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v3.1
 
  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# ARM610
  8config CPU_ARM610
  9	bool "Support ARM610 processor" if ARCH_RPC
 10	select CPU_32v3
 11	select CPU_CACHE_V3
 12	select CPU_CACHE_VIVT
 13	select CPU_CP15_MMU
 14	select CPU_COPY_V3 if MMU
 15	select CPU_TLB_V3 if MMU
 16	select CPU_PABRT_LEGACY
 17	help
 18	  The ARM610 is the successor to the ARM3 processor
 19	  and was produced by VLSI Technology Inc.
 20
 21	  Say Y if you want support for the ARM610 processor.
 22	  Otherwise, say N.
 23
 24# ARM7TDMI
 25config CPU_ARM7TDMI
 26	bool "Support ARM7TDMI processor"
 27	depends on !MMU
 28	select CPU_32v4T
 29	select CPU_ABRT_LV4T
 30	select CPU_PABRT_LEGACY
 31	select CPU_CACHE_V4
 
 32	help
 33	  A 32-bit RISC microprocessor based on the ARM7 processor core
 34	  which has no memory control unit and cache.
 35
 36	  Say Y if you want support for the ARM7TDMI processor.
 37	  Otherwise, say N.
 38
 39# ARM710
 40config CPU_ARM710
 41	bool "Support ARM710 processor" if ARCH_RPC
 42	select CPU_32v3
 43	select CPU_CACHE_V3
 44	select CPU_CACHE_VIVT
 45	select CPU_CP15_MMU
 46	select CPU_COPY_V3 if MMU
 47	select CPU_TLB_V3 if MMU
 48	select CPU_PABRT_LEGACY
 49	help
 50	  A 32-bit RISC microprocessor based on the ARM7 processor core
 51	  designed by Advanced RISC Machines Ltd. The ARM710 is the
 52	  successor to the ARM610 processor. It was released in
 53	  July 1994 by VLSI Technology Inc.
 54
 55	  Say Y if you want support for the ARM710 processor.
 56	  Otherwise, say N.
 57
 58# ARM720T
 59config CPU_ARM720T
 60	bool "Support ARM720T processor" if ARCH_INTEGRATOR
 61	select CPU_32v4T
 62	select CPU_ABRT_LV4T
 63	select CPU_PABRT_LEGACY
 64	select CPU_CACHE_V4
 65	select CPU_CACHE_VIVT
 66	select CPU_CP15_MMU
 67	select CPU_COPY_V4WT if MMU
 
 
 
 68	select CPU_TLB_V4WT if MMU
 69	help
 70	  A 32-bit RISC processor with 8kByte Cache, Write Buffer and
 71	  MMU built around an ARM7TDMI core.
 72
 73	  Say Y if you want support for the ARM720T processor.
 74	  Otherwise, say N.
 75
 76# ARM740T
 77config CPU_ARM740T
 78	bool "Support ARM740T processor" if ARCH_INTEGRATOR
 79	depends on !MMU
 80	select CPU_32v4T
 81	select CPU_ABRT_LV4T
 82	select CPU_PABRT_LEGACY
 83	select CPU_CACHE_V3	# although the core is v4t
 84	select CPU_CP15_MPU
 
 
 85	help
 86	  A 32-bit RISC processor with 8KB cache or 4KB variants,
 87	  write buffer and MPU(Protection Unit) built around
 88	  an ARM7TDMI core.
 89
 90	  Say Y if you want support for the ARM740T processor.
 91	  Otherwise, say N.
 92
 93# ARM9TDMI
 94config CPU_ARM9TDMI
 95	bool "Support ARM9TDMI processor"
 96	depends on !MMU
 97	select CPU_32v4T
 98	select CPU_ABRT_NOMMU
 99	select CPU_PABRT_LEGACY
100	select CPU_CACHE_V4
 
101	help
102	  A 32-bit RISC microprocessor based on the ARM9 processor core
103	  which has no memory control unit and cache.
104
105	  Say Y if you want support for the ARM9TDMI processor.
106	  Otherwise, say N.
107
108# ARM920T
109config CPU_ARM920T
110	bool "Support ARM920T processor" if ARCH_INTEGRATOR
111	select CPU_32v4T
112	select CPU_ABRT_EV4T
113	select CPU_PABRT_LEGACY
114	select CPU_CACHE_V4WT
115	select CPU_CACHE_VIVT
116	select CPU_CP15_MMU
117	select CPU_COPY_V4WB if MMU
 
 
 
118	select CPU_TLB_V4WBI if MMU
119	help
120	  The ARM920T is licensed to be produced by numerous vendors,
121	  and is used in the Cirrus EP93xx and the Samsung S3C2410.
122
123	  Say Y if you want support for the ARM920T processor.
124	  Otherwise, say N.
125
126# ARM922T
127config CPU_ARM922T
128	bool "Support ARM922T processor" if ARCH_INTEGRATOR
129	select CPU_32v4T
130	select CPU_ABRT_EV4T
131	select CPU_PABRT_LEGACY
132	select CPU_CACHE_V4WT
133	select CPU_CACHE_VIVT
134	select CPU_CP15_MMU
135	select CPU_COPY_V4WB if MMU
 
 
 
136	select CPU_TLB_V4WBI if MMU
137	help
138	  The ARM922T is a version of the ARM920T, but with smaller
139	  instruction and data caches. It is used in Altera's
140	  Excalibur XA device family and Micrel's KS8695 Centaur.
141
142	  Say Y if you want support for the ARM922T processor.
143	  Otherwise, say N.
144
145# ARM925T
146config CPU_ARM925T
147 	bool "Support ARM925T processor" if ARCH_OMAP1
148	select CPU_32v4T
149	select CPU_ABRT_EV4T
150	select CPU_PABRT_LEGACY
151	select CPU_CACHE_V4WT
152	select CPU_CACHE_VIVT
153	select CPU_CP15_MMU
154	select CPU_COPY_V4WB if MMU
 
 
 
155	select CPU_TLB_V4WBI if MMU
156 	help
157 	  The ARM925T is a mix between the ARM920T and ARM926T, but with
158	  different instruction and data caches. It is used in TI's OMAP
159 	  device family.
160
161 	  Say Y if you want support for the ARM925T processor.
162 	  Otherwise, say N.
163
164# ARM926T
165config CPU_ARM926T
166	bool "Support ARM926T processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB
167	select CPU_32v5
168	select CPU_ABRT_EV5TJ
169	select CPU_PABRT_LEGACY
170	select CPU_CACHE_VIVT
171	select CPU_CP15_MMU
172	select CPU_COPY_V4WB if MMU
 
 
 
