xref: /openbmc/linux/arch/arm/mm/Kconfig (revision 08f3e087)
1# SPDX-License-Identifier: GPL-2.0
2comment "Processor Type"
3
4# Select CPU types depending on the architecture selected.  This selects
5# which CPUs we support in the kernel image, and the compiler instruction
6# optimiser behaviour.
7
8# ARM7TDMI
9config CPU_ARM7TDMI
10	bool
11	depends on !MMU
12	select CPU_32v4T
13	select CPU_ABRT_LV4T
14	select CPU_CACHE_V4
15	select CPU_PABRT_LEGACY
16	help
17	  A 32-bit RISC microprocessor based on the ARM7 processor core
18	  which has no memory control unit and cache.
19
20	  Say Y if you want support for the ARM7TDMI processor.
21	  Otherwise, say N.
22
23# ARM720T
24config CPU_ARM720T
25	bool
26	select CPU_32v4T
27	select CPU_ABRT_LV4T
28	select CPU_CACHE_V4
29	select CPU_CACHE_VIVT
30	select CPU_COPY_V4WT if MMU
31	select CPU_CP15_MMU
32	select CPU_PABRT_LEGACY
33	select CPU_THUMB_CAPABLE
34	select CPU_TLB_V4WT if MMU
35	help
36	  A 32-bit RISC processor with 8kByte Cache, Write Buffer and
37	  MMU built around an ARM7TDMI core.
38
39	  Say Y if you want support for the ARM720T processor.
40	  Otherwise, say N.
41
42# ARM740T
43config CPU_ARM740T
44	bool
45	depends on !MMU
46	select CPU_32v4T
47	select CPU_ABRT_LV4T
48	select CPU_CACHE_V4
49	select CPU_CP15_MPU
50	select CPU_PABRT_LEGACY
51	select CPU_THUMB_CAPABLE
52	help
53	  A 32-bit RISC processor with 8KB cache or 4KB variants,
54	  write buffer and MPU(Protection Unit) built around
55	  an ARM7TDMI core.
56
57	  Say Y if you want support for the ARM740T processor.
58	  Otherwise, say N.
59
60# ARM9TDMI
61config CPU_ARM9TDMI
62	bool
63	depends on !MMU
64	select CPU_32v4T
65	select CPU_ABRT_NOMMU
66	select CPU_CACHE_V4
67	select CPU_PABRT_LEGACY
68	help
69	  A 32-bit RISC microprocessor based on the ARM9 processor core
70	  which has no memory control unit and cache.
71
72	  Say Y if you want support for the ARM9TDMI processor.
73	  Otherwise, say N.
74
75# ARM920T
76config CPU_ARM920T
77	bool
78	select CPU_32v4T
79	select CPU_ABRT_EV4T
80	select CPU_CACHE_V4WT
81	select CPU_CACHE_VIVT
82	select CPU_COPY_V4WB if MMU
83	select CPU_CP15_MMU
84	select CPU_PABRT_LEGACY
85	select CPU_THUMB_CAPABLE
86	select CPU_TLB_V4WBI if MMU
87	help
88	  The ARM920T is licensed to be produced by numerous vendors,
89	  and is used in the Cirrus EP93xx and the Samsung S3C2410.
90
91	  Say Y if you want support for the ARM920T processor.
92	  Otherwise, say N.
93
94# ARM922T
95config CPU_ARM922T
96	bool
97	select CPU_32v4T
98	select CPU_ABRT_EV4T
99	select CPU_CACHE_V4WT
100	select CPU_CACHE_VIVT
101	select CPU_COPY_V4WB if MMU
102	select CPU_CP15_MMU
103	select CPU_PABRT_LEGACY
104	select CPU_THUMB_CAPABLE
105	select CPU_TLB_V4WBI if MMU
106	help
107	  The ARM922T is a version of the ARM920T, but with smaller
108	  instruction and data caches. It is used in Altera's
109	  Excalibur XA device family and the ARM Integrator.
110
111	  Say Y if you want support for the ARM922T processor.
112	  Otherwise, say N.
113
114# ARM925T
115config CPU_ARM925T
116	bool
117	select CPU_32v4T
118	select CPU_ABRT_EV4T
119	select CPU_CACHE_V4WT
120	select CPU_CACHE_VIVT
121	select CPU_COPY_V4WB if MMU
122	select CPU_CP15_MMU
123	select CPU_PABRT_LEGACY
124	select CPU_THUMB_CAPABLE
125	select CPU_TLB_V4WBI if MMU
126 	help
127 	  The ARM925T is a mix between the ARM920T and ARM926T, but with
128	  different instruction and data caches. It is used in TI's OMAP
129 	  device family.
130
131 	  Say Y if you want support for the ARM925T processor.
132 	  Otherwise, say N.
133
134# ARM926T
135config CPU_ARM926T
136	bool
137	select CPU_32v5
138	select CPU_ABRT_EV5TJ
139	select CPU_CACHE_VIVT
140	select CPU_COPY_V4WB if MMU
141	select CPU_CP15_MMU
142	select CPU_PABRT_LEGACY
143	select CPU_THUMB_CAPABLE
144	select CPU_TLB_V4WBI if MMU
145	help
146	  This is a variant of the ARM920.  It has slightly different
147	  instruction sequences for cache and TLB operations.  Curiously,
148	  there is no documentation on it at the ARM corporate website.
