xref: /openbmc/linux/arch/arm/mm/Kconfig (revision e23feb16)
1comment "Processor Type"
2
3# Select CPU types depending on the architecture selected.  This selects
4# which CPUs we support in the kernel image, and the compiler instruction
5# optimiser behaviour.
6
7# ARM7TDMI
8config CPU_ARM7TDMI
9	bool "Support ARM7TDMI processor"
10	depends on !MMU
11	select CPU_32v4T
12	select CPU_ABRT_LV4T
13	select CPU_CACHE_V4
14	select CPU_PABRT_LEGACY
15	help
16	  A 32-bit RISC microprocessor based on the ARM7 processor core
17	  which has no memory control unit and cache.
18
19	  Say Y if you want support for the ARM7TDMI processor.
20	  Otherwise, say N.
21
22# ARM720T
23config CPU_ARM720T
24	bool "Support ARM720T processor" if ARCH_INTEGRATOR
25	select CPU_32v4T
26	select CPU_ABRT_LV4T
27	select CPU_CACHE_V4
28	select CPU_CACHE_VIVT
29	select CPU_COPY_V4WT if MMU
30	select CPU_CP15_MMU
31	select CPU_PABRT_LEGACY
32	select CPU_TLB_V4WT if MMU
33	help
34	  A 32-bit RISC processor with 8kByte Cache, Write Buffer and
35	  MMU built around an ARM7TDMI core.
36
37	  Say Y if you want support for the ARM720T processor.
38	  Otherwise, say N.
39
40# ARM740T
41config CPU_ARM740T
42	bool "Support ARM740T processor" if ARCH_INTEGRATOR
43	depends on !MMU
44	select CPU_32v4T
45	select CPU_ABRT_LV4T
46	select CPU_CACHE_V4
47	select CPU_CP15_MPU
48	select CPU_PABRT_LEGACY
49	help
50	  A 32-bit RISC processor with 8KB cache or 4KB variants,
51	  write buffer and MPU(Protection Unit) built around
52	  an ARM7TDMI core.
53
54	  Say Y if you want support for the ARM740T processor.
55	  Otherwise, say N.
56
57# ARM9TDMI
58config CPU_ARM9TDMI
59	bool "Support ARM9TDMI processor"
60	depends on !MMU
61	select CPU_32v4T
62	select CPU_ABRT_NOMMU
63	select CPU_CACHE_V4
64	select CPU_PABRT_LEGACY
65	help
66	  A 32-bit RISC microprocessor based on the ARM9 processor core
67	  which has no memory control unit and cache.
68
69	  Say Y if you want support for the ARM9TDMI processor.
70	  Otherwise, say N.
71
72# ARM920T
73config CPU_ARM920T
74	bool "Support ARM920T processor" if ARCH_INTEGRATOR
75	select CPU_32v4T
76	select CPU_ABRT_EV4T
77	select CPU_CACHE_V4WT
78	select CPU_CACHE_VIVT
79	select CPU_COPY_V4WB if MMU
80	select CPU_CP15_MMU
81	select CPU_PABRT_LEGACY
82	select CPU_TLB_V4WBI if MMU
83	help
84	  The ARM920T is licensed to be produced by numerous vendors,
85	  and is used in the Cirrus EP93xx and the Samsung S3C2410.
86
87	  Say Y if you want support for the ARM920T processor.
88	  Otherwise, say N.
89
90# ARM922T
91config CPU_ARM922T
92	bool "Support ARM922T processor" if ARCH_INTEGRATOR
93	select CPU_32v4T
94	select CPU_ABRT_EV4T
95	select CPU_CACHE_V4WT
96	select CPU_CACHE_VIVT
97	select CPU_COPY_V4WB if MMU
98	select CPU_CP15_MMU
99	select CPU_PABRT_LEGACY
100	select CPU_TLB_V4WBI if MMU
101	help
102	  The ARM922T is a version of the ARM920T, but with smaller
103	  instruction and data caches. It is used in Altera's
104	  Excalibur XA device family and Micrel's KS8695 Centaur.
105
106	  Say Y if you want support for the ARM922T processor.
107	  Otherwise, say N.
108
109# ARM925T
110config CPU_ARM925T
111 	bool "Support ARM925T processor" if ARCH_OMAP1
112	select CPU_32v4T
113	select CPU_ABRT_EV4T
114	select CPU_CACHE_V4WT
115	select CPU_CACHE_VIVT
116	select CPU_COPY_V4WB if MMU
117	select CPU_CP15_MMU
118	select CPU_PABRT_LEGACY
119	select CPU_TLB_V4WBI if MMU
120 	help
121 	  The ARM925T is a mix between the ARM920T and ARM926T, but with
122	  different instruction and data caches. It is used in TI's OMAP
123 	  device family.