173	select CPU_TLB_V4WBI if MMU
174	help
175	  This is a variant of the ARM920.  It has slightly different
176	  instruction sequences for cache and TLB operations.  Curiously,
177	  there is no documentation on it at the ARM corporate website.
178
179	  Say Y if you want support for the ARM926T processor.
180	  Otherwise, say N.
181
182# FA526
183config CPU_FA526
184	bool
185	select CPU_32v4
186	select CPU_ABRT_EV4
187	select CPU_PABRT_LEGACY
188	select CPU_CACHE_VIVT
189	select CPU_CP15_MMU
190	select CPU_CACHE_FA
 
191	select CPU_COPY_FA if MMU
 
 
192	select CPU_TLB_FA if MMU
193	help
194	  The FA526 is a version of the ARMv4 compatible processor with
195	  Branch Target Buffer, Unified TLB and cache line size 16.
196
197	  Say Y if you want support for the FA526 processor.
198	  Otherwise, say N.
199
200# ARM940T
201config CPU_ARM940T
202	bool "Support ARM940T processor" if ARCH_INTEGRATOR
203	depends on !MMU
204	select CPU_32v4T
205	select CPU_ABRT_NOMMU
206	select CPU_PABRT_LEGACY
207	select CPU_CACHE_VIVT
208	select CPU_CP15_MPU
 
 
209	help
210	  ARM940T is a member of the ARM9TDMI family of general-
211	  purpose microprocessors with MPU and separate 4KB
212	  instruction and 4KB data cases, each with a 4-word line
213	  length.
214
215	  Say Y if you want support for the ARM940T processor.
216	  Otherwise, say N.
217
218# ARM946E-S
219config CPU_ARM946E
220	bool "Support ARM946E-S processor" if ARCH_INTEGRATOR
221	depends on !MMU
222	select CPU_32v5
223	select CPU_ABRT_NOMMU
224	select CPU_PABRT_LEGACY
225	select CPU_CACHE_VIVT
226	select CPU_CP15_MPU
 
 
227	help
228	  ARM946E-S is a member of the ARM9E-S family of high-
229	  performance, 32-bit system-on-chip processor solutions.
230	  The TCM and ARMv5TE 32-bit instruction set is supported.
231
232	  Say Y if you want support for the ARM946E-S processor.
233	  Otherwise, say N.
234
235# ARM1020 - needs validating
236config CPU_ARM1020
237	bool "Support ARM1020T (rev 0) processor" if ARCH_INTEGRATOR
238	select CPU_32v5
239	select CPU_ABRT_EV4T
240	select CPU_PABRT_LEGACY
241	select CPU_CACHE_V4WT
242	select CPU_CACHE_VIVT
243	select CPU_CP15_MMU
244	select CPU_COPY_V4WB if MMU
 
 
 
245	select CPU_TLB_V4WBI if MMU
246	help
247	  The ARM1020 is the 32K cached version of the ARM10 processor,
248	  with an addition of a floating-point unit.
249
250	  Say Y if you want support for the ARM1020 processor.
251	  Otherwise, say N.
252
253# ARM1020E - needs validating
254config CPU_ARM1020E
255	bool "Support ARM1020E processor" if ARCH_INTEGRATOR
 
256	select CPU_32v5
257	select CPU_ABRT_EV4T
258	select CPU_PABRT_LEGACY
259	select CPU_CACHE_V4WT
260	select CPU_CACHE_VIVT
261	select CPU_CP15_MMU
262	select CPU_COPY_V4WB if MMU
 
 
 
263	select CPU_TLB_V4WBI if MMU
264	depends on n
265
266# ARM1022E
267config CPU_ARM1022
268	bool "Support ARM1022E processor" if ARCH_INTEGRATOR
269	select CPU_32v5
270	select CPU_ABRT_EV4T
271	select CPU_PABRT_LEGACY
272	select CPU_CACHE_VIVT
273	select CPU_CP15_MMU
274	select CPU_COPY_V4WB if MMU # can probably do better
 
 
 
275	select CPU_TLB_V4WBI if MMU
276	help
277	  The ARM1022E is an implementation of the ARMv5TE architecture
278	  based upon the ARM10 integer core with a 16KiB L1 Harvard cache,
279	  embedded trace macrocell, and a floating-point unit.
280
281	  Say Y if you want support for the ARM1022E processor.
282	  Otherwise, say N.
283
284# ARM1026EJ-S
285config CPU_ARM1026
286	bool "Support ARM1026EJ-S processor" if ARCH_INTEGRATOR
287	select CPU_32v5
288	select CPU_ABRT_EV5T # But need Jazelle, but EV5TJ ignores bit 10
289	select CPU_PABRT_LEGACY
290	select CPU_CACHE_VIVT
291	select CPU_CP15_MMU
292	select CPU_COPY_V4WB if MMU # can probably do better
 
 
 
293	select CPU_TLB_V4WBI if MMU
294	help
295	  The ARM1026EJ-S is an implementation of the ARMv5TEJ architecture
296	  based upon the ARM10 integer core.
297
298	  Say Y if you want support for the ARM1026EJ-S processor.
299	  Otherwise, say N.
300
301# SA110
302config CPU_SA110
303	bool "Support StrongARM(R) SA-110 processor" if ARCH_RPC
304	select CPU_32v3 if ARCH_RPC
305	select CPU_32v4 if !ARCH_RPC
306	select CPU_ABRT_EV4
307	select CPU_PABRT_LEGACY
308	select CPU_CACHE_V4WB
309	select CPU_CACHE_VIVT
310	select CPU_CP15_MMU
311	select CPU_COPY_V4WB if MMU
 
 
312	select CPU_TLB_V4WB if MMU
313	help
314	  The Intel StrongARM(R) SA-110 is a 32-bit microprocessor and
315	  is available at five speeds ranging from 100 MHz to 233 MHz.
316	  More information is available at
317	  <http://developer.intel.com/design/strong/sa110.htm>.
318
319	  Say Y if you want support for the SA-110 processor.
320	  Otherwise, say N.
321
322# SA1100
323config CPU_SA1100
324	bool
325	select CPU_32v4
326	select CPU_ABRT_EV4
327	select CPU_PABRT_LEGACY
328	select CPU_CACHE_V4WB
329	select CPU_CACHE_VIVT
330	select CPU_CP15_MMU
 
331	select CPU_TLB_V4WB if MMU
332
333# XScale
334config CPU_XSCALE
335	bool
336	select CPU_32v5
337	select CPU_ABRT_EV5T
338	select CPU_PABRT_LEGACY
339	select CPU_CACHE_VIVT
340	select CPU_CP15_MMU
 
 
341	select CPU_TLB_V4WBI if MMU
342
343# XScale Core Version 3
344config CPU_XSC3
345	bool
346	select CPU_32v5
347	select CPU_ABRT_EV5T
348	select CPU_PABRT_LEGACY
349	select CPU_CACHE_VIVT
350	select CPU_CP15_MMU
 
