r/o permissions of VM areas also to their linear aliases"
1700	default y
1701	help
1702	  Apply read-only attributes of VM areas to the linear alias of
1703	  the backing pages as well. This prevents code or read-only data
1704	  from being modified (inadvertently or intentionally) via another
1705	  mapping of the same memory page. This additional enhancement can
1706	  be turned off at runtime by passing rodata=[off|on] (and turned on
1707	  with rodata=full if this option is set to 'n')
1708
1709	  This requires the linear region to be mapped down to pages,
1710	  which may adversely affect performance in some cases.
1711
1712config ARM64_SW_TTBR0_PAN
1713	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
1714	depends on !KCSAN
1715	select ARM64_PAN
1716	help
1717	  Enabling this option prevents the kernel from accessing
1718	  user-space memory directly by pointing TTBR0_EL1 to a reserved
1719	  zeroed area and reserved ASID. The user access routines
1720	  restore the valid TTBR0_EL1 temporarily.
1721
1722config ARM64_TAGGED_ADDR_ABI
1723	bool "Enable the tagged user addresses syscall ABI"
1724	default y
1725	help
1726	  When this option is enabled, user applications can opt in to a
1727	  relaxed ABI via prctl() allowing tagged addresses to be passed
1728	  to system calls as pointer arguments. For details, see
1729	  Documentation/arch/arm64/tagged-address-abi.rst.
1730
1731menuconfig COMPAT
1732	bool "Kernel support for 32-bit EL0"
1733	depends on ARM64_4K_PAGES || EXPERT
1734	select HAVE_UID16
1735	select OLD_SIGSUSPEND3
1736	select COMPAT_OLD_SIGACTION
1737	help
1738	  This option enables support for a 32-bit EL0 running under a 64-bit
1739	  kernel at EL1. AArch32-specific components such as system calls,
1740	  the user helper functions, VFP support and the ptrace interface are
1741	  handled appropriately by the kernel.
1742
1743	  If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
1744	  that you will only be able to execute AArch32 binaries that were compiled
1745	  with page size aligned segments.
1746
1747	  If you want to execute 32-bit userspace applications, say Y.
1748
1749if COMPAT
1750
1751config KUSER_HELPERS
1752	bool "Enable kuser helpers page for 32-bit applications"
1753	default y
1754	help
1755	  Warning: disabling this option may break 32-bit user programs.
1756
1757	  Provide kuser helpers to compat tasks. The kernel provides
1758	  helper code to userspace in read only form at a fixed location
1759	  to allow userspace to be independent of the CPU type fitted to
1760	  the system. This permits binaries to be run on ARMv4 through
1761	  to ARMv8 without modification.
1762
1763	  See Documentation/arch/arm/kernel_user_helpers.rst for details.
1764
1765	  However, the fixed address nature of these helpers can be used
1766	  by ROP (return orientated programming) authors when creating
1767	  exploits.
1768
1769	  If all of the binaries and libraries which run on your platform
1770	  are built specifically for your platform, and make no use of
1771	  these helpers, then you can turn this option off to hinder
1772	  such exploits. However, in that case, if a binary or library
1773	  relying on those helpers is run, it will not function correctly.
1774
1775	  Say N here only if you are absolutely certain that you do not
1776	  need these helpers; otherwise, the safe option is to say Y.
1777
1778config COMPAT_VDSO
1779	bool "Enable vDSO for 32-bit applications"
1780	depends on !CPU_BIG_ENDIAN
1781	depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != ""
1782	select GENERIC_COMPAT_VDSO
1783	default y
1784	help
1785	  Place in the process address space of 32-bit applications an
1786	  ELF shared object providing fast implementations of gettimeofday
1787	  and clock_gettime.
1788
1789	  You must have a 32-bit build of glibc 2.22 or later for programs
1790	  to seamlessly take advantage of this.
1791
1792config THUMB2_COMPAT_VDSO
1793	bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT
1794	depends on COMPAT_VDSO
1795	default y
1796	help
1797	  Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y,
1798	  otherwise with '-marm'.
