xref: /openbmc/linux/arch/arm/Kconfig (revision 6aeadf78)
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 MODULES_USE_ELF_REL
131	select NEED_DMA_MAP_STATE
132	select OF_EARLY_FLATTREE if OF
133	select OLD_SIGACTION
134	select OLD_SIGSUSPEND3
135	select PCI_DOMAINS_GENERIC if PCI
136	select PCI_SYSCALL if PCI
137	select PERF_USE_VMALLOC
138	select RTC_LIB
139	select SPARSE_IRQ if !(ARCH_FOOTBRIDGE || ARCH_RPC)
140	select SYS_SUPPORTS_APM_EMULATION
141	select THREAD_INFO_IN_TASK
142	select TIMER_OF if OF
143	select HAVE_ARCH_VMAP_STACK if MMU && ARM_HAS_GROUP_RELOCS
144	select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M
145	select USE_OF if !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
146	# Above selects are sorted alphabetically; please add new ones
147	# according to that.  Thanks.
148	help
149	  The ARM series is a line of low-power-consumption RISC chip designs
150	  licensed by ARM Ltd and targeted at embedded applications and
151	  handhelds such as the Compaq IPAQ.  ARM-based PCs are no longer
152	  manufactured, but legacy ARM-based PC hardware remains popular in
153	  Europe.  There is an ARM Linux project with a web page at
154	  <http://www.arm.linux.org.uk/>.
155
156config ARM_HAS_GROUP_RELOCS
157	def_bool y
158	depends on !LD_IS_LLD || LLD_VERSION >= 140000
159	depends on !COMPILE_TEST
160	help
161	  Whether or not to use R_ARM_ALU_PC_Gn or R_ARM_LDR_PC_Gn group
162	  relocations, which have been around for a long time, but were not
163	  supported in LLD until version 14. The combined range is -/+ 256 MiB,
164	  which is usually sufficient, but not for allyesconfig, so we disable
165	  this feature when doing compile testing.
166
167config ARM_DMA_USE_IOMMU
168	bool
169	select NEED_SG_DMA_LENGTH
170
171if ARM_DMA_USE_IOMMU
172
173config ARM_DMA_IOMMU_ALIGNMENT
174	int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
175	range 4 9
176	default 8
177	help
178	  DMA mapping framework by default aligns all buffers to the smallest
179	  PAGE_SIZE order which is greater than or equal to the requested buffer
180	  size. This works well for buffers up to a few hundreds kilobytes, but
181	  for larger buffers it just a waste of address space. Drivers which has
182	  relatively small addressing window (like 64Mib) might run out of
183	  virtual space with just a few allocations.
184
185	  With this parameter you can specify the maximum PAGE_SIZE order for
186	  DMA IOMMU buffers. Larger buffers will be aligned only to this
187	  specified order. The order is expressed as a power of two multiplied
188	  by the PAGE_SIZE.
189
190endif
191
192config SYS_SUPPORTS_APM_EMULATION
193	bool
194
195config HAVE_TCM
196	bool
197	select GENERIC_ALLOCATOR
198
199config HAVE_PROC_CPU
200	bool
201
202config NO_IOPORT_MAP
203	bool
204
205config SBUS
206	bool
207
208config STACKTRACE_SUPPORT
209	bool
210	default y
211
212config LOCKDEP_SUPPORT
213	bool
214	default y
215
216config ARCH_HAS_ILOG2_U32
217	bool
218
219config ARCH_HAS_ILOG2_U64
220	bool
221
222config ARCH_HAS_BANDGAP
223	bool
224
225config FIX_EARLYCON_MEM
226	def_bool y if MMU
227
228config GENERIC_HWEIGHT
229	bool
230	default y
231
232config GENERIC_CALIBRATE_DELAY
233	bool
234	default y
235
236config ARCH_MAY_HAVE_PC_FDC
237	bool
238
239config ARCH_SUPPORTS_UPROBES
240	def_bool y
241
242config GENERIC_ISA_DMA
243	bool
244
245config FIQ
246	bool
247
248config ARCH_MTD_XIP
249	bool
250
251config ARM_PATCH_PHYS_VIRT
252	bool "Patch physical to virtual translations at runtime" if EMBEDDED
253	default y
254	depends on MMU
255	help
256	  Patch phys-to-virt and virt-to-phys translation functions at
257	  boot and module load time according to the position of the
258	  kernel in system memory.
259
260	  This can only be used with non-XIP MMU kernels where the base
261	  of physical memory is at a 2 MiB boundary.
262
263	  Only disable this option if you know that you do not require
264	  this feature (eg, building a kernel for a single machine) and
265	  you need to shrink the kernel to the minimal size.
266
267config NEED_MACH_IO_H
268	bool
269	help
270	  Select this when mach/io.h is required to provide special
271	  definitions for this platform.  The need for mach/io.h should
272	  be avoided when possible.
273
274config NEED_MACH_MEMORY_H
275	bool
276	help
277	  Select this when mach/memory.h is required to provide special
278	  definitions for this platform.  The need for mach/memory.h should
279	  be avoided when possible.
280
281config PHYS_OFFSET
282	hex "Physical address of main memory" if MMU
283	depends on !ARM_PATCH_PHYS_VIRT || !AUTO_ZRELADDR
284	default DRAM_BASE if !MMU
285	default 0x00000000 if ARCH_FOOTBRIDGE
286	default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
287	default 0xa0000000 if ARCH_PXA
288	default 0xc0000000 if ARCH_EP93XX || ARCH_SA1100
289	default 0
290	help
291	  Please provide the physical address corresponding to the
292	  location of main memory in your system.
293
294config GENERIC_BUG
295	def_bool y
296	depends on BUG
297
298config PGTABLE_LEVELS
299	int
300	default 3 if ARM_LPAE
301	default 2
302
303menu "System Type"
304
305config MMU
306	bool "MMU-based Paged Memory Management Support"
307	default y
308	help
309	  Select if you want MMU-based virtualised addressing space
310	  support by paged memory management. If unsure, say 'Y'.
311
312config ARM_SINGLE_ARMV7M
313	def_bool !MMU
314	select ARM_NVIC
315	select CPU_V7M
316	select NO_IOPORT_MAP
317
318config ARCH_MMAP_RND_BITS_MIN
319	default 8
320
321config ARCH_MMAP_RND_BITS_MAX
322	default 14 if PAGE_OFFSET=0x40000000
323	default 15 if PAGE_OFFSET=0x80000000
324	default 16
325
326config ARCH_MULTIPLATFORM
327	bool "Require kernel to be portable to multiple machines" if EXPERT
328	depends on MMU && !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
329	default y
330	help
331	  In general, all Arm machines can be supported in a single
332	  kernel image, covering either Armv4/v5 or Armv6/v7.
333
334	  However, some configuration options require hardcoding machine
335	  specific physical addresses or enable errata workarounds that may
336	  break other machines.