 
351	select CPU_TLB_V4WBI if MMU
352	select IO_36
353
354# Marvell PJ1 (Mohawk)
355config CPU_MOHAWK
356	bool
357	select CPU_32v5
358	select CPU_ABRT_EV5T
359	select CPU_PABRT_LEGACY
360	select CPU_CACHE_VIVT
 
361	select CPU_CP15_MMU
 
 
362	select CPU_TLB_V4WBI if MMU
363	select CPU_COPY_V4WB if MMU
364
365# Feroceon
366config CPU_FEROCEON
367	bool
368	select CPU_32v5
369	select CPU_ABRT_EV5T
370	select CPU_PABRT_LEGACY
371	select CPU_CACHE_VIVT
372	select CPU_CP15_MMU
373	select CPU_COPY_FEROCEON if MMU
 
 
 
374	select CPU_TLB_FEROCEON if MMU
375
376config CPU_FEROCEON_OLD_ID
377	bool "Accept early Feroceon cores with an ARM926 ID"
378	depends on CPU_FEROCEON && !CPU_ARM926T
379	default y
380	help
381	  This enables the usage of some old Feroceon cores
382	  for which the CPU ID is equal to the ARM926 ID.
383	  Relevant for Feroceon-1850 and early Feroceon-2850.
384
385# Marvell PJ4
386config CPU_PJ4
387	bool
388	select CPU_V7
389	select ARM_THUMBEE
 
 
 
 
 
390
391# ARMv6
392config CPU_V6
393	bool "Support ARM V6 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
394	select CPU_32v6
395	select CPU_ABRT_EV6
396	select CPU_PABRT_V6
397	select CPU_CACHE_V6
398	select CPU_CACHE_VIPT
 
399	select CPU_CP15_MMU
400	select CPU_HAS_ASID if MMU
401	select CPU_COPY_V6 if MMU
 
402	select CPU_TLB_V6 if MMU
403
404# ARMv6k
405config CPU_V6K
406	bool "Support ARM V6K processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
407	select CPU_32v6
408	select CPU_32v6K
409	select CPU_ABRT_EV6
410	select CPU_PABRT_V6
411	select CPU_CACHE_V6
412	select CPU_CACHE_VIPT
 
413	select CPU_CP15_MMU
414	select CPU_HAS_ASID if MMU
415	select CPU_COPY_V6 if MMU
 
416	select CPU_TLB_V6 if MMU
417
418# ARMv7
419config CPU_V7
420	bool "Support ARM V7 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
421	select CPU_32v6K
422	select CPU_32v7
423	select CPU_ABRT_EV7
424	select CPU_PABRT_V7
425	select CPU_CACHE_V7
426	select CPU_CACHE_VIPT
427	select CPU_CP15_MMU
428	select CPU_HAS_ASID if MMU
429	select CPU_COPY_V6 if MMU
 
 
 
 
 
 
430	select CPU_TLB_V7 if MMU
431
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
432# Figure out what processor architecture version we should be using.
433# This defines the compiler instruction set which depends on the machine type.
434config CPU_32v3
435	bool
436	select TLS_REG_EMUL if SMP || !MMU
437	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
438	select CPU_USE_DOMAINS if MMU
 
 
 
439
440config CPU_32v4
441	bool
442	select TLS_REG_EMUL if SMP || !MMU
443	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
444	select CPU_USE_DOMAINS if MMU
 
 
 
445
446config CPU_32v4T
447	bool
448	select TLS_REG_EMUL if SMP || !MMU
449	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
450	select CPU_USE_DOMAINS if MMU
 
 
 
451
452config CPU_32v5
453	bool
454	select TLS_REG_EMUL if SMP || !MMU
455	select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
456	select CPU_USE_DOMAINS if MMU
 
 
457
458config CPU_32v6
459	bool
460	select TLS_REG_EMUL if !CPU_32v6K && !MMU
461	select CPU_USE_DOMAINS if CPU_V6 && MMU
462
463config CPU_32v6K
464	bool
465
466config CPU_32v7
467	bool
468
 
 
 
469# The abort model
470config CPU_ABRT_NOMMU
471	bool
472
473config CPU_ABRT_EV4
474	bool
475
476config CPU_ABRT_EV4T
477	bool
478
479config CPU_ABRT_LV4T
480	bool
481
482config CPU_ABRT_EV5T
483	bool
484
485config CPU_ABRT_EV5TJ
486	bool
487
488config CPU_ABRT_EV6
489	bool
490
491config CPU_ABRT_EV7
492	bool
493
494config CPU_PABRT_LEGACY
495	bool
496
497config CPU_PABRT_V6
498	bool
499
500config CPU_PABRT_V7
501	bool
502
503# The cache model
504config CPU_CACHE_V3
505	bool
506
507config CPU_CACHE_V4
508	bool
509
510config CPU_CACHE_V4WT
511	bool
512
513config CPU_CACHE_V4WB
514	bool
515
516config CPU_CACHE_V6
517	bool
518
519config CPU_CACHE_V7
520	bool
521
 
 
 
522config CPU_CACHE_VIVT
523	bool
524
525config CPU_CACHE_VIPT
526	bool
527
528config CPU_CACHE_FA
529	bool
530
531if MMU
532# The copy-page model
533config CPU_COPY_V3
534	bool
535
 