124
125 	  Say Y if you want support for the ARM925T processor.
126 	  Otherwise, say N.
127
128# ARM926T
129config CPU_ARM926T
130	bool "Support ARM926T processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB
131	select CPU_32v5
132	select CPU_ABRT_EV5TJ
133	select CPU_CACHE_VIVT
134	select CPU_COPY_V4WB if MMU
135	select CPU_CP15_MMU
136	select CPU_PABRT_LEGACY
137	select CPU_TLB_V4WBI if MMU
138	help
139	  This is a variant of the ARM920.  It has slightly different
140	  instruction sequences for cache and TLB operations.  Curiously,
141	  there is no documentation on it at the ARM corporate website.
142
143	  Say Y if you want support for the ARM926T processor.
144	  Otherwise, say N.
145
146# FA526
147config CPU_FA526
148	bool
149	select CPU_32v4
150	select CPU_ABRT_EV4
151	select CPU_CACHE_FA
152	select CPU_CACHE_VIVT
153	select CPU_COPY_FA if MMU
154	select CPU_CP15_MMU
155	select CPU_PABRT_LEGACY
156	select CPU_TLB_FA if MMU
157	help
158	  The FA526 is a version of the ARMv4 compatible processor with
159	  Branch Target Buffer, Unified TLB and cache line size 16.
160
161	  Say Y if you want support for the FA526 processor.
162	  Otherwise, say N.
163
164# ARM940T
165config CPU_ARM940T
166	bool "Support ARM940T processor" if ARCH_INTEGRATOR
167	depends on !MMU
168	select CPU_32v4T
169	select CPU_ABRT_NOMMU
170	select CPU_CACHE_VIVT
171	select CPU_CP15_MPU
172	select CPU_PABRT_LEGACY
173	help
174	  ARM940T is a member of the ARM9TDMI family of general-
175	  purpose microprocessors with MPU and separate 4KB
176	  instruction and 4KB data cases, each with a 4-word line
177	  length.
178
179	  Say Y if you want support for the ARM940T processor.
180	  Otherwise, say N.
181
182# ARM946E-S
183config CPU_ARM946E
184	bool "Support ARM946E-S processor" if ARCH_INTEGRATOR
185	depends on !MMU
186	select CPU_32v5
187	select CPU_ABRT_NOMMU
188	select CPU_CACHE_VIVT
189	select CPU_CP15_MPU
190	select CPU_PABRT_LEGACY
191	help
192	  ARM946E-S is a member of the ARM9E-S family of high-
193	  performance, 32-bit system-on-chip processor solutions.
194	  The TCM and ARMv5TE 32-bit instruction set is supported.
195
196	  Say Y if you want support for the ARM946E-S processor.
197	  Otherwise, say N.
198
199# ARM1020 - needs validating
200config CPU_ARM1020
201	bool "Support ARM1020T (rev 0) processor" if ARCH_INTEGRATOR
202	select CPU_32v5
203	select CPU_ABRT_EV4T
204	select CPU_CACHE_V4WT
205	select CPU_CACHE_VIVT
206	select CPU_COPY_V4WB if MMU
207	select CPU_CP15_MMU
208	select CPU_PABRT_LEGACY
209	select CPU_TLB_V4WBI if MMU
210	help
211	  The ARM1020 is the 32K cached version of the ARM10 processor,
212	  with an addition of a floating-point unit.