1799
1800config COMPAT_ALIGNMENT_FIXUPS
1801	bool "Fix up misaligned multi-word loads and stores in user space"
1802
1803menuconfig ARMV8_DEPRECATED
1804	bool "Emulate deprecated/obsolete ARMv8 instructions"
1805	depends on SYSCTL
1806	help
1807	  Legacy software support may require certain instructions
1808	  that have been deprecated or obsoleted in the architecture.
1809
1810	  Enable this config to enable selective emulation of these
1811	  features.
1812
1813	  If unsure, say Y
1814
1815if ARMV8_DEPRECATED
1816
1817config SWP_EMULATION
1818	bool "Emulate SWP/SWPB instructions"
1819	help
1820	  ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
1821	  they are always undefined. Say Y here to enable software
1822	  emulation of these instructions for userspace using LDXR/STXR.
1823	  This feature can be controlled at runtime with the abi.swp
1824	  sysctl which is disabled by default.
1825
1826	  In some older versions of glibc [<=2.8] SWP is used during futex
1827	  trylock() operations with the assumption that the code will not
1828	  be preempted. This invalid assumption may be more likely to fail
1829	  with SWP emulation enabled, leading to deadlock of the user
1830	  application.
1831
1832	  NOTE: when accessing uncached shared regions, LDXR/STXR rely
1833	  on an external transaction monitoring block called a global
1834	  monitor to maintain update atomicity. If your system does not
1835	  implement a global monitor, this option can cause programs that
1836	  perform SWP operations to uncached memory to deadlock.
1837
1838	  If unsure, say Y
1839
1840config CP15_BARRIER_EMULATION
1841	bool "Emulate CP15 Barrier instructions"
1842	help
1843	  The CP15 barrier instructions - CP15ISB, CP15DSB, and
1844	  CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
1845	  strongly recommended to use the ISB, DSB, and DMB
1846	  instructions instead.
1847
1848	  Say Y here to enable software emulation of these
1849	  instructions for AArch32 userspace code. When this option is
1850	  enabled, CP15 barrier usage is traced which can help
1851	  identify software that needs updating. This feature can be
1852	  controlled at runtime with the abi.cp15_barrier sysctl.
1853
1854	  If unsure, say Y
1855
1856config SETEND_EMULATION
1857	bool "Emulate SETEND instruction"
1858	help
1859	  The SETEND instruction alters the data-endianness of the
1860	  AArch32 EL0, and is deprecated in ARMv8.
1861
1862	  Say Y here to enable software emulation of the instruction
1863	  for AArch32 userspace code. This feature can be controlled
1864	  at runtime with the abi.setend sysctl.
1865
1866	  Note: All the cpus on the system must have mixed endian support at EL0
1867	  for this feature to be enabled. If a new CPU - which doesn't support mixed
1868	  endian - is hotplugged in after this feature has been enabled, there could
1869	  be unexpected results in the applications.
1870
1871	  If unsure, say Y
1872endif # ARMV8_DEPRECATED
1873
1874endif # COMPAT
1875
1876menu "ARMv8.1 architectural features"
1877
1878config ARM64_HW_AFDBM
1879	bool "Support for hardware updates of the Access and Dirty page flags"
1880	default y
1881	help
1882	  The ARMv8.1 architecture extensions introduce support for
1883	  hardware updates of the access and dirty information in page
1884	  table entries. When enabled in TCR_EL1 (HA and HD bits) on
1885	  capable processors, accesses to pages with PTE_AF cleared will
1886	  set this bit instead of raising an access flag fault.
1887	  Similarly, writes to read-only pages with the DBM bit set will
1888	  clear the read-only bit (AP[2]) instead of raising a
1889	  permission fault.
1890
1891	  Kernels built with this configuration option enabled continue
1892	  to work on pre-ARMv8.1 hardware and the performance impact is
1893	  minimal. If unsure, say Y.