 
536config CPU_COPY_V4WT
537	bool
538
539config CPU_COPY_V4WB
540	bool
541
542config CPU_COPY_FEROCEON
543	bool
544
545config CPU_COPY_FA
546	bool
547
548config CPU_COPY_V6
549	bool
550
551# This selects the TLB model
552config CPU_TLB_V3
553	bool
554	help
555	  ARM Architecture Version 3 TLB.
556
557config CPU_TLB_V4WT
558	bool
559	help
560	  ARM Architecture Version 4 TLB with writethrough cache.
561
562config CPU_TLB_V4WB
563	bool
564	help
565	  ARM Architecture Version 4 TLB with writeback cache.
566
567config CPU_TLB_V4WBI
568	bool
569	help
570	  ARM Architecture Version 4 TLB with writeback cache and invalidate
571	  instruction cache entry.
572
573config CPU_TLB_FEROCEON
574	bool
575	help
576	  Feroceon TLB (v4wbi with non-outer-cachable page table walks).
577
578config CPU_TLB_FA
579	bool
580	help
581	  Faraday ARM FA526 architecture, unified TLB with writeback cache
582	  and invalidate instruction cache entry. Branch target buffer is
583	  also supported.
584
585config CPU_TLB_V6
586	bool
587
588config CPU_TLB_V7
589	bool
590
591config VERIFY_PERMISSION_FAULT
592	bool
593endif
594
595config CPU_HAS_ASID
596	bool
597	help
598	  This indicates whether the CPU has the ASID register; used to
599	  tag TLB and possibly cache entries.
600
601config CPU_CP15
602	bool
603	help
604	  Processor has the CP15 register.
605
606config CPU_CP15_MMU
607	bool
608	select CPU_CP15
609	help
610	  Processor has the CP15 register, which has MMU related registers.
611
612config CPU_CP15_MPU
613	bool
614	select CPU_CP15
615	help
616	  Processor has the CP15 register, which has MPU related registers.
617
618config CPU_USE_DOMAINS
619	bool
620	help
621	  This option enables or disables the use of domain switching
622	  via the set_fs() function.
623
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
624#
625# CPU supports 36-bit I/O
626#
627config IO_36
628	bool
629
630comment "Processor Features"
631
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
632config ARM_THUMB
633	bool "Support Thumb user binaries"
634	depends on CPU_ARM720T || CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_V6 || CPU_V6K || CPU_V7 || CPU_FEROCEON
635	default y
636	help
637	  Say Y if you want to include kernel support for running user space
638	  Thumb binaries.
639
640	  The Thumb instruction set is a compressed form of the standard ARM
641	  instruction set resulting in smaller binaries at the expense of
642	  slightly less efficient code.
643
 
 
 
 
644	  If you don't know what this all is, saying Y is a safe choice.
645
646config ARM_THUMBEE
647	bool "Enable ThumbEE CPU extension"
648	depends on CPU_V7
649	help
650	  Say Y here if you have a CPU with the ThumbEE extension and code to
651	  make use of it. Say N for code that can run on CPUs without ThumbEE.
652
 
 
 
 
 
 
 
 
 
 
 
 
653config SWP_EMULATE
654	bool "Emulate SWP/SWPB instructions"
655	depends on !CPU_USE_DOMAINS && CPU_V7
656	select HAVE_PROC_CPU if PROC_FS
657	default y if SMP
 
658	help
659	  ARMv6 architecture deprecates use of the SWP/SWPB instructions.
660	  ARMv7 multiprocessing extensions introduce the ability to disable
661	  these instructions, triggering an undefined instruction exception
662	  when executed. Say Y here to enable software emulation of these
663	  instructions for userspace (not kernel) using LDREX/STREX.
664	  Also creates /proc/cpu/swp_emulation for statistics.
665
666	  In some older versions of glibc [<=2.8] SWP is used during futex
667	  trylock() operations with the assumption that the code will not
668	  be preempted. This invalid assumption may be more likely to fail
669	  with SWP emulation enabled, leading to deadlock of the user
670	  application.
671
672	  NOTE: when accessing uncached shared regions, LDREX/STREX rely
673	  on an external transaction monitoring block called a global
674	  monitor to maintain update atomicity. If your system does not
675	  implement a global monitor, this option can cause programs that
676	  perform SWP operations to uncached memory to deadlock.
677
678	  If unsure, say Y.
679
680config CPU_BIG_ENDIAN
681	bool "Build big-endian kernel"
682	depends on ARCH_SUPPORTS_BIG_ENDIAN
683	help
684	  Say Y if you plan on running a kernel in big-endian mode.
685	  Note that your board must be properly built and your board
686	  port must properly enable any big-endian related features
687	  of your chipset/board/processor.
688
689config CPU_ENDIAN_BE8
690	bool
691	depends on CPU_BIG_ENDIAN
692	default CPU_V6 || CPU_V6K || CPU_V7
693	help
694	  Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors.
695
696config CPU_ENDIAN_BE32
697	bool
698	depends on CPU_BIG_ENDIAN
699	default !CPU_ENDIAN_BE8
700	help
701	  Support for the BE-32 (big-endian) mode on pre-ARMv6 processors.
702
703config CPU_HIGH_VECTOR
704	depends on !MMU && CPU_CP15 && !CPU_ARM740T
705	bool "Select the High exception vector"
706	help
707	  Say Y here to select high exception vector(0xFFFF0000~).
708	  The exception vector can be vary depending on the platform
709	  design in nommu mode. If your platform needs to select
710	  high exception vector, say Y.
711	  Otherwise or if you are unsure, say N, and the low exception
712	  vector (0x00000000~) will be used.
713
714config CPU_ICACHE_DISABLE
715	bool "Disable I-Cache (I-bit)"
716	depends on CPU_CP15 && !(CPU_ARM610 || CPU_ARM710 || CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)
717	help
718	  Say Y here to disable the processor instruction cache. Unless
719	  you have a reason not to or are unsure, say N.
720
 
 
 
 
 
 
 
 
721config CPU_DCACHE_DISABLE
722	bool "Disable D-Cache (C-bit)"
723	depends on CPU_CP15
724	help
725	  Say Y here to disable the processor data cache. Unless
726	  you have a reason not to or are unsure, say N.
727
728config CPU_DCACHE_SIZE
729	hex
730	depends on CPU_ARM740T || CPU_ARM946E
731	default 0x00001000 if CPU_ARM740T
732	default 0x00002000 # default size for ARM946E-S
733	help
734	  Some cores are synthesizable to have various sized cache. For
735	  ARM946E-S case, it can vary from 0KB to 1MB.
736	  To support such cache operations, it is efficient to know the size
737	  before compile time.
738	  If your SoC is configured to have a different size, define the value
739	  here with proper conditions.
740
741config CPU_DCACHE_WRITETHROUGH
742	bool "Force write through D-cache"
743	depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_FA526) && !CPU_DCACHE_DISABLE
744	default y if CPU_ARM925T
745	help
746	  Say Y here to use the data cache in writethrough mode. Unless you
747	  specifically require this or are unsure, say N.
748
749config CPU_CACHE_ROUND_ROBIN
750	bool "Round robin I and D cache replacement algorithm"
751	depends on (CPU_ARM926T || CPU_ARM946E || CPU_ARM1020) && (!CPU_ICACHE_DISABLE || !CPU_DCACHE_DISABLE)
752	help
753	  Say Y here to use the predictable round-robin cache replacement
754	  policy.  Unless you specifically require this or are unsure, say N.
755
756config CPU_BPREDICT_DISABLE
757	bool "Disable branch prediction"
758	depends on CPU_ARM1020 || CPU_V6 || CPU_V6K || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526
759	help
760	  Say Y here to disable branch prediction.  If unsure, say N.
761
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
762config TLS_REG_EMUL
763	bool
 
764	help
765	  An SMP system using a pre-ARMv6 processor (there are apparently
766	  a few prototypes like that in existence) and therefore access to
767	  that required register must be emulated.
768
769config NEEDS_SYSCALL_FOR_CMPXCHG
770	bool
 
