arm64: fix R/O permissions of FDT mapping
[linux-2.6-block.git] / arch / arm64 / Kconfig
CommitLineData
8c2c3df3
CM
1config ARM64
2 def_bool y
b6197b93 3 select ACPI_CCA_REQUIRED if ACPI
d8f4f161 4 select ACPI_GENERIC_GSI if ACPI
6933de0c 5 select ACPI_REDUCED_HARDWARE_ONLY if ACPI
8c2c3df3 6 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
2b68f6ca 7 select ARCH_HAS_ELF_RANDOMIZE
957e3fac 8 select ARCH_HAS_GCOV_PROFILE_ALL
308c09f1 9 select ARCH_HAS_SG_CHAIN
1f85008e 10 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
c63c8700 11 select ARCH_USE_CMPXCHG_LOCKREF
4badad35 12 select ARCH_SUPPORTS_ATOMIC_RMW
9170100e 13 select ARCH_WANT_OPTIONAL_GPIOLIB
6212a512 14 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
b6f35981 15 select ARCH_WANT_FRAME_POINTERS
25c92a37 16 select ARM_AMBA
1aee5d7a 17 select ARM_ARCH_TIMER
c4188edc 18 select ARM_GIC
875cbf3e 19 select AUDIT_ARCH_COMPAT_GENERIC
853a33ce 20 select ARM_GIC_V2M if PCI_MSI
021f6537 21 select ARM_GIC_V3
19812729 22 select ARM_GIC_V3_ITS if PCI_MSI
bff60792 23 select ARM_PSCI_FW
adace895 24 select BUILDTIME_EXTABLE_SORT
db2789b5 25 select CLONE_BACKWARDS
7ca2ef33 26 select COMMON_CLK
166936ba 27 select CPU_PM if (SUSPEND || CPU_IDLE)
7bc13fd3 28 select DCACHE_WORD_ACCESS
ef37566c 29 select EDAC_SUPPORT
d4932f9e 30 select GENERIC_ALLOCATOR
8c2c3df3 31 select GENERIC_CLOCKEVENTS
4b3dc967 32 select GENERIC_CLOCKEVENTS_BROADCAST
3be1a5c4 33 select GENERIC_CPU_AUTOPROBE
bf4b558e 34 select GENERIC_EARLY_IOREMAP
2314ee4d 35 select GENERIC_IDLE_POLL_SETUP
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36 select GENERIC_IRQ_PROBE
37 select GENERIC_IRQ_SHOW
6544e67b 38 select GENERIC_IRQ_SHOW_LEVEL
cb61f676 39 select GENERIC_PCI_IOMAP
65cd4f6c 40 select GENERIC_SCHED_CLOCK
8c2c3df3 41 select GENERIC_SMP_IDLE_THREAD
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42 select GENERIC_STRNCPY_FROM_USER
43 select GENERIC_STRNLEN_USER
8c2c3df3 44 select GENERIC_TIME_VSYSCALL
a1ddc74a 45 select HANDLE_DOMAIN_IRQ
8c2c3df3 46 select HARDIRQS_SW_RESEND
5284e1b4 47 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
875cbf3e 48 select HAVE_ARCH_AUDITSYSCALL
8e7a4cef 49 select HAVE_ARCH_BITREVERSE
9732cafd 50 select HAVE_ARCH_JUMP_LABEL
39d114dd 51 select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP
9529247d 52 select HAVE_ARCH_KGDB
a1ae65b2 53 select HAVE_ARCH_SECCOMP_FILTER
8c2c3df3 54 select HAVE_ARCH_TRACEHOOK
e54bcde3 55 select HAVE_BPF_JIT
af64d2aa 56 select HAVE_C_RECORDMCOUNT
c0c264ae 57 select HAVE_CC_STACKPROTECTOR
5284e1b4 58 select HAVE_CMPXCHG_DOUBLE
95eff6b2 59 select HAVE_CMPXCHG_LOCAL
9b2a60c4 60 select HAVE_DEBUG_BUGVERBOSE
b69ec42b 61 select HAVE_DEBUG_KMEMLEAK
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62 select HAVE_DMA_API_DEBUG
63 select HAVE_DMA_ATTRS
6ac2104d 64 select HAVE_DMA_CONTIGUOUS
bd7d38db 65 select HAVE_DYNAMIC_FTRACE
50afc33a 66 select HAVE_EFFICIENT_UNALIGNED_ACCESS
af64d2aa 67 select HAVE_FTRACE_MCOUNT_RECORD
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68 select HAVE_FUNCTION_TRACER
69 select HAVE_FUNCTION_GRAPH_TRACER
8c2c3df3 70 select HAVE_GENERIC_DMA_COHERENT
8c2c3df3 71 select HAVE_HW_BREAKPOINT if PERF_EVENTS
8c2c3df3 72 select HAVE_MEMBLOCK
55834a77 73 select HAVE_PATA_PLATFORM
8c2c3df3 74 select HAVE_PERF_EVENTS
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75 select HAVE_PERF_REGS
76 select HAVE_PERF_USER_STACK_DUMP
5e5f6dc1 77 select HAVE_RCU_TABLE_FREE
055b1212 78 select HAVE_SYSCALL_TRACEPOINTS
8c2c3df3 79 select IRQ_DOMAIN
e8557d1f 80 select IRQ_FORCED_THREADING