149
150	  Say Y if you want support for the ARM926T processor.
151	  Otherwise, say N.
152
153# FA526
154config CPU_FA526
155	bool
156	select CPU_32v4
157	select CPU_ABRT_EV4
158	select CPU_CACHE_FA
159	select CPU_CACHE_VIVT
160	select CPU_COPY_FA if MMU
161	select CPU_CP15_MMU
162	select CPU_PABRT_LEGACY
163	select CPU_TLB_FA if MMU
164	help
165	  The FA526 is a version of the ARMv4 compatible processor with
166	  Branch Target Buffer, Unified TLB and cache line size 16.
167
168	  Say Y if you want support for the FA526 processor.
169	  Otherwise, say N.
170
171# ARM940T
172config CPU_ARM940T
173	bool
174	depends on !MMU
175	select CPU_32v4T
176	select CPU_ABRT_NOMMU
177	select CPU_CACHE_VIVT
178	select CPU_CP15_MPU
179	select CPU_PABRT_LEGACY
180	select CPU_THUMB_CAPABLE
181	help
182	  ARM940T is a member of the ARM9TDMI family of general-
183	  purpose microprocessors with MPU and separate 4KB
184	  instruction and 4KB data cases, each with a 4-word line
185	  length.
186
187	  Say Y if you want support for the ARM940T processor.
188	  Otherwise, say N.
189
190# ARM946E-S
191config CPU_ARM946E
192	bool
193	depends on !MMU
194	select CPU_32v5
195	select CPU_ABRT_NOMMU
196	select CPU_CACHE_VIVT
197	select CPU_CP15_MPU
198	select CPU_PABRT_LEGACY
199	select CPU_THUMB_CAPABLE
200	help
201	  ARM946E-S is a member of the ARM9E-S family of high-
202	  performance, 32-bit system-on-chip processor solutions.
203	  The TCM and ARMv5TE 32-bit instruction set is supported.
204
205	  Say Y if you want support for the ARM946E-S processor.
206	  Otherwise, say N.
207
208# ARM1020 - needs validating
209config CPU_ARM1020
210	bool
211	select CPU_32v5
212	select CPU_ABRT_EV4T
213	select CPU_CACHE_V4WT
214	select CPU_CACHE_VIVT
215	select CPU_COPY_V4WB if MMU
216	select CPU_CP15_MMU
217	select CPU_PABRT_LEGACY
218	select CPU_THUMB_CAPABLE
219	select CPU_TLB_V4WBI if MMU
220	help
221	  The ARM1020 is the 32K cached version of the ARM10 processor,
222	  with an addition of a floating-point unit.
223
224	  Say Y if you want support for the ARM1020 processor.
225	  Otherwise, say N.
226
227# ARM1020E - needs validating
228config CPU_ARM1020E
229	bool
230	depends on n
231	select CPU_32v5
232	select CPU_ABRT_EV4T
233	select CPU_CACHE_V4WT
234	select CPU_CACHE_VIVT
235	select CPU_COPY_V4WB if MMU
236	select CPU_CP15_MMU
237	select CPU_PABRT_LEGACY
238	select CPU_THUMB_CAPABLE
239	select CPU_TLB_V4WBI if MMU
240
241# ARM1022E
242config CPU_ARM1022
243	bool
244	select CPU_32v5
245	select CPU_ABRT_EV4T
246	select CPU_CACHE_VIVT
247	select CPU_COPY_V4WB if MMU # can probably do better
248	select CPU_CP15_MMU
249	select CPU_PABRT_LEGACY
250	select CPU_THUMB_CAPABLE
251	select CPU_TLB_V4WBI if MMU
252	help
253	  The ARM1022E is an implementation of the ARMv5TE architecture
254	  based upon the ARM10 integer core with a 16KiB L1 Harvard cache,
255	  embedded trace macrocell, and a floating-point unit.
256
257	  Say Y if you want support for the ARM1022E processor.
258	  Otherwise, say N.
259
260# ARM1026EJ-S
261config CPU_ARM1026
262	bool
263	select CPU_32v5
264	select CPU_ABRT_EV5T # But need Jazelle, but EV5TJ ignores bit 10
265	select CPU_CACHE_VIVT
266	select CPU_COPY_V4WB if MMU # can probably do better
267	select CPU_CP15_MMU
268	select CPU_PABRT_LEGACY
269	select CPU_THUMB_CAPABLE
270	select CPU_TLB_V4WBI if MMU
271	help
272	  The ARM1026EJ-S is an implementation of the ARMv5TEJ architecture
273	  based upon the ARM10 integer core.