 
 
 
 
771	help
772	  SMP on a pre-ARMv6 processor?  Well OK then.
773	  Forget about fast user space cmpxchg support.
774	  It is just not possible.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
775
776config DMA_CACHE_RWFO
777	bool "Enable read/write for ownership DMA cache maintenance"
778	depends on CPU_V6K && SMP
779	default y
780	help
781	  The Snoop Control Unit on ARM11MPCore does not detect the
782	  cache maintenance operations and the dma_{map,unmap}_area()
783	  functions may leave stale cache entries on other CPUs. By
784	  enabling this option, Read or Write For Ownership in the ARMv6
785	  DMA cache maintenance functions is performed. These LDR/STR
786	  instructions change the cache line state to shared or modified
787	  so that the cache operation has the desired effect.
788
789	  Note that the workaround is only valid on processors that do
790	  not perform speculative loads into the D-cache. For such
791	  processors, if cache maintenance operations are not broadcast
792	  in hardware, other workarounds are needed (e.g. cache
793	  maintenance broadcasting in software via FIQ).
794
795config OUTER_CACHE
796	bool
797
798config OUTER_CACHE_SYNC
799	bool
 
800	help
801	  The outer cache has a outer_cache_fns.sync function pointer
802	  that can be used to drain the write buffer of the outer cache.
803
 
 
 
 
 
 
 
 
804config CACHE_FEROCEON_L2
805	bool "Enable the Feroceon L2 cache controller"
806	depends on ARCH_KIRKWOOD || ARCH_MV78XX0
807	default y
808	select OUTER_CACHE
809	help
810	  This option enables the Feroceon L2 cache controller.
811
812config CACHE_FEROCEON_L2_WRITETHROUGH
813	bool "Force Feroceon L2 cache write through"
814	depends on CACHE_FEROCEON_L2
815	help
816	  Say Y here to use the Feroceon L2 cache in writethrough mode.
817	  Unless you specifically require this, say N for writeback mode.
818
 
 
 
 
 
 
 
 
 
 
 
 
 
 
819config CACHE_L2X0
820	bool "Enable the L2x0 outer cache controller"
821	depends on REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || MACH_REALVIEW_PB1176 || \
822		   REALVIEW_EB_A9MP || SOC_IMX35 || SOC_IMX31 || MACH_REALVIEW_PBX || \
823		   ARCH_NOMADIK || ARCH_OMAP4 || ARCH_EXYNOS4 || ARCH_TEGRA || \
824		   ARCH_U8500 || ARCH_VEXPRESS_CA9X4 || ARCH_SHMOBILE || \
825		   ARCH_PRIMA2 || ARCH_ZYNQ || ARCH_CNS3XXX
826	default y
827	select OUTER_CACHE
828	select OUTER_CACHE_SYNC
829	help
830	  This option enables the L2x0 PrimeCell.
831
832config CACHE_PL310
833	bool
834	depends on CACHE_L2X0
835	default y if CPU_V7 && !(CPU_V6 || CPU_V6K)
836	help
837	  This option enables optimisations for the PL310 cache
838	  controller.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
839
840config CACHE_TAUROS2
841	bool "Enable the Tauros2 L2 cache controller"
842	depends on (ARCH_DOVE || ARCH_MMP || CPU_PJ4)
843	default y
844	select OUTER_CACHE
845	help
846	  This option enables the Tauros2 L2 cache controller (as
847	  found on PJ1/PJ4).
848
 
 
 
 
 
 
 
 
 
 
849config CACHE_XSC3L2
850	bool "Enable the L2 cache on XScale3"
851	depends on CPU_XSC3
852	default y
853	select OUTER_CACHE
854	help
855	  This option enables the L2 cache on XScale3.
856
857config ARM_L1_CACHE_SHIFT_6
858	bool
 
859	help
860	  Setting ARM L1 cache line size to 64 Bytes.
861
 
 
 
 
 
862config ARM_L1_CACHE_SHIFT
863	int
 
864	default 6 if ARM_L1_CACHE_SHIFT_6
865	default 5
866
867config ARM_DMA_MEM_BUFFERABLE
868	bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K) && !CPU_V7
869	depends on !(MACH_REALVIEW_PB1176 || REALVIEW_EB_ARM11MP || \
870		     MACH_REALVIEW_PB11MP)
871	default y if CPU_V6 || CPU_V6K || CPU_V7
872	help
873	  Historically, the kernel has used strongly ordered mappings to
874	  provide DMA coherent memory.  With the advent of ARMv7, mapping
875	  memory with differing types results in unpredictable behaviour,
876	  so on these CPUs, this option is forced on.
877
878	  Multiple mappings with differing attributes is also unpredictable
879	  on ARMv6 CPUs, but since they do not have aggressive speculative
880	  prefetch, no harm appears to occur.
881
882	  However, drivers may be missing the necessary barriers for ARMv6,
883	  and therefore turning this on may result in unpredictable driver
884	  behaviour.  Therefore, we offer this as an option.
885
 
 
 
 
886	  You are recommended say 'Y' here and debug any affected drivers.
887
888config ARCH_HAS_BARRIERS
 
 
 
889	bool
890	help
891	  This option allows the use of custom mandatory barriers
892	  included via the mach/barriers.h file.
 
 
 
 
 
 
 
 
 
 
 