fea2acaa 81 select MODULES_USE_ELF_RELA
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82 select NO_BOOTMEM
83 select OF
84 select OF_EARLY_FLATTREE
9bf14b7c 85 select OF_RESERVED_MEM
8c2c3df3 86 select PERF_USE_VMALLOC
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87 select POWER_RESET
88 select POWER_SUPPLY
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89 select RTC_LIB
90 select SPARSE_IRQ
7ac57a89 91 select SYSCTL_EXCEPTION_TRACE
6c81fe79 92 select HAVE_CONTEXT_TRACKING
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93 help
94 ARM 64-bit (AArch64) Linux support.
95
96config 64BIT
97 def_bool y
98
99config ARCH_PHYS_ADDR_T_64BIT
100 def_bool y
101
102config MMU
103 def_bool y
104
ce816fa8 105config NO_IOPORT_MAP
d1e6dc91 106 def_bool y if !PCI
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107
108config STACKTRACE_SUPPORT
109 def_bool y
110
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111config ILLEGAL_POINTER_VALUE
112 hex
113 default 0xdead000000000000
114
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115config LOCKDEP_SUPPORT
116 def_bool y
117
118config TRACE_IRQFLAGS_SUPPORT
119 def_bool y
120
c209f799 121config RWSEM_XCHGADD_ALGORITHM
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122 def_bool y
123
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124config GENERIC_BUG
125 def_bool y
126 depends on BUG
127
128config GENERIC_BUG_RELATIVE_POINTERS
129 def_bool y
130 depends on GENERIC_BUG
131
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132config GENERIC_HWEIGHT
133 def_bool y
134
135config GENERIC_CSUM
136 def_bool y
137
138config GENERIC_CALIBRATE_DELAY
139 def_bool y
140
19e7640d 141config ZONE_DMA
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142 def_bool y
143
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144config HAVE_GENERIC_RCU_GUP
145 def_bool y
146
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147config ARCH_DMA_ADDR_T_64BIT
148 def_bool y
149
150config NEED_DMA_MAP_STATE
151 def_bool y
152
153config NEED_SG_DMA_LENGTH
154 def_bool y
155
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156config SMP
157 def_bool y
158
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159config SWIOTLB
160 def_bool y
161
162config IOMMU_HELPER
163 def_bool SWIOTLB
164
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165config KERNEL_MODE_NEON
166 def_bool y
167
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168config FIX_EARLYCON_MEM
169 def_bool y
170
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171config PGTABLE_LEVELS
172 int
21539939 173 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
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174 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
175 default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48
176 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
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177 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
178 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
9f25e6ad 179
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180source "init/Kconfig"
181
182source "kernel/Kconfig.freezer"
183
6a377491 184source "arch/arm64/Kconfig.platforms"
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185
186menu "Bus support"
187
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188config PCI
189 bool "PCI support"
190 help
191 This feature enables support for PCI bus system. If you say Y
192 here, the kernel will include drivers and infrastructure code
193 to support PCI bus devices.