1894
1895config ARM64_PAN
1896	bool "Enable support for Privileged Access Never (PAN)"
1897	default y
1898	help
1899	  Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
1900	  prevents the kernel or hypervisor from accessing user-space (EL0)
1901	  memory directly.
1902
1903	  Choosing this option will cause any unprotected (not using
1904	  copy_to_user et al) memory access to fail with a permission fault.
1905
1906	  The feature is detected at runtime, and will remain as a 'nop'
1907	  instruction if the cpu does not implement the feature.
1908
1909config ARM64_LSE_ATOMICS
1910	bool
1911	default ARM64_USE_LSE_ATOMICS
1912
1913config ARM64_USE_LSE_ATOMICS
1914	bool "Atomic instructions"
1915	default y
1916	help
1917	  As part of the Large System Extensions, ARMv8.1 introduces new
1918	  atomic instructions that are designed specifically to scale in
1919	  very large systems.
1920
1921	  Say Y here to make use of these instructions for the in-kernel
1922	  atomic routines. This incurs a small overhead on CPUs that do
1923	  not support these instructions.
1924
1925endmenu # "ARMv8.1 architectural features"
1926
1927menu "ARMv8.2 architectural features"
1928
1929config ARM64_PMEM
1930	bool "Enable support for persistent memory"
1931	select ARCH_HAS_PMEM_API
1932	select ARCH_HAS_UACCESS_FLUSHCACHE
1933	help
1934	  Say Y to enable support for the persistent memory API based on the
1935	  ARMv8.2 DCPoP feature.
1936
1937	  The feature is detected at runtime, and the kernel will use DC CVAC
1938	  operations if DC CVAP is not supported (following the behaviour of
1939	  DC CVAP itself if the system does not define a point of persistence).
1940
1941config ARM64_RAS_EXTN
1942	bool "Enable support for RAS CPU Extensions"
1943	default y
1944	help
1945	  CPUs that support the Reliability, Availability and Serviceability
1946	  (RAS) Extensions, part of ARMv8.2 are able to track faults and
1947	  errors, classify them and report them to software.
1948
1949	  On CPUs with these extensions system software can use additional
1950	  barriers to determine if faults are pending and read the
1951	  classification from a new set of registers.
1952
1953	  Selecting this feature will allow the kernel to use these barriers
1954	  and access the new registers if the system supports the extension.
1955	  Platform RAS features may additionally depend on firmware support.
1956
1957config ARM64_CNP
1958	bool "Enable support for Common Not Private (CNP) translations"
1959	default y
1960	help
1961	  Common Not Private (CNP) allows translation table entries to
1962	  be shared between different PEs in the same inner shareable
1963	  domain, so the hardware can use this fact to optimise the
1964	  caching of such entries in the TLB.
1965
1966	  Selecting this option allows the CNP feature to be detected
1967	  at runtime, and does not affect PEs that do not implement
1968	  this feature.
1969
1970endmenu # "ARMv8.2 architectural features"
1971
1972menu "ARMv8.3 architectural features"
1973
1974config ARM64_PTR_AUTH
1975	bool "Enable support for pointer authentication"
1976	default y
1977	help
1978	  Pointer authentication (part of the ARMv8.3 Extensions) provides
1979	  instructions for signing and authenticating pointers against secret
1980	  keys, which can be used to mitigate Return Oriented Programming (ROP)
1981	  and other attacks.
1982
1983	  This option enables these instructions at EL0 (i.e. for userspace).
1984	  Choosing this option will cause the kernel to initialise secret keys
1985	  for each process at exec() time, with these keys being
1986	  context-switched along with the process.
1987
1988	  The feature is detected at runtime. If the feature is not present in
1989	  hardware it will not be advertised to userspace/KVM guest nor will it
1990	  be enabled.
1991
1992	  If the feature is present on the boot CPU but not on a late CPU, then
1993	  the late CPU will be parked. Also, if the boot CPU does not have
1994	  address auth and the late CPU has then the late CPU will still boot
1995	  but with the feature disabled. On such a system, this option should
1996	  not be selected.