337
338	  Selecting N here allows using those options, including
339	  DEBUG_UNCOMPRESS, XIP_KERNEL and ZBOOT_ROM. If unsure, say Y.
340
341menu "Platform selection"
342	depends on MMU
343
344comment "CPU Core family selection"
345
346config ARCH_MULTI_V4
347	bool "ARMv4 based platforms (FA526, StrongARM)"
348	depends on !ARCH_MULTI_V6_V7
349	# https://github.com/llvm/llvm-project/issues/50764
350	depends on !LD_IS_LLD || LLD_VERSION >= 160000
351	select ARCH_MULTI_V4_V5
352	select CPU_FA526 if !(CPU_SA110 || CPU_SA1100)
353
354config ARCH_MULTI_V4T
355	bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
356	depends on !ARCH_MULTI_V6_V7
357	# https://github.com/llvm/llvm-project/issues/50764
358	depends on !LD_IS_LLD || LLD_VERSION >= 160000
359	select ARCH_MULTI_V4_V5
360	select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
361		CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
362		CPU_ARM925T || CPU_ARM940T)
363
364config ARCH_MULTI_V5
365	bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
366	depends on !ARCH_MULTI_V6_V7
367	select ARCH_MULTI_V4_V5
368	select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
369		CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
370		CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
371
372config ARCH_MULTI_V4_V5
373	bool
374
375config ARCH_MULTI_V6
376	bool "ARMv6 based platforms (ARM11)"
377	select ARCH_MULTI_V6_V7
378	select CPU_V6K
379
380config ARCH_MULTI_V7
381	bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
382	default y
383	select ARCH_MULTI_V6_V7
384	select CPU_V7
385	select HAVE_SMP
386
387config ARCH_MULTI_V6_V7
388	bool
389	select MIGHT_HAVE_CACHE_L2X0
390
391config ARCH_MULTI_CPU_AUTO
392	def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
393	select ARCH_MULTI_V5
394
395endmenu
396
397config ARCH_VIRT
398	bool "Dummy Virtual Machine"
399	depends on ARCH_MULTI_V7
400	select ARM_AMBA
401	select ARM_GIC
402	select ARM_GIC_V2M if PCI
403	select ARM_GIC_V3
404	select ARM_GIC_V3_ITS if PCI
405	select ARM_PSCI
406	select HAVE_ARM_ARCH_TIMER
407
408config ARCH_AIROHA
409	bool "Airoha SoC Support"
410	depends on ARCH_MULTI_V7
411	select ARM_AMBA
412	select ARM_GIC
413	select ARM_GIC_V3
414	select ARM_PSCI
415	select HAVE_ARM_ARCH_TIMER
416	help
417	  Support for Airoha EN7523 SoCs
418
419#
420# This is sorted alphabetically by mach-* pathname.  However, plat-*
421# Kconfigs may be included either alphabetically (according to the
422# plat- suffix) or along side the corresponding mach-* source.
423#
424source "arch/arm/mach-actions/Kconfig"
425
426source "arch/arm/mach-alpine/Kconfig"
427
428source "arch/arm/mach-artpec/Kconfig"
429
430source "arch/arm/mach-asm9260/Kconfig"
431
432source "arch/arm/mach-aspeed/Kconfig"
433
434source "arch/arm/mach-at91/Kconfig"
435
436source "arch/arm/mach-axxia/Kconfig"
437
438source "arch/arm/mach-bcm/Kconfig"
439
440source "arch/arm/mach-berlin/Kconfig"
441
442source "arch/arm/mach-clps711x/Kconfig"
443
444source "arch/arm/mach-davinci/Kconfig"
445
446source "arch/arm/mach-digicolor/Kconfig"
447
448source "arch/arm/mach-dove/Kconfig"
449
450source "arch/arm/mach-ep93xx/Kconfig"
451
452source "arch/arm/mach-exynos/Kconfig"
453
454source "arch/arm/mach-footbridge/Kconfig"
455
456source "arch/arm/mach-gemini/Kconfig"
457
458source "arch/arm/mach-highbank/Kconfig"
459
460source "arch/arm/mach-hisi/Kconfig"
461
462source "arch/arm/mach-hpe/Kconfig"
463
464source "arch/arm/mach-imx/Kconfig"
465
466source "arch/arm/mach-ixp4xx/Kconfig"
467
468source "arch/arm/mach-keystone/Kconfig"
469
470source "arch/arm/mach-lpc32xx/Kconfig"
471
472source "arch/arm/mach-mediatek/Kconfig"
473
474source "arch/arm/mach-meson/Kconfig"
475
476source "arch/arm/mach-milbeaut/Kconfig"
477
478source "arch/arm/mach-mmp/Kconfig"
479
480source "arch/arm/mach-moxart/Kconfig"
481
482source "arch/arm/mach-mstar/Kconfig"
483
484source "arch/arm/mach-mv78xx0/Kconfig"
485
486source "arch/arm/mach-mvebu/Kconfig"
487
488source "arch/arm/mach-mxs/Kconfig"
489
490source "arch/arm/mach-nomadik/Kconfig"
491
492source "arch/arm/mach-npcm/Kconfig"
493
494source "arch/arm/mach-nspire/Kconfig"
495
496source "arch/arm/mach-omap1/Kconfig"
497
498source "arch/arm/mach-omap2/Kconfig"
499
500source "arch/arm/mach-orion5x/Kconfig"
501
502source "arch/arm/mach-pxa/Kconfig"
503
504source "arch/arm/mach-qcom/Kconfig"
505
506source "arch/arm/mach-rda/Kconfig"
507
508source "arch/arm/mach-realtek/Kconfig"
509
510source "arch/arm/mach-rpc/Kconfig"
511
512source "arch/arm/mach-rockchip/Kconfig"
513
514source "arch/arm/mach-s3c/Kconfig"
515
516source "arch/arm/mach-s5pv210/Kconfig"
517
518source "arch/arm/mach-sa1100/Kconfig"
519
520source "arch/arm/mach-shmobile/Kconfig"
521
522source "arch/arm/mach-socfpga/Kconfig"
523
524source "arch/arm/mach-spear/Kconfig"
525
526source "arch/arm/mach-sti/Kconfig"
527
528source "arch/arm/mach-stm32/Kconfig"
529
530source "arch/arm/mach-sunplus/Kconfig"
531
532source "arch/arm/mach-sunxi/Kconfig"
533
534source "arch/arm/mach-tegra/Kconfig"
535
536source "arch/arm/mach-uniphier/Kconfig"
537
538source "arch/arm/mach-ux500/Kconfig"
539
540source "arch/arm/mach-versatile/Kconfig"
541
542source "arch/arm/mach-vt8500/Kconfig"
543
544source "arch/arm/mach-zynq/Kconfig"
545
546# ARMv7-M architecture
547config ARCH_LPC18XX
548	bool "NXP LPC18xx/LPC43xx"
549	depends on ARM_SINGLE_ARMV7M
550	select ARCH_HAS_RESET_CONTROLLER
551	select ARM_AMBA
552	select CLKSRC_LPC32XX
553	select PINCTRL
554	help
555	  Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
556	  high performance microcontrollers.
557
558config ARCH_MPS2
559	bool "ARM MPS2 platform"
560	depends on ARM_SINGLE_ARMV7M
561	select ARM_AMBA
562	select CLKSRC_MPS2
563	help
564	  Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
565	  with a range of available cores like Cortex-M3/M4/M7.
566
567	  Please, note that depends which Application Note is used memory map
568	  for the platform may vary, so adjustment of RAM base might be needed.
569
570# Definitions to make life easier
571config ARCH_ACORN
572	bool
573
574config PLAT_ORION
575	bool
576	select CLKSRC_MMIO
577	select GENERIC_IRQ_CHIP
578	select IRQ_DOMAIN
579
580config PLAT_ORION_LEGACY
581	bool
582	select PLAT_ORION
583
584config PLAT_VERSATILE
585	bool
586
587source "arch/arm/mm/Kconfig"
588
589config IWMMXT
590	bool "Enable iWMMXt support"
591	depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
592	default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
593	help
594	  Enable support for iWMMXt context switching at run time if
595	  running on a CPU that supports it.
596
597if !MMU
598source "arch/arm/Kconfig-nommu"
599endif
600
601config PJ4B_ERRATA_4742
602	bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
603	depends on CPU_PJ4B && MACH_ARMADA_370
604	default y
605	help
606	  When coming out of either a Wait for Interrupt (WFI) or a Wait for
607	  Event (WFE) IDLE states, a specific timing sensitivity exists between
608	  the retiring WFI/WFE instructions and the newly issued subsequent
609	  instructions.  This sensitivity can result in a CPU hang scenario.