194
195config PCI_DOMAINS
196 def_bool PCI
197
198config PCI_DOMAINS_GENERIC
199 def_bool PCI
200
201config PCI_SYSCALL
202 def_bool PCI
203
204source "drivers/pci/Kconfig"
205source "drivers/pci/pcie/Kconfig"
206source "drivers/pci/hotplug/Kconfig"
207
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208endmenu
209
210menu "Kernel Features"
211
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212menu "ARM errata workarounds via the alternatives framework"
213
214config ARM64_ERRATUM_826319
215 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
216 default y
217 help
218 This option adds an alternative code sequence to work around ARM
219 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
220 AXI master interface and an L2 cache.
221
222 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
223 and is unable to accept a certain write via this interface, it will
224 not progress on read data presented on the read data channel and the
225 system can deadlock.
226
227 The workaround promotes data cache clean instructions to
228 data cache clean-and-invalidate.
229 Please note that this does not necessarily enable the workaround,
230 as it depends on the alternative framework, which will only patch
231 the kernel if an affected CPU is detected.
232
233 If unsure, say Y.
234
235config ARM64_ERRATUM_827319
236 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
237 default y
238 help
239 This option adds an alternative code sequence to work around ARM
240 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
241 master interface and an L2 cache.
242
243 Under certain conditions this erratum can cause a clean line eviction
244 to occur at the same time as another transaction to the same address
245 on the AMBA 5 CHI interface, which can cause data corruption if the
246 interconnect reorders the two transactions.
247
248 The workaround promotes data cache clean instructions to
249 data cache clean-and-invalidate.
250 Please note that this does not necessarily enable the workaround,
251 as it depends on the alternative framework, which will only patch
252 the kernel if an affected CPU is detected.
253
254 If unsure, say Y.
255
256config ARM64_ERRATUM_824069
257 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
258 default y
259 help
260 This option adds an alternative code sequence to work around ARM
261 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
262 to a coherent interconnect.
263
264 If a Cortex-A53 processor is executing a store or prefetch for
265 write instruction at the same time as a processor in another
266 cluster is executing a cache maintenance operation to the same
267 address, then this erratum might cause a clean cache line to be
268 incorrectly marked as dirty.
269
270 The workaround promotes data cache clean instructions to
271 data cache clean-and-invalidate.
272 Please note that this option does not necessarily enable the
273 workaround, as it depends on the alternative framework, which will
274 only patch the kernel if an affected CPU is detected.
275
276 If unsure, say Y.
277
278config ARM64_ERRATUM_819472
279 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
280 default y
281 help
282 This option adds an alternative code sequence to work around ARM
283 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
284 present when it is connected to a coherent interconnect.
285
286 If the processor is executing a load and store exclusive sequence at
287 the same time as a processor in another cluster is executing a cache
288 maintenance operation to the same address, then this erratum might
289 cause data corruption.
290
291 The workaround promotes data cache clean instructions to
292 data cache clean-and-invalidate.
293 Please note that this does not necessarily enable the workaround,
294 as it depends on the alternative framework, which will only patch
295 the kernel if an affected CPU is detected.
296
297 If unsure, say Y.
298
299config ARM64_ERRATUM_832075
300 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
301 default y
302 help
303 This option adds an alternative code sequence to work around ARM
304 erratum 832075 on Cortex-A57 parts up to r1p2.
305
306 Affected Cortex-A57 parts might deadlock when exclusive load/store
307 instructions to Write-Back memory are mixed with Device loads.