1997
1998config ARM64_PTR_AUTH_KERNEL
1999	bool "Use pointer authentication for kernel"
2000	default y
2001	depends on ARM64_PTR_AUTH
2002	# Modern compilers insert a .note.gnu.property section note for PAC
2003	# which is only understood by binutils starting with version 2.33.1.
2004	depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100)
2005	depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
2006	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2007	help
2008	  If the compiler supports the -mbranch-protection or
2009	  -msign-return-address flag (e.g. GCC 7 or later), then this option
2010	  will cause the kernel itself to be compiled with return address
2011	  protection. In this case, and if the target hardware is known to
2012	  support pointer authentication, then CONFIG_STACKPROTECTOR can be
2013	  disabled with minimal loss of protection.
2014
2015	  This feature works with FUNCTION_GRAPH_TRACER option only if
2016	  DYNAMIC_FTRACE_WITH_ARGS is enabled.
2017
2018config CC_HAS_BRANCH_PROT_PAC_RET
2019	# GCC 9 or later, clang 8 or later
2020	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf)
2021
2022config AS_HAS_CFI_NEGATE_RA_STATE
2023	# binutils 2.34+
2024	def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n)
2025
2026endmenu # "ARMv8.3 architectural features"
2027
2028menu "ARMv8.4 architectural features"
2029
2030config ARM64_AMU_EXTN
2031	bool "Enable support for the Activity Monitors Unit CPU extension"
2032	default y
2033	help
2034	  The activity monitors extension is an optional extension introduced
2035	  by the ARMv8.4 CPU architecture. This enables support for version 1
2036	  of the activity monitors architecture, AMUv1.
2037
2038	  To enable the use of this extension on CPUs that implement it, say Y.
2039
2040	  Note that for architectural reasons, firmware _must_ implement AMU
2041	  support when running on CPUs that present the activity monitors
2042	  extension. The required support is present in:
2043	    * Version 1.5 and later of the ARM Trusted Firmware
2044
2045	  For kernels that have this configuration enabled but boot with broken
2046	  firmware, you may need to say N here until the firmware is fixed.
2047	  Otherwise you may experience firmware panics or lockups when
2048	  accessing the counter registers. Even if you are not observing these
2049	  symptoms, the values returned by the register reads might not
2050	  correctly reflect reality. Most commonly, the value read will be 0,
2051	  indicating that the counter is not enabled.
2052
2053config ARM64_TLB_RANGE
2054	bool "Enable support for tlbi range feature"
2055	default y
2056	help
2057	  ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a
2058	  range of input addresses.
2059
2060endmenu # "ARMv8.4 architectural features"
2061
2062menu "ARMv8.5 architectural features"
2063
2064config AS_HAS_ARMV8_5
2065	def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a)
2066
2067config ARM64_BTI
2068	bool "Branch Target Identification support"
2069	default y
2070	help
2071	  Branch Target Identification (part of the ARMv8.5 Extensions)
2072	  provides a mechanism to limit the set of locations to which computed
2073	  branch instructions such as BR or BLR can jump.
2074
2075	  To make use of BTI on CPUs that support it, say Y.
2076
2077	  BTI is intended to provide complementary protection to other control
2078	  flow integrity protection mechanisms, such as the Pointer
2079	  authentication mechanism provided as part of the ARMv8.3 Extensions.
2080	  For this reason, it does not make sense to enable this option without
2081	  also enabling support for pointer authentication.  Thus, when
2082	  enabling this option you should also select ARM64_PTR_AUTH=y.
2083
2084	  Userspace binaries must also be specifically compiled to make use of
2085	  this mechanism.  If you say N here or the hardware does not support
2086	  BTI, such binaries can still run, but you get no additional
2087	  enforcement of branch destinations.