274
275	  Say Y if you want support for the ARM1026EJ-S processor.
276	  Otherwise, say N.
277
278# SA110
279config CPU_SA110
280	bool
281	select CPU_32v3 if ARCH_RPC
282	select CPU_32v4 if !ARCH_RPC
283	select CPU_ABRT_EV4
284	select CPU_CACHE_V4WB
285	select CPU_CACHE_VIVT
286	select CPU_COPY_V4WB if MMU
287	select CPU_CP15_MMU
288	select CPU_PABRT_LEGACY
289	select CPU_TLB_V4WB if MMU
290	help
291	  The Intel StrongARM(R) SA-110 is a 32-bit microprocessor and
292	  is available at five speeds ranging from 100 MHz to 233 MHz.
293	  More information is available at
294	  <http://developer.intel.com/design/strong/sa110.htm>.
295
296	  Say Y if you want support for the SA-110 processor.
297	  Otherwise, say N.
298
299# SA1100
300config CPU_SA1100
301	bool
302	select CPU_32v4
303	select CPU_ABRT_EV4
304	select CPU_CACHE_V4WB
305	select CPU_CACHE_VIVT
306	select CPU_CP15_MMU
307	select CPU_PABRT_LEGACY
308	select CPU_TLB_V4WB if MMU
309
310# XScale
311config CPU_XSCALE
312	bool
313	select CPU_32v5
314	select CPU_ABRT_EV5T
315	select CPU_CACHE_VIVT
316	select CPU_CP15_MMU
317	select CPU_PABRT_LEGACY
318	select CPU_THUMB_CAPABLE
319	select CPU_TLB_V4WBI if MMU
320
321# XScale Core Version 3
322config CPU_XSC3
323	bool
324	select CPU_32v5
325	select CPU_ABRT_EV5T
326	select CPU_CACHE_VIVT
327	select CPU_CP15_MMU
328	select CPU_PABRT_LEGACY
329	select CPU_THUMB_CAPABLE
330	select CPU_TLB_V4WBI if MMU
331	select IO_36
332
333# Marvell PJ1 (Mohawk)
334config CPU_MOHAWK
335	bool
336	select CPU_32v5
337	select CPU_ABRT_EV5T
338	select CPU_CACHE_VIVT
339	select CPU_COPY_V4WB if MMU
340	select CPU_CP15_MMU
341	select CPU_PABRT_LEGACY
342	select CPU_THUMB_CAPABLE
343	select CPU_TLB_V4WBI if MMU
344
345# Feroceon
346config CPU_FEROCEON
347	bool
348	select CPU_32v5
349	select CPU_ABRT_EV5T
350	select CPU_CACHE_VIVT
351	select CPU_COPY_FEROCEON if MMU
352	select CPU_CP15_MMU
353	select CPU_PABRT_LEGACY
354	select CPU_THUMB_CAPABLE
355	select CPU_TLB_FEROCEON if MMU
356
357config CPU_FEROCEON_OLD_ID
358	bool "Accept early Feroceon cores with an ARM926 ID"
359	depends on CPU_FEROCEON && !CPU_ARM926T
360	default y
361	help
362	  This enables the usage of some old Feroceon cores
363	  for which the CPU ID is equal to the ARM926 ID.
364	  Relevant for Feroceon-1850 and early Feroceon-2850.
365
366# Marvell PJ4
367config CPU_PJ4
368	bool
369	select ARM_THUMBEE
370	select CPU_V7
371
372config CPU_PJ4B
373	bool
374	select CPU_V7
375
376# ARMv6
377config CPU_V6
378	bool
379	select CPU_32v6
380	select CPU_ABRT_EV6
381	select CPU_CACHE_V6
382	select CPU_CACHE_VIPT
383	select CPU_COPY_V6 if MMU
384	select CPU_CP15_MMU
385	select CPU_HAS_ASID if MMU
386	select CPU_PABRT_V6
387	select CPU_THUMB_CAPABLE
388	select CPU_TLB_V6 if MMU
389
390# ARMv6k
391config CPU_V6K
392	bool
393	select CPU_32v6
394	select CPU_32v6K
395	select CPU_ABRT_EV6
396	select CPU_CACHE_V6
397	select CPU_CACHE_VIPT
398	select CPU_COPY_V6 if MMU
399	select CPU_CP15_MMU
400	select CPU_HAS_ASID if MMU
401	select CPU_PABRT_V6
402	select CPU_THUMB_CAPABLE
403	select CPU_TLB_V6 if MMU
404
405# ARMv7
406config CPU_V7
407	bool
408	select CPU_32v6K
409	select CPU_32v7
410	select CPU_ABRT_EV7
411	select CPU_CACHE_V7
412	select CPU_CACHE_VIPT
413	select CPU_COPY_V6 if MMU
414	select CPU_CP15_MMU if MMU
415	select CPU_CP15_MPU if !MMU
416	select CPU_HAS_ASID if MMU
417	select CPU_PABRT_V7
418	select CPU_SPECTRE if MMU
419	select CPU_THUMB_CAPABLE
420	select CPU_TLB_V7 if MMU
421
422# ARMv7M
423config CPU_V7M
424	bool
425	select CPU_32v7M
426	select CPU_ABRT_NOMMU
427	select CPU_CACHE_V7M
428	select CPU_CACHE_NOP
429	select CPU_PABRT_LEGACY
430	select CPU_THUMBONLY
431
432config CPU_THUMBONLY
433	bool
434	select CPU_THUMB_CAPABLE
435	# There are no CPUs available with MMU that don't implement an ARM ISA:
436	depends on !MMU
437	help
438	  Select this if your CPU doesn't support the 32 bit ARM instructions.
439
440config CPU_THUMB_CAPABLE
441	bool
442	help
443	  Select this if your CPU can support Thumb mode.
444
445# Figure out what processor architecture version we should be using.