308
309 The workaround is to promote device loads to use Load-Acquire
310 semantics.
311 Please note that this does not necessarily enable the workaround,
312 as it depends on the alternative framework, which will only patch
313 the kernel if an affected CPU is detected.
314
315 If unsure, say Y.
316
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317config ARM64_ERRATUM_845719
318 bool "Cortex-A53: 845719: a load might read incorrect data"
319 depends on COMPAT
320 default y
321 help
322 This option adds an alternative code sequence to work around ARM
323 erratum 845719 on Cortex-A53 parts up to r0p4.
324
325 When running a compat (AArch32) userspace on an affected Cortex-A53
326 part, a load at EL0 from a virtual address that matches the bottom 32
327 bits of the virtual address used by a recent load at (AArch64) EL1
328 might return incorrect data.
329
330 The workaround is to write the contextidr_el1 register on exception
331 return to a 32-bit task.
332 Please note that this does not necessarily enable the workaround,
333 as it depends on the alternative framework, which will only patch
334 the kernel if an affected CPU is detected.
335
336 If unsure, say Y.
337
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338config ARM64_ERRATUM_843419
339 bool "Cortex-A53: 843419: A load or store might access an incorrect address"
340 depends on MODULES
341 default y
342 help
343 This option builds kernel modules using the large memory model in
344 order to avoid the use of the ADRP instruction, which can cause
345 a subsequent memory access to use an incorrect address on Cortex-A53
346 parts up to r0p4.
347
348 Note that the kernel itself must be linked with a version of ld
349 which fixes potentially affected ADRP instructions through the
350 use of veneers.
351
352 If unsure, say Y.
353
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354endmenu
355
356
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357choice
358 prompt "Page size"
359 default ARM64_4K_PAGES
360 help
361 Page size (translation granule) configuration.
362
363config ARM64_4K_PAGES
364 bool "4KB"
365 help
366 This feature enables 4KB pages support.
367
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368config ARM64_16K_PAGES
369 bool "16KB"
370 help
371 The system will use 16KB pages support. AArch32 emulation
372 requires applications compiled with 16K (or a multiple of 16K)
373 aligned segments.
374
8c2c3df3 375config ARM64_64K_PAGES
e41ceed0 376 bool "64KB"
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377 help
378 This feature enables 64KB pages support (4KB by default)
379 allowing only two levels of page tables and faster TLB
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380 look-up. AArch32 emulation requires applications compiled
381 with 64K aligned segments.
8c2c3df3 382
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383endchoice
384
385choice
386 prompt "Virtual address space size"
387 default ARM64_VA_BITS_39 if ARM64_4K_PAGES
44eaacf1 388 default ARM64_VA_BITS_47 if ARM64_16K_PAGES
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389 default ARM64_VA_BITS_42 if ARM64_64K_PAGES
390 help
391 Allows choosing one of multiple possible virtual address
392 space sizes. The level of translation table is determined by
393 a combination of page size and virtual address space size.
394
21539939 395config ARM64_VA_BITS_36
56a3f30e 396 bool "36-bit" if EXPERT
21539939
SP
397 depends on ARM64_16K_PAGES
398
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399config ARM64_VA_BITS_39
400 bool "39-bit"
401 depends on ARM64_4K_PAGES
402
403config ARM64_VA_BITS_42
404 bool "42-bit"
405 depends on ARM64_64K_PAGES
406
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407config ARM64_VA_BITS_47
408 bool "47-bit"
409 depends on ARM64_16K_PAGES
410
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411config ARM64_VA_BITS_48
412 bool "48-bit"
c79b954b 413
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414endchoice
415
416config ARM64_VA_BITS
417 int
21539939 418 default 36 if ARM64_VA_BITS_36
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419 default 39 if ARM64_VA_BITS_39
420 default 42 if ARM64_VA_BITS_42
44eaacf1 421 default 47 if ARM64_VA_BITS_47
c79b954b 422 default 48 if ARM64_VA_BITS_48
e41ceed0 423
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424config CPU_BIG_ENDIAN
425 bool "Build big-endian kernel"
426 help
427 Say Y if you plan on running a kernel in big-endian mode.
428
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429config SCHED_MC
430 bool "Multi-core scheduler support"
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431 help
432 Multi-core scheduler support improves the CPU scheduler's decision
433 making when dealing with multi-core CPU chips at a cost of slightly
434 increased overhead in some places. If unsure say N here.