 
v5.4
   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
 604config VERIFY_PERMISSION_FAULT
 605	bool
 606endif
 607
 608config CPU_HAS_ASID
 609	bool
 610	help
 611	  This indicates whether the CPU has the ASID register; used to
 612	  tag TLB and possibly cache entries.
 613
 614config CPU_CP15
 615	bool
 616	help
 617	  Processor has the CP15 register.
 618
 619config CPU_CP15_MMU
 620	bool
 621	select CPU_CP15
 622	help
 623	  Processor has the CP15 register, which has MMU related registers.
 624
 625config CPU_CP15_MPU
 626	bool
 627	select CPU_CP15
 628	help
 629	  Processor has the CP15 register, which has MPU related registers.
 630
 631config CPU_USE_DOMAINS
 632	bool
 633	help
 634	  This option enables or disables the use of domain switching
 635	  via the set_fs() function.
 636
 637config CPU_V7M_NUM_IRQ
 638	int "Number of external interrupts connected to the NVIC"
 639	depends on CPU_V7M
 640	default 90 if ARCH_STM32
 641	default 38 if ARCH_EFM32
 642	default 112 if SOC_VF610
 643	default 240
 644	help
 645	  This option indicates the number of interrupts connected to the NVIC.
 646	  The value can be larger than the real number of interrupts supported
 647	  by the system, but must not be lower.
 648	  The default value is 240, corresponding to the maximum number of
 649	  interrupts supported by the NVIC on Cortex-M family.
 650
 651	  If unsure, keep default value.
 652
 653#
 654# CPU supports 36-bit I/O
 655#
 656config IO_36
 657	bool
 658
 659comment "Processor Features"
 660
 661config ARM_LPAE
 662	bool "Support for the Large Physical Address Extension"
 663	depends on MMU && CPU_32v7 && !CPU_32v6 && !CPU_32v5 && \
 664		!CPU_32v4 && !CPU_32v3
 665	select PHYS_ADDR_T_64BIT
 666	select SWIOTLB
 667	help
 668	  Say Y if you have an ARMv7 processor supporting the LPAE page
 669	  table format and you would like to access memory beyond the
 670	  4GB limit. The resulting kernel image will not run on
 671	  processors without the LPA extension.
 672
 673	  If unsure, say N.
 674
 675config ARM_PV_FIXUP
 676	def_bool y
 677	depends on ARM_LPAE && ARM_PATCH_PHYS_VIRT && ARCH_KEYSTONE
 678
 679config ARM_THUMB
 680	bool "Support Thumb user binaries" if !CPU_THUMBONLY && EXPERT
 681	depends on CPU_THUMB_CAPABLE
 682	default y
 683	help
 684	  Say Y if you want to include kernel support for running user space
 685	  Thumb binaries.
 686
 687	  The Thumb instruction set is a compressed form of the standard ARM
 688	  instruction set resulting in smaller binaries at the expense of
 689	  slightly less efficient code.
 690
 691	  If this option is disabled, and you run userspace that switches to
 692	  Thumb mode, signal handling will not work correctly, resulting in
 693	  segmentation faults or illegal instruction aborts.
 694
 695	  If you don't know what this all is, saying Y is a safe choice.
 696
 697config ARM_THUMBEE
 698	bool "Enable ThumbEE CPU extension"
 699	depends on CPU_V7
 700	help
 701	  Say Y here if you have a CPU with the ThumbEE extension and code to
 702	  make use of it. Say N for code that can run on CPUs without ThumbEE.
 703
 704config ARM_VIRT_EXT
 705	bool
 706	default y if CPU_V7
 707	help
 708	  Enable the kernel to make use of the ARM Virtualization
 709	  Extensions to install hypervisors without run-time firmware
 710	  assistance.
 711
 712	  A compliant bootloader is required in order to make maximum
 713	  use of this feature.  Refer to Documentation/arm/booting.rst for
 714	  details.
 715
 716config SWP_EMULATE
 717	bool "Emulate SWP/SWPB instructions" if !SMP
 718	depends on CPU_V7
 