446# This defines the compiler instruction set which depends on the machine type.
447config CPU_32v3
448	bool
449	select CPU_USE_DOMAINS if MMU
450	select NEED_KUSER_HELPERS
451	select TLS_REG_EMUL if SMP || !MMU
452	select CPU_NO_EFFICIENT_FFS
453
454config CPU_32v4
455	bool
456	select CPU_USE_DOMAINS if MMU
457	select NEED_KUSER_HELPERS
458	select TLS_REG_EMUL if SMP || !MMU
459	select CPU_NO_EFFICIENT_FFS
460
461config CPU_32v4T
462	bool
463	select CPU_USE_DOMAINS if MMU
464	select NEED_KUSER_HELPERS
465	select TLS_REG_EMUL if SMP || !MMU
466	select CPU_NO_EFFICIENT_FFS
467
468config CPU_32v5
469	bool
470	select CPU_USE_DOMAINS if MMU
471	select NEED_KUSER_HELPERS
472	select TLS_REG_EMUL if SMP || !MMU
473
474config CPU_32v6
475	bool
476	select TLS_REG_EMUL if !CPU_32v6K && !MMU
477
478config CPU_32v6K
479	bool
480
481config CPU_32v7
482	bool
483
484config CPU_32v7M
485	bool
486
487# The abort model
488config CPU_ABRT_NOMMU
489	bool
490
491config CPU_ABRT_EV4
492	bool
493
494config CPU_ABRT_EV4T
495	bool
496
497config CPU_ABRT_LV4T
498	bool
499
500config CPU_ABRT_EV5T
501	bool
502
503config CPU_ABRT_EV5TJ
504	bool
505
506config CPU_ABRT_EV6
507	bool
508
509config CPU_ABRT_EV7
510	bool
511
512config CPU_PABRT_LEGACY
513	bool
514
515config CPU_PABRT_V6
516	bool
517
518config CPU_PABRT_V7
519	bool
520
521# The cache model
522config CPU_CACHE_V4
523	bool
524
525config CPU_CACHE_V4WT
526	bool
527
528config CPU_CACHE_V4WB
529	bool
530
531config CPU_CACHE_V6
532	bool
533
534config CPU_CACHE_V7
535	bool
536
537config CPU_CACHE_NOP
538	bool
539
540config CPU_CACHE_VIVT
541	bool
542
543config CPU_CACHE_VIPT
544	bool
545
546config CPU_CACHE_FA
547	bool
548
549config CPU_CACHE_V7M
550	bool
551
552if MMU
553# The copy-page model
554config CPU_COPY_V4WT
555	bool
556
557config CPU_COPY_V4WB
558	bool
559
560config CPU_COPY_FEROCEON
561	bool
562
563config CPU_COPY_FA
564	bool
565
566config CPU_COPY_V6
567	bool
568
569# This selects the TLB model
570config CPU_TLB_V4WT
571	bool
572	help
573	  ARM Architecture Version 4 TLB with writethrough cache.
574
575config CPU_TLB_V4WB
576	bool
577	help
578	  ARM Architecture Version 4 TLB with writeback cache.
579
580config CPU_TLB_V4WBI
581	bool
582	help
583	  ARM Architecture Version 4 TLB with writeback cache and invalidate
584	  instruction cache entry.
585
586config CPU_TLB_FEROCEON
587	bool
588	help
589	  Feroceon TLB (v4wbi with non-outer-cachable page table walks).
590
591config CPU_TLB_FA
592	bool
593	help
594	  Faraday ARM FA526 architecture, unified TLB with writeback cache
595	  and invalidate instruction cache entry. Branch target buffer is
596	  also supported.
597
598config CPU_TLB_V6
599	bool
600
601config CPU_TLB_V7
602	bool
603
604endif
605
606config CPU_HAS_ASID
607	bool
608	help
609	  This indicates whether the CPU has the ASID register; used to
610	  tag TLB and possibly cache entries.
611
612config CPU_CP15
613	bool
614	help
615	  Processor has the CP15 register.
616
617config CPU_CP15_MMU
618	bool
619	select CPU_CP15
620	help
621	  Processor has the CP15 register, which has MMU related registers.
622
623config CPU_CP15_MPU
624	bool
625	select CPU_CP15
626	help
627	  Processor has the CP15 register, which has MPU related registers.
628
629config CPU_USE_DOMAINS
630	bool
631	help
632	  This option enables or disables the use of domain switching
633	  via the set_fs() function.