2088
2089config ARM64_BTI_KERNEL
2090	bool "Use Branch Target Identification for kernel"
2091	default y
2092	depends on ARM64_BTI
2093	depends on ARM64_PTR_AUTH_KERNEL
2094	depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
2095	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
2096	depends on !CC_IS_GCC || GCC_VERSION >= 100100
2097	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
2098	depends on !CC_IS_GCC
2099	depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
2100	help
2101	  Build the kernel with Branch Target Identification annotations
2102	  and enable enforcement of this for kernel code. When this option
2103	  is enabled and the system supports BTI all kernel code including
2104	  modular code must have BTI enabled.
2105
2106config CC_HAS_BRANCH_PROT_PAC_RET_BTI
2107	# GCC 9 or later, clang 8 or later
2108	def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti)
2109
2110config ARM64_E0PD
2111	bool "Enable support for E0PD"
2112	default y
2113	help
2114	  E0PD (part of the ARMv8.5 extensions) allows us to ensure
2115	  that EL0 accesses made via TTBR1 always fault in constant time,
2116	  providing similar benefits to KASLR as those provided by KPTI, but
2117	  with lower overhead and without disrupting legitimate access to
2118	  kernel memory such as SPE.
2119
2120	  This option enables E0PD for TTBR1 where available.
2121
2122config ARM64_AS_HAS_MTE
2123	# Initial support for MTE went in binutils 2.32.0, checked with
2124	# ".arch armv8.5-a+memtag" below. However, this was incomplete
2125	# as a late addition to the final architecture spec (LDGM/STGM)
2126	# is only supported in the newer 2.32.x and 2.33 binutils
2127	# versions, hence the extra "stgm" instruction check below.
2128	def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0])
2129
2130config ARM64_MTE
2131	bool "Memory Tagging Extension support"
2132	default y
2133	depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
2134	depends on AS_HAS_ARMV8_5
2135	# Required for tag checking in the uaccess routines
2136	select ARM64_PAN
2137	select ARCH_HAS_SUBPAGE_FAULTS
2138	select ARCH_USES_HIGH_VMA_FLAGS
2139	select ARCH_USES_PG_ARCH_2
2140	select ARCH_USES_PG_ARCH_3
2141	help
2142	  Memory Tagging (part of the ARMv8.5 Extensions) provides
2143	  architectural support for run-time, always-on detection of
2144	  various classes of memory error to aid with software debugging
2145	  to eliminate vulnerabilities arising from memory-unsafe
2146	  languages.
2147
2148	  This option enables the support for the Memory Tagging
2149	  Extension at EL0 (i.e. for userspace).
2150
2151	  Selecting this option allows the feature to be detected at
2152	  runtime. Any secondary CPU not implementing this feature will
2153	  not be allowed a late bring-up.
2154
2155	  Userspace binaries that want to use this feature must
2156	  explicitly opt in. The mechanism for the userspace is
2157	  described in:
2158
2159	  Documentation/arch/arm64/memory-tagging-extension.rst.
2160
2161endmenu # "ARMv8.5 architectural features"
2162
2163menu "ARMv8.7 architectural features"
2164
2165config ARM64_EPAN
2166	bool "Enable support for Enhanced Privileged Access Never (EPAN)"
2167	default y
2168	depends on ARM64_PAN
2169	help
2170	  Enhanced Privileged Access Never (EPAN) allows Privileged
2171	  Access Never to be used with Execute-only mappings.
2172
2173	  The feature is detected at runtime, and will remain disabled
2174	  if the cpu does not implement the feature.
2175endmenu # "ARMv8.7 architectural features"
2176
2177config AS_HAS_MOPS
2178	def_bool $(as-instr,.arch_extension mops)
2179
2180menu "ARMv8.9 architectural features"
2181
2182config ARM64_POE
2183	prompt "Permission Overlay Extension"
2184	def_bool y
2185	select ARCH_USES_HIGH_VMA_FLAGS
2186	select ARCH_HAS_PKEYS
2187	help
2188	  The Permission Overlay Extension is used to implement Memory
2189	  Protection Keys. Memory Protection Keys provides a mechanism for
2190	  enforcing page-based protections, but without requiring modification
2191	  of the page tables when an application changes protection domains.