 719	default y if SMP
 720	select HAVE_PROC_CPU if PROC_FS
 721	help
 722	  ARMv6 architecture deprecates use of the SWP/SWPB instructions.
 723	  ARMv7 multiprocessing extensions introduce the ability to disable
 724	  these instructions, triggering an undefined instruction exception
 725	  when executed. Say Y here to enable software emulation of these
 726	  instructions for userspace (not kernel) using LDREX/STREX.
 727	  Also creates /proc/cpu/swp_emulation for statistics.
 728
 729	  In some older versions of glibc [<=2.8] SWP is used during futex
 730	  trylock() operations with the assumption that the code will not
 731	  be preempted. This invalid assumption may be more likely to fail
 732	  with SWP emulation enabled, leading to deadlock of the user
 733	  application.
 734
 735	  NOTE: when accessing uncached shared regions, LDREX/STREX rely
 736	  on an external transaction monitoring block called a global
 737	  monitor to maintain update atomicity. If your system does not
 738	  implement a global monitor, this option can cause programs that
 739	  perform SWP operations to uncached memory to deadlock.
 740
 741	  If unsure, say Y.
 742
 743config CPU_BIG_ENDIAN
 744	bool "Build big-endian kernel"
 745	depends on ARCH_SUPPORTS_BIG_ENDIAN
 746	help
 747	  Say Y if you plan on running a kernel in big-endian mode.
 748	  Note that your board must be properly built and your board
 749	  port must properly enable any big-endian related features
 750	  of your chipset/board/processor.
 751
 752config CPU_ENDIAN_BE8
 753	bool
 754	depends on CPU_BIG_ENDIAN
 755	default CPU_V6 || CPU_V6K || CPU_V7
 756	help
 757	  Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors.
 758
 759config CPU_ENDIAN_BE32
 760	bool
 761	depends on CPU_BIG_ENDIAN
 762	default !CPU_ENDIAN_BE8
 763	help
 764	  Support for the BE-32 (big-endian) mode on pre-ARMv6 processors.
 765
 766config CPU_HIGH_VECTOR
 767	depends on !MMU && CPU_CP15 && !CPU_ARM740T
 768	bool "Select the High exception vector"
 769	help
 770	  Say Y here to select high exception vector(0xFFFF0000~).
 771	  The exception vector can vary depending on the platform
 772	  design in nommu mode. If your platform needs to select
 773	  high exception vector, say Y.
 774	  Otherwise or if you are unsure, say N, and the low exception
 775	  vector (0x00000000~) will be used.
 776
 777config CPU_ICACHE_DISABLE
 778	bool "Disable I-Cache (I-bit)"
 779	depends on (CPU_CP15 && !(CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)) || CPU_V7M
 780	help
 781	  Say Y here to disable the processor instruction cache. Unless
 782	  you have a reason not to or are unsure, say N.
 783
 784config CPU_ICACHE_MISMATCH_WORKAROUND
 785	bool "Workaround for I-Cache line size mismatch between CPU cores"
 786	depends on SMP && CPU_V7
 787	help
 788	  Some big.LITTLE systems have I-Cache line size mismatch between
 789	  LITTLE and big cores.  Say Y here to enable a workaround for
 790	  proper I-Cache support on such systems.  If unsure, say N.
 791
 792config CPU_DCACHE_DISABLE
 793	bool "Disable D-Cache (C-bit)"
 794	depends on (CPU_CP15 && !SMP) || CPU_V7M
 795	help
 796	  Say Y here to disable the processor data cache. Unless
 797	  you have a reason not to or are unsure, say N.
 798
 799config CPU_DCACHE_SIZE
 800	hex
 801	depends on CPU_ARM740T || CPU_ARM946E
 802	default 0x00001000 if CPU_ARM740T
 803	default 0x00002000 # default size for ARM946E-S
 804	help
 805	  Some cores are synthesizable to have various sized cache. For
 806	  ARM946E-S case, it can vary from 0KB to 1MB.
 807	  To support such cache operations, it is efficient to know the size
 808	  before compile time.
 809	  If your SoC is configured to have a different size, define the value
 810	  here with proper conditions.
 811
 812config CPU_DCACHE_WRITETHROUGH
 813	bool "Force write through D-cache"
 814	depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_FA526) && !CPU_DCACHE_DISABLE
 815	default y if CPU_ARM925T
 816	help
 817	  Say Y here to use the data cache in writethrough mode. Unless you
 818	  specifically require this or are unsure, say N.
 819
 820config CPU_CACHE_ROUND_ROBIN
 821	bool "Round robin I and D cache replacement algorithm"
 822	depends on (CPU_ARM926T || CPU_ARM946E || CPU_ARM1020) && (!CPU_ICACHE_DISABLE || !CPU_DCACHE_DISABLE)
 823	help
 824	  Say Y here to use the predictable round-robin cache replacement
 825	  policy.  Unless you specifically require this or are unsure, say N.
 826
 827config CPU_BPREDICT_DISABLE
 828	bool "Disable branch prediction"
 829	depends on CPU_ARM1020 || CPU_V6 || CPU_V6K || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526 || CPU_V7M
 830	help
 831	  Say Y here to disable branch prediction.  If unsure, say N.
 832
 833config CPU_SPECTRE
 834	bool
 835
 836config HARDEN_BRANCH_PREDICTOR
 837	bool "Harden the branch predictor against aliasing attacks" if EXPERT
 838	depends on CPU_SPECTRE
 839	default y
 840	help
 841	   Speculation attacks against some high-performance processors rely
 842	   on being able to manipulate the branch predictor for a victim
 843	   context by executing aliasing branches in the attacker context.
 844	   Such attacks can be partially mitigated against by clearing
 845	   internal branch predictor state and limiting the prediction
 846	   logic in some situations.
 847
 848	   This config option will take CPU-specific actions to harden
 849	   the branch predictor against aliasing attacks and may rely on
 850	   specific instruction sequences or control bits being set by
 851	   the system firmware.
 852
 853	   If unsure, say Y.
 854
 855config TLS_REG_EMUL
 856	bool
 857	select NEED_KUSER_HELPERS
 858	help
 859	  An SMP system using a pre-ARMv6 processor (there are apparently
 860	  a few prototypes like that in existence) and therefore access to
 861	  that required register must be emulated.
 862
 863config NEED_KUSER_HELPERS
 864	bool
 865
 866config KUSER_HELPERS
 867	bool "Enable kuser helpers in vector page" if !NEED_KUSER_HELPERS
 868	depends on MMU
 869	default y
 870	help
 871	  Warning: disabling this option may break user programs.
 872
 873	  Provide kuser helpers in the vector page.  The kernel provides
 874	  helper code to userspace in read only form at a fixed location
 875	  in the high vector page to allow userspace to be independent of
 876	  the CPU type fitted to the system.  This permits binaries to be
 877	  run on ARMv4 through to ARMv7 without modification.
 878
 879	  See Documentation/arm/kernel_user_helpers.rst for details.
 880
 881	  However, the fixed address nature of these helpers can be used
 882	  by ROP (return orientated programming) authors when creating
 883	  exploits.
 884
 885	  If all of the binaries and libraries which run on your platform
 886	  are built specifically for your platform, and make no use of
 887	  these helpers, then you can turn this option off to hinder
 888	  such exploits. However, in that case, if a binary or library
 889	  relying on those helpers is run, it will receive a SIGILL signal,
 890	  which will terminate the program.
 891
 892	  Say N here only if you are absolutely certain that you do not
 893	  need these helpers; otherwise, the safe option is to say Y.
 894
 895config VDSO
 896	bool "Enable VDSO for acceleration of some system calls"
 897	depends on AEABI && MMU && CPU_V7
 898	default y if ARM_ARCH_TIMER
 899	select GENERIC_TIME_VSYSCALL
 900	help
 901	  Place in the process address space an ELF shared object
 902	  providing fast implementations of gettimeofday and
 903	  clock_gettime.  Systems that implement the ARM architected
 904	  timer will receive maximum benefit.
 905
 906	  You must have glibc 2.22 or later for programs to seamlessly
 907	  take advantage of this.
 908
 909config DMA_CACHE_RWFO
 910	bool "Enable read/write for ownership DMA cache maintenance"
 911	depends on CPU_V6K && SMP
 912	default y
 913	help
 914	  The Snoop Control Unit on ARM11MPCore does not detect the
 915	  cache maintenance operations and the dma_{map,unmap}_area()
 916	  functions may leave stale cache entries on other CPUs. By
 917	  enabling this option, Read or Write For Ownership in the ARMv6
 918	  DMA cache maintenance functions is performed. These LDR/STR
 919	  instructions change the cache line state to shared or modified
 920	  so that the cache operation has the desired effect.
 921
 922	  Note that the workaround is only valid on processors that do
 923	  not perform speculative loads into the D-cache. For such
 924	  processors, if cache maintenance operations are not broadcast
 925	  in hardware, other workarounds are needed (e.g. cache
 926	  maintenance broadcasting in software via FIQ).
 927
 928config OUTER_CACHE
 929	bool
 930
 931config OUTER_CACHE_SYNC
 932	bool
 933	select ARM_HEAVY_MB
 934	help
 935	  The outer cache has a outer_cache_fns.sync function pointer
 936	  that can be used to drain the write buffer of the outer cache.
 937
 938config CACHE_B15_RAC
 939	bool "Enable the Broadcom Brahma-B15 read-ahead cache controller"
 940	depends on ARCH_BRCMSTB
 941	default y
 942	help
 943	  This option enables the Broadcom Brahma-B15 read-ahead cache
 944	  controller. If disabled, the read-ahead cache remains off.
 945
 946config CACHE_FEROCEON_L2
 947	bool "Enable the Feroceon L2 cache controller"
 948	depends on ARCH_MV78XX0 || ARCH_MVEBU
 949	default y
 950	select OUTER_CACHE
 951	help
 952	  This option enables the Feroceon L2 cache controller.
 953
 954config CACHE_FEROCEON_L2_WRITETHROUGH
 955	bool "Force Feroceon L2 cache write through"
 956	depends on CACHE_FEROCEON_L2
 957	help
 958	  Say Y here to use the Feroceon L2 cache in writethrough mode.
 959	  Unless you specifically require this, say N for writeback mode.
 960
 961config MIGHT_HAVE_CACHE_L2X0
 962	bool
 963	help
 964	  This option should be selected by machines which have a L2x0
 965	  or PL310 cache controller, but where its use is optional.
 966
 967	  The only effect of this option is to make CACHE_L2X0 and
 968	  related options available to the user for configuration.
 969
 970	  Boards or SoCs which always require the cache controller
 971	  support to be present should select CACHE_L2X0 directly
 972	  instead of this option, thus preventing the user from
 973	  inadvertently configuring a broken kernel.
 974
 975config CACHE_L2X0
 976	bool "Enable the L2x0 outer cache controller" if MIGHT_HAVE_CACHE_L2X0
 977	default MIGHT_HAVE_CACHE_L2X0
 