634
635config CPU_V7M_NUM_IRQ
636	int "Number of external interrupts connected to the NVIC"
637	depends on CPU_V7M
638	default 90 if ARCH_STM32
639	default 112 if SOC_VF610
640	default 240
641	help
642	  This option indicates the number of interrupts connected to the NVIC.
643	  The value can be larger than the real number of interrupts supported
644	  by the system, but must not be lower.
645	  The default value is 240, corresponding to the maximum number of
646	  interrupts supported by the NVIC on Cortex-M family.
647
648	  If unsure, keep default value.
649
650#
651# CPU supports 36-bit I/O
652#
653config IO_36
654	bool
655
656comment "Processor Features"
657
658config ARM_LPAE
659	bool "Support for the Large Physical Address Extension"
660	depends on MMU && CPU_32v7 && !CPU_32v6 && !CPU_32v5 && \
661		!CPU_32v4 && !CPU_32v3
662	select PHYS_ADDR_T_64BIT
663	select SWIOTLB
664	help
665	  Say Y if you have an ARMv7 processor supporting the LPAE page
666	  table format and you would like to access memory beyond the
667	  4GB limit. The resulting kernel image will not run on
668	  processors without the LPA extension.
669
670	  If unsure, say N.
671
672config ARM_PV_FIXUP
673	def_bool y
674	depends on ARM_LPAE && ARM_PATCH_PHYS_VIRT && ARCH_KEYSTONE
675
676config ARM_THUMB
677	bool "Support Thumb user binaries" if !CPU_THUMBONLY && EXPERT
678	depends on CPU_THUMB_CAPABLE
679	default y
680	help
681	  Say Y if you want to include kernel support for running user space
682	  Thumb binaries.
683
684	  The Thumb instruction set is a compressed form of the standard ARM
685	  instruction set resulting in smaller binaries at the expense of
686	  slightly less efficient code.
687
688	  If this option is disabled, and you run userspace that switches to
689	  Thumb mode, signal handling will not work correctly, resulting in
690	  segmentation faults or illegal instruction aborts.
691
692	  If you don't know what this all is, saying Y is a safe choice.
693
694config ARM_THUMBEE
695	bool "Enable ThumbEE CPU extension"
696	depends on CPU_V7
697	help
698	  Say Y here if you have a CPU with the ThumbEE extension and code to
699	  make use of it. Say N for code that can run on CPUs without ThumbEE.
700
701config ARM_VIRT_EXT
702	bool
703	default y if CPU_V7
704	help
705	  Enable the kernel to make use of the ARM Virtualization
706	  Extensions to install hypervisors without run-time firmware
707	  assistance.
708
709	  A compliant bootloader is required in order to make maximum
710	  use of this feature.  Refer to Documentation/arm/booting.rst for
711	  details.
712
713config SWP_EMULATE
714	bool "Emulate SWP/SWPB instructions" if !SMP
715	depends on CPU_V7
716	default y if SMP
717	select HAVE_PROC_CPU if PROC_FS
718	help
719	  ARMv6 architecture deprecates use of the SWP/SWPB instructions.
720	  ARMv7 multiprocessing extensions introduce the ability to disable
721	  these instructions, triggering an undefined instruction exception
722	  when executed. Say Y here to enable software emulation of these
723	  instructions for userspace (not kernel) using LDREX/STREX.
724	  Also creates /proc/cpu/swp_emulation for statistics.
725
726	  In some older versions of glibc [<=2.8] SWP is used during futex
727	  trylock() operations with the assumption that the code will not
728	  be preempted. This invalid assumption may be more likely to fail
729	  with SWP emulation enabled, leading to deadlock of the user
730	  application.
731
732	  NOTE: when accessing uncached shared regions, LDREX/STREX rely
733	  on an external transaction monitoring block called a global
734	  monitor to maintain update atomicity. If your system does not
735	  implement a global monitor, this option can cause programs that
736	  perform SWP operations to uncached memory to deadlock.
737
738	  If unsure, say Y.
739
740config CPU_BIG_ENDIAN
741	bool "Build big-endian kernel"
742	depends on ARCH_SUPPORTS_BIG_ENDIAN
743	depends on !LD_IS_LLD
744	help
745	  Say Y if you plan on running a kernel in big-endian mode.
746	  Note that your board must be properly built and your board
747	  port must properly enable any big-endian related features
748	  of your chipset/board/processor.
749
750config CPU_ENDIAN_BE8
751	bool
752	depends on CPU_BIG_ENDIAN
753	default CPU_V6 || CPU_V6K || CPU_V7
754	help
755	  Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors.