2192
2193	  For details, see Documentation/core-api/protection-keys.rst
2194
2195	  If unsure, say y.
2196
2197config ARCH_PKEY_BITS
2198	int
2199	default 3
2200
2201config ARM64_HAFT
2202	bool "Support for Hardware managed Access Flag for Table Descriptors"
2203	depends on ARM64_HW_AFDBM
2204	default y
2205	help
2206	  The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access
2207	  Flag for Table descriptors. When enabled an architectural executed
2208	  memory access will update the Access Flag in each Table descriptor
2209	  which is accessed during the translation table walk and for which
2210	  the Access Flag is 0. The Access Flag of the Table descriptor use
2211	  the same bit of PTE_AF.
2212
2213	  The feature will only be enabled if all the CPUs in the system
2214	  support this feature. If unsure, say Y.
2215
2216endmenu # "ARMv8.9 architectural features"
2217
2218menu "v9.4 architectural features"
2219
2220config ARM64_GCS
2221	bool "Enable support for Guarded Control Stack (GCS)"
2222	default y
2223	select ARCH_HAS_USER_SHADOW_STACK
2224	select ARCH_USES_HIGH_VMA_FLAGS
2225	depends on !UPROBES
2226	help
2227	  Guarded Control Stack (GCS) provides support for a separate
2228	  stack with restricted access which contains only return
2229	  addresses.  This can be used to harden against some attacks
2230	  by comparing return address used by the program with what is
2231	  stored in the GCS, and may also be used to efficiently obtain
2232	  the call stack for applications such as profiling.
2233
2234	  The feature is detected at runtime, and will remain disabled
2235	  if the system does not implement the feature.
2236
2237endmenu # "v9.4 architectural features"
2238
2239config ARM64_SVE
2240	bool "ARM Scalable Vector Extension support"
2241	default y
2242	help
2243	  The Scalable Vector Extension (SVE) is an extension to the AArch64
2244	  execution state which complements and extends the SIMD functionality
2245	  of the base architecture to support much larger vectors and to enable
2246	  additional vectorisation opportunities.
2247
2248	  To enable use of this extension on CPUs that implement it, say Y.
2249
2250	  On CPUs that support the SVE2 extensions, this option will enable
2251	  those too.
2252
2253	  Note that for architectural reasons, firmware _must_ implement SVE
2254	  support when running on SVE capable hardware.  The required support
2255	  is present in:
2256
2257	    * version 1.5 and later of the ARM Trusted Firmware
2258	    * the AArch64 boot wrapper since commit 5e1261e08abf
2259	      ("bootwrapper: SVE: Enable SVE for EL2 and below").
2260
2261	  For other firmware implementations, consult the firmware documentation
2262	  or vendor.
2263
2264	  If you need the kernel to boot on SVE-capable hardware with broken
2265	  firmware, you may need to say N here until you get your firmware
2266	  fixed.  Otherwise, you may experience firmware panics or lockups when
2267	  booting the kernel.  If unsure and you are not observing these
2268	  symptoms, you should assume that it is safe to say Y.
2269
2270config ARM64_SME
2271	bool "ARM Scalable Matrix Extension support"
2272	default y
2273	depends on ARM64_SVE
2274	help
2275	  The Scalable Matrix Extension (SME) is an extension to the AArch64
2276	  execution state which utilises a substantial subset of the SVE
2277	  instruction set, together with the addition of new architectural
2278	  register state capable of holding two dimensional matrix tiles to
2279	  enable various matrix operations.
2280
2281config ARM64_PSEUDO_NMI
2282	bool "Support for NMI-like interrupts"
2283	select ARM_GIC_V3
2284	help
2285	  Adds support for mimicking Non-Maskable Interrupts through the use of
2286	  GIC interrupt priority. This support requires version 3 or later of
2287	  ARM GIC.
2288
2289	  This high priority configuration for interrupts needs to be
2290	  explicitly enabled by setting the kernel parameter
2291	  "irqchip.gicv3_pseudo_nmi" to 1.