 
 
 
 
 978	select OUTER_CACHE
 979	select OUTER_CACHE_SYNC
 980	help
 981	  This option enables the L2x0 PrimeCell.
 982
 983config CACHE_L2X0_PMU
 984	bool "L2x0 performance monitor support" if CACHE_L2X0
 985	depends on PERF_EVENTS
 986	help
 987	  This option enables support for the performance monitoring features
 988	  of the L220 and PL310 outer cache controllers.
 989
 990if CACHE_L2X0
 991
 992config PL310_ERRATA_588369
 993	bool "PL310 errata: Clean & Invalidate maintenance operations do not invalidate clean lines"
 994	help
 995	   The PL310 L2 cache controller implements three types of Clean &
 996	   Invalidate maintenance operations: by Physical Address
 997	   (offset 0x7F0), by Index/Way (0x7F8) and by Way (0x7FC).
 998	   They are architecturally defined to behave as the execution of a
 999	   clean operation followed immediately by an invalidate operation,
1000	   both performing to the same memory location. This functionality
1001	   is not correctly implemented in PL310 prior to r2p0 (fixed in r2p0)
1002	   as clean lines are not invalidated as a result of these operations.
1003
1004config PL310_ERRATA_727915
1005	bool "PL310 errata: Background Clean & Invalidate by Way operation can cause data corruption"
1006	help
1007	  PL310 implements the Clean & Invalidate by Way L2 cache maintenance
1008	  operation (offset 0x7FC). This operation runs in background so that
1009	  PL310 can handle normal accesses while it is in progress. Under very
1010	  rare circumstances, due to this erratum, write data can be lost when
1011	  PL310 treats a cacheable write transaction during a Clean &
1012	  Invalidate by Way operation.  Revisions prior to r3p1 are affected by
1013	  this errata (fixed in r3p1).
1014
1015config PL310_ERRATA_753970
1016	bool "PL310 errata: cache sync operation may be faulty"
1017	help
1018	  This option enables the workaround for the 753970 PL310 (r3p0) erratum.
1019
1020	  Under some condition the effect of cache sync operation on
1021	  the store buffer still remains when the operation completes.
1022	  This means that the store buffer is always asked to drain and
1023	  this prevents it from merging any further writes. The workaround
1024	  is to replace the normal offset of cache sync operation (0x730)
1025	  by another offset targeting an unmapped PL310 register 0x740.
1026	  This has the same effect as the cache sync operation: store buffer
1027	  drain and waiting for all buffers empty.
1028
1029config PL310_ERRATA_769419
1030	bool "PL310 errata: no automatic Store Buffer drain"
1031	help
1032	  On revisions of the PL310 prior to r3p2, the Store Buffer does
1033	  not automatically drain. This can cause normal, non-cacheable
1034	  writes to be retained when the memory system is idle, leading
1035	  to suboptimal I/O performance for drivers using coherent DMA.
1036	  This option adds a write barrier to the cpu_idle loop so that,
1037	  on systems with an outer cache, the store buffer is drained
1038	  explicitly.
1039
1040endif
1041
1042config CACHE_TAUROS2
1043	bool "Enable the Tauros2 L2 cache controller"
1044	depends on (ARCH_DOVE || ARCH_MMP || CPU_PJ4)
1045	default y
1046	select OUTER_CACHE
1047	help
1048	  This option enables the Tauros2 L2 cache controller (as
1049	  found on PJ1/PJ4).
1050
1051config CACHE_UNIPHIER
1052	bool "Enable the UniPhier outer cache controller"
1053	depends on ARCH_UNIPHIER
1054	select ARM_L1_CACHE_SHIFT_7
1055	select OUTER_CACHE
1056	select OUTER_CACHE_SYNC
1057	help
1058	  This option enables the UniPhier outer cache (system cache)
1059	  controller.
1060
1061config CACHE_XSC3L2
1062	bool "Enable the L2 cache on XScale3"
1063	depends on CPU_XSC3
1064	default y
1065	select OUTER_CACHE
1066	help
1067	  This option enables the L2 cache on XScale3.
1068
1069config ARM_L1_CACHE_SHIFT_6
1070	bool
1071	default y if CPU_V7
1072	help
1073	  Setting ARM L1 cache line size to 64 Bytes.
1074
1075config ARM_L1_CACHE_SHIFT_7
1076	bool
1077	help
1078	  Setting ARM L1 cache line size to 128 Bytes.
1079
1080config ARM_L1_CACHE_SHIFT
1081	int
1082	default 7 if ARM_L1_CACHE_SHIFT_7
1083	default 6 if ARM_L1_CACHE_SHIFT_6
1084	default 5
1085
1086config ARM_DMA_MEM_BUFFERABLE
1087	bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K || CPU_V7M) && !CPU_V7
1088	default y if CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M
 
 
1089	help
1090	  Historically, the kernel has used strongly ordered mappings to
1091	  provide DMA coherent memory.  With the advent of ARMv7, mapping
1092	  memory with differing types results in unpredictable behaviour,
1093	  so on these CPUs, this option is forced on.
1094
1095	  Multiple mappings with differing attributes is also unpredictable
1096	  on ARMv6 CPUs, but since they do not have aggressive speculative
1097	  prefetch, no harm appears to occur.
1098
1099	  However, drivers may be missing the necessary barriers for ARMv6,
1100	  and therefore turning this on may result in unpredictable driver
1101	  behaviour.  Therefore, we offer this as an option.
1102
1103	  On some of the beefier ARMv7-M machines (with DMA and write
1104	  buffers) you likely want this enabled, while those that
1105	  didn't need it until now also won't need it in the future.
1106
1107	  You are recommended say 'Y' here and debug any affected drivers.
1108
1109config ARM_HEAVY_MB
1110	bool
1111
1112config ARCH_SUPPORTS_BIG_ENDIAN
1113	bool
1114	help
1115	  This option specifies the architecture can support big endian
1116	  operation.
1117
1118config DEBUG_ALIGN_RODATA
1119	bool "Make rodata strictly non-executable"
1120	depends on STRICT_KERNEL_RWX
1121	default y
1122	help
1123	  If this is set, rodata will be made explicitly non-executable. This
1124	  provides protection on the rare chance that attackers might find and
1125	  use ROP gadgets that exist in the rodata section. This adds an
1126	  additional section-aligned split of rodata from kernel text so it
1127	  can be made explicitly non-executable. This padding may waste memory
1128	  space to gain the additional protection.