213
214	  Say Y if you want support for the ARM1020 processor.
215	  Otherwise, say N.
216
217# ARM1020E - needs validating
218config CPU_ARM1020E
219	bool "Support ARM1020E processor" if ARCH_INTEGRATOR
220	depends on n
221	select CPU_32v5
222	select CPU_ABRT_EV4T
223	select CPU_CACHE_V4WT
224	select CPU_CACHE_VIVT
225	select CPU_COPY_V4WB if MMU
226	select CPU_CP15_MMU
227	select CPU_PABRT_LEGACY
228	select CPU_TLB_V4WBI if MMU
229
230# ARM1022E
231config CPU_ARM1022
232	bool "Support ARM1022E processor" if ARCH_INTEGRATOR
233	select CPU_32v5
234	select CPU_ABRT_EV4T
235	select CPU_CACHE_VIVT
236	select CPU_COPY_V4WB if MMU # can probably do better
237	select CPU_CP15_MMU
238	select CPU_PABRT_LEGACY
239	select CPU_TLB_V4WBI if MMU
240	help
241	  The ARM1022E is an implementation of the ARMv5TE architecture
242	  based upon the ARM10 integer core with a 16KiB L1 Harvard cache,
243	  embedded trace macrocell, and a floating-point unit.
244
245	  Say Y if you want support for the ARM1022E processor.
246	  Otherwise, say N.
247
248# ARM1026EJ-S
249config CPU_ARM1026
250	bool "Support ARM1026EJ-S processor" if ARCH_INTEGRATOR
251	select CPU_32v5
252	select CPU_ABRT_EV5T # But need Jazelle, but EV5TJ ignores bit 10
253	select CPU_CACHE_VIVT
254	select CPU_COPY_V4WB if MMU # can probably do better
255	select CPU_CP15_MMU
256	select CPU_PABRT_LEGACY
257	select CPU_TLB_V4WBI if MMU
258	help
259	  The ARM1026EJ-S is an implementation of the ARMv5TEJ architecture
260	  based upon the ARM10 integer core.
261
262	  Say Y if you want support for the ARM1026EJ-S processor.
263	  Otherwise, say N.
264
265# SA110
266config CPU_SA110
267	bool "Support StrongARM(R) SA-110 processor" if ARCH_RPC
268	select CPU_32v3 if ARCH_RPC
269	select CPU_32v4 if !ARCH_RPC
270	select CPU_ABRT_EV4
271	select CPU_CACHE_V4WB
272	select CPU_CACHE_VIVT
273	select CPU_COPY_V4WB if MMU
274	select CPU_CP15_MMU
275	select CPU_PABRT_LEGACY
276	select CPU_TLB_V4WB if MMU
277	help
278	  The Intel StrongARM(R) SA-110 is a 32-bit microprocessor and
279	  is available at five speeds ranging from 100 MHz to 233 MHz.
280	  More information is available at
281	  <http://developer.intel.com/design/strong/sa110.htm>.
282
283	  Say Y if you want support for the SA-110 processor.
284	  Otherwise, say N.
285
286# SA1100
287config CPU_SA1100
288	bool
289	select CPU_32v4
290	select CPU_ABRT_EV4
291	select CPU_CACHE_V4WB
292	select CPU_CACHE_VIVT
293	select CPU_CP15_MMU
294	select CPU_PABRT_LEGACY
295	select CPU_TLB_V4WB if MMU
296
297# XScale
298config CPU_XSCALE
299	bool
300	select CPU_32v5
301	select CPU_ABRT_EV5T
302	select CPU_CACHE_VIVT
303	select CPU_CP15_MMU
304	select CPU_PABRT_LEGACY
305	select CPU_TLB_V4WBI if MMU
306
307# XScale Core Version 3
308config CPU_XSC3
309	bool
310	select CPU_32v5
311	select CPU_ABRT_EV5T
312	select CPU_CACHE_VIVT
313	select CPU_CP15_MMU
314	select CPU_PABRT_LEGACY
315	select CPU_TLB_V4WBI if MMU
316	select IO_36
317
318# Marvell PJ1 (Mohawk)
319config CPU_MOHAWK
320	bool
321	select CPU_32v5
322	select CPU_ABRT_EV5T
323	select CPU_CACHE_VIVT
324	select CPU_COPY_V4WB if MMU
325	select CPU_CP15_MMU
326	select CPU_PABRT_LEGACY
327	select CPU_TLB_V4WBI if MMU
328
329# Feroceon
330config CPU_FEROCEON
331	bool
332	select CPU_32v5
333	select CPU_ABRT_EV5T
334	select CPU_CACHE_VIVT
335	select CPU_COPY_FEROCEON if MMU
336	select CPU_CP15_MMU
337	select CPU_PABRT_LEGACY
338	select CPU_TLB_FEROCEON if MMU
339
340config CPU_FEROCEON_OLD_ID
341	bool "Accept early Feroceon cores with an ARM926 ID"
342	depends on CPU_FEROCEON && !CPU_ARM926T
343	default y
344	help
345	  This enables the usage of some old Feroceon cores
346	  for which the CPU ID is equal to the ARM926 ID.