435
436config SCHED_SMT
437 bool "SMT scheduler support"
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438 help
439 Improves the CPU scheduler's decision making when dealing with
440 MultiThreading at a cost of slightly increased overhead in some
441 places. If unsure say N here.
442
8c2c3df3 443config NR_CPUS
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444 int "Maximum number of CPUs (2-4096)"
445 range 2 4096
15942853 446 # These have to remain sorted largest to smallest
e3672649 447 default "64"
8c2c3df3 448
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449config HOTPLUG_CPU
450 bool "Support for hot-pluggable CPUs"
217d453d 451 select GENERIC_IRQ_MIGRATION
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452 help
453 Say Y here to experiment with turning CPUs off and on. CPUs
454 can be controlled through /sys/devices/system/cpu.
455
8c2c3df3 456source kernel/Kconfig.preempt
f90df5e2 457source kernel/Kconfig.hz
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458
459config ARCH_HAS_HOLES_MEMORYMODEL
460 def_bool y if SPARSEMEM
461
462config ARCH_SPARSEMEM_ENABLE
463 def_bool y
464 select SPARSEMEM_VMEMMAP_ENABLE
465
466config ARCH_SPARSEMEM_DEFAULT
467 def_bool ARCH_SPARSEMEM_ENABLE
468
469config ARCH_SELECT_MEMORY_MODEL
470 def_bool ARCH_SPARSEMEM_ENABLE
471
472config HAVE_ARCH_PFN_VALID
473 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
474
475config HW_PERF_EVENTS
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476 def_bool y
477 depends on ARM_PMU
8c2c3df3 478
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479config SYS_SUPPORTS_HUGETLBFS
480 def_bool y
481
482config ARCH_WANT_GENERAL_HUGETLB
483 def_bool y
484
485config ARCH_WANT_HUGE_PMD_SHARE
21539939 486 def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
084bd298 487
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488config HAVE_ARCH_TRANSPARENT_HUGEPAGE
489 def_bool y
490
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491config ARCH_HAS_CACHE_LINE_SIZE
492 def_bool y
493
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494source "mm/Kconfig"
495
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496config SECCOMP
497 bool "Enable seccomp to safely compute untrusted bytecode"
498 ---help---
499 This kernel feature is useful for number crunching applications
500 that may need to compute untrusted bytecode during their
501 execution. By using pipes or other transports made available to
502 the process as file descriptors supporting the read/write
503 syscalls, it's possible to isolate those applications in
504 their own address space using seccomp. Once seccomp is
505 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506 and the task is only allowed to execute a few safe syscalls
507 defined by each seccomp mode.
508
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509config XEN_DOM0
510 def_bool y
511 depends on XEN
512
513config XEN
c2ba1f7d 514 bool "Xen guest support on ARM64"
aa42aa13 515 depends on ARM64 && OF
83862ccf 516 select SWIOTLB_XEN
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517 help
518 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
519
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520config FORCE_MAX_ZONEORDER
521 int
522 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
44eaacf1 523 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
d03bb145 524 default "11"
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525 help
526 The kernel memory allocator divides physically contiguous memory
527 blocks into "zones", where each zone is a power of two number of
528 pages. This option selects the largest power of two that the kernel
529 keeps in the memory allocator. If you need to allocate very large
530 blocks of physically contiguous memory, then you may need to
531 increase this value.