2292
2293	  If unsure, say N
2294
2295if ARM64_PSEUDO_NMI
2296config ARM64_DEBUG_PRIORITY_MASKING
2297	bool "Debug interrupt priority masking"
2298	help
2299	  This adds runtime checks to functions enabling/disabling
2300	  interrupts when using priority masking. The additional checks verify
2301	  the validity of ICC_PMR_EL1 when calling concerned functions.
2302
2303	  If unsure, say N
2304endif # ARM64_PSEUDO_NMI
2305
2306config RELOCATABLE
2307	bool "Build a relocatable kernel image" if EXPERT
2308	select ARCH_HAS_RELR
2309	default y
2310	help
2311	  This builds the kernel as a Position Independent Executable (PIE),
2312	  which retains all relocation metadata required to relocate the
2313	  kernel binary at runtime to a different virtual address than the
2314	  address it was linked at.
2315	  Since AArch64 uses the RELA relocation format, this requires a
2316	  relocation pass at runtime even if the kernel is loaded at the
2317	  same address it was linked at.
2318
2319config RANDOMIZE_BASE
2320	bool "Randomize the address of the kernel image"
2321	select RELOCATABLE
2322	help
2323	  Randomizes the virtual address at which the kernel image is
2324	  loaded, as a security feature that deters exploit attempts
2325	  relying on knowledge of the location of kernel internals.
2326
2327	  It is the bootloader's job to provide entropy, by passing a
2328	  random u64 value in /chosen/kaslr-seed at kernel entry.
2329
2330	  When booting via the UEFI stub, it will invoke the firmware's
2331	  EFI_RNG_PROTOCOL implementation (if available) to supply entropy
2332	  to the kernel proper. In addition, it will randomise the physical
2333	  location of the kernel Image as well.
2334
2335	  If unsure, say N.
2336
2337config RANDOMIZE_MODULE_REGION_FULL
2338	bool "Randomize the module region over a 2 GB range"
2339	depends on RANDOMIZE_BASE
2340	default y
2341	help
2342	  Randomizes the location of the module region inside a 2 GB window
2343	  covering the core kernel. This way, it is less likely for modules
2344	  to leak information about the location of core kernel data structures
2345	  but it does imply that function calls between modules and the core
2346	  kernel will need to be resolved via veneers in the module PLT.
2347
2348	  When this option is not set, the module region will be randomized over
2349	  a limited range that contains the [_stext, _etext] interval of the
2350	  core kernel, so branch relocations are almost always in range unless
2351	  the region is exhausted. In this particular case of region
2352	  exhaustion, modules might be able to fall back to a larger 2GB area.
2353
2354config CC_HAVE_STACKPROTECTOR_SYSREG
2355	def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
2356
2357config STACKPROTECTOR_PER_TASK
2358	def_bool y
2359	depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG
2360
2361config UNWIND_PATCH_PAC_INTO_SCS
2362	bool "Enable shadow call stack dynamically using code patching"
2363	# needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated
2364	depends on CC_IS_CLANG && CLANG_VERSION >= 150000
2365	depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET
2366	depends on SHADOW_CALL_STACK
2367	select UNWIND_TABLES
2368	select DYNAMIC_SCS
2369
2370config ARM64_CONTPTE
2371	bool "Contiguous PTE mappings for user memory" if EXPERT
2372	depends on TRANSPARENT_HUGEPAGE
2373	default y
2374	help
2375	  When enabled, user mappings are configured using the PTE contiguous
2376	  bit, for any mappings that meet the size and alignment requirements.