347	  Relevant for Feroceon-1850 and early Feroceon-2850.
348
349# Marvell PJ4
350config CPU_PJ4
351	bool
352	select ARM_THUMBEE
353	select CPU_V7
354
355config CPU_PJ4B
356	bool
357	select CPU_V7
358
359# ARMv6
360config CPU_V6
361	bool "Support ARM V6 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
362	select CPU_32v6
363	select CPU_ABRT_EV6
364	select CPU_CACHE_V6
365	select CPU_CACHE_VIPT
366	select CPU_COPY_V6 if MMU
367	select CPU_CP15_MMU
368	select CPU_HAS_ASID if MMU
369	select CPU_PABRT_V6
370	select CPU_TLB_V6 if MMU
371
372# ARMv6k
373config CPU_V6K
374	bool "Support ARM V6K processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
375	select CPU_32v6
376	select CPU_32v6K
377	select CPU_ABRT_EV6
378	select CPU_CACHE_V6
379	select CPU_CACHE_VIPT
380	select CPU_COPY_V6 if MMU
381	select CPU_CP15_MMU
382	select CPU_HAS_ASID if MMU
383	select CPU_PABRT_V6
384	select CPU_TLB_V6 if MMU
385
386# ARMv7
387config CPU_V7
388	bool "Support ARM V7 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
389	select CPU_32v6K
390	select CPU_32v7
391	select CPU_ABRT_EV7
392	select CPU_CACHE_V7
393	select CPU_CACHE_VIPT
394	select CPU_COPY_V6 if MMU
395	select CPU_CP15_MMU if MMU
396	select CPU_CP15_MPU if !MMU
397	select CPU_HAS_ASID if MMU
398	select CPU_PABRT_V7
399	select CPU_TLB_V7 if MMU
400
401# ARMv7M
402config CPU_V7M
403	bool
404	select CPU_32v7M
405	select CPU_ABRT_NOMMU
406	select CPU_CACHE_NOP
407	select CPU_PABRT_LEGACY
408	select CPU_THUMBONLY
409
410config CPU_THUMBONLY
411	bool
412	# There are no CPUs available with MMU that don't implement an ARM ISA:
413	depends on !MMU
414	help
415	  Select this if your CPU doesn't support the 32 bit ARM instructions.
416
417# Figure out what processor architecture version we should be using.
418# This defines the compiler instruction set which depends on the machine type.