532
533 This config option is actually maximum order plus one. For example,
534 a value of 11 means that the largest free memory block is 2^10 pages.
535
536 We make sure that we can allocate upto a HugePage size for each configuration.
537 Hence we have :
538 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
539
540 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
541 4M allocations matching the default size used by generic code.
d03bb145 542
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543menuconfig ARMV8_DEPRECATED
544 bool "Emulate deprecated/obsolete ARMv8 instructions"
545 depends on COMPAT
546 help
547 Legacy software support may require certain instructions
548 that have been deprecated or obsoleted in the architecture.
549
550 Enable this config to enable selective emulation of these
551 features.
552
553 If unsure, say Y
554
555if ARMV8_DEPRECATED
556
557config SWP_EMULATION
558 bool "Emulate SWP/SWPB instructions"
559 help
560 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
561 they are always undefined. Say Y here to enable software
562 emulation of these instructions for userspace using LDXR/STXR.
563
564 In some older versions of glibc [<=2.8] SWP is used during futex
565 trylock() operations with the assumption that the code will not
566 be preempted. This invalid assumption may be more likely to fail
567 with SWP emulation enabled, leading to deadlock of the user
568 application.
569
570 NOTE: when accessing uncached shared regions, LDXR/STXR rely
571 on an external transaction monitoring block called a global
572 monitor to maintain update atomicity. If your system does not
573 implement a global monitor, this option can cause programs that
574 perform SWP operations to uncached memory to deadlock.
575
576 If unsure, say Y
577
578config CP15_BARRIER_EMULATION
579 bool "Emulate CP15 Barrier instructions"
580 help
581 The CP15 barrier instructions - CP15ISB, CP15DSB, and
582 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
583 strongly recommended to use the ISB, DSB, and DMB
584 instructions instead.
585
586 Say Y here to enable software emulation of these
587 instructions for AArch32 userspace code. When this option is
588 enabled, CP15 barrier usage is traced which can help
589 identify software that needs updating.
590
591 If unsure, say Y
592
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593config SETEND_EMULATION
594 bool "Emulate SETEND instruction"
595 help
596 The SETEND instruction alters the data-endianness of the
597 AArch32 EL0, and is deprecated in ARMv8.
598
599 Say Y here to enable software emulation of the instruction
600 for AArch32 userspace code.
601
602 Note: All the cpus on the system must have mixed endian support at EL0
603 for this feature to be enabled. If a new CPU - which doesn't support mixed
604 endian - is hotplugged in after this feature has been enabled, there could
605 be unexpected results in the applications.
606
607 If unsure, say Y
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608endif
609
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610menu "ARMv8.1 architectural features"
611
612config ARM64_HW_AFDBM
613 bool "Support for hardware updates of the Access and Dirty page flags"
614 default y
615 help
616 The ARMv8.1 architecture extensions introduce support for
617 hardware updates of the access and dirty information in page
618 table entries. When enabled in TCR_EL1 (HA and HD bits) on
619 capable processors, accesses to pages with PTE_AF cleared will
620 set this bit instead of raising an access flag fault.
621 Similarly, writes to read-only pages with the DBM bit set will
622 clear the read-only bit (AP[2]) instead of raising a
623 permission fault.
624
625 Kernels built with this configuration option enabled continue
626 to work on pre-ARMv8.1 hardware and the performance impact is
627 minimal. If unsure, say Y.
628
629config ARM64_PAN
630 bool "Enable support for Privileged Access Never (PAN)"
631 default y
632 help
633 Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
634 prevents the kernel or hypervisor from accessing user-space (EL0)
635 memory directly.
636
637 Choosing this option will cause any unprotected (not using
638 copy_to_user et al) memory access to fail with a permission fault.
639
640 The feature is detected at runtime, and will remain as a 'nop'
641 instruction if the cpu does not implement the feature.
642
643config ARM64_LSE_ATOMICS
644 bool "Atomic instructions"
645 help
646 As part of the Large System Extensions, ARMv8.1 introduces new
647 atomic instructions that are designed specifically to scale in
648 very large systems.