2377	  This reduces TLB pressure and improves performance.
2378
2379endmenu # "Kernel Features"
2380
2381menu "Boot options"
2382
2383config ARM64_ACPI_PARKING_PROTOCOL
2384	bool "Enable support for the ARM64 ACPI parking protocol"
2385	depends on ACPI
2386	help
2387	  Enable support for the ARM64 ACPI parking protocol. If disabled
2388	  the kernel will not allow booting through the ARM64 ACPI parking
2389	  protocol even if the corresponding data is present in the ACPI
2390	  MADT table.
2391
2392config CMDLINE
2393	string "Default kernel command string"
2394	default ""
2395	help
2396	  Provide a set of default command-line options at build time by
2397	  entering them here. As a minimum, you should specify the the
2398	  root device (e.g. root=/dev/nfs).
2399
2400choice
2401	prompt "Kernel command line type"
2402	depends on CMDLINE != ""
2403	default CMDLINE_FROM_BOOTLOADER
2404	help
2405	  Choose how the kernel will handle the provided default kernel
2406	  command line string.
2407
2408config CMDLINE_FROM_BOOTLOADER
2409	bool "Use bootloader kernel arguments if available"
2410	help
2411	  Uses the command-line options passed by the boot loader. If
2412	  the boot loader doesn't provide any, the default kernel command
2413	  string provided in CMDLINE will be used.
2414
2415config CMDLINE_FORCE
2416	bool "Always use the default kernel command string"
2417	help
2418	  Always use the default kernel command string, even if the boot
2419	  loader passes other arguments to the kernel.
2420	  This is useful if you cannot or don't want to change the
2421	  command-line options your boot loader passes to the kernel.
2422
2423endchoice
2424
2425config EFI_STUB
2426	bool
2427
2428config EFI
2429	bool "UEFI runtime support"
2430	depends on OF && !CPU_BIG_ENDIAN
2431	depends on KERNEL_MODE_NEON
2432	select ARCH_SUPPORTS_ACPI
2433	select LIBFDT
2434	select UCS2_STRING
2435	select EFI_PARAMS_FROM_FDT
2436	select EFI_RUNTIME_WRAPPERS
2437	select EFI_STUB
2438	select EFI_GENERIC_STUB
2439	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
2440	default y
2441	help
2442	  This option provides support for runtime services provided
2443	  by UEFI firmware (such as non-volatile variables, realtime
2444	  clock, and platform reset). A UEFI stub is also provided to
2445	  allow the kernel to be booted as an EFI application. This
2446	  is only useful on systems that have UEFI firmware.
2447
2448config COMPRESSED_INSTALL
2449	bool "Install compressed image by default"
2450	help
2451	  This makes the regular "make install" install the compressed
2452	  image we built, not the legacy uncompressed one.
2453
2454	  You can check that a compressed image works for you by doing
2455	  "make zinstall" first, and verifying that everything is fine
2456	  in your environment before making "make install" do this for
2457	  you.
2458
2459config DMI
2460	bool "Enable support for SMBIOS (DMI) tables"
2461	depends on EFI
2462	default y
2463	help
2464	  This enables SMBIOS/DMI feature for systems.
2465
2466	  This option is only useful on systems that have UEFI firmware.
2467	  However, even with this option, the resultant kernel should
2468	  continue to boot on existing non-UEFI platforms.
2469
2470endmenu # "Boot options"
2471
2472menu "Power management options"
2473
2474source "kernel/power/Kconfig"
2475
2476config ARCH_HIBERNATION_POSSIBLE
2477	def_bool y
2478	depends on CPU_PM
2479
2480config ARCH_HIBERNATION_HEADER
2481	def_bool y
2482	depends on HIBERNATION
2483
2484config ARCH_SUSPEND_POSSIBLE
2485	def_bool y
2486
2487endmenu # "Power management options"
2488
2489menu "CPU Power Management"
2490
2491source "drivers/cpuidle/Kconfig"
2492
2493source "drivers/cpufreq/Kconfig"
2494
2495endmenu # "CPU Power Management"
2496
2497source "drivers/acpi/Kconfig"
2498
2499source "arch/arm64/kvm/Kconfig"
2500
2501