419config CPU_32v3
420	bool
421	select CPU_USE_DOMAINS if MMU
422	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
423	select TLS_REG_EMUL if SMP || !MMU
424	select NEED_KUSER_HELPERS
425
426config CPU_32v4
427	bool
428	select CPU_USE_DOMAINS if MMU
429	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
430	select TLS_REG_EMUL if SMP || !MMU
431	select NEED_KUSER_HELPERS
432
433config CPU_32v4T
434	bool
435	select CPU_USE_DOMAINS if MMU
436	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
437	select TLS_REG_EMUL if SMP || !MMU
438	select NEED_KUSER_HELPERS
439
440config CPU_32v5
441	bool
442	select CPU_USE_DOMAINS if MMU
443	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
444	select TLS_REG_EMUL if SMP || !MMU
445	select NEED_KUSER_HELPERS
446
447config CPU_32v6
448	bool
449	select CPU_USE_DOMAINS if CPU_V6 && MMU
450	select TLS_REG_EMUL if !CPU_32v6K && !MMU
451
452config CPU_32v6K
453	bool
454
455config CPU_32v7
456	bool
457
458config CPU_32v7M
459	bool
460
461# The abort model
462config CPU_ABRT_NOMMU
463	bool
464
465config CPU_ABRT_EV4
466	bool
467
468config CPU_ABRT_EV4T
469	bool
470
471config CPU_ABRT_LV4T
472	bool
473
474config CPU_ABRT_EV5T
475	bool
476
477config CPU_ABRT_EV5TJ
478	bool
479
480config CPU_ABRT_EV6
481	bool
482
483config CPU_ABRT_EV7
484	bool
485
486config CPU_PABRT_LEGACY
487	bool
488
489config CPU_PABRT_V6
490	bool
491
492config CPU_PABRT_V7
493	bool
494
495# The cache model
496config CPU_CACHE_V4
497	bool
498
499config CPU_CACHE_V4WT
500	bool
501
502config CPU_CACHE_V4WB
503	bool
504
505config CPU_CACHE_V6
506	bool
507
508config CPU_CACHE_V7
509	bool
510
511config CPU_CACHE_NOP
512	bool
513
514config CPU_CACHE_VIVT
515	bool
516
517config CPU_CACHE_VIPT
518	bool
519
520config CPU_CACHE_FA
521	bool
522
523if MMU
524# The copy-page model
525config CPU_COPY_V4WT
526	bool
527
528config CPU_COPY_V4WB
529	bool
530
531config CPU_COPY_FEROCEON
532	bool
533
534config CPU_COPY_FA
535	bool
536
537config CPU_COPY_V6
538	bool
539
540# This selects the TLB model
541config CPU_TLB_V4WT
542	bool
543	help
544	  ARM Architecture Version 4 TLB with writethrough cache.
545
546config CPU_TLB_V4WB
547	bool
548	help
549	  ARM Architecture Version 4 TLB with writeback cache.
550
551config CPU_TLB_V4WBI
552	bool
553	help
554	  ARM Architecture Version 4 TLB with writeback cache and invalidate
555	  instruction cache entry.
556
557config CPU_TLB_FEROCEON
558	bool
559	help
560	  Feroceon TLB (v4wbi with non-outer-cachable page table walks).
561
562config CPU_TLB_FA
563	bool
564	help
565	  Faraday ARM FA526 architecture, unified TLB with writeback cache
566	  and invalidate instruction cache entry. Branch target buffer is
567	  also supported.
568
569config CPU_TLB_V6
570	bool
571
572config CPU_TLB_V7
573	bool
574
575config VERIFY_PERMISSION_FAULT
576	bool
577endif
578
579config CPU_HAS_ASID
580	bool
581	help
582	  This indicates whether the CPU has the ASID register; used to
583	  tag TLB and possibly cache entries.
584
585config CPU_CP15
586	bool
587	help
588	  Processor has the CP15 register.
589
590config CPU_CP15_MMU
591	bool
592	select CPU_CP15
593	help
594	  Processor has the CP15 register, which has MMU related registers.
595
596config CPU_CP15_MPU
597	bool
598	select CPU_CP15
599	help
600	  Processor has the CP15 register, which has MPU related registers.
601
602config CPU_USE_DOMAINS
603	bool
604	help
605	  This option enables or disables the use of domain switching
606	  via the set_fs() function.
607
608#
609# CPU supports 36-bit I/O
610#
611config IO_36
612	bool
613
614comment "Processor Features"
615
616config ARM_LPAE
617	bool "Support for the Large Physical Address Extension"
618	depends on MMU && CPU_32v7 && !CPU_32v6 && !CPU_32v5 && \
619		!CPU_32v4 && !CPU_32v3
620	help
621	  Say Y if you have an ARMv7 processor supporting the LPAE page
622	  table format and you would like to access memory beyond the
623	  4GB limit. The resulting kernel image will not run on
624	  processors without the LPA extension.