610	  Workaround:
611	  The software must insert either a Data Synchronization Barrier (DSB)
612	  or Data Memory Barrier (DMB) command immediately after the WFI/WFE
613	  instruction
614
615config ARM_ERRATA_326103
616	bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
617	depends on CPU_V6
618	help
619	  Executing a SWP instruction to read-only memory does not set bit 11
620	  of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
621	  treat the access as a read, preventing a COW from occurring and
622	  causing the faulting task to livelock.
623
624config ARM_ERRATA_411920
625	bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
626	depends on CPU_V6 || CPU_V6K
627	help
628	  Invalidation of the Instruction Cache operation can
629	  fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
630	  It does not affect the MPCore. This option enables the ARM Ltd.
631	  recommended workaround.
632
633config ARM_ERRATA_430973
634	bool "ARM errata: Stale prediction on replaced interworking branch"
635	depends on CPU_V7
636	help
637	  This option enables the workaround for the 430973 Cortex-A8
638	  r1p* erratum. If a code sequence containing an ARM/Thumb
639	  interworking branch is replaced with another code sequence at the
640	  same virtual address, whether due to self-modifying code or virtual
641	  to physical address re-mapping, Cortex-A8 does not recover from the
642	  stale interworking branch prediction. This results in Cortex-A8
643	  executing the new code sequence in the incorrect ARM or Thumb state.
644	  The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
645	  and also flushes the branch target cache at every context switch.
646	  Note that setting specific bits in the ACTLR register may not be
647	  available in non-secure mode.
648
649config ARM_ERRATA_458693
650	bool "ARM errata: Processor deadlock when a false hazard is created"
651	depends on CPU_V7
652	depends on !ARCH_MULTIPLATFORM
653	help
654	  This option enables the workaround for the 458693 Cortex-A8 (r2p0)
655	  erratum. For very specific sequences of memory operations, it is
656	  possible for a hazard condition intended for a cache line to instead
657	  be incorrectly associated with a different cache line. This false
658	  hazard might then cause a processor deadlock. The workaround enables
659	  the L1 caching of the NEON accesses and disables the PLD instruction
660	  in the ACTLR register. Note that setting specific bits in the ACTLR
661	  register may not be available in non-secure mode and thus is not
662	  available on a multiplatform kernel. This should be applied by the
663	  bootloader instead.
664
665config ARM_ERRATA_460075
666	bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
667	depends on CPU_V7
668	depends on !ARCH_MULTIPLATFORM
669	help
670	  This option enables the workaround for the 460075 Cortex-A8 (r2p0)
671	  erratum. Any asynchronous access to the L2 cache may encounter a
672	  situation in which recent store transactions to the L2 cache are lost
673	  and overwritten with stale memory contents from external memory. The
674	  workaround disables the write-allocate mode for the L2 cache via the
675	  ACTLR register. Note that setting specific bits in the ACTLR register
676	  may not be available in non-secure mode and thus is not available on
677	  a multiplatform kernel. This should be applied by the bootloader
678	  instead.
679
680config ARM_ERRATA_742230
681	bool "ARM errata: DMB operation may be faulty"
682	depends on CPU_V7 && SMP
683	depends on !ARCH_MULTIPLATFORM
684	help
685	  This option enables the workaround for the 742230 Cortex-A9
686	  (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
687	  between two write operations may not ensure the correct visibility
688	  ordering of the two writes. This workaround sets a specific bit in
689	  the diagnostic register of the Cortex-A9 which causes the DMB
690	  instruction to behave as a DSB, ensuring the correct behaviour of
691	  the two writes. Note that setting specific bits in the diagnostics
692	  register may not be available in non-secure mode and thus is not
693	  available on a multiplatform kernel. This should be applied by the
694	  bootloader instead.
695
696config ARM_ERRATA_742231
697	bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
698	depends on CPU_V7 && SMP
699	depends on !ARCH_MULTIPLATFORM
700	help
701	  This option enables the workaround for the 742231 Cortex-A9
702	  (r2p0..r2p2) erratum. Under certain conditions, specific to the
703	  Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
704	  accessing some data located in the same cache line, may get corrupted
705	  data due to bad handling of the address hazard when the line gets
706	  replaced from one of the CPUs at the same time as another CPU is
707	  accessing it. This workaround sets specific bits in the diagnostic
708	  register of the Cortex-A9 which reduces the linefill issuing
709	  capabilities of the processor. Note that setting specific bits in the
710	  diagnostics register may not be available in non-secure mode and thus
711	  is not available on a multiplatform kernel. This should be applied by
712	  the bootloader instead.
713
714config ARM_ERRATA_643719
715	bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
716	depends on CPU_V7 && SMP
717	default y
718	help
719	  This option enables the workaround for the 643719 Cortex-A9 (prior to
720	  r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
721	  register returns zero when it should return one. The workaround
722	  corrects this value, ensuring cache maintenance operations which use
723	  it behave as intended and avoiding data corruption.
724
725config ARM_ERRATA_720789
726	bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
727	depends on CPU_V7
728	help
729	  This option enables the workaround for the 720789 Cortex-A9 (prior to
730	  r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
731	  broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
732	  As a consequence of this erratum, some TLB entries which should be
733	  invalidated are not, resulting in an incoherency in the system page
734	  tables. The workaround changes the TLB flushing routines to invalidate
735	  entries regardless of the ASID.
736
737config ARM_ERRATA_743622
738	bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
739	depends on CPU_V7
740	depends on !ARCH_MULTIPLATFORM
741	help
742	  This option enables the workaround for the 743622 Cortex-A9
743	  (r2p*) erratum. Under very rare conditions, a faulty
744	  optimisation in the Cortex-A9 Store Buffer may lead to data
745	  corruption. This workaround sets a specific bit in the diagnostic
746	  register of the Cortex-A9 which disables the Store Buffer
747	  optimisation, preventing the defect from occurring. This has no
748	  visible impact on the overall performance or power consumption of the
749	  processor. Note that setting specific bits in the diagnostics register
750	  may not be available in non-secure mode and thus is not available on a
751	  multiplatform kernel. This should be applied by the bootloader instead.
752
753config ARM_ERRATA_751472
754	bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
755	depends on CPU_V7
756	depends on !ARCH_MULTIPLATFORM
757	help
758	  This option enables the workaround for the 751472 Cortex-A9 (prior
759	  to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
760	  completion of a following broadcasted operation if the second
761	  operation is received by a CPU before the ICIALLUIS has completed,
762	  potentially leading to corrupted entries in the cache or TLB.
763	  Note that setting specific bits in the diagnostics register may
764	  not be available in non-secure mode and thus is not available on
765	  a multiplatform kernel. This should be applied by the bootloader
766	  instead.
767
768config ARM_ERRATA_754322
769	bool "ARM errata: possible faulty MMU translations following an ASID switch"
770	depends on CPU_V7
771	help
772	  This option enables the workaround for the 754322 Cortex-A9 (r2p*,
773	  r3p*) erratum. A speculative memory access may cause a page table walk
774	  which starts prior to an ASID switch but completes afterwards. This
775	  can populate the micro-TLB with a stale entry which may be hit with
776	  the new ASID. This workaround places two dsb instructions in the mm
777	  switching code so that no page table walks can cross the ASID switch.
778
779config ARM_ERRATA_754327
780	bool "ARM errata: no automatic Store Buffer drain"
781	depends on CPU_V7 && SMP
782	help
783	  This option enables the workaround for the 754327 Cortex-A9 (prior to
784	  r2p0) erratum. The Store Buffer does not have any automatic draining
785	  mechanism and therefore a livelock may occur if an external agent
786	  continuously polls a memory location waiting to observe an update.
787	  This workaround defines cpu_relax() as smp_mb(), preventing correctly
788	  written polling loops from denying visibility of updates to memory.
789
790config ARM_ERRATA_364296
791	bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
792	depends on CPU_V6
793	help
794	  This options enables the workaround for the 364296 ARM1136
795	  r0p2 erratum (possible cache data corruption with
796	  hit-under-miss enabled). It sets the undocumented bit 31 in
797	  the auxiliary control register and the FI bit in the control
798	  register, thus disabling hit-under-miss without putting the
799	  processor into full low interrupt latency mode. ARM11MPCore
800	  is not affected.
801
802config ARM_ERRATA_764369
803	bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
804	depends on CPU_V7 && SMP
805	help
806	  This option enables the workaround for erratum 764369
807	  affecting Cortex-A9 MPCore with two or more processors (all
808	  current revisions). Under certain timing circumstances, a data
809	  cache line maintenance operation by MVA targeting an Inner
810	  Shareable memory region may fail to proceed up to either the
811	  Point of Coherency or to the Point of Unification of the
812	  system. This workaround adds a DSB instruction before the
813	  relevant cache maintenance functions and sets a specific bit
814	  in the diagnostic control register of the SCU.
815
816config ARM_ERRATA_764319
817	bool "ARM errata: Read to DBGPRSR and DBGOSLSR may generate Undefined instruction"
818	depends on CPU_V7
819	help
820	  This option enables the workaround for the 764319 Cortex A-9 erratum.
821	  CP14 read accesses to the DBGPRSR and DBGOSLSR registers generate an
822	  unexpected Undefined Instruction exception when the DBGSWENABLE
823	  external pin is set to 0, even when the CP14 accesses are performed
824	  from a privileged mode. This work around catches the exception in a
825	  way the kernel does not stop execution.
826
827config ARM_ERRATA_775420
828       bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
829       depends on CPU_V7
830       help
831	 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
832	 r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance
833	 operation aborts with MMU exception, it might cause the processor
834	 to deadlock. This workaround puts DSB before executing ISB if
835	 an abort may occur on cache maintenance.
836
837config ARM_ERRATA_798181
838	bool "ARM errata: TLBI/DSB failure on Cortex-A15"
839	depends on CPU_V7 && SMP
840	help
841	  On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
842	  adequately shooting down all use of the old entries. This
843	  option enables the Linux kernel workaround for this erratum
844	  which sends an IPI to the CPUs that are running the same ASID
845	  as the one being invalidated.
846
847config ARM_ERRATA_773022
848	bool "ARM errata: incorrect instructions may be executed from loop buffer"
849	depends on CPU_V7
850	help
851	  This option enables the workaround for the 773022 Cortex-A15
852	  (up to r0p4) erratum. In certain rare sequences of code, the
853	  loop buffer may deliver incorrect instructions. This
854	  workaround disables the loop buffer to avoid the erratum.
855
856config ARM_ERRATA_818325_852422
857	bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
858	depends on CPU_V7
859	help
860	  This option enables the workaround for:
861	  - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
862	    instruction might deadlock.  Fixed in r0p1.
863	  - Cortex-A12 852422: Execution of a sequence of instructions might
864	    lead to either a data corruption or a CPU deadlock.  Not fixed in
865	    any Cortex-A12 cores yet.
866	  This workaround for all both errata involves setting bit[12] of the
867	  Feature Register. This bit disables an optimisation applied to a
868	  sequence of 2 instructions that use opposing condition codes.
869
870config ARM_ERRATA_821420
871	bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
872	depends on CPU_V7
873	help
874	  This option enables the workaround for the 821420 Cortex-A12
875	  (all revs) erratum. In very rare timing conditions, a sequence
876	  of VMOV to Core registers instructions, for which the second
877	  one is in the shadow of a branch or abort, can lead to a
878	  deadlock when the VMOV instructions are issued out-of-order.
879
880config ARM_ERRATA_825619
881	bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
882	depends on CPU_V7
883	help
884	  This option enables the workaround for the 825619 Cortex-A12
885	  (all revs) erratum. Within rare timing constraints, executing a
886	  DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
887	  and Device/Strongly-Ordered loads and stores might cause deadlock
888
889config ARM_ERRATA_857271
890	bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
891	depends on CPU_V7
892	help
893	  This option enables the workaround for the 857271 Cortex-A12
894	  (all revs) erratum. Under very rare timing conditions, the CPU might
895	  hang. The workaround is expected to have a < 1% performance impact.
896
897config ARM_ERRATA_852421
898	bool "ARM errata: A17: DMB ST might fail to create order between stores"
899	depends on CPU_V7
900	help
901	  This option enables the workaround for the 852421 Cortex-A17
902	  (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
903	  execution of a DMB ST instruction might fail to properly order
904	  stores from GroupA and stores from GroupB.
905
906config ARM_ERRATA_852423
907	bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
908	depends on CPU_V7
909	help
910	  This option enables the workaround for:
911	  - Cortex-A17 852423: Execution of a sequence of instructions might
912	    lead to either a data corruption or a CPU deadlock.  Not fixed in
913	    any Cortex-A17 cores yet.
914	  This is identical to Cortex-A12 erratum 852422.  It is a separate
915	  config option from the A12 erratum due to the way errata are checked
916	  for and handled.
917
918config ARM_ERRATA_857272
919	bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
920	depends on CPU_V7
921	help
922	  This option enables the workaround for the 857272 Cortex-A17 erratum.
923	  This erratum is not known to be fixed in any A17 revision.
924	  This is identical to Cortex-A12 erratum 857271.  It is a separate
925	  config option from the A12 erratum due to the way errata are checked
926	  for and handled.
927
928endmenu
929
930source "arch/arm/common/Kconfig"
931
932menu "Bus support"
933
934config ISA
935	bool
936	help
937	  Find out whether you have ISA slots on your motherboard.  ISA is the
938	  name of a bus system, i.e. the way the CPU talks to the other stuff
939	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
940	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
941	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
942
943# Select ISA DMA interface
944config ISA_DMA_API
945	bool
946
947config ARM_ERRATA_814220
948	bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
949	depends on CPU_V7
950	help
951	  The v7 ARM states that all cache and branch predictor maintenance
952	  operations that do not specify an address execute, relative to
953	  each other, in program order.
954	  However, because of this erratum, an L2 set/way cache maintenance
955	  operation can overtake an L1 set/way cache maintenance operation.
956	  This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
957	  r0p4, r0p5.
958
959endmenu
960
961menu "Kernel Features"
962
963config HAVE_SMP
964	bool
965	help
966	  This option should be selected by machines which have an SMP-
967	  capable CPU.
968
969	  The only effect of this option is to make the SMP-related
970	  options available to the user for configuration.
971
972config SMP
973	bool "Symmetric Multi-Processing"
974	depends on CPU_V6K || CPU_V7
975	depends on HAVE_SMP
976	depends on MMU || ARM_MPU
977	select IRQ_WORK
978	help
979	  This enables support for systems with more than one CPU. If you have
980	  a system with only one CPU, say N. If you have a system with more
981	  than one CPU, say Y.
982
983	  If you say N here, the kernel will run on uni- and multiprocessor
984	  machines, but will use only one CPU of a multiprocessor machine. If
985	  you say Y here, the kernel will run on many, but not all,
986	  uniprocessor machines. On a uniprocessor machine, the kernel
987	  will run faster if you say N here.
988
989	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
990	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
991	  <http://tldp.org/HOWTO/SMP-HOWTO.html>.
992
993	  If you don't know what to do here, say N.
994
995config SMP_ON_UP
996	bool "Allow booting SMP kernel on uniprocessor systems"
997	depends on SMP && MMU
998	default y
999	help
1000	  SMP kernels contain instructions which fail on non-SMP processors.
1001	  Enabling this option allows the kernel to modify itself to make
1002	  these instructions safe.  Disabling it allows about 1K of space
1003	  savings.
1004
1005	  If you don't know what to do here, say Y.
1006
1007
1008config CURRENT_POINTER_IN_TPIDRURO
1009	def_bool y
1010	depends on CPU_32v6K && !CPU_V6
1011
1012config IRQSTACKS
1013	def_bool y
1014	select HAVE_IRQ_EXIT_ON_IRQ_STACK
1015	select HAVE_SOFTIRQ_ON_OWN_STACK
1016
1017config ARM_CPU_TOPOLOGY
1018	bool "Support cpu topology definition"
1019	depends on SMP && CPU_V7
1020	default y
1021	help
1022	  Support ARM cpu topology definition. The MPIDR register defines
1023	  affinity between processors which is then used to describe the cpu
1024	  topology of an ARM System.
1025
1026config SCHED_MC
1027	bool "Multi-core scheduler support"
1028	depends on ARM_CPU_TOPOLOGY
1029	help
1030	  Multi-core scheduler support improves the CPU scheduler's decision
1031	  making when dealing with multi-core CPU chips at a cost of slightly
1032	  increased overhead in some places. If unsure say N here.
1033
1034config SCHED_SMT
1035	bool "SMT scheduler support"
1036	depends on ARM_CPU_TOPOLOGY
1037	help
1038	  Improves the CPU scheduler's decision making when dealing with
1039	  MultiThreading at a cost of slightly increased overhead in some
1040	  places. If unsure say N here.
1041
1042config HAVE_ARM_SCU
1043	bool
1044	help
1045	  This option enables support for the ARM snoop control unit
1046
1047config HAVE_ARM_ARCH_TIMER
1048	bool "Architected timer support"
1049	depends on CPU_V7
1050	select ARM_ARCH_TIMER
1051	help
1052	  This option enables support for the ARM architected timer
1053
1054config HAVE_ARM_TWD
1055	bool
1056	help
1057	  This options enables support for the ARM timer and watchdog unit
1058
1059config MCPM
1060	bool "Multi-Cluster Power Management"
1061	depends on CPU_V7 && SMP
1062	help
1063	  This option provides the common power management infrastructure
1064	  for (multi-)cluster based systems, such as big.LITTLE based
1065	  systems.
1066
1067config MCPM_QUAD_CLUSTER
1068	bool
1069	depends on MCPM
1070	help
1071	  To avoid wasting resources unnecessarily, MCPM only supports up
1072	  to 2 clusters by default.
1073	  Platforms with 3 or 4 clusters that use MCPM must select this
1074	  option to allow the additional clusters to be managed.
1075
1076config BIG_LITTLE
1077	bool "big.LITTLE support (Experimental)"
1078	depends on CPU_V7 && SMP
1079	select MCPM
1080	help
1081	  This option enables support selections for the big.LITTLE
1082	  system architecture.
1083
1084config BL_SWITCHER
1085	bool "big.LITTLE switcher support"
1086	depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1087	select CPU_PM
1088	help
1089	  The big.LITTLE "switcher" provides the core functionality to
1090	  transparently handle transition between a cluster of A15's
1091	  and a cluster of A7's in a big.LITTLE system.
1092
1093config BL_SWITCHER_DUMMY_IF
1094	tristate "Simple big.LITTLE switcher user interface"
1095	depends on BL_SWITCHER && DEBUG_KERNEL
1096	help
1097	  This is a simple and dummy char dev interface to control
1098	  the big.LITTLE switcher core code.  It is meant for
1099	  debugging purposes only.
1100
1101choice
1102	prompt "Memory split"
1103	depends on MMU
1104	default VMSPLIT_3G
1105	help
1106	  Select the desired split between kernel and user memory.
1107
1108	  If you are not absolutely sure what you are doing, leave this
1109	  option alone!
1110
1111	config VMSPLIT_3G
1112		bool "3G/1G user/kernel split"
1113	config VMSPLIT_3G_OPT
1114		depends on !ARM_LPAE
1115		bool "3G/1G user/kernel split (for full 1G low memory)"
1116	config VMSPLIT_2G
1117		bool "2G/2G user/kernel split"
1118	config VMSPLIT_1G
1119		bool "1G/3G user/kernel split"
1120endchoice
1121
1122config PAGE_OFFSET
1123	hex
1124	default PHYS_OFFSET if !MMU
1125	default 0x40000000 if VMSPLIT_1G
1126	default 0x80000000 if VMSPLIT_2G
1127	default 0xB0000000 if VMSPLIT_3G_OPT
1128	default 0xC0000000
1129
1130config KASAN_SHADOW_OFFSET
1131	hex
1132	depends on KASAN
1133	default 0x1f000000 if PAGE_OFFSET=0x40000000
1134	default 0x5f000000 if PAGE_OFFSET=0x80000000
1135	default 0x9f000000 if PAGE_OFFSET=0xC0000000
1136	default 0x8f000000 if PAGE_OFFSET=0xB0000000
1137	default 0xffffffff
1138
1139config NR_CPUS
1140	int "Maximum number of CPUs (2-32)"
1141	range 2 16 if DEBUG_KMAP_LOCAL
1142	range 2 32 if !DEBUG_KMAP_LOCAL
1143	depends on SMP
1144	default "4"
1145	help
1146	  The maximum number of CPUs that the kernel can support.
1147	  Up to 32 CPUs can be supported, or up to 16 if kmap_local()
1148	  debugging is enabled, which uses half of the per-CPU fixmap
1149	  slots as guard regions.
1150
1151config HOTPLUG_CPU
1152	bool "Support for hot-pluggable CPUs"
1153	depends on SMP
1154	select GENERIC_IRQ_MIGRATION
1155	help
1156	  Say Y here to experiment with turning CPUs off and on.  CPUs
1157	  can be controlled through /sys/devices/system/cpu.
1158
1159config ARM_PSCI
1160	bool "Support for the ARM Power State Coordination Interface (PSCI)"
1161	depends on HAVE_ARM_SMCCC
1162	select ARM_PSCI_FW
1163	help
1164	  Say Y here if you want Linux to communicate with system firmware
1165	  implementing the PSCI specification for CPU-centric power
1166	  management operations described in ARM document number ARM DEN
1167	  0022A ("Power State Coordination Interface System Software on
1168	  ARM processors").
1169
1170config HZ_FIXED
1171	int
1172	default 128 if SOC_AT91RM9200
1173	default 0
1174
1175choice
1176	depends on HZ_FIXED = 0
1177	prompt "Timer frequency"
1178
1179config HZ_100
1180	bool "100 Hz"
1181
1182config HZ_200
1183	bool "200 Hz"
1184
1185config HZ_250
1186	bool "250 Hz"
1187
1188config HZ_300
1189	bool "300 Hz"
1190
1191config HZ_500
1192	bool "500 Hz"
1193
1194config HZ_1000
1195	bool "1000 Hz"
1196
1197endchoice
1198
1199config HZ
1200	int
1201	default HZ_FIXED if HZ_FIXED != 0
1202	default 100 if HZ_100
1203	default 200 if HZ_200
1204	default 250 if HZ_250
1205	default 300 if HZ_300
1206	default 500 if HZ_500
1207	default 1000
1208
1209config SCHED_HRTICK
1210	def_bool HIGH_RES_TIMERS
1211
1212config THUMB2_KERNEL
1213	bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1214	depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1215	default y if CPU_THUMBONLY
1216	select ARM_UNWIND
1217	help
1218	  By enabling this option, the kernel will be compiled in
1219	  Thumb-2 mode.
1220
1221	  If unsure, say N.
1222
1223config ARM_PATCH_IDIV
1224	bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1225	depends on CPU_32v7
1226	default y
1227	help
1228	  The ARM compiler inserts calls to __aeabi_idiv() and
1229	  __aeabi_uidiv() when it needs to perform division on signed
1230	  and unsigned integers. Some v7 CPUs have support for the sdiv
1231	  and udiv instructions that can be used to implement those
1232	  functions.
1233
1234	  Enabling this option allows the kernel to modify itself to
1235	  replace the first two instructions of these library functions
1236	  with the sdiv or udiv plus "bx lr" instructions when the CPU
1237	  it is running on supports them. Typically this will be faster
1238	  and less power intensive than running the original library
1239	  code to do integer division.
1240
1241config AEABI
1242	bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
1243		!CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
1244	default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
1245	help
1246	  This option allows for the kernel to be compiled using the latest
1247	  ARM ABI (aka EABI).  This is only useful if you are using a user
1248	  space environment that is also compiled with EABI.
1249
1250	  Since there are major incompatibilities between the legacy ABI and
1251	  EABI, especially with regard to structure member alignment, this
1252	  option also changes the kernel syscall calling convention to
1253	  disambiguate both ABIs and allow for backward compatibility support
1254	  (selected with CONFIG_OABI_COMPAT).
1255
1256	  To use this you need GCC version 4.0.0 or later.
1257
1258config OABI_COMPAT
1259	bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1260	depends on AEABI && !THUMB2_KERNEL
1261	help
1262	  This option preserves the old syscall interface along with the
1263	  new (ARM EABI) one. It also provides a compatibility layer to
1264	  intercept syscalls that have structure arguments which layout
1265	  in memory differs between the legacy ABI and the new ARM EABI
1266	  (only for non "thumb" binaries). This option adds a tiny
1267	  overhead to all syscalls and produces a slightly larger kernel.
1268
1269	  The seccomp filter system will not be available when this is
1270	  selected, since there is no way yet to sensibly distinguish
1271	  between calling conventions during filtering.
1272
1273	  If you know you'll be using only pure EABI user space then you
1274	  can say N here. If this option is not selected and you attempt
1275	  to execute a legacy ABI binary then the result will be
1276	  UNPREDICTABLE (in fact it can be predicted that it won't work
1277	  at all). If in doubt say N.
1278
1279config ARCH_SELECT_MEMORY_MODEL
1280	def_bool y
1281
1282config ARCH_FLATMEM_ENABLE
1283	def_bool !(ARCH_RPC || ARCH_SA1100)
1284
1285config ARCH_SPARSEMEM_ENABLE
1286	def_bool !ARCH_FOOTBRIDGE
1287	select SPARSEMEM_STATIC if SPARSEMEM
1288
1289config HIGHMEM
1290	bool "High Memory Support"
1291	depends on MMU
1292	select KMAP_LOCAL
1293	select KMAP_LOCAL_NON_LINEAR_PTE_ARRAY
1294	help
1295	  The address space of ARM processors is only 4 Gigabytes large
1296	  and it has to accommodate user address space, kernel address
1297	  space as well as some memory mapped IO. That means that, if you
1298	  have a large amount of physical memory and/or IO, not all of the
1299	  memory can be "permanently mapped" by the kernel. The physical
1300	  memory that is not permanently mapped is called "high memory".
1301
1302	  Depending on the selected kernel/user memory split, minimum
1303	  vmalloc space and actual amount of RAM, you may not need this
1304	  option which should result in a slightly faster kernel.
1305
1306	  If unsure, say n.
1307
1308config HIGHPTE
1309	bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1310	depends on HIGHMEM
1311	default y
1312	help
1313	  The VM uses one page of physical memory for each page table.
1314	  For systems with a lot of processes, this can use a lot of
1315	  precious low memory, eventually leading to low memory being
1316	  consumed by page tables.  Setting this option will allow
1317	  user-space 2nd level page tables to reside in high memory.
1318
1319config CPU_SW_DOMAIN_PAN
1320	bool "Enable use of CPU domains to implement privileged no-access"
1321	depends on MMU && !ARM_LPAE
1322	default y
1323	help
1324	  Increase kernel security by ensuring that normal kernel accesses
1325	  are unable to access userspace addresses.  This can help prevent
1326	  use-after-free bugs becoming an exploitable privilege escalation
1327	  by ensuring that magic values (such as LIST_POISON) will always
1328	  fault when dereferenced.
1329
1330	  CPUs with low-vector mappings use a best-efforts implementation.
1331	  Their lower 1MB needs to remain accessible for the vectors, but
1332	  the remainder of userspace will become appropriately inaccessible.
1333
1334config HW_PERF_EVENTS
1335	def_bool y
1336	depends on ARM_PMU
1337
1338config ARM_MODULE_PLTS
1339	bool "Use PLTs to allow module memory to spill over into vmalloc area"
1340	depends on MODULES
1341	select KASAN_VMALLOC if KASAN
1342	default y
1343	help
1344	  Allocate PLTs when loading modules so that jumps and calls whose
1345	  targets are too far away for their relative offsets to be encoded
1346	  in the instructions themselves can be bounced via veneers in the
1347	  module's PLT. This allows modules to be allocated in the generic
1348	  vmalloc area after the dedicated module memory area has been
1349	  exhausted. The modules will use slightly more memory, but after
1350	  rounding up to page size, the actual memory footprint is usually
1351	  the same.
1352
1353	  Disabling this is usually safe for small single-platform
1354	  configurations. If unsure, say y.
1355
1356config ARCH_FORCE_MAX_ORDER
1357	int "Order of maximal physically contiguous allocations"
1358	default "11" if SOC_AM33XX
1359	default "8" if SA1111
1360	default "10"
1361	help
1362	  The kernel page allocator limits the size of maximal physically
1363	  contiguous allocations. The limit is called MAX_ORDER and it
1364	  defines the maximal power of two of number of pages that can be
1365	  allocated as a single contiguous block. This option allows
1366	  overriding the default setting when ability to allocate very
1367	  large blocks of physically contiguous memory is required.
1368
1369	  Don't change if unsure.
1370
1371config ALIGNMENT_TRAP
1372	def_bool CPU_CP15_MMU
1373	select HAVE_PROC_CPU if PROC_FS
1374	help
1375	  ARM processors cannot fetch/store information which is not
1376	  naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1377	  address divisible by 4. On 32-bit ARM processors, these non-aligned
1378	  fetch/store instructions will be emulated in software if you say
1379	  here, which has a severe performance impact. This is necessary for
1380	  correct operation of some network protocols. With an IP-only
1381	  configuration it is safe to say N, otherwise say Y.
1382
1383config UACCESS_WITH_MEMCPY
1384	bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1385	depends on MMU
1386	default y if CPU_FEROCEON
1387	help
1388	  Implement faster copy_to_user and clear_user methods for CPU
1389	  cores where a 8-word STM instruction give significantly higher
1390	  memory write throughput than a sequence of individual 32bit stores.
1391
1392	  A possible side effect is a slight increase in scheduling latency
1393	  between threads sharing the same address space if they invoke
1394	  such copy operations with large buffers.
1395
1396	  However, if the CPU data cache is using a write-allocate mode,
1397	  this option is unlikely to provide any performance gain.
1398
1399config PARAVIRT
1400	bool "Enable paravirtualization code"
1401	help
1402	  This changes the kernel so it can modify itself when it is run
1403	  under a hypervisor, potentially improving performance significantly
1404	  over full virtualization.
1405
1406config PARAVIRT_TIME_ACCOUNTING
1407	bool "Paravirtual steal time accounting"
1408	select PARAVIRT
1409	help
1410	  Select this option to enable fine granularity task steal time
1411	  accounting. Time spent executing other tasks in parallel with
1412	  the current vCPU is discounted from the vCPU power. To account for
1413	  that, there can be a small performance impact.
1414
1415	  If in doubt, say N here.
1416
1417config XEN_DOM0
1418	def_bool y
1419	depends on XEN
1420
1421config XEN
1422	bool "Xen guest support on ARM"
1423	depends on ARM && AEABI && OF
1424	depends on CPU_V7 && !CPU_V6
1425	depends on !GENERIC_ATOMIC64
1426	depends on MMU
1427	select ARCH_DMA_ADDR_T_64BIT
1428	select ARM_PSCI
1429	select SWIOTLB
1430	select SWIOTLB_XEN
1431	select PARAVIRT
1432	help
1433	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1434
1435config CC_HAVE_STACKPROTECTOR_TLS
1436	def_bool $(cc-option,-mtp=cp15 -mstack-protector-guard=tls -mstack-protector-guard-offset=0)
1437
1438config STACKPROTECTOR_PER_TASK
1439	bool "Use a unique stack canary value for each task"
1440	depends on STACKPROTECTOR && CURRENT_POINTER_IN_TPIDRURO && !XIP_DEFLATED_DATA
1441	depends on GCC_PLUGINS || CC_HAVE_STACKPROTECTOR_TLS
1442	select GCC_PLUGIN_ARM_SSP_PER_TASK if !CC_HAVE_STACKPROTECTOR_TLS
1443	default y
1444	help
1445	  Due to the fact that GCC uses an ordinary symbol reference from
1446	  which to load the value of the stack canary, this value can only
1447	  change at reboot time on SMP systems, and all tasks running in the
1448	  kernel's address space are forced to use the same canary value for
1449	  the entire duration that the system is up.
1450
1451	  Enable this option to switch to a different method that uses a
1452	  different canary value for each task.
1453
1454endmenu
1455
1456menu "Boot options"
1457
1458config USE_OF
1459	bool "Flattened Device Tree support"
1460	select IRQ_DOMAIN
1461	select OF
1462	help
1463	  Include support for flattened device tree machine descriptions.
1464
1465config ATAGS
1466	bool "Support for the traditional ATAGS boot data passing"
1467	default y
1468	help
1469	  This is the traditional way of passing data to the kernel at boot
1470	  time. If you are solely relying on the flattened device tree (or
1471	  the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1472	  to remove ATAGS support from your kernel binary.
1473
1474config DEPRECATED_PARAM_STRUCT
1475	bool "Provide old way to pass kernel parameters"
1476	depends on ATAGS
1477	help
1478	  This was deprecated in 2001 and announced to live on for 5 years.
1479	  Some old boot loaders still use this way.
1480
1481# Compressed boot loader in ROM.  Yes, we really want to ask about
1482# TEXT and BSS so we preserve their values in the config files.
1483config ZBOOT_ROM_TEXT
1484	hex "Compressed ROM boot loader base address"
1485	default 0x0
1486	help
1487	  The physical address at which the ROM-able zImage is to be
1488	  placed in the target.  Platforms which normally make use of
1489	  ROM-able zImage formats normally set this to a suitable
1490	  value in their defconfig file.
1491
1492	  If ZBOOT_ROM is not enabled, this has no effect.
1493
1494config ZBOOT_ROM_BSS
1495	hex "Compressed ROM boot loader BSS address"
1496	default 0x0
1497	help
1498	  The base address of an area of read/write memory in the target
1499	  for the ROM-able zImage which must be available while the
1500	  decompressor is running. It must be large enough to hold the
1501	  entire decompressed kernel plus an additional 128 KiB.
1502	  Platforms which normally make use of ROM-able zImage formats
1503	  normally set this to a suitable value in their defconfig file.
1504
1505	  If ZBOOT_ROM is not enabled, this has no effect.
1506
1507config ZBOOT_ROM
1508	bool "Compressed boot loader in ROM/flash"
1509	depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1510	depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1511	help
1512	  Say Y here if you intend to execute your compressed kernel image
1513	  (zImage) directly from ROM or flash.  If unsure, say N.
1514
1515config ARM_APPENDED_DTB
1516	bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1517	depends on OF
1518	help
1519	  With this option, the boot code will look for a device tree binary
1520	  (DTB) appended to zImage
1521	  (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1522
1523	  This is meant as a backward compatibility convenience for those
1524	  systems with a bootloader that can't be upgraded to accommodate
1525	  the documented boot protocol using a device tree.
1526
1527	  Beware that there is very little in terms of protection against
1528	  this option being confused by leftover garbage in memory that might
1529	  look like a DTB header after a reboot if no actual DTB is appended
1530	  to zImage.  Do not leave this option active in a production kernel
1531	  if you don't intend to always append a DTB.  Proper passing of the
1532	  location into r2 of a bootloader provided DTB is always preferable
1533	  to this option.
1534
1535config ARM_ATAG_DTB_COMPAT
1536	bool "Supplement the appended DTB with traditional ATAG information"
1537	depends on ARM_APPENDED_DTB
1538	help
1539	  Some old bootloaders can't be updated to a DTB capable one, yet
1540	  they provide ATAGs with memory configuration, the ramdisk address,
1541	  the kernel cmdline string, etc.  Such information is dynamically
1542	  provided by the bootloader and can't always be stored in a static
1543	  DTB.  To allow a device tree enabled kernel to be used with such
1544	  bootloaders, this option allows zImage to extract the information
1545	  from the ATAG list and store it at run time into the appended DTB.
1546
1547choice
1548	prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1549	default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1550
1551config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1552	bool "Use bootloader kernel arguments if available"
1553	help
1554	  Uses the command-line options passed by the boot loader instead of
1555	  the device tree bootargs property. If the boot loader doesn't provide
1556	  any, the device tree bootargs property will be used.
1557
1558config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1559	bool "Extend with bootloader kernel arguments"
1560	help
1561	  The command-line arguments provided by the boot loader will be
1562	  appended to the the device tree bootargs property.
1563
1564endchoice
1565
1566config CMDLINE
1567	string "Default kernel command string"
1568	default ""
1569	help
1570	  On some architectures (e.g. CATS), there is currently no way
1571	  for the boot loader to pass arguments to the kernel. For these
1572	  architectures, you should supply some command-line options at build
1573	  time by entering them here. As a minimum, you should specify the
1574	  memory size and the root device (e.g., mem=64M root=/dev/nfs).
1575
1576choice
1577	prompt "Kernel command line type" if CMDLINE != ""
1578	default CMDLINE_FROM_BOOTLOADER
1579
1580config CMDLINE_FROM_BOOTLOADER
1581	bool "Use bootloader kernel arguments if available"
1582	help
1583	  Uses the command-line options passed by the boot loader. If
1584	  the boot loader doesn't provide any, the default kernel command
1585	  string provided in CMDLINE will be used.
1586
1587config CMDLINE_EXTEND
1588	bool "Extend bootloader kernel arguments"
1589	help
1590	  The command-line arguments provided by the boot loader will be
1591	  appended to the default kernel command string.
1592
1593config CMDLINE_FORCE
1594	bool "Always use the default kernel command string"
1595	help
1596	  Always use the default kernel command string, even if the boot
1597	  loader passes other arguments to the kernel.
1598	  This is useful if you cannot or don't want to change the
1599	  command-line options your boot loader passes to the kernel.
1600endchoice
1601
1602config XIP_KERNEL
1603	bool "Kernel Execute-In-Place from ROM"
1604	depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1605	depends on !ARM_PATCH_IDIV && !ARM_PATCH_PHYS_VIRT && !SMP_ON_UP
1606	help
1607	  Execute-In-Place allows the kernel to run from non-volatile storage
1608	  directly addressable by the CPU, such as NOR flash. This saves RAM
1609	  space since the text section of the kernel is not loaded from flash
1610	  to RAM.  Read-write sections, such as the data section and stack,
1611	  are still copied to RAM.  The XIP kernel is not compressed since
1612	  it has to run directly from flash, so it will take more space to
1613	  store it.  The flash address used to link the kernel object files,
1614	  and for storing it, is configuration dependent. Therefore, if you
1615	  say Y here, you must know the proper physical address where to
1616	  store the kernel image depending on your own flash memory usage.
1617
1618	  Also note that the make target becomes "make xipImage" rather than
1619	  "make zImage" or "make Image".  The final kernel binary to put in
1620	  ROM memory will be arch/arm/boot/xipImage.
1621
1622	  If unsure, say N.
1623
1624config XIP_PHYS_ADDR
1625	hex "XIP Kernel Physical Location"
1626	depends on XIP_KERNEL
1627	default "0x00080000"
1628	help
1629	  This is the physical address in your flash memory the kernel will
1630	  be linked for and stored to.  This address is dependent on your
1631	  own flash usage.
1632
1633config XIP_DEFLATED_DATA
1634	bool "Store kernel .data section compressed in ROM"
1635	depends on XIP_KERNEL
1636	select ZLIB_INFLATE
1637	help
1638	  Before the kernel is actually executed, its .data section has to be
1639	  copied to RAM from ROM. This option allows for storing that data
1640	  in compressed form and decompressed to RAM rather than merely being
1641	  copied, saving some precious ROM space. A possible drawback is a
1642	  slightly longer boot delay.
1643
1644config KEXEC
1645	bool "Kexec system call (EXPERIMENTAL)"
1646	depends on (!SMP || PM_SLEEP_SMP)
1647	depends on MMU
1648	select KEXEC_CORE
1649	help
1650	  kexec is a system call that implements the ability to shutdown your
1651	  current kernel, and to start another kernel.  It is like a reboot
1652	  but it is independent of the system firmware.   And like a reboot
1653	  you can start any kernel with it, not just Linux.
1654
1655	  It is an ongoing process to be certain the hardware in a machine
1656	  is properly shutdown, so do not be surprised if this code does not
1657	  initially work for you.
1658
1659config ATAGS_PROC
1660	bool "Export atags in procfs"
1661	depends on ATAGS && KEXEC
1662	default y
1663	help
1664	  Should the atags used to boot the kernel be exported in an "atags"
1665	  file in procfs. Useful with kexec.
1666
1667config CRASH_DUMP
1668	bool "Build kdump crash kernel (EXPERIMENTAL)"
1669	help
1670	  Generate crash dump after being started by kexec. This should
1671	  be normally only set in special crash dump kernels which are
1672	  loaded in the main kernel with kexec-tools into a specially
1673	  reserved region and then later executed after a crash by
1674	  kdump/kexec. The crash dump kernel must be compiled to a
1675	  memory address not used by the main kernel
1676
1677	  For more details see Documentation/admin-guide/kdump/kdump.rst
1678
1679config AUTO_ZRELADDR
1680	bool "Auto calculation of the decompressed kernel image address" if !ARCH_MULTIPLATFORM
1681	default !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
1682	help
1683	  ZRELADDR is the physical address where the decompressed kernel
1684	  image will be placed. If AUTO_ZRELADDR is selected, the address
1685	  will be determined at run-time, either by masking the current IP
1686	  with 0xf8000000, or, if invalid, from the DTB passed in r2.
1687	  This assumes the zImage being placed in the first 128MB from
1688	  start of memory.
1689
1690config EFI_STUB
1691	bool
1692
1693config EFI
1694	bool "UEFI runtime support"
1695	depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
1696	select UCS2_STRING
1697	select EFI_PARAMS_FROM_FDT
1698	select EFI_STUB
1699	select EFI_GENERIC_STUB
1700	select EFI_RUNTIME_WRAPPERS
1701	help
1702	  This option provides support for runtime services provided
1703	  by UEFI firmware (such as non-volatile variables, realtime
1704	  clock, and platform reset). A UEFI stub is also provided to
1705	  allow the kernel to be booted as an EFI application. This
1706	  is only useful for kernels that may run on systems that have
1707	  UEFI firmware.
1708
1709config DMI
1710	bool "Enable support for SMBIOS (DMI) tables"
1711	depends on EFI
1712	default y
1713	help
1714	  This enables SMBIOS/DMI feature for systems.
1715
1716	  This option is only useful on systems that have UEFI firmware.
1717	  However, even with this option, the resultant kernel should
1718	  continue to boot on existing non-UEFI platforms.
1719
1720	  NOTE: This does *NOT* enable or encourage the use of DMI quirks,
1721	  i.e., the the practice of identifying the platform via DMI to
1722	  decide whether certain workarounds for buggy hardware and/or
1723	  firmware need to be enabled. This would require the DMI subsystem
1724	  to be enabled much earlier than we do on ARM, which is non-trivial.
1725
1726endmenu
1727
1728menu "CPU Power Management"
1729
1730source "drivers/cpufreq/Kconfig"
1731
1732source "drivers/cpuidle/Kconfig"
1733
1734endmenu
1735
1736menu "Floating point emulation"
1737
1738comment "At least one emulation must be selected"
1739
1740config FPE_NWFPE
1741	bool "NWFPE math emulation"
1742	depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
1743	help
1744	  Say Y to include the NWFPE floating point emulator in the kernel.
1745	  This is necessary to run most binaries. Linux does not currently
1746	  support floating point hardware so you need to say Y here even if
1747	  your machine has an FPA or floating point co-processor podule.
1748
1749	  You may say N here if you are going to load the Acorn FPEmulator
1750	  early in the bootup.
1751
1752config FPE_NWFPE_XP
1753	bool "Support extended precision"
1754	depends on FPE_NWFPE
1755	help
1756	  Say Y to include 80-bit support in the kernel floating-point
1757	  emulator.  Otherwise, only 32 and 64-bit support is compiled in.
1758	  Note that gcc does not generate 80-bit operations by default,
1759	  so in most cases this option only enlarges the size of the
1760	  floating point emulator without any good reason.
1761
1762	  You almost surely want to say N here.
1763
1764config FPE_FASTFPE
1765	bool "FastFPE math emulation (EXPERIMENTAL)"
1766	depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
1767	help
1768	  Say Y here to include the FAST floating point emulator in the kernel.
1769	  This is an experimental much faster emulator which now also has full
1770	  precision for the mantissa.  It does not support any exceptions.
1771	  It is very simple, and approximately 3-6 times faster than NWFPE.
1772
1773	  It should be sufficient for most programs.  It may be not suitable
1774	  for scientific calculations, but you have to check this for yourself.
1775	  If you do not feel you need a faster FP emulation you should better
1776	  choose NWFPE.
1777
1778config VFP
1779	bool "VFP-format floating point maths"
1780	depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1781	help
1782	  Say Y to include VFP support code in the kernel. This is needed
1783	  if your hardware includes a VFP unit.
1784
1785	  Please see <file:Documentation/arch/arm/vfp/release-notes.rst> for
1786	  release notes and additional status information.
1787
1788	  Say N if your target does not have VFP hardware.
1789
1790config VFPv3
1791	bool
1792	depends on VFP
1793	default y if CPU_V7
1794
1795config NEON
1796	bool "Advanced SIMD (NEON) Extension support"
1797	depends on VFPv3 && CPU_V7
1798	help
1799	  Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1800	  Extension.
1801
1802config KERNEL_MODE_NEON
1803	bool "Support for NEON in kernel mode"
1804	depends on NEON && AEABI
1805	help
1806	  Say Y to include support for NEON in kernel mode.
1807
1808endmenu
1809
1810menu "Power management options"
1811
1812source "kernel/power/Kconfig"
1813
1814config ARCH_SUSPEND_POSSIBLE
1815	depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
1816		CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
1817	def_bool y
1818
1819config ARM_CPU_SUSPEND
1820	def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
1821	depends on ARCH_SUSPEND_POSSIBLE
1822
1823config ARCH_HIBERNATION_POSSIBLE
1824	bool
1825	depends on MMU
1826	default y if ARCH_SUSPEND_POSSIBLE
1827
1828endmenu
1829
1830source "arch/arm/Kconfig.assembler"
1831