xref: /openbmc/linux/arch/arm/Kconfig (revision db66795f)
1# SPDX-License-Identifier: GPL-2.0
2config ARM
3	bool
4	default y
5	select ARCH_32BIT_OFF_T
6	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE if HAVE_KRETPROBES && FRAME_POINTER && !ARM_UNWIND
7	select ARCH_HAS_BINFMT_FLAT
8	select ARCH_HAS_CPU_FINALIZE_INIT if MMU
9	select ARCH_HAS_CURRENT_STACK_POINTER
10	select ARCH_HAS_DEBUG_VIRTUAL if MMU
11	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
12	select ARCH_HAS_ELF_RANDOMIZE
13	select ARCH_HAS_FORTIFY_SOURCE
14	select ARCH_HAS_KEEPINITRD
15	select ARCH_HAS_KCOV
16	select ARCH_HAS_MEMBARRIER_SYNC_CORE
17	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
18	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
19	select ARCH_HAS_SETUP_DMA_OPS
20	select ARCH_HAS_SET_MEMORY
21	select ARCH_STACKWALK
22	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
23	select ARCH_HAS_STRICT_MODULE_RWX if MMU
24	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
25	select ARCH_HAS_SYNC_DMA_FOR_CPU
26	select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
27	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
28	select ARCH_HAVE_NMI_SAFE_CMPXCHG if CPU_V7 || CPU_V7M || CPU_V6K
29	select ARCH_HAS_GCOV_PROFILE_ALL
30	select ARCH_KEEP_MEMBLOCK
31	select ARCH_HAS_UBSAN_SANITIZE_ALL
32	select ARCH_MIGHT_HAVE_PC_PARPORT
33	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
34	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
35	select ARCH_SUPPORTS_ATOMIC_RMW
36	select ARCH_SUPPORTS_HUGETLBFS if ARM_LPAE
37	select ARCH_USE_BUILTIN_BSWAP
38	select ARCH_USE_CMPXCHG_LOCKREF
39	select ARCH_USE_MEMTEST
40	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
41	select ARCH_WANT_GENERAL_HUGETLB
42	select ARCH_WANT_IPC_PARSE_VERSION
43	select ARCH_WANT_LD_ORPHAN_WARN
44	select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
45	select BUILDTIME_TABLE_SORT if MMU
46	select COMMON_CLK if !(ARCH_RPC || ARCH_FOOTBRIDGE)
47	select CLONE_BACKWARDS
48	select CPU_PM if SUSPEND || CPU_IDLE
49	select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
50	select DMA_DECLARE_COHERENT
51	select DMA_GLOBAL_POOL if !MMU
52	select DMA_OPS
53	select DMA_NONCOHERENT_MMAP if MMU
54	select EDAC_SUPPORT
55	select EDAC_ATOMIC_SCRUB
56	select GENERIC_ALLOCATOR
57	select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
58	select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
59	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
60	select GENERIC_IRQ_IPI if SMP
61	select GENERIC_CPU_AUTOPROBE
62	select GENERIC_EARLY_IOREMAP
63	select GENERIC_IDLE_POLL_SETUP
64	select GENERIC_IRQ_MULTI_HANDLER
65	select GENERIC_IRQ_PROBE
66	select GENERIC_IRQ_SHOW
67	select GENERIC_IRQ_SHOW_LEVEL
68	select GENERIC_LIB_DEVMEM_IS_ALLOWED
69	select GENERIC_PCI_IOMAP
70	select GENERIC_SCHED_CLOCK
71	select GENERIC_SMP_IDLE_THREAD
72	select HARDIRQS_SW_RESEND
73	select HAS_IOPORT
74	select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
75	select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
76	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
77	select HAVE_ARCH_KFENCE if MMU && !XIP_KERNEL
78	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
79	select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
80	select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
81	select HAVE_ARCH_MMAP_RND_BITS if MMU
82	select HAVE_ARCH_PFN_VALID
83	select HAVE_ARCH_SECCOMP
84	select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
85	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
86	select HAVE_ARCH_TRACEHOOK
87	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARM_LPAE
88	select HAVE_ARM_SMCCC if CPU_V7
89	select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
90	select HAVE_CONTEXT_TRACKING_USER
91	select HAVE_C_RECORDMCOUNT
92	select HAVE_BUILDTIME_MCOUNT_SORT
93	select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
94	select HAVE_DMA_CONTIGUOUS if MMU
95	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
96	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
97	select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
98	select HAVE_EXIT_THREAD
99	select HAVE_FAST_GUP if ARM_LPAE
100	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
101	select HAVE_FUNCTION_ERROR_INJECTION
102	select HAVE_FUNCTION_GRAPH_TRACER
103	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
104	select HAVE_GCC_PLUGINS
105	select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
106	select HAVE_IRQ_TIME_ACCOUNTING
107	select HAVE_KERNEL_GZIP
108	select HAVE_KERNEL_LZ4
109	select HAVE_KERNEL_LZMA
110	select HAVE_KERNEL_LZO
111	select HAVE_KERNEL_XZ
112	select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
113	select HAVE_KRETPROBES if HAVE_KPROBES
114	select HAVE_MOD_ARCH_SPECIFIC
115	select HAVE_NMI
116	select HAVE_OPTPROBES if !THUMB2_KERNEL
117	select HAVE_PCI if MMU
118	select HAVE_PERF_EVENTS
119	select HAVE_PERF_REGS
120	select HAVE_PERF_USER_STACK_DUMP
121	select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
122	select HAVE_REGS_AND_STACK_ACCESS_API
123	select HAVE_RSEQ
124	select HAVE_STACKPROTECTOR
125	select HAVE_SYSCALL_TRACEPOINTS
126	select HAVE_UID16
127	select HAVE_VIRT_CPU_ACCOUNTING_GEN
128	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
129	select IRQ_FORCED_THREADING
130	select LOCK_MM_AND_FIND_VMA
131	select MODULES_USE_ELF_REL
132	select NEED_DMA_MAP_STATE
133	select OF_EARLY_FLATTREE if OF
134	select OLD_SIGACTION
135	select OLD_SIGSUSPEND3
136	select PCI_DOMAINS_GENERIC if PCI
137	select PCI_SYSCALL if PCI
138	select PERF_USE_VMALLOC
139	select RTC_LIB
140	select SPARSE_IRQ if !(ARCH_FOOTBRIDGE || ARCH_RPC)
141	select SYS_SUPPORTS_APM_EMULATION
142	select THREAD_INFO_IN_TASK
143	select TIMER_OF if OF
144	select HAVE_ARCH_VMAP_STACK if MMU && ARM_HAS_GROUP_RELOCS
145	select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M
146	select USE_OF if !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
147	# Above selects are sorted alphabetically; please add new ones
148	# according to that.  Thanks.
149	help
150	  The ARM series is a line of low-power-consumption RISC chip designs
151	  licensed by ARM Ltd and targeted at embedded applications and
152	  handhelds such as the Compaq IPAQ.  ARM-based PCs are no longer
153	  manufactured, but legacy ARM-based PC hardware remains popular in
154	  Europe.  There is an ARM Linux project with a web page at
155	  <http://www.arm.linux.org.uk/>.
156
157config ARM_HAS_GROUP_RELOCS
158	def_bool y
159	depends on !LD_IS_LLD || LLD_VERSION >= 140000
160	depends on !COMPILE_TEST
161	help
162	  Whether or not to use R_ARM_ALU_PC_Gn or R_ARM_LDR_PC_Gn group
163	  relocations, which have been around for a long time, but were not
164	  supported in LLD until version 14. The combined range is -/+ 256 MiB,
165	  which is usually sufficient, but not for allyesconfig, so we disable
166	  this feature when doing compile testing.
167
168config ARM_DMA_USE_IOMMU
169	bool
170	select NEED_SG_DMA_LENGTH
171
172if ARM_DMA_USE_IOMMU
173
174config ARM_DMA_IOMMU_ALIGNMENT
175	int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
176	range 4 9
177	default 8
178	help
179	  DMA mapping framework by default aligns all buffers to the smallest
180	  PAGE_SIZE order which is greater than or equal to the requested buffer
181	  size. This works well for buffers up to a few hundreds kilobytes, but
182	  for larger buffers it just a waste of address space. Drivers which has
183	  relatively small addressing window (like 64Mib) might run out of
184	  virtual space with just a few allocations.
185
186	  With this parameter you can specify the maximum PAGE_SIZE order for
187	  DMA IOMMU buffers. Larger buffers will be aligned only to this
188	  specified order. The order is expressed as a power of two multiplied
189	  by the PAGE_SIZE.