625
626	  If unsure, say N.
627
628config ARCH_PHYS_ADDR_T_64BIT
629	def_bool ARM_LPAE
630
631config ARCH_DMA_ADDR_T_64BIT
632	bool
633
634config ARM_THUMB
635	bool "Support Thumb user binaries" if !CPU_THUMBONLY
636	depends on CPU_ARM720T || CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || \
637		CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || \
638		CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
639		CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_V6 || CPU_V6K || \
640		CPU_V7 || CPU_FEROCEON || CPU_V7M
641	default y
642	help
643	  Say Y if you want to include kernel support for running user space
644	  Thumb binaries.
645
646	  The Thumb instruction set is a compressed form of the standard ARM
647	  instruction set resulting in smaller binaries at the expense of
648	  slightly less efficient code.
649
650	  If you don't know what this all is, saying Y is a safe choice.
651
652config ARM_THUMBEE
653	bool "Enable ThumbEE CPU extension"
654	depends on CPU_V7
655	help
656	  Say Y here if you have a CPU with the ThumbEE extension and code to
657	  make use of it. Say N for code that can run on CPUs without ThumbEE.
658
659config ARM_VIRT_EXT
660	bool
661	depends on MMU
662	default y if CPU_V7
663	help
664	  Enable the kernel to make use of the ARM Virtualization
665	  Extensions to install hypervisors without run-time firmware
666	  assistance.
667
668	  A compliant bootloader is required in order to make maximum
669	  use of this feature.  Refer to Documentation/arm/Booting for
670	  details.
671
672config SWP_EMULATE
673	bool "Emulate SWP/SWPB instructions"
674	depends on !CPU_USE_DOMAINS && CPU_V7
675	default y if SMP
676	select HAVE_PROC_CPU if PROC_FS
677	help
678	  ARMv6 architecture deprecates use of the SWP/SWPB instructions.
679	  ARMv7 multiprocessing extensions introduce the ability to disable
680	  these instructions, triggering an undefined instruction exception
681	  when executed. Say Y here to enable software emulation of these
682	  instructions for userspace (not kernel) using LDREX/STREX.
683	  Also creates /proc/cpu/swp_emulation for statistics.
684
685	  In some older versions of glibc [<=2.8] SWP is used during futex
686	  trylock() operations with the assumption that the code will not
687	  be preempted. This invalid assumption may be more likely to fail
688	  with SWP emulation enabled, leading to deadlock of the user
689	  application.
690
691	  NOTE: when accessing uncached shared regions, LDREX/STREX rely
692	  on an external transaction monitoring block called a global
693	  monitor to maintain update atomicity. If your system does not
694	  implement a global monitor, this option can cause programs that
695	  perform SWP operations to uncached memory to deadlock.
696
697	  If unsure, say Y.
698
699config CPU_BIG_ENDIAN
700	bool "Build big-endian kernel"
701	depends on ARCH_SUPPORTS_BIG_ENDIAN
702	help
703	  Say Y if you plan on running a kernel in big-endian mode.
704	  Note that your board must be properly built and your board
705	  port must properly enable any big-endian related features
706	  of your chipset/board/processor.
707
708config CPU_ENDIAN_BE8
709	bool
710	depends on CPU_BIG_ENDIAN
711	default CPU_V6 || CPU_V6K || CPU_V7
712	help
713	  Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors.
714
715config CPU_ENDIAN_BE32
716	bool
717	depends on CPU_BIG_ENDIAN
718	default !CPU_ENDIAN_BE8
719	help
720	  Support for the BE-32 (big-endian) mode on pre-ARMv6 processors.
721
722config CPU_HIGH_VECTOR
723	depends on !MMU && CPU_CP15 && !CPU_ARM740T
724	bool "Select the High exception vector"
725	help
726	  Say Y here to select high exception vector(0xFFFF0000~).
727	  The exception vector can vary depending on the platform
728	  design in nommu mode. If your platform needs to select
729	  high exception vector, say Y.
730	  Otherwise or if you are unsure, say N, and the low exception
731	  vector (0x00000000~) will be used.
732
733config CPU_ICACHE_DISABLE
734	bool "Disable I-Cache (I-bit)"
735	depends on CPU_CP15 && !(CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)
736	help
737	  Say Y here to disable the processor instruction cache. Unless
738	  you have a reason not to or are unsure, say N.