649
650 Say Y here to make use of these instructions for the in-kernel
651 atomic routines. This incurs a small overhead on CPUs that do
652 not support these instructions and requires the kernel to be
653 built with binutils >= 2.25.
654
655endmenu
656
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657endmenu
658
659menu "Boot options"
660
661config CMDLINE
662 string "Default kernel command string"
663 default ""
664 help
665 Provide a set of default command-line options at build time by
666 entering them here. As a minimum, you should specify the the
667 root device (e.g. root=/dev/nfs).
668
669config CMDLINE_FORCE
670 bool "Always use the default kernel command string"
671 help
672 Always use the default kernel command string, even if the boot
673 loader passes other arguments to the kernel.
674 This is useful if you cannot or don't want to change the
675 command-line options your boot loader passes to the kernel.
676
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677config EFI_STUB
678 bool
679
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680config EFI
681 bool "UEFI runtime support"
682 depends on OF && !CPU_BIG_ENDIAN
683 select LIBFDT
684 select UCS2_STRING
685 select EFI_PARAMS_FROM_FDT
e15dd494 686 select EFI_RUNTIME_WRAPPERS
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687 select EFI_STUB
688 select EFI_ARMSTUB
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689 default y
690 help
691 This option provides support for runtime services provided
692 by UEFI firmware (such as non-volatile variables, realtime
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693 clock, and platform reset). A UEFI stub is also provided to
694 allow the kernel to be booted as an EFI application. This
695 is only useful on systems that have UEFI firmware.
f84d0275 696
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697config DMI
698 bool "Enable support for SMBIOS (DMI) tables"
699 depends on EFI
700 default y
701 help
702 This enables SMBIOS/DMI feature for systems.
703
704 This option is only useful on systems that have UEFI firmware.
705 However, even with this option, the resultant kernel should
706 continue to boot on existing non-UEFI platforms.
707
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708endmenu
709
710menu "Userspace binary formats"
711
712source "fs/Kconfig.binfmt"
713
714config COMPAT
715 bool "Kernel support for 32-bit EL0"
755e70b7 716 depends on ARM64_4K_PAGES || EXPERT
8c2c3df3 717 select COMPAT_BINFMT_ELF
af1839eb 718 select HAVE_UID16
84b9e9b4 719 select OLD_SIGSUSPEND3
51682036 720 select COMPAT_OLD_SIGACTION
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721 help
722 This option enables support for a 32-bit EL0 running under a 64-bit
723 kernel at EL1. AArch32-specific components such as system calls,
724 the user helper functions, VFP support and the ptrace interface are
725 handled appropriately by the kernel.
726
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727 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
728 that you will only be able to execute AArch32 binaries that were compiled
729 with page size aligned segments.
a8fcd8b1 730
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731 If you want to execute 32-bit userspace applications, say Y.
732
733config SYSVIPC_COMPAT
734 def_bool y
735 depends on COMPAT && SYSVIPC
736
737endmenu
738
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739menu "Power management options"
740
741source "kernel/power/Kconfig"
742
743config ARCH_SUSPEND_POSSIBLE
744 def_bool y
745
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746endmenu
747
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748menu "CPU Power Management"
749
750source "drivers/cpuidle/Kconfig"
751
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752source "drivers/cpufreq/Kconfig"
753
754endmenu
755
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756source "net/Kconfig"
757
758source "drivers/Kconfig"
759
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760source "drivers/firmware/Kconfig"
761
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762source "drivers/acpi/Kconfig"
763
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764source "fs/Kconfig"
765
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766source "arch/arm64/kvm/Kconfig"
767
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768source "arch/arm64/Kconfig.debug"
769
770source "security/Kconfig"
771
772source "crypto/Kconfig"
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773if CRYPTO
774source "arch/arm64/crypto/Kconfig"
775endif
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776
777source "lib/Kconfig"