190
191endif
192
193config SYS_SUPPORTS_APM_EMULATION
194	bool
195
196config HAVE_TCM
197	bool
198	select GENERIC_ALLOCATOR
199
200config HAVE_PROC_CPU
201	bool
202
203config NO_IOPORT_MAP
204	bool
205
206config SBUS
207	bool
208
209config STACKTRACE_SUPPORT
210	bool
211	default y
212
213config LOCKDEP_SUPPORT
214	bool
215	default y
216
217config ARCH_HAS_ILOG2_U32
218	bool
219
220config ARCH_HAS_ILOG2_U64
221	bool
222
223config ARCH_HAS_BANDGAP
224	bool
225
226config FIX_EARLYCON_MEM
227	def_bool y if MMU
228
229config GENERIC_HWEIGHT
230	bool
231	default y
232
233config GENERIC_CALIBRATE_DELAY
234	bool
235	default y
236
237config ARCH_MAY_HAVE_PC_FDC
238	bool
239
240config ARCH_SUPPORTS_UPROBES
241	def_bool y
242
243config GENERIC_ISA_DMA
244	bool
245
246config FIQ
247	bool
248
249config ARCH_MTD_XIP
250	bool
251
252config ARM_PATCH_PHYS_VIRT
253	bool "Patch physical to virtual translations at runtime" if EMBEDDED
254	default y
255	depends on MMU
256	help
257	  Patch phys-to-virt and virt-to-phys translation functions at
258	  boot and module load time according to the position of the
259	  kernel in system memory.
260
261	  This can only be used with non-XIP MMU kernels where the base
262	  of physical memory is at a 2 MiB boundary.
263
264	  Only disable this option if you know that you do not require
265	  this feature (eg, building a kernel for a single machine) and
266	  you need to shrink the kernel to the minimal size.
267
268config NEED_MACH_IO_H
269	bool
270	help
271	  Select this when mach/io.h is required to provide special
272	  definitions for this platform.  The need for mach/io.h should
273	  be avoided when possible.
274
275config NEED_MACH_MEMORY_H
276	bool
277	help
278	  Select this when mach/memory.h is required to provide special
279	  definitions for this platform.  The need for mach/memory.h should
280	  be avoided when possible.
281
282config PHYS_OFFSET
283	hex "Physical address of main memory" if MMU
284	depends on !ARM_PATCH_PHYS_VIRT || !AUTO_ZRELADDR
285	default DRAM_BASE if !MMU
286	default 0x00000000 if ARCH_FOOTBRIDGE
287	default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
288	default 0xa0000000 if ARCH_PXA
289	default 0xc0000000 if ARCH_EP93XX || ARCH_SA1100
290	default 0
291	help
292	  Please provide the physical address corresponding to the
293	  location of main memory in your system.
294
295config GENERIC_BUG
296	def_bool y
297	depends on BUG
298
299config PGTABLE_LEVELS
300	int
301	default 3 if ARM_LPAE
302	default 2
303
304menu "System Type"
305
306config MMU
307	bool "MMU-based Paged Memory Management Support"
308	default y
309	help
310	  Select if you want MMU-based virtualised addressing space
311	  support by paged memory management. If unsure, say 'Y'.
312
313config ARM_SINGLE_ARMV7M
314	def_bool !MMU
315	select ARM_NVIC
316	select CPU_V7M
317	select NO_IOPORT_MAP
318
319config ARCH_MMAP_RND_BITS_MIN
320	default 8
321
322config ARCH_MMAP_RND_BITS_MAX
323	default 14 if PAGE_OFFSET=0x40000000
324	default 15 if PAGE_OFFSET=0x80000000
325	default 16
326
327config ARCH_MULTIPLATFORM
328	bool "Require kernel to be portable to multiple machines" if EXPERT
329	depends on MMU && !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
330	default y
331	help
332	  In general, all Arm machines can be supported in a single
333	  kernel image, covering either Armv4/v5 or Armv6/v7.
334
335	  However, some configuration options require hardcoding machine
336	  specific physical addresses or enable errata workarounds that may
337	  break other machines.
338
339	  Selecting N here allows using those options, including
340	  DEBUG_UNCOMPRESS, XIP_KERNEL and ZBOOT_ROM. If unsure, say Y.
341
342menu "Platform selection"
343	depends on MMU
344
345comment "CPU Core family selection"
346
347config ARCH_MULTI_V4
348	bool "ARMv4 based platforms (FA526, StrongARM)"
349	depends on !ARCH_MULTI_V6_V7
350	# https://github.com/llvm/llvm-project/issues/50764
351	depends on !LD_IS_LLD || LLD_VERSION >= 160000
352	select ARCH_MULTI_V4_V5
353	select CPU_FA526 if !(CPU_SA110 || CPU_SA1100)
354
355config ARCH_MULTI_V4T
356	bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
357	depends on !ARCH_MULTI_V6_V7
358	# https://github.com/llvm/llvm-project/issues/50764
359	depends on !LD_IS_LLD || LLD_VERSION >= 160000
360	select ARCH_MULTI_V4_V5
361	select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
362		CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
363		CPU_ARM925T || CPU_ARM940T)
364
365config ARCH_MULTI_V5
366	bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
367	depends on !ARCH_MULTI_V6_V7
368	select ARCH_MULTI_V4_V5
369	select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
370		CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
371		CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
372
373config ARCH_MULTI_V4_V5
374	bool
375
376config ARCH_MULTI_V6
377	bool "ARMv6 based platforms (ARM11)"
378	select ARCH_MULTI_V6_V7
379	select CPU_V6K
380
381config ARCH_MULTI_V7
382	bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
383	default y
384	select ARCH_MULTI_V6_V7
385	select CPU_V7
386	select HAVE_SMP
387
388config ARCH_MULTI_V6_V7
389	bool
390	select MIGHT_HAVE_CACHE_L2X0
391
392config ARCH_MULTI_CPU_AUTO
393	def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
394	select ARCH_MULTI_V5
395
396endmenu
397
398config ARCH_VIRT
399	bool "Dummy Virtual Machine"
400	depends on ARCH_MULTI_V7
401	select ARM_AMBA
402	select ARM_GIC
403	select ARM_GIC_V2M if PCI
404	select ARM_GIC_V3
405	select ARM_GIC_V3_ITS if PCI
406	select ARM_PSCI
407	select HAVE_ARM_ARCH_TIMER
408
409config ARCH_AIROHA
410	bool "Airoha SoC Support"
411	depends on ARCH_MULTI_V7
412	select ARM_AMBA
413	select ARM_GIC
414	select ARM_GIC_V3
415	select ARM_PSCI
416	select HAVE_ARM_ARCH_TIMER
417	help
418	  Support for Airoha EN7523 SoCs
419
420#
421# This is sorted alphabetically by mach-* pathname.  However, plat-*
422# Kconfigs may be included either alphabetically (according to the
423# plat- suffix) or along side the corresponding mach-* source.
424#
425source "arch/arm/mach-actions/Kconfig"
426
427source "arch/arm/mach-alpine/Kconfig"
428
429source "arch/arm/mach-artpec/Kconfig"
430
431source "arch/arm/mach-asm9260/Kconfig"
432
433source "arch/arm/mach-aspeed/Kconfig"
434
435source "arch/arm/mach-at91/Kconfig"
436
437source "arch/arm/mach-axxia/Kconfig"
438
439source "arch/arm/mach-bcm/Kconfig"
440
441source "arch/arm/mach-berlin/Kconfig"
442
443source "arch/arm/mach-clps711x/Kconfig"
444
445source "arch/arm/mach-davinci/Kconfig"
446
447source "arch/arm/mach-digicolor/Kconfig"
448
449source "arch/arm/mach-dove/Kconfig"
450
451source "arch/arm/mach-ep93xx/Kconfig"
452
453source "arch/arm/mach-exynos/Kconfig"
454
455source "arch/arm/mach-footbridge/Kconfig"
456
457source "arch/arm/mach-gemini/Kconfig"
458
459source "arch/arm/mach-highbank/Kconfig"
460
461source "arch/arm/mach-hisi/Kconfig"
462
463source "arch/arm/mach-hpe/Kconfig"
464
465source "arch/arm/mach-imx/Kconfig"
466
467source "arch/arm/mach-ixp4xx/Kconfig"
468
469source "arch/arm/mach-keystone/Kconfig"
470
471source "arch/arm/mach-lpc32xx/Kconfig"
472
473source "arch/arm/mach-mediatek/Kconfig"
474
475source "arch/arm/mach-meson/Kconfig"
476
477source "arch/arm/mach-milbeaut/Kconfig"
478
479source "arch/arm/mach-mmp/Kconfig"
480
481source "arch/arm/mach-moxart/Kconfig"
482
483source "arch/arm/mach-mstar/Kconfig"
484
485source "arch/arm/mach-mv78xx0/Kconfig"
486
487source "arch/arm/mach-mvebu/Kconfig"
488
489source "arch/arm/mach-mxs/Kconfig"
490
491source "arch/arm/mach-nomadik/Kconfig"
492
493source "arch/arm/mach-npcm/Kconfig"
494
495source "arch/arm/mach-nspire/Kconfig"
496
497source "arch/arm/mach-omap1/Kconfig"
498
499source "arch/arm/mach-omap2/Kconfig"
500
501source "arch/arm/mach-orion5x/Kconfig"
502
503source "arch/arm/mach-pxa/Kconfig"
504
505source "arch/arm/mach-qcom/Kconfig"
506
507source "arch/arm/mach-rda/Kconfig"
508
509source "arch/arm/mach-realtek/Kconfig"
510
511source "arch/arm/mach-rpc/Kconfig"
512
513source "arch/arm/mach-rockchip/Kconfig"
514
515source "arch/arm/mach-s3c/Kconfig"
516
517source "arch/arm/mach-s5pv210/Kconfig"
518
519source "arch/arm/mach-sa1100/Kconfig"
520
521source "arch/arm/mach-shmobile/Kconfig"
522
523source "arch/arm/mach-socfpga/Kconfig"
524
525source "arch/arm/mach-spear/Kconfig"
526
527source "arch/arm/mach-sti/Kconfig"
528
529source "arch/arm/mach-stm32/Kconfig"
530
531source "arch/arm/mach-sunplus/Kconfig"
532
533source "arch/arm/mach-sunxi/Kconfig"
534
535source "arch/arm/mach-tegra/Kconfig"
536
537source "arch/arm/mach-uniphier/Kconfig"
538
539source "arch/arm/mach-ux500/Kconfig"
540
541source "arch/arm/mach-versatile/Kconfig"
542
543source "arch/arm/mach-vt8500/Kconfig"
544
545source "arch/arm/mach-zynq/Kconfig"
546
547# ARMv7-M architecture
548config ARCH_LPC18XX
549	bool "NXP LPC18xx/LPC43xx"
550	depends on ARM_SINGLE_ARMV7M
551	select ARCH_HAS_RESET_CONTROLLER
552	select ARM_AMBA
553	select CLKSRC_LPC32XX
554	select PINCTRL
555	help
556	  Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
557	  high performance microcontrollers.
558
559config ARCH_MPS2
560	bool "ARM MPS2 platform"
561	depends on ARM_SINGLE_ARMV7M
562	select ARM_AMBA
563	select CLKSRC_MPS2
564	help
565	  Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
566	  with a range of available cores like Cortex-M3/M4/M7.
567
568	  Please, note that depends which Application Note is used memory map
569	  for the platform may vary, so adjustment of RAM base might be needed.
570
571# Definitions to make life easier
572config ARCH_ACORN
573	bool
574
575config PLAT_ORION
576	bool
577	select CLKSRC_MMIO
578	select GENERIC_IRQ_CHIP
579	select IRQ_DOMAIN
580
581config PLAT_ORION_LEGACY
582	bool
583	select PLAT_ORION
584
585config PLAT_VERSATILE
586	bool
587
588source "arch/arm/mm/Kconfig"
589
590config IWMMXT
591	bool "Enable iWMMXt support"
592	depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
593	default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
594	help
595	  Enable support for iWMMXt context switching at run time if
596	  running on a CPU that supports it.
597
598if !MMU
599source "arch/arm/Kconfig-nommu"
600endif
601
602config PJ4B_ERRATA_4742
603	bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
604	depends on CPU_PJ4B && MACH_ARMADA_370
605	default y
606	help
607	  When coming out of either a Wait for Interrupt (WFI) or a Wait for
608	  Event (WFE) IDLE states, a specific timing sensitivity exists between
609	  the retiring WFI/WFE instructions and the newly issued subsequent
610	  instructions.  This sensitivity can result in a CPU hang scenario.
611	  Workaround:
612	  The software must insert either a Data Synchronization Barrier (DSB)
613	  or Data Memory Barrier (DMB) command immediately after the WFI/WFE
614	  instruction
615
616config ARM_ERRATA_326103
617	bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
618	depends on CPU_V6
619	help
620	  Executing a SWP instruction to read-only memory does not set bit 11
621	  of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
622	  treat the access as a read, preventing a COW from occurring and
623	  causing the faulting task to livelock.
624
625config ARM_ERRATA_411920
626	bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
627	depends on CPU_V6 || CPU_V6K
628	help
629	  Invalidation of the Instruction Cache operation can
630	  fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
631	  It does not affect the MPCore. This option enables the ARM Ltd.
632	  recommended workaround.
633
634config ARM_ERRATA_430973
635	bool "ARM errata: Stale prediction on replaced interworking branch"
636	depends on CPU_V7
637	help
638	  This option enables the workaround for the 430973 Cortex-A8
639	  r1p* erratum. If a code sequence containing an ARM/Thumb
640	  interworking branch is replaced with another code sequence at the
641	  same virtual address, whether due to self-modifying code or virtual
642	  to physical address re-mapping, Cortex-A8 does not recover from the
643	  stale interworking branch prediction. This results in Cortex-A8
644	  executing the new code sequence in the incorrect ARM or Thumb state.
645	  The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
646	  and also flushes the branch target cache at every context switch.
647	  Note that setting specific bits in the ACTLR register may not be
648	  available in non-secure mode.
649
650config ARM_ERRATA_458693
651	bool "ARM errata: Processor deadlock when a false hazard is created"
652	depends on CPU_V7
653	depends on !ARCH_MULTIPLATFORM
654	help
655	  This option enables the workaround for the 458693 Cortex-A8 (r2p0)
656	  erratum. For very specific sequences of memory operations, it is
657	  possible for a hazard condition intended for a cache line to instead
658	  be incorrectly associated with a different cache line. This false
659	  hazard might then cause a processor deadlock. The workaround enables
660	  the L1 caching of the NEON accesses and disables the PLD instruction
661	  in the ACTLR register. Note that setting specific bits in the ACTLR
662	  register may not be available in non-secure mode and thus is not
663	  available on a multiplatform kernel. This should be applied by the
664	  bootloader instead.
665
666config ARM_ERRATA_460075
667	bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
668	depends on CPU_V7
669	depends on !ARCH_MULTIPLATFORM
670	help
671	  This option enables the workaround for the 460075 Cortex-A8 (r2p0)
672	  erratum. Any asynchronous access to the L2 cache may encounter a
673	  situation in which recent store transactions to the L2 cache are lost
674	  and overwritten with stale memory contents from external memory. The
675	  workaround disables the write-allocate mode for the L2 cache via the
676	  ACTLR register. Note that setting specific bits in the ACTLR register
677	  may not be available in non-secure mode and thus is not available on
678	  a multiplatform kernel. This should be applied by the bootloader
679	  instead.
680
681config ARM_ERRATA_742230
682	bool "ARM errata: DMB operation may be faulty"
683	depends on CPU_V7 && SMP
684	depends on !ARCH_MULTIPLATFORM
685	help
686	  This option enables the workaround for the 742230 Cortex-A9
687	  (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
688	  between two write operations may not ensure the correct visibility
689	  ordering of the two writes. This workaround sets a specific bit in
690	  the diagnostic register of the Cortex-A9 which causes the DMB
691	  instruction to behave as a DSB, ensuring the correct behaviour of
692	  the two writes. Note that setting specific bits in the diagnostics
693	  register may not be available in non-secure mode and thus is not
694	  available on a multiplatform kernel. This should be applied by the
695	  bootloader instead.
696
697config ARM_ERRATA_742231
698	bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
699	depends on CPU_V7 && SMP
700	depends on !ARCH_MULTIPLATFORM
701	help
702	  This option enables the workaround for the 742231 Cortex-A9
703	  (r2p0..r2p2) erratum. Under certain conditions, specific to the
704	  Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
705	  accessing some data located in the same cache line, may get corrupted
706	  data due to bad handling of the address hazard when the line gets
707	  replaced from one of the CPUs at the same time as another CPU is
708	  accessing it. This workaround sets specific bits in the diagnostic
709	  register of the Cortex-A9 which reduces the linefill issuing
710	  capabilities of the processor. Note that setting specific bits in the
711	  diagnostics register may not be available in non-secure mode and thus
712	  is not available on a multiplatform kernel. This should be applied by
713	  the bootloader instead.
714
715config ARM_ERRATA_643719
716	bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
717	depends on CPU_V7 && SMP
718	default y
719	help
720	  This option enables the workaround for the 643719 Cortex-A9 (prior to
721	  r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
722	  register returns zero when it should return one. The workaround
723	  corrects this value, ensuring cache maintenance operations which use
724	  it behave as intended and avoiding data corruption.
725
726config ARM_ERRATA_720789
727	bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
728	depends on CPU_V7
729	help
730	  This option enables the workaround for the 720789 Cortex-A9 (prior to
731	  r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
732	  broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
733	  As a consequence of this erratum, some TLB entries which should be
734	  invalidated are not, resulting in an incoherency in the system page
735	  tables. The workaround changes the TLB flushing routines to invalidate
736	  entries regardless of the ASID.
737
738config ARM_ERRATA_743622
739	bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
740	depends on CPU_V7
741	depends on !ARCH_MULTIPLATFORM
742	help
743	  This option enables the workaround for the 743622 Cortex-A9
744	  (r2p*) erratum. Under very rare conditions, a faulty
745	  optimisation in the Cortex-A9 Store Buffer may lead to data
746	  corruption. This workaround sets a specific bit in the diagnostic
747	  register of the Cortex-A9 which disables the Store Buffer
748	  optimisation, preventing the defect from occurring. This has no
749	  visible impact on the overall performance or power consumption of the
750	  processor. Note that setting specific bits in the diagnostics register
751	  may not be available in non-secure mode and thus is not available on a
752	  multiplatform kernel. This should be applied by the bootloader instead.
753
754config ARM_ERRATA_751472
755	bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
756	depends on CPU_V7
757	depends on !ARCH_MULTIPLATFORM
758	help
759	  This option enables the workaround for the 751472 Cortex-A9 (prior
760	  to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
761	  completion of a following broadcasted operation if the second
762	  operation is received by a CPU before the ICIALLUIS has completed,
763	  potentially leading to corrupted entries in the cache or TLB.
764	  Note that setting specific bits in the diagnostics register may
765	  not be available in non-secure mode and thus is not available on
766	  a multiplatform kernel. This should be applied by the bootloader
767	  instead.
768
769config ARM_ERRATA_754322
770	bool "ARM errata: possible faulty MMU translations following an ASID switch"
771	depends on CPU_V7
772	help
773	  This option enables the workaround for the 754322 Cortex-A9 (r2p*,
774	  r3p*) erratum. A speculative memory access may cause a page table walk
775	  which starts prior to an ASID switch but completes afterwards. This
776	  can populate the micro-TLB with a stale entry which may be hit with
777	  the new ASID. This workaround places two dsb instructions in the mm
778	  switching code so that no page table walks can cross the ASID switch.
779
780config ARM_ERRATA_754327
781	bool "ARM errata: no automatic Store Buffer drain"
782	depends on CPU_V7 && SMP
783	help
784	  This option enables the workaround for the 754327 Cortex-A9 (prior to
785	  r2p0) erratum. The Store Buffer does not have any automatic draining
786	  mechanism and therefore a livelock may occur if an external agent
787	  continuously polls a memory location waiting to observe an update.
788	  This workaround defines cpu_relax() as smp_mb(), preventing correctly
789	  written polling loops from denying visibility of updates to memory.
790
791config ARM_ERRATA_364296
792	bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
793	depends on CPU_V6
794	help
795	  This options enables the workaround for the 364296 ARM1136
796	  r0p2 erratum (possible cache data corruption with
797	  hit-under-miss enabled). It sets the undocumented bit 31 in
798	  the auxiliary control register and the FI bit in the control
799	  register, thus disabling hit-under-miss without putting the
800	  processor into full low interrupt latency mode. ARM11MPCore
801	  is not affected.
802
803config ARM_ERRATA_764369
804	bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
805	depends on CPU_V7 && SMP
806	help
807	  This option enables the workaround for erratum 764369
808	  affecting Cortex-A9 MPCore with two or more processors (all
809	  current revisions). Under certain timing circumstances, a data
810	  cache line maintenance operation by MVA targeting an Inner
811	  Shareable memory region may fail to proceed up to either the
812	  Point of Coherency or to the Point of Unification of the
813	  system. This workaround adds a DSB instruction before the
814	  relevant cache maintenance functions and sets a specific bit
815	  in the diagnostic control register of the SCU.
816
817config ARM_ERRATA_764319
818	bool "ARM errata: Read to DBGPRSR and DBGOSLSR may generate Undefined instruction"
819	depends on CPU_V7
820	help
821	  This option enables the workaround for the 764319 Cortex A-9 erratum.
822	  CP14 read accesses to the DBGPRSR and DBGOSLSR registers generate an
823	  unexpected Undefined Instruction exception when the DBGSWENABLE
824	  external pin is set to 0, even when the CP14 accesses are performed
825	  from a privileged mode. This work around catches the exception in a
826	  way the kernel does not stop execution.
827
828config ARM_ERRATA_775420
829       bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
830       depends on CPU_V7
831       help
832	 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
833	 r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance
834	 operation aborts with MMU exception, it might cause the processor
835	 to deadlock. This workaround puts DSB before executing ISB if
836	 an abort may occur on cache maintenance.
837
838config ARM_ERRATA_798181
839	bool "ARM errata: TLBI/DSB failure on Cortex-A15"
840	depends on CPU_V7 && SMP
841	help
842	  On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
843	  adequately shooting down all use of the old entries. This
844	  option enables the Linux kernel workaround for this erratum
845	  which sends an IPI to the CPUs that are running the same ASID
846	  as the one being invalidated.
847
848config ARM_ERRATA_773022
849	bool "ARM errata: incorrect instructions may be executed from loop buffer"
850	depends on CPU_V7
851	help
852	  This option enables the workaround for the 773022 Cortex-A15
853	  (up to r0p4) erratum. In certain rare sequences of code, the
854	  loop buffer may deliver incorrect instructions. This
855	  workaround disables the loop buffer to avoid the erratum.
856
857config ARM_ERRATA_818325_852422
858	bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
859	depends on CPU_V7
860	help
861	  This option enables the workaround for:
862	  - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
863	    instruction might deadlock.  Fixed in r0p1.
864	  - Cortex-A12 852422: Execution of a sequence of instructions might
865	    lead to either a data corruption or a CPU deadlock.  Not fixed in
866	    any Cortex-A12 cores yet.
867	  This workaround for all both errata involves setting bit[12] of the
868	  Feature Register. This bit disables an optimisation applied to a
869	  sequence of 2 instructions that use opposing condition codes.
870
871config ARM_ERRATA_821420
872	bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
873	depends on CPU_V7
874	help
875	  This option enables the workaround for the 821420 Cortex-A12
876	  (all revs) erratum. In very rare timing conditions, a sequence
877	  of VMOV to Core registers instructions, for which the second
878	  one is in the shadow of a branch or abort, can lead to a
879	  deadlock when the VMOV instructions are issued out-of-order.
880
881config ARM_ERRATA_825619
882	bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
883	depends on CPU_V7
884	help
885	  This option enables the workaround for the 825619 Cortex-A12
886	  (all revs) erratum. Within rare timing constraints, executing a
887	  DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
888	  and Device/Strongly-Ordered loads and stores might cause deadlock
889
890config ARM_ERRATA_857271
891	bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
892	depends on CPU_V7
893	help
894	  This option enables the workaround for the 857271 Cortex-A12
895	  (all revs) erratum. Under very rare timing conditions, the CPU might
896	  hang. The workaround is expected to have a < 1% performance impact.
897
898config ARM_ERRATA_852421
899	bool "ARM errata: A17: DMB ST might fail to create order between stores"
900	depends on CPU_V7
901	help
902	  This option enables the workaround for the 852421 Cortex-A17
903	  (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
904	  execution of a DMB ST instruction might fail to properly order
905	  stores from GroupA and stores from GroupB.
906
907config ARM_ERRATA_852423
908	bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
909	depends on CPU_V7
910	help
911	  This option enables the workaround for:
912	  - Cortex-A17 852423: Execution of a sequence of instructions might
913	    lead to either a data corruption or a CPU deadlock.  Not fixed in
914	    any Cortex-A17 cores yet.
915	  This is identical to Cortex-A12 erratum 852422.  It is a separate
916	  config option from the A12 erratum due to the way errata are checked
917	  for and handled.
918
919config ARM_ERRATA_857272
920	bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
921	depends on CPU_V7
922	help
923	  This option enables the workaround for the 857272 Cortex-A17 erratum.
924	  This erratum is not known to be fixed in any A17 revision.
925	  This is identical to Cortex-A12 erratum 857271.  It is a separate
926	  config option from the A12 erratum due to the way errata are checked
927	  for and handled.
928
929endmenu
930
931source "arch/arm/common/Kconfig"
932
933menu "Bus support"
934
935config ISA
936	bool
937	help
938	  Find out whether you have ISA slots on your motherboard.  ISA is the
939	  name of a bus system, i.e. the way the CPU talks to the other stuff
940	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
941	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
942	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
943
944# Select ISA DMA interface
945config ISA_DMA_API
946	bool
947
948config ARM_ERRATA_814220
949	bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
950	depends on CPU_V7
951	help
952	  The v7 ARM states that all cache and branch predictor maintenance
953	  operations that do not specify an address execute, relative to
954	  each other, in program order.
955	  However, because of this erratum, an L2 set/way cache maintenance
956	  operation can overtake an L1 set/way cache maintenance operation.
957	  This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
958	  r0p4, r0p5.
959
960endmenu
961
962menu "Kernel Features"
963
964config HAVE_SMP
965	bool
966	help
967	  This option should be selected by machines which have an SMP-
968	  capable CPU.
969
970	  The only effect of this option is to make the SMP-related
971	  options available to the user for configuration.
972
973config SMP
974	bool "Symmetric Multi-Processing"
975	depends on CPU_V6K || CPU_V7
976	depends on HAVE_SMP
977	depends on MMU || ARM_MPU
978	select IRQ_WORK
979	help
980	  This enables support for systems with more than one CPU. If you have
981	  a system with only one CPU, say N. If you have a system with more
982	  than one CPU, say Y.
983
984	  If you say N here, the kernel will run on uni- and multiprocessor
985	  machines, but will use only one CPU of a multiprocessor machine. If
986	  you say Y here, the kernel will run on many, but not all,
987	  uniprocessor machines. On a uniprocessor machine, the kernel
988	  will run faster if you say N here.
989
990	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
991	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
992	  <http://tldp.org/HOWTO/SMP-HOWTO.html>.
993
994	  If you don't know what to do here, say N.
995
996config SMP_ON_UP
997	bool "Allow booting SMP kernel on uniprocessor systems"
998	depends on SMP && MMU
999	default y
1000	help
1001	  SMP kernels contain instructions which fail on non-SMP processors.
1002	  Enabling this option allows the kernel to modify itself to make
1003	  these instructions safe.  Disabling it allows about 1K of space
1004	  savings.
1005
1006	  If you don't know what to do here, say Y.
1007
1008
1009config CURRENT_POINTER_IN_TPIDRURO
1010	def_bool y
1011	depends on CPU_32v6K && !CPU_V6
1012
1013config IRQSTACKS
1014	def_bool y
1015	select HAVE_IRQ_EXIT_ON_IRQ_STACK
1016	select HAVE_SOFTIRQ_ON_OWN_STACK
1017
1018config ARM_CPU_TOPOLOGY
1019	bool "Support cpu topology definition"
1020	depends on SMP && CPU_V7
1021	default y
1022	help
1023	  Support ARM cpu topology definition. The MPIDR register defines
1024	  affinity between processors which is then used to describe the cpu
1025	  topology of an ARM System.
1026
1027config SCHED_MC
1028	bool "Multi-core scheduler support"
1029	depends on ARM_CPU_TOPOLOGY
1030	help
1031	  Multi-core scheduler support improves the CPU scheduler's decision
1032	  making when dealing with multi-core CPU chips at a cost of slightly
1033	  increased overhead in some places. If unsure say N here.
1034
1035config SCHED_SMT
1036	bool "SMT scheduler support"
1037	depends on ARM_CPU_TOPOLOGY
1038	help
1039	  Improves the CPU scheduler's decision making when dealing with
1040	  MultiThreading at a cost of slightly increased overhead in some
1041	  places. If unsure say N here.
1042
1043config HAVE_ARM_SCU
1044	bool
1045	help
1046	  This option enables support for the ARM snoop control unit
1047
1048config HAVE_ARM_ARCH_TIMER
1049	bool "Architected timer support"
1050	depends on CPU_V7
1051	select ARM_ARCH_TIMER
1052	help
1053	  This option enables support for the ARM architected timer
1054
1055config HAVE_ARM_TWD
1056	bool
1057	help
1058	  This options enables support for the ARM timer and watchdog unit
1059
1060config MCPM
1061	bool "Multi-Cluster Power Management"
1062	depends on CPU_V7 && SMP
1063	help
1064	  This option provides the common power management infrastructure
1065	  for (multi-)cluster based systems, such as big.LITTLE based
1066	  systems.
1067
1068config MCPM_QUAD_CLUSTER
1069	bool
1070	depends on MCPM
1071	help
1072	  To avoid wasting resources unnecessarily, MCPM only supports up
1073	  to 2 clusters by default.
1074	  Platforms with 3 or 4 clusters that use MCPM must select this
1075	  option to allow the additional clusters to be managed.
1076
1077config BIG_LITTLE
1078	bool "big.LITTLE support (Experimental)"
1079	depends on CPU_V7 && SMP
1080	select MCPM
1081	help
1082	  This option enables support selections for the big.LITTLE
1083	  system architecture.
1084
1085config BL_SWITCHER
1086	bool "big.LITTLE switcher support"
1087	depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1088	select CPU_PM
1089	help
1090	  The big.LITTLE "switcher" provides the core functionality to
1091	  transparently handle transition between a cluster of A15's
1092	  and a cluster of A7's in a big.LITTLE system.
1093
1094config BL_SWITCHER_DUMMY_IF
1095	tristate "Simple big.LITTLE switcher user interface"
1096	depends on BL_SWITCHER && DEBUG_KERNEL
1097	help
1098	  This is a simple and dummy char dev interface to control
1099	  the big.LITTLE switcher core code.  It is meant for
1100	  debugging purposes only.
1101
1102choice
1103	prompt "Memory split"
1104	depends on MMU
1105	default VMSPLIT_3G
1106	help
1107	  Select the desired split between kernel and user memory.
1108
1109	  If you are not absolutely sure what you are doing, leave this
1110	  option alone!
1111
1112	config VMSPLIT_3G
1113		bool "3G/1G user/kernel split"
1114	config VMSPLIT_3G_OPT
1115		depends on !ARM_LPAE
1116		bool "3G/1G user/kernel split (for full 1G low memory)"
1117	config VMSPLIT_2G
1118		bool "2G/2G user/kernel split"
1119	config VMSPLIT_1G
1120		bool "1G/3G user/kernel split"
1121endchoice
1122
1123config PAGE_OFFSET
1124	hex
1125	default PHYS_OFFSET if !MMU
1126	default 0x40000000 if VMSPLIT_1G
1127	default 0x80000000 if VMSPLIT_2G
1128	default 0xB0000000 if VMSPLIT_3G_OPT
1129	default 0xC0000000
1130
1131config KASAN_SHADOW_OFFSET
1132	hex
1133	depends on KASAN
1134	default 0x1f000000 if PAGE_OFFSET=0x40000000
1135	default 0x5f000000 if PAGE_OFFSET=0x80000000
1136	default 0x9f000000 if PAGE_OFFSET=0xC0000000
1137	default 0x8f000000 if PAGE_OFFSET=0xB0000000
1138	default 0xffffffff
1139
1140config NR_CPUS
1141	int "Maximum number of CPUs (2-32)"
1142	range 2 16 if DEBUG_KMAP_LOCAL
1143	range 2 32 if !DEBUG_KMAP_LOCAL
1144	depends on SMP
1145	default "4"
1146	help
1147	  The maximum number of CPUs that the kernel can support.
1148	  Up to 32 CPUs can be supported, or up to 16 if kmap_local()
1149	  debugging is enabled, which uses half of the per-CPU fixmap
1150	  slots as guard regions.
1151
1152config HOTPLUG_CPU
1153	bool "Support for hot-pluggable CPUs"
1154	depends on SMP
1155	select GENERIC_IRQ_MIGRATION
1156	help
1157	  Say Y here to experiment with turning CPUs off and on.  CPUs
1158	  can be controlled through /sys/devices/system/cpu.
1159
1160config ARM_PSCI
1161	bool "Support for the ARM Power State Coordination Interface (PSCI)"
1162	depends on HAVE_ARM_SMCCC
1163	select ARM_PSCI_FW
1164	help
1165	  Say Y here if you want Linux to communicate with system firmware
1166	  implementing the PSCI specification for CPU-centric power
1167	  management operations described in ARM document number ARM DEN
1168	  0022A ("Power State Coordination Interface System Software on
1169	  ARM processors").
1170
1171config HZ_FIXED
1172	int
1173	default 128 if SOC_AT91RM9200
1174	default 0
1175
1176choice
1177	depends on HZ_FIXED = 0
1178	prompt "Timer frequency"
1179
1180config HZ_100
1181	bool "100 Hz"
1182
1183config HZ_200
1184	bool "200 Hz"
1185
1186config HZ_250
1187	bool "250 Hz"
1188
1189config HZ_300
1190	bool "300 Hz"
1191
1192config HZ_500
1193	bool "500 Hz"
1194
1195config HZ_1000
1196	bool "1000 Hz"
1197
1198endchoice
1199
1200config HZ
1201	int
1202	default HZ_FIXED if HZ_FIXED != 0
1203	default 100 if HZ_100
1204	default 200 if HZ_200
1205	default 250 if HZ_250
1206	default 300 if HZ_300
1207	default 500 if HZ_500
1208	default 1000
1209
1210config SCHED_HRTICK
1211	def_bool HIGH_RES_TIMERS
1212
1213config THUMB2_KERNEL
1214	bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1215	depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1216	default y if CPU_THUMBONLY
1217	select ARM_UNWIND
1218	help
1219	  By enabling this option, the kernel will be compiled in
1220	  Thumb-2 mode.
1221
1222	  If unsure, say N.
1223
1224config ARM_PATCH_IDIV
1225	bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1226	depends on CPU_32v7
1227	default y
1228	help
1229	  The ARM compiler inserts calls to __aeabi_idiv() and
1230	  __aeabi_uidiv() when it needs to perform division on signed
1231	  and unsigned integers. Some v7 CPUs have support for the sdiv
1232	  and udiv instructions that can be used to implement those
1233	  functions.
1234
1235	  Enabling this option allows the kernel to modify itself to
1236	  replace the first two instructions of these library functions
1237	  with the sdiv or udiv plus "bx lr" instructions when the CPU
1238	  it is running on supports them. Typically this will be faster
1239	  and less power intensive than running the original library
1240	  code to do integer division.
1241
1242config AEABI
1243	bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
1244		!CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
1245	default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
1246	help
1247	  This option allows for the kernel to be compiled using the latest
1248	  ARM ABI (aka EABI).  This is only useful if you are using a user
1249	  space environment that is also compiled with EABI.
1250
1251	  Since there are major incompatibilities between the legacy ABI and
1252	  EABI, especially with regard to structure member alignment, this
1253	  option also changes the kernel syscall calling convention to
1254	  disambiguate both ABIs and allow for backward compatibility support
1255	  (selected with CONFIG_OABI_COMPAT).
1256
1257	  To use this you need GCC version 4.0.0 or later.
1258
1259config OABI_COMPAT
1260	bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1261	depends on AEABI && !THUMB2_KERNEL
1262	help
1263	  This option preserves the old syscall interface along with the
1264	  new (ARM EABI) one. It also provides a compatibility layer to
1265	  intercept syscalls that have structure arguments which layout
1266	  in memory differs between the legacy ABI and the new ARM EABI
1267	  (only for non "thumb" binaries). This option adds a tiny
1268	  overhead to all syscalls and produces a slightly larger kernel.
1269
1270	  The seccomp filter system will not be available when this is
1271	  selected, since there is no way yet to sensibly distinguish
1272	  between calling conventions during filtering.
1273
1274	  If you know you'll be using only pure EABI user space then you
1275	  can say N here. If this option is not selected and you attempt
1276	  to execute a legacy ABI binary then the result will be
1277	  UNPREDICTABLE (in fact it can be predicted that it won't work
1278	  at all). If in doubt say N.
1279
1280config ARCH_SELECT_MEMORY_MODEL
1281	def_bool y
1282
1283config ARCH_FLATMEM_ENABLE
1284	def_bool !(ARCH_RPC || ARCH_SA1100)
1285
1286config ARCH_SPARSEMEM_ENABLE
1287	def_bool !ARCH_FOOTBRIDGE
1288	select SPARSEMEM_STATIC if SPARSEMEM
1289
1290config HIGHMEM
1291	bool "High Memory Support"
1292	depends on MMU
1293	select KMAP_LOCAL
1294	select KMAP_LOCAL_NON_LINEAR_PTE_ARRAY
1295	help
1296	  The address space of ARM processors is only 4 Gigabytes large
1297	  and it has to accommodate user address space, kernel address
1298	  space as well as some memory mapped IO. That means that, if you
1299	  have a large amount of physical memory and/or IO, not all of the
1300	  memory can be "permanently mapped" by the kernel. The physical
1301	  memory that is not permanently mapped is called "high memory".
1302
1303	  Depending on the selected kernel/user memory split, minimum
1304	  vmalloc space and actual amount of RAM, you may not need this
1305	  option which should result in a slightly faster kernel.
1306
1307	  If unsure, say n.
1308
1309config HIGHPTE
1310	bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1311	depends on HIGHMEM
1312	default y
1313	help
1314	  The VM uses one page of physical memory for each page table.
1315	  For systems with a lot of processes, this can use a lot of
1316	  precious low memory, eventually leading to low memory being
1317	  consumed by page tables.  Setting this option will allow
1318	  user-space 2nd level page tables to reside in high memory.
1319
1320config CPU_SW_DOMAIN_PAN
1321	bool "Enable use of CPU domains to implement privileged no-access"
1322	depends on MMU && !ARM_LPAE
1323	default y
1324	help
1325	  Increase kernel security by ensuring that normal kernel accesses
1326	  are unable to access userspace addresses.  This can help prevent
1327	  use-after-free bugs becoming an exploitable privilege escalation
1328	  by ensuring that magic values (such as LIST_POISON) will always
1329	  fault when dereferenced.
1330
1331	  CPUs with low-vector mappings use a best-efforts implementation.
1332	  Their lower 1MB needs to remain accessible for the vectors, but
1333	  the remainder of userspace will become appropriately inaccessible.
1334
1335config HW_PERF_EVENTS
1336	def_bool y
1337	depends on ARM_PMU
1338
1339config ARM_MODULE_PLTS
1340	bool "Use PLTs to allow module memory to spill over into vmalloc area"
1341	depends on MODULES
1342	select KASAN_VMALLOC if KASAN
1343	default y
1344	help
1345	  Allocate PLTs when loading modules so that jumps and calls whose
1346	  targets are too far away for their relative offsets to be encoded
1347	  in the instructions themselves can be bounced via veneers in the
1348	  module's PLT. This allows modules to be allocated in the generic
1349	  vmalloc area after the dedicated module memory area has been
1350	  exhausted. The modules will use slightly more memory, but after
1351	  rounding up to page size, the actual memory footprint is usually
1352	  the same.
1353
1354	  Disabling this is usually safe for small single-platform
1355	  configurations. If unsure, say y.
1356
1357config ARCH_FORCE_MAX_ORDER
1358	int "Order of maximal physically contiguous allocations"
1359	default "11" if SOC_AM33XX
1360	default "8" if SA1111
1361	default "10"
1362	help
1363	  The kernel page allocator limits the size of maximal physically
1364	  contiguous allocations. The limit is called MAX_ORDER and it
1365	  defines the maximal power of two of number of pages that can be
1366	  allocated as a single contiguous block. This option allows
1367	  overriding the default setting when ability to allocate very
1368	  large blocks of physically contiguous memory is required.
1369
1370	  Don't change if unsure.
1371
1372config ALIGNMENT_TRAP
1373	def_bool CPU_CP15_MMU
1374	select HAVE_PROC_CPU if PROC_FS
1375	help
1376	  ARM processors cannot fetch/store information which is not
1377	  naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1378	  address divisible by 4. On 32-bit ARM processors, these non-aligned
1379	  fetch/store instructions will be emulated in software if you say
1380	  here, which has a severe performance impact. This is necessary for
1381	  correct operation of some network protocols. With an IP-only
1382	  configuration it is safe to say N, otherwise say Y.
1383
1384config UACCESS_WITH_MEMCPY
1385	bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1386	depends on MMU
1387	default y if CPU_FEROCEON
1388	help
1389	  Implement faster copy_to_user and clear_user methods for CPU
1390	  cores where a 8-word STM instruction give significantly higher
1391	  memory write throughput than a sequence of individual 32bit stores.
1392
1393	  A possible side effect is a slight increase in scheduling latency
1394	  between threads sharing the same address space if they invoke
1395	  such copy operations with large buffers.
1396
1397	  However, if the CPU data cache is using a write-allocate mode,
1398	  this option is unlikely to provide any performance gain.
1399
1400config PARAVIRT
1401	bool "Enable paravirtualization code"
1402	help
1403	  This changes the kernel so it can modify itself when it is run
1404	  under a hypervisor, potentially improving performance significantly
1405	  over full virtualization.
1406
1407config PARAVIRT_TIME_ACCOUNTING
1408	bool "Paravirtual steal time accounting"
1409	select PARAVIRT
1410	help
1411	  Select this option to enable fine granularity task steal time
1412	  accounting. Time spent executing other tasks in parallel with
1413	  the current vCPU is discounted from the vCPU power. To account for
1414	  that, there can be a small performance impact.
1415
1416	  If in doubt, say N here.
1417
1418config XEN_DOM0
1419	def_bool y
1420	depends on XEN
1421
1422config XEN
1423	bool "Xen guest support on ARM"
1424	depends on ARM && AEABI && OF
1425	depends on CPU_V7 && !CPU_V6
1426	depends on !GENERIC_ATOMIC64
1427	depends on MMU
1428	select ARCH_DMA_ADDR_T_64BIT
1429	select ARM_PSCI
1430	select SWIOTLB
1431	select SWIOTLB_XEN
1432	select PARAVIRT
1433	help
1434	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1435
1436config CC_HAVE_STACKPROTECTOR_TLS
1437	def_bool $(cc-option,-mtp=cp15 -mstack-protector-guard=tls -mstack-protector-guard-offset=0)
1438
1439config STACKPROTECTOR_PER_TASK
1440	bool "Use a unique stack canary value for each task"
1441	depends on STACKPROTECTOR && CURRENT_POINTER_IN_TPIDRURO && !XIP_DEFLATED_DATA
1442	depends on GCC_PLUGINS || CC_HAVE_STACKPROTECTOR_TLS
1443	select GCC_PLUGIN_ARM_SSP_PER_TASK if !CC_HAVE_STACKPROTECTOR_TLS
1444	default y
1445	help
1446	  Due to the fact that GCC uses an ordinary symbol reference from
1447	  which to load the value of the stack canary, this value can only
1448	  change at reboot time on SMP systems, and all tasks running in the
1449	  kernel's address space are forced to use the same canary value for
1450	  the entire duration that the system is up.
1451
1452	  Enable this option to switch to a different method that uses a
1453	  different canary value for each task.
1454
1455endmenu
1456
1457menu "Boot options"
1458
1459config USE_OF
1460	bool "Flattened Device Tree support"
1461	select IRQ_DOMAIN
1462	select OF
1463	help
1464	  Include support for flattened device tree machine descriptions.
1465
1466config ARCH_WANT_FLAT_DTB_INSTALL
1467	def_bool y
1468
1469config ATAGS
1470	bool "Support for the traditional ATAGS boot data passing"
1471	default y
1472	help
1473	  This is the traditional way of passing data to the kernel at boot
1474	  time. If you are solely relying on the flattened device tree (or
1475	  the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1476	  to remove ATAGS support from your kernel binary.
1477
1478config DEPRECATED_PARAM_STRUCT
1479	bool "Provide old way to pass kernel parameters"
1480	depends on ATAGS
1481	help
1482	  This was deprecated in 2001 and announced to live on for 5 years.
1483	  Some old boot loaders still use this way.
1484
1485# Compressed boot loader in ROM.  Yes, we really want to ask about
1486# TEXT and BSS so we preserve their values in the config files.
1487config ZBOOT_ROM_TEXT
1488	hex "Compressed ROM boot loader base address"
1489	default 0x0
1490	help
1491	  The physical address at which the ROM-able zImage is to be
1492	  placed in the target.  Platforms which normally make use of
1493	  ROM-able zImage formats normally set this to a suitable
1494	  value in their defconfig file.
1495
1496	  If ZBOOT_ROM is not enabled, this has no effect.
1497
1498config ZBOOT_ROM_BSS
1499	hex "Compressed ROM boot loader BSS address"
1500	default 0x0
1501	help
1502	  The base address of an area of read/write memory in the target
1503	  for the ROM-able zImage which must be available while the
1504	  decompressor is running. It must be large enough to hold the
1505	  entire decompressed kernel plus an additional 128 KiB.
1506	  Platforms which normally make use of ROM-able zImage formats
1507	  normally set this to a suitable value in their defconfig file.
1508
1509	  If ZBOOT_ROM is not enabled, this has no effect.
1510
1511config ZBOOT_ROM
1512	bool "Compressed boot loader in ROM/flash"
1513	depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1514	depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1515	help
1516	  Say Y here if you intend to execute your compressed kernel image
1517	  (zImage) directly from ROM or flash.  If unsure, say N.
1518
1519config ARM_APPENDED_DTB
1520	bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1521	depends on OF
1522	help
1523	  With this option, the boot code will look for a device tree binary
1524	  (DTB) appended to zImage
1525	  (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1526
1527	  This is meant as a backward compatibility convenience for those
1528	  systems with a bootloader that can't be upgraded to accommodate
1529	  the documented boot protocol using a device tree.
1530
1531	  Beware that there is very little in terms of protection against
1532	  this option being confused by leftover garbage in memory that might
1533	  look like a DTB header after a reboot if no actual DTB is appended
1534	  to zImage.  Do not leave this option active in a production kernel
1535	  if you don't intend to always append a DTB.  Proper passing of the
1536	  location into r2 of a bootloader provided DTB is always preferable
1537	  to this option.
1538
1539config ARM_ATAG_DTB_COMPAT
1540	bool "Supplement the appended DTB with traditional ATAG information"
1541	depends on ARM_APPENDED_DTB
1542	help
1543	  Some old bootloaders can't be updated to a DTB capable one, yet
1544	  they provide ATAGs with memory configuration, the ramdisk address,
1545	  the kernel cmdline string, etc.  Such information is dynamically
1546	  provided by the bootloader and can't always be stored in a static
1547	  DTB.  To allow a device tree enabled kernel to be used with such
1548	  bootloaders, this option allows zImage to extract the information
1549	  from the ATAG list and store it at run time into the appended DTB.
1550
1551choice
1552	prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1553	default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1554
1555config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1556	bool "Use bootloader kernel arguments if available"
1557	help
1558	  Uses the command-line options passed by the boot loader instead of
1559	  the device tree bootargs property. If the boot loader doesn't provide
1560	  any, the device tree bootargs property will be used.
1561
1562config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1563	bool "Extend with bootloader kernel arguments"
1564	help
1565	  The command-line arguments provided by the boot loader will be
1566	  appended to the the device tree bootargs property.
1567
1568endchoice
1569
1570config CMDLINE
1571	string "Default kernel command string"
1572	default ""
1573	help
1574	  On some architectures (e.g. CATS), there is currently no way
1575	  for the boot loader to pass arguments to the kernel. For these
1576	  architectures, you should supply some command-line options at build
1577	  time by entering them here. As a minimum, you should specify the
1578	  memory size and the root device (e.g., mem=64M root=/dev/nfs).
1579
1580choice
1581	prompt "Kernel command line type" if CMDLINE != ""
1582	default CMDLINE_FROM_BOOTLOADER
1583
1584config CMDLINE_FROM_BOOTLOADER
1585	bool "Use bootloader kernel arguments if available"
1586	help
1587	  Uses the command-line options passed by the boot loader. If
1588	  the boot loader doesn't provide any, the default kernel command
1589	  string provided in CMDLINE will be used.
1590
1591config CMDLINE_EXTEND
1592	bool "Extend bootloader kernel arguments"
1593	help
1594	  The command-line arguments provided by the boot loader will be
1595	  appended to the default kernel command string.
1596
1597config CMDLINE_FORCE
1598	bool "Always use the default kernel command string"
1599	help
1600	  Always use the default kernel command string, even if the boot
1601	  loader passes other arguments to the kernel.
1602	  This is useful if you cannot or don't want to change the
1603	  command-line options your boot loader passes to the kernel.
1604endchoice
1605
1606config XIP_KERNEL
1607	bool "Kernel Execute-In-Place from ROM"
1608	depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1609	depends on !ARM_PATCH_IDIV && !ARM_PATCH_PHYS_VIRT && !SMP_ON_UP
1610	help
1611	  Execute-In-Place allows the kernel to run from non-volatile storage
1612	  directly addressable by the CPU, such as NOR flash. This saves RAM
1613	  space since the text section of the kernel is not loaded from flash
1614	  to RAM.  Read-write sections, such as the data section and stack,
1615	  are still copied to RAM.  The XIP kernel is not compressed since
1616	  it has to run directly from flash, so it will take more space to
1617	  store it.  The flash address used to link the kernel object files,
1618	  and for storing it, is configuration dependent. Therefore, if you
1619	  say Y here, you must know the proper physical address where to
1620	  store the kernel image depending on your own flash memory usage.
1621
1622	  Also note that the make target becomes "make xipImage" rather than
1623	  "make zImage" or "make Image".  The final kernel binary to put in
1624	  ROM memory will be arch/arm/boot/xipImage.
1625
1626	  If unsure, say N.
1627
1628config XIP_PHYS_ADDR
1629	hex "XIP Kernel Physical Location"
1630	depends on XIP_KERNEL
1631	default "0x00080000"
1632	help
1633	  This is the physical address in your flash memory the kernel will
1634	  be linked for and stored to.  This address is dependent on your
1635	  own flash usage.
1636
1637config XIP_DEFLATED_DATA
1638	bool "Store kernel .data section compressed in ROM"
1639	depends on XIP_KERNEL
1640	select ZLIB_INFLATE
1641	help
1642	  Before the kernel is actually executed, its .data section has to be
1643	  copied to RAM from ROM. This option allows for storing that data
1644	  in compressed form and decompressed to RAM rather than merely being
1645	  copied, saving some precious ROM space. A possible drawback is a
1646	  slightly longer boot delay.
1647
1648config KEXEC
1649	bool "Kexec system call (EXPERIMENTAL)"
1650	depends on (!SMP || PM_SLEEP_SMP)
1651	depends on MMU
1652	select KEXEC_CORE
1653	help
1654	  kexec is a system call that implements the ability to shutdown your
1655	  current kernel, and to start another kernel.  It is like a reboot
1656	  but it is independent of the system firmware.   And like a reboot
1657	  you can start any kernel with it, not just Linux.
1658
1659	  It is an ongoing process to be certain the hardware in a machine
1660	  is properly shutdown, so do not be surprised if this code does not
1661	  initially work for you.
1662
1663config ATAGS_PROC
1664	bool "Export atags in procfs"
1665	depends on ATAGS && KEXEC
1666	default y
1667	help
1668	  Should the atags used to boot the kernel be exported in an "atags"
1669	  file in procfs. Useful with kexec.
1670
1671config CRASH_DUMP
1672	bool "Build kdump crash kernel (EXPERIMENTAL)"
1673	help
1674	  Generate crash dump after being started by kexec. This should
1675	  be normally only set in special crash dump kernels which are
1676	  loaded in the main kernel with kexec-tools into a specially
1677	  reserved region and then later executed after a crash by
1678	  kdump/kexec. The crash dump kernel must be compiled to a
1679	  memory address not used by the main kernel
1680
1681	  For more details see Documentation/admin-guide/kdump/kdump.rst
1682
1683config AUTO_ZRELADDR
1684	bool "Auto calculation of the decompressed kernel image address" if !ARCH_MULTIPLATFORM
1685	default !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
1686	help
1687	  ZRELADDR is the physical address where the decompressed kernel
1688	  image will be placed. If AUTO_ZRELADDR is selected, the address
1689	  will be determined at run-time, either by masking the current IP
1690	  with 0xf8000000, or, if invalid, from the DTB passed in r2.
1691	  This assumes the zImage being placed in the first 128MB from
1692	  start of memory.
1693
1694config EFI_STUB
1695	bool
1696
1697config EFI
1698	bool "UEFI runtime support"
1699	depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
1700	select UCS2_STRING
1701	select EFI_PARAMS_FROM_FDT
1702	select EFI_STUB
1703	select EFI_GENERIC_STUB
1704	select EFI_RUNTIME_WRAPPERS
1705	help
1706	  This option provides support for runtime services provided
1707	  by UEFI firmware (such as non-volatile variables, realtime
1708	  clock, and platform reset). A UEFI stub is also provided to
1709	  allow the kernel to be booted as an EFI application. This
1710	  is only useful for kernels that may run on systems that have
1711	  UEFI firmware.
1712
1713config DMI
1714	bool "Enable support for SMBIOS (DMI) tables"
1715	depends on EFI
1716	default y
1717	help
1718	  This enables SMBIOS/DMI feature for systems.
1719
1720	  This option is only useful on systems that have UEFI firmware.
1721	  However, even with this option, the resultant kernel should
1722	  continue to boot on existing non-UEFI platforms.
1723
1724	  NOTE: This does *NOT* enable or encourage the use of DMI quirks,
1725	  i.e., the the practice of identifying the platform via DMI to
1726	  decide whether certain workarounds for buggy hardware and/or
1727	  firmware need to be enabled. This would require the DMI subsystem
1728	  to be enabled much earlier than we do on ARM, which is non-trivial.
1729
1730endmenu
1731
1732menu "CPU Power Management"
1733
1734source "drivers/cpufreq/Kconfig"
1735
1736source "drivers/cpuidle/Kconfig"
1737
1738endmenu
1739
1740menu "Floating point emulation"
1741
1742comment "At least one emulation must be selected"
1743
1744config FPE_NWFPE
1745	bool "NWFPE math emulation"
1746	depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
1747	help
1748	  Say Y to include the NWFPE floating point emulator in the kernel.
1749	  This is necessary to run most binaries. Linux does not currently
1750	  support floating point hardware so you need to say Y here even if
1751	  your machine has an FPA or floating point co-processor podule.
1752
1753	  You may say N here if you are going to load the Acorn FPEmulator
1754	  early in the bootup.
1755
1756config FPE_NWFPE_XP
1757	bool "Support extended precision"
1758	depends on FPE_NWFPE
1759	help
1760	  Say Y to include 80-bit support in the kernel floating-point
1761	  emulator.  Otherwise, only 32 and 64-bit support is compiled in.
1762	  Note that gcc does not generate 80-bit operations by default,
1763	  so in most cases this option only enlarges the size of the
1764	  floating point emulator without any good reason.
1765
1766	  You almost surely want to say N here.
1767
1768config FPE_FASTFPE
1769	bool "FastFPE math emulation (EXPERIMENTAL)"
1770	depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
1771	help
1772	  Say Y here to include the FAST floating point emulator in the kernel.
1773	  This is an experimental much faster emulator which now also has full
1774	  precision for the mantissa.  It does not support any exceptions.
1775	  It is very simple, and approximately 3-6 times faster than NWFPE.
1776
1777	  It should be sufficient for most programs.  It may be not suitable
1778	  for scientific calculations, but you have to check this for yourself.
1779	  If you do not feel you need a faster FP emulation you should better
1780	  choose NWFPE.
1781
1782config VFP
1783	bool "VFP-format floating point maths"
1784	depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1785	help
1786	  Say Y to include VFP support code in the kernel. This is needed
1787	  if your hardware includes a VFP unit.
1788
1789	  Please see <file:Documentation/arch/arm/vfp/release-notes.rst> for
1790	  release notes and additional status information.
1791
1792	  Say N if your target does not have VFP hardware.
1793
1794config VFPv3
1795	bool
1796	depends on VFP
1797	default y if CPU_V7
1798
1799config NEON
1800	bool "Advanced SIMD (NEON) Extension support"
1801	depends on VFPv3 && CPU_V7
1802	help
1803	  Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1804	  Extension.
1805
1806config KERNEL_MODE_NEON
1807	bool "Support for NEON in kernel mode"
1808	depends on NEON && AEABI
1809	help
1810	  Say Y to include support for NEON in kernel mode.
1811
1812endmenu
1813
1814menu "Power management options"
1815
1816source "kernel/power/Kconfig"
1817
1818config ARCH_SUSPEND_POSSIBLE
1819	depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
1820		CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
1821	def_bool y
1822
1823config ARM_CPU_SUSPEND
1824	def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
1825	depends on ARCH_SUSPEND_POSSIBLE
1826
1827config ARCH_HIBERNATION_POSSIBLE
1828	bool
1829	depends on MMU
1830	default y if ARCH_SUSPEND_POSSIBLE
1831
1832endmenu
1833
1834source "arch/arm/Kconfig.assembler"
1835