739
740config CPU_DCACHE_DISABLE
741	bool "Disable D-Cache (C-bit)"
742	depends on CPU_CP15
743	help
744	  Say Y here to disable the processor data cache. Unless
745	  you have a reason not to or are unsure, say N.
746
747config CPU_DCACHE_SIZE
748	hex
749	depends on CPU_ARM740T || CPU_ARM946E
750	default 0x00001000 if CPU_ARM740T
751	default 0x00002000 # default size for ARM946E-S
752	help
753	  Some cores are synthesizable to have various sized cache. For
754	  ARM946E-S case, it can vary from 0KB to 1MB.
755	  To support such cache operations, it is efficient to know the size
756	  before compile time.
757	  If your SoC is configured to have a different size, define the value
758	  here with proper conditions.
759
760config CPU_DCACHE_WRITETHROUGH
761	bool "Force write through D-cache"
762	depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_FA526) && !CPU_DCACHE_DISABLE
763	default y if CPU_ARM925T
764	help
765	  Say Y here to use the data cache in writethrough mode. Unless you
766	  specifically require this or are unsure, say N.
767
768config CPU_CACHE_ROUND_ROBIN
769	bool "Round robin I and D cache replacement algorithm"
770	depends on (CPU_ARM926T || CPU_ARM946E || CPU_ARM1020) && (!CPU_ICACHE_DISABLE || !CPU_DCACHE_DISABLE)
771	help
772	  Say Y here to use the predictable round-robin cache replacement
773	  policy.  Unless you specifically require this or are unsure, say N.
774
775config CPU_BPREDICT_DISABLE
776	bool "Disable branch prediction"
777	depends on CPU_ARM1020 || CPU_V6 || CPU_V6K || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526
778	help
779	  Say Y here to disable branch prediction.  If unsure, say N.
780
781config TLS_REG_EMUL
782	bool
783	select NEED_KUSER_HELPERS
784	help
785	  An SMP system using a pre-ARMv6 processor (there are apparently
786	  a few prototypes like that in existence) and therefore access to
787	  that required register must be emulated.
788
789config NEEDS_SYSCALL_FOR_CMPXCHG
790	bool
791	select NEED_KUSER_HELPERS
792	help
793	  SMP on a pre-ARMv6 processor?  Well OK then.
794	  Forget about fast user space cmpxchg support.
795	  It is just not possible.
796
797config NEED_KUSER_HELPERS
798	bool
799
800config KUSER_HELPERS
801	bool "Enable kuser helpers in vector page" if !NEED_KUSER_HELPERS
802	default y
803	help
804	  Warning: disabling this option may break user programs.
805
806	  Provide kuser helpers in the vector page.  The kernel provides
807	  helper code to userspace in read only form at a fixed location
808	  in the high vector page to allow userspace to be independent of
809	  the CPU type fitted to the system.  This permits binaries to be
810	  run on ARMv4 through to ARMv7 without modification.
811
812	  See Documentation/arm/kernel_user_helpers.txt for details.
813
814	  However, the fixed address nature of these helpers can be used
815	  by ROP (return orientated programming) authors when creating
816	  exploits.
817
818	  If all of the binaries and libraries which run on your platform
819	  are built specifically for your platform, and make no use of
820	  these helpers, then you can turn this option off to hinder
821	  such exploits. However, in that case, if a binary or library
822	  relying on those helpers is run, it will receive a SIGILL signal,
823	  which will terminate the program.
824
825	  Say N here only if you are absolutely certain that you do not
826	  need these helpers; otherwise, the safe option is to say Y.
827
828config DMA_CACHE_RWFO
829	bool "Enable read/write for ownership DMA cache maintenance"
830	depends on CPU_V6K && SMP
831	default y
832	help
833	  The Snoop Control Unit on ARM11MPCore does not detect the
834	  cache maintenance operations and the dma_{map,unmap}_area()
835	  functions may leave stale cache entries on other CPUs. By
836	  enabling this option, Read or Write For Ownership in the ARMv6
837	  DMA cache maintenance functions is performed. These LDR/STR
838	  instructions change the cache line state to shared or modified
839	  so that the cache operation has the desired effect.