756
757config CPU_ENDIAN_BE32
758	bool
759	depends on CPU_BIG_ENDIAN
760	default !CPU_ENDIAN_BE8
761	help
762	  Support for the BE-32 (big-endian) mode on pre-ARMv6 processors.
763
764config CPU_HIGH_VECTOR
765	depends on !MMU && CPU_CP15 && !CPU_ARM740T
766	bool "Select the High exception vector"
767	help
768	  Say Y here to select high exception vector(0xFFFF0000~).
769	  The exception vector can vary depending on the platform
770	  design in nommu mode. If your platform needs to select
771	  high exception vector, say Y.
772	  Otherwise or if you are unsure, say N, and the low exception
773	  vector (0x00000000~) will be used.
774
775config CPU_ICACHE_DISABLE
776	bool "Disable I-Cache (I-bit)"
777	depends on (CPU_CP15 && !(CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)) || CPU_V7M
778	help
779	  Say Y here to disable the processor instruction cache. Unless
780	  you have a reason not to or are unsure, say N.
781
782config CPU_ICACHE_MISMATCH_WORKAROUND
783	bool "Workaround for I-Cache line size mismatch between CPU cores"
784	depends on SMP && CPU_V7
785	help
786	  Some big.LITTLE systems have I-Cache line size mismatch between
787	  LITTLE and big cores.  Say Y here to enable a workaround for
788	  proper I-Cache support on such systems.  If unsure, say N.
789
790config CPU_DCACHE_DISABLE
791	bool "Disable D-Cache (C-bit)"
792	depends on (CPU_CP15 && !SMP) || CPU_V7M
793	help
794	  Say Y here to disable the processor data cache. Unless
795	  you have a reason not to or are unsure, say N.
796
797config CPU_DCACHE_SIZE
798	hex
799	depends on CPU_ARM740T || CPU_ARM946E
800	default 0x00001000 if CPU_ARM740T
801	default 0x00002000 # default size for ARM946E-S
802	help
803	  Some cores are synthesizable to have various sized cache. For
804	  ARM946E-S case, it can vary from 0KB to 1MB.
805	  To support such cache operations, it is efficient to know the size
806	  before compile time.
807	  If your SoC is configured to have a different size, define the value
808	  here with proper conditions.
809
810config CPU_DCACHE_WRITETHROUGH
811	bool "Force write through D-cache"
812	depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_FA526) && !CPU_DCACHE_DISABLE
813	default y if CPU_ARM925T
814	help
815	  Say Y here to use the data cache in writethrough mode. Unless you
816	  specifically require this or are unsure, say N.
817
818config CPU_CACHE_ROUND_ROBIN
819	bool "Round robin I and D cache replacement algorithm"
820	depends on (CPU_ARM926T || CPU_ARM946E || CPU_ARM1020) && (!CPU_ICACHE_DISABLE || !CPU_DCACHE_DISABLE)
821	help
822	  Say Y here to use the predictable round-robin cache replacement
823	  policy.  Unless you specifically require this or are unsure, say N.
824
825config CPU_BPREDICT_DISABLE
826	bool "Disable branch prediction"
827	depends on CPU_ARM1020 || CPU_V6 || CPU_V6K || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526 || CPU_V7M
828	help
829	  Say Y here to disable branch prediction.  If unsure, say N.
830
831config CPU_SPECTRE
832	bool
833
834config HARDEN_BRANCH_PREDICTOR
835	bool "Harden the branch predictor against aliasing attacks" if EXPERT
836	depends on CPU_SPECTRE
837	default y
838	help
839	   Speculation attacks against some high-performance processors rely
840	   on being able to manipulate the branch predictor for a victim
841	   context by executing aliasing branches in the attacker context.
842	   Such attacks can be partially mitigated against by clearing
843	   internal branch predictor state and limiting the prediction
844	   logic in some situations.
845
846	   This config option will take CPU-specific actions to harden
847	   the branch predictor against aliasing attacks and may rely on
848	   specific instruction sequences or control bits being set by
849	   the system firmware.
850
851	   If unsure, say Y.
852
853config TLS_REG_EMUL
854	bool
855	select NEED_KUSER_HELPERS
856	help
857	  An SMP system using a pre-ARMv6 processor (there are apparently
858	  a few prototypes like that in existence) and therefore access to
859	  that required register must be emulated.
860
861config NEED_KUSER_HELPERS
862	bool
863
864config KUSER_HELPERS
865	bool "Enable kuser helpers in vector page" if !NEED_KUSER_HELPERS
866	depends on MMU
867	default y
868	help
869	  Warning: disabling this option may break user programs.
870
871	  Provide kuser helpers in the vector page.  The kernel provides
872	  helper code to userspace in read only form at a fixed location
873	  in the high vector page to allow userspace to be independent of
874	  the CPU type fitted to the system.  This permits binaries to be
875	  run on ARMv4 through to ARMv7 without modification.
876
877	  See Documentation/arm/kernel_user_helpers.rst for details.
878
879	  However, the fixed address nature of these helpers can be used
880	  by ROP (return orientated programming) authors when creating
881	  exploits.
882
883	  If all of the binaries and libraries which run on your platform
884	  are built specifically for your platform, and make no use of
885	  these helpers, then you can turn this option off to hinder
886	  such exploits. However, in that case, if a binary or library
887	  relying on those helpers is run, it will receive a SIGILL signal,
888	  which will terminate the program.
889
890	  Say N here only if you are absolutely certain that you do not
891	  need these helpers; otherwise, the safe option is to say Y.
892
893config VDSO
894	bool "Enable VDSO for acceleration of some system calls"
895	depends on AEABI && MMU && CPU_V7
896	default y if ARM_ARCH_TIMER
897	select HAVE_GENERIC_VDSO
898	select GENERIC_TIME_VSYSCALL
899	select GENERIC_VDSO_32
900	select GENERIC_GETTIMEOFDAY
901	help
902	  Place in the process address space an ELF shared object
903	  providing fast implementations of gettimeofday and
904	  clock_gettime.  Systems that implement the ARM architected
905	  timer will receive maximum benefit.
906
907	  You must have glibc 2.22 or later for programs to seamlessly
908	  take advantage of this.
909
910config DMA_CACHE_RWFO
911	bool "Enable read/write for ownership DMA cache maintenance"
912	depends on CPU_V6K && SMP
913	default y
914	help
915	  The Snoop Control Unit on ARM11MPCore does not detect the
916	  cache maintenance operations and the dma_{map,unmap}_area()
917	  functions may leave stale cache entries on other CPUs. By
918	  enabling this option, Read or Write For Ownership in the ARMv6
919	  DMA cache maintenance functions is performed. These LDR/STR
920	  instructions change the cache line state to shared or modified
921	  so that the cache operation has the desired effect.
922
923	  Note that the workaround is only valid on processors that do
924	  not perform speculative loads into the D-cache. For such
925	  processors, if cache maintenance operations are not broadcast
926	  in hardware, other workarounds are needed (e.g. cache
927	  maintenance broadcasting in software via FIQ).
928
929config OUTER_CACHE
930	bool
931
932config OUTER_CACHE_SYNC
933	bool
934	select ARM_HEAVY_MB
935	help
936	  The outer cache has a outer_cache_fns.sync function pointer
937	  that can be used to drain the write buffer of the outer cache.
938
939config CACHE_B15_RAC
940	bool "Enable the Broadcom Brahma-B15 read-ahead cache controller"
941	depends on ARCH_BRCMSTB
942	default y
943	help
944	  This option enables the Broadcom Brahma-B15 read-ahead cache
945	  controller. If disabled, the read-ahead cache remains off.
946
947config CACHE_FEROCEON_L2
948	bool "Enable the Feroceon L2 cache controller"
949	depends on ARCH_MV78XX0 || ARCH_MVEBU
950	default y
951	select OUTER_CACHE
952	help
953	  This option enables the Feroceon L2 cache controller.
954
955config CACHE_FEROCEON_L2_WRITETHROUGH
956	bool "Force Feroceon L2 cache write through"
957	depends on CACHE_FEROCEON_L2
958	help
959	  Say Y here to use the Feroceon L2 cache in writethrough mode.
960	  Unless you specifically require this, say N for writeback mode.
961
962config MIGHT_HAVE_CACHE_L2X0
963	bool
964	help
965	  This option should be selected by machines which have a L2x0
966	  or PL310 cache controller, but where its use is optional.
967
968	  The only effect of this option is to make CACHE_L2X0 and
969	  related options available to the user for configuration.
970
971	  Boards or SoCs which always require the cache controller
972	  support to be present should select CACHE_L2X0 directly
973	  instead of this option, thus preventing the user from
974	  inadvertently configuring a broken kernel.
975
976config CACHE_L2X0
977	bool "Enable the L2x0 outer cache controller" if MIGHT_HAVE_CACHE_L2X0
978	default MIGHT_HAVE_CACHE_L2X0
979	select OUTER_CACHE
980	select OUTER_CACHE_SYNC
981	help
982	  This option enables the L2x0 PrimeCell.
983
984config CACHE_L2X0_PMU
985	bool "L2x0 performance monitor support" if CACHE_L2X0
986	depends on PERF_EVENTS
987	help
988	  This option enables support for the performance monitoring features
989	  of the L220 and PL310 outer cache controllers.
990
991if CACHE_L2X0
992
993config PL310_ERRATA_588369
994	bool "PL310 errata: Clean & Invalidate maintenance operations do not invalidate clean lines"
995	help
996	   The PL310 L2 cache controller implements three types of Clean &
997	   Invalidate maintenance operations: by Physical Address
998	   (offset 0x7F0), by Index/Way (0x7F8) and by Way (0x7FC).
999	   They are architecturally defined to behave as the execution of a
1000	   clean operation followed immediately by an invalidate operation,
1001	   both performing to the same memory location. This functionality
1002	   is not correctly implemented in PL310 prior to r2p0 (fixed in r2p0)
1003	   as clean lines are not invalidated as a result of these operations.
1004
1005config PL310_ERRATA_727915
1006	bool "PL310 errata: Background Clean & Invalidate by Way operation can cause data corruption"
1007	help
1008	  PL310 implements the Clean & Invalidate by Way L2 cache maintenance
1009	  operation (offset 0x7FC). This operation runs in background so that
1010	  PL310 can handle normal accesses while it is in progress. Under very
1011	  rare circumstances, due to this erratum, write data can be lost when
1012	  PL310 treats a cacheable write transaction during a Clean &
1013	  Invalidate by Way operation.  Revisions prior to r3p1 are affected by
1014	  this errata (fixed in r3p1).
1015
1016config PL310_ERRATA_753970
1017	bool "PL310 errata: cache sync operation may be faulty"
1018	help
1019	  This option enables the workaround for the 753970 PL310 (r3p0) erratum.
1020
1021	  Under some condition the effect of cache sync operation on
1022	  the store buffer still remains when the operation completes.
1023	  This means that the store buffer is always asked to drain and
1024	  this prevents it from merging any further writes. The workaround
1025	  is to replace the normal offset of cache sync operation (0x730)
1026	  by another offset targeting an unmapped PL310 register 0x740.
1027	  This has the same effect as the cache sync operation: store buffer
1028	  drain and waiting for all buffers empty.
1029
1030config PL310_ERRATA_769419
1031	bool "PL310 errata: no automatic Store Buffer drain"
1032	help
1033	  On revisions of the PL310 prior to r3p2, the Store Buffer does
1034	  not automatically drain. This can cause normal, non-cacheable
1035	  writes to be retained when the memory system is idle, leading
1036	  to suboptimal I/O performance for drivers using coherent DMA.
1037	  This option adds a write barrier to the cpu_idle loop so that,
1038	  on systems with an outer cache, the store buffer is drained
1039	  explicitly.
1040
1041endif
1042
1043config CACHE_TAUROS2
1044	bool "Enable the Tauros2 L2 cache controller"
1045	depends on (CPU_MOHAWK || CPU_PJ4)
1046	default y
1047	select OUTER_CACHE
1048	help
1049	  This option enables the Tauros2 L2 cache controller (as
1050	  found on PJ1/PJ4).
1051
1052config CACHE_UNIPHIER
1053	bool "Enable the UniPhier outer cache controller"
1054	depends on ARCH_UNIPHIER
1055	select ARM_L1_CACHE_SHIFT_7
1056	select OUTER_CACHE
1057	select OUTER_CACHE_SYNC
1058	help
1059	  This option enables the UniPhier outer cache (system cache)
1060	  controller.
1061
1062config CACHE_XSC3L2
1063	bool "Enable the L2 cache on XScale3"
1064	depends on CPU_XSC3
1065	default y
1066	select OUTER_CACHE
1067	help
1068	  This option enables the L2 cache on XScale3.
1069
1070config ARM_L1_CACHE_SHIFT_6
1071	bool
1072	default y if CPU_V7
1073	help
1074	  Setting ARM L1 cache line size to 64 Bytes.
1075
1076config ARM_L1_CACHE_SHIFT_7
1077	bool
1078	help
1079	  Setting ARM L1 cache line size to 128 Bytes.
1080
1081config ARM_L1_CACHE_SHIFT
1082	int
1083	default 7 if ARM_L1_CACHE_SHIFT_7
1084	default 6 if ARM_L1_CACHE_SHIFT_6
1085	default 5
1086
1087config ARM_DMA_MEM_BUFFERABLE
1088	bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K || CPU_V7M) && !CPU_V7
1089	default y if CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M
1090	help
1091	  Historically, the kernel has used strongly ordered mappings to
1092	  provide DMA coherent memory.  With the advent of ARMv7, mapping
1093	  memory with differing types results in unpredictable behaviour,
1094	  so on these CPUs, this option is forced on.
1095
1096	  Multiple mappings with differing attributes is also unpredictable
1097	  on ARMv6 CPUs, but since they do not have aggressive speculative
1098	  prefetch, no harm appears to occur.
1099
1100	  However, drivers may be missing the necessary barriers for ARMv6,
1101	  and therefore turning this on may result in unpredictable driver
1102	  behaviour.  Therefore, we offer this as an option.
1103
1104	  On some of the beefier ARMv7-M machines (with DMA and write
1105	  buffers) you likely want this enabled, while those that
1106	  didn't need it until now also won't need it in the future.
1107
1108	  You are recommended say 'Y' here and debug any affected drivers.
1109
1110config ARM_HEAVY_MB
1111	bool
1112
1113config ARCH_SUPPORTS_BIG_ENDIAN
1114	bool
1115	help
1116	  This option specifies the architecture can support big endian
1117	  operation.
1118
1119config DEBUG_ALIGN_RODATA
1120	bool "Make rodata strictly non-executable"
1121	depends on STRICT_KERNEL_RWX
1122	default y
1123	help
1124	  If this is set, rodata will be made explicitly non-executable. This
1125	  provides protection on the rare chance that attackers might find and
1126	  use ROP gadgets that exist in the rodata section. This adds an
1127	  additional section-aligned split of rodata from kernel text so it
1128	  can be made explicitly non-executable. This padding may waste memory
1129	  space to gain the additional protection.
1130