840
841	  Note that the workaround is only valid on processors that do
842	  not perform speculative loads into the D-cache. For such
843	  processors, if cache maintenance operations are not broadcast
844	  in hardware, other workarounds are needed (e.g. cache
845	  maintenance broadcasting in software via FIQ).
846
847config OUTER_CACHE
848	bool
849
850config OUTER_CACHE_SYNC
851	bool
852	help
853	  The outer cache has a outer_cache_fns.sync function pointer
854	  that can be used to drain the write buffer of the outer cache.
855
856config CACHE_FEROCEON_L2
857	bool "Enable the Feroceon L2 cache controller"
858	depends on ARCH_KIRKWOOD || ARCH_MV78XX0
859	default y
860	select OUTER_CACHE
861	help
862	  This option enables the Feroceon L2 cache controller.
863
864config CACHE_FEROCEON_L2_WRITETHROUGH
865	bool "Force Feroceon L2 cache write through"
866	depends on CACHE_FEROCEON_L2
867	help
868	  Say Y here to use the Feroceon L2 cache in writethrough mode.
869	  Unless you specifically require this, say N for writeback mode.
870
871config MIGHT_HAVE_CACHE_L2X0
872	bool
873	help
874	  This option should be selected by machines which have a L2x0
875	  or PL310 cache controller, but where its use is optional.
876
877	  The only effect of this option is to make CACHE_L2X0 and
878	  related options available to the user for configuration.
879
880	  Boards or SoCs which always require the cache controller
881	  support to be present should select CACHE_L2X0 directly
882	  instead of this option, thus preventing the user from
883	  inadvertently configuring a broken kernel.
884
885config CACHE_L2X0
886	bool "Enable the L2x0 outer cache controller" if MIGHT_HAVE_CACHE_L2X0
887	default MIGHT_HAVE_CACHE_L2X0
888	select OUTER_CACHE
889	select OUTER_CACHE_SYNC
890	help
891	  This option enables the L2x0 PrimeCell.
892
893config CACHE_PL310
894	bool
895	depends on CACHE_L2X0
896	default y if CPU_V7 && !(CPU_V6 || CPU_V6K)
897	help
898	  This option enables optimisations for the PL310 cache
899	  controller.
900
901config CACHE_TAUROS2
902	bool "Enable the Tauros2 L2 cache controller"
903	depends on (ARCH_DOVE || ARCH_MMP || CPU_PJ4)
904	default y
905	select OUTER_CACHE
906	help
907	  This option enables the Tauros2 L2 cache controller (as
908	  found on PJ1/PJ4).
909
910config CACHE_XSC3L2
911	bool "Enable the L2 cache on XScale3"
912	depends on CPU_XSC3
913	default y
914	select OUTER_CACHE
915	help
916	  This option enables the L2 cache on XScale3.
917
918config ARM_L1_CACHE_SHIFT_6
919	bool
920	default y if CPU_V7
921	help
922	  Setting ARM L1 cache line size to 64 Bytes.
923
924config ARM_L1_CACHE_SHIFT
925	int
926	default 6 if ARM_L1_CACHE_SHIFT_6
927	default 5
928
929config ARM_DMA_MEM_BUFFERABLE
930	bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K) && !CPU_V7
931	depends on !(MACH_REALVIEW_PB1176 || REALVIEW_EB_ARM11MP || \
932		     MACH_REALVIEW_PB11MP)
933	default y if CPU_V6 || CPU_V6K || CPU_V7
934	help
935	  Historically, the kernel has used strongly ordered mappings to
936	  provide DMA coherent memory.  With the advent of ARMv7, mapping
937	  memory with differing types results in unpredictable behaviour,
938	  so on these CPUs, this option is forced on.
939
940	  Multiple mappings with differing attributes is also unpredictable
941	  on ARMv6 CPUs, but since they do not have aggressive speculative
942	  prefetch, no harm appears to occur.
943
944	  However, drivers may be missing the necessary barriers for ARMv6,
945	  and therefore turning this on may result in unpredictable driver
946	  behaviour.  Therefore, we offer this as an option.
947
948	  You are recommended say 'Y' here and debug any affected drivers.
949
950config ARCH_HAS_BARRIERS
951	bool
952	help
953	  This option allows the use of custom mandatory barriers
954	  included via the mach/barriers.